Add archive promotion locks

docs/cli.md

@@ -6,7 +6,7 @@
 narratio run --session-id 2026-04-04
 ```
 
-This command uses default discovery for `pipeline.yml` and `session.yml`; both files must be discoverable unless you pass explicit `--config` and `--session` paths.
+This command uses default discovery for `pipeline.yml`, `campaign.yml`, and local `session.yml`. If local session discovery misses and S3 storage is configured, `--session-id` can load remote `session.yml` from the canonical session prefix.
 
 ## Command Overview
 
@@ -28,31 +28,39 @@ For config semantics, see [docs/config.md](./config.md). For operator lifecycle
 ### `run`
 
 - `--config <path>`: optional explicit `pipeline.yml` path.
+- `--campaign <path>`: optional explicit `campaign.yml` path.
 - `--session <path>`: optional explicit `session.yml` path.
 - `--session-id <value>`: session template variable value.
+- `--previous-session-id <value>`: previous-session template variable value.
 - `--force`: force stage execution.
 - `--artifacts <names>`: analyze artifact keys to execute (repeatable or comma-separated).
 
 ### `plan`
 
 - `--config <path>`
+- `--campaign <path>`
 - `--session <path>`
 - `--session-id <value>`
+- `--previous-session-id <value>`
 - `--force`
 
 ### `resume`
 
 - `--config <path>`
+- `--campaign <path>`
 - `--session <path>`
 - `--session-id <value>`
+- `--previous-session-id <value>`
 - `--force`
 - `--artifacts <names>`: analyze artifact keys to execute (repeatable or comma-separated).
 
 ### `run-stage`
 
 - `--config <path>`
+- `--campaign <path>`
 - `--session <path>`
 - `--session-id <value>`
+- `--previous-session-id <value>`
 - `--force`
 - `--artifacts <names>`: analyze artifact keys to execute (repeatable or comma-separated).
 - positional `<stage>`: required stage name.
@@ -72,8 +80,10 @@ Valid stage names:
 ### `restore`
 
 - `--config <path>`
+- `--campaign <path>`
 - `--session <path>`
 - `--session-id <value>`
+- `--previous-session-id <value>`
 - `--dry-run`: plan restore actions without writing local files.
 - `--force`: overwrite local conflicting files with remote archive files.
 - `--include-audio`: include durable archived `audio/**` files in restore scope.
@@ -92,14 +102,15 @@ Purpose:
 Syntax:
 
 ```bash
-narratio run [--config <pipeline.yml>] [--session <session.yml>] [--session-id <id>] [--force] [--artifacts <name[,name...]>]
+narratio run [--config <pipeline.yml>] [--campaign <campaign.yml>] [--session <session.yml>] [--session-id <id>] [--previous-session-id <id>] [--force] [--artifacts <name[,name...]>]
 ```
 
 Success output:
 - `narratio run: session <session_id>; executed=<n> skipped=<n>; manifest=<path>`
 
 Common failure cases:
-- missing default config/session paths when flags omitted.
+- missing default config/campaign/session paths when flags omitted.
+- missing local session plus missing/unavailable remote `session.yml`.
 - invalid template/rendered session mismatch.
 - unknown/invalid `--artifacts` value.
 - `--artifacts` with unknown configured artifact key.
@@ -112,7 +123,7 @@ Purpose:
 Syntax:
 
 ```bash
-narratio plan [--config <pipeline.yml>] [--session <session.yml>] [--session-id <id>] [--force]
+narratio plan [--config <pipeline.yml>] [--campaign <campaign.yml>] [--session <session.yml>] [--session-id <id>] [--previous-session-id <id>] [--force]
 ```
 
 Success output includes:
@@ -121,7 +132,8 @@ Success output includes:
 - `totals: run=<n> skip=<n>`
 
 Common failure cases:
-- same config/session discovery and validation failures as `run`.
+- same config/campaign/session discovery and validation failures as `run`.
+- remote session fallback failures when local session discovery misses.
 - secrets directory read failures when `pipeline.secrets.env_dir` is configured.
 
 ### `resume`
@@ -132,7 +144,7 @@ Purpose:
 Syntax:
 
 ```bash
-narratio resume [--config <pipeline.yml>] [--session <session.yml>] [--session-id <id>] [--force] [--artifacts <name[,name...]>]
+narratio resume [--config <pipeline.yml>] [--campaign <campaign.yml>] [--session <session.yml>] [--session-id <id>] [--previous-session-id <id>] [--force] [--artifacts <name[,name...]>]
 ```
 
 Success output:
@@ -172,7 +184,7 @@ Purpose:
 Syntax:
 
 ```bash
-narratio run-stage [--config <pipeline.yml>] [--session <session.yml>] [--session-id <id>] [--force] [--artifacts <name[,name...]>] <stage>
+narratio run-stage [--config <pipeline.yml>] [--campaign <campaign.yml>] [--session <session.yml>] [--session-id <id>] [--previous-session-id <id>] [--force] [--artifacts <name[,name...]>] <stage>
 ```
 
 Success output:
@@ -191,12 +203,12 @@ Common failure cases:
 ### `restore`
 
 Purpose:
-- Restore durable session state (`manifest.json`, `transcripts/**`, `artifacts/**`, and optional `audio/**`) from the committed remote archive current state.
+- Restore durable session state (`manifest.json`, `transcripts/**`, `artifacts/**`, `previous/**`, and optional `audio/**`) from the committed remote archive current state.
 
 Syntax:
 
 ```bash
-narratio restore [--config <pipeline.yml>] [--session <session.yml>] [--session-id <id>] [--dry-run] [--force] [--include-audio]
+narratio restore [--config <pipeline.yml>] [--campaign <campaign.yml>] [--session <session.yml>] [--session-id <id>] [--previous-session-id <id>] [--dry-run] [--force] [--include-audio]
 ```
 
 Success output (dry-run):
@@ -260,6 +272,12 @@ narratio restore --session-id 2026-04-04
 narratio run-stage --session-id 2026-04-04 --force analyze
 ```
 
+Rehydrate canonical previous-session inputs after artifact-input changes:
+
+```bash
+narratio run-stage --session-id 2026-04-04 --force prepare
+```
+
 ## Diagnostic / Recovery Commands
 
 Inspect stage status:

docs/config.md

@@ -2,12 +2,13 @@
 
 ## 1. Overview
 
-Narratio loads two YAML files:
+Narratio loads three YAML files:
 
 - `pipeline.yml`: pipeline-level runtime configuration.
-- `session.yml`: per-session metadata and input selection.
+- `campaign.yml`: stable campaign identity and campaign-level input defaults.
+- `session.yml`: per-session metadata and input selection, loaded locally or from the configured S3 backend.
 
-These commands load and validate both files before running:
+These commands load and validate all three files before running:
 
 - `narratio run`
 - `narratio plan`
@@ -19,7 +20,10 @@ Behavior:
 
 - strict YAML decode is enabled (`KnownFields(true)`): unknown fields fail.
 - session templates render before session YAML decode.
+- remote `session.yml` uses the same strict decode and template behavior as local `session.yml`.
 - defaults are applied for optional pipeline fields.
+- campaign-level stable input paths fill missing session input paths.
+- session-level stable input paths override campaign-level input paths.
 - validation enforces required fields, value formats, and cross-field constraints.
 
 ## 2. Config file discovery
@@ -32,25 +36,41 @@ Pipeline config lookup for `run`, `plan`, `resume`, `run-stage`, and `restore`:
   2. `/etc/narratio/pipeline.yml`
 - first existing file wins.
 
+Campaign config lookup for `run`, `plan`, `resume`, `run-stage`, and `restore`:
+
+- if `--campaign <path>` is provided, that path is used.
+- if omitted, Narratio searches in order:
+  1. `./campaign.yml`
+  2. `/usr/local/etc/narratio/campaign.yml`
+  3. `/etc/narratio/campaign.yml`
+- first existing file wins.
+
 ## 3. Session file discovery and templating
 
 Session config lookup for `run`, `plan`, `resume`, `run-stage`, and `restore`:
 
 - if `--session <path>` is provided, that path is used.
-- if omitted, Narratio searches in order:
+- if `--session` is omitted, Narratio searches locally in order:
   1. `./session.yml`
   2. `/usr/local/etc/narratio/session.yml`
   3. `/etc/narratio/session.yml`
-- first existing file wins.
+- first existing local file wins.
+- if no local session file is found, `--session-id <value>` is present, storage is configured, and campaign identity is resolved, Narratio loads remote `session.yml` from:
+  - `{root_prefix}/campaigns/{campaign}/sessions/{session_id}/session.yml`
+- local discovery always runs before remote fallback.
 
 Template behavior:
 
 - supported placeholders:
   - `{{session_id}}`
   - `{{ session_id }}`
+  - `{{previous_session_id}}`
+  - `{{ previous_session_id }}`
 - `--session-id <value>` supplies the placeholder value.
+- `--previous-session-id <value>` supplies the previous-session placeholder value.
 - unresolved placeholders fail load.
 - if rendered `session_id` mismatches `--session-id`, load fails.
+- if rendered `previous_session_id` mismatches `--previous-session-id`, load fails.
 
 ## 4. Minimal pipeline config
 
@@ -67,20 +87,41 @@ Why this is sufficient:
 
 ## 5. Minimal session template
 
+`campaign.yml`:
+
 ```yaml
-session_id: "{{ session_id }}"
 campaign: sample-campaign
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+```
+
+`session.yml`:
+
+```yaml
+session_id: "{{ session_id }}"
 inputs:
   audio_dir: ./audio
-  speakers_file: ./examples/speakers.yml
-  autocorrect_file: ./examples/autocorrect.yml
-  glossary_file: ./examples/glossary.yml
 ```
 
 Usage:
 
 ```bash
-narratio run --config /path/to/pipeline.yml --session ./session.yml --session-id 2026-05-03
+narratio run --config /path/to/pipeline.yml --campaign ./campaign.yml --session ./session.yml --session-id 2026-05-03
+```
+
+Previous-session-enabled variant:
+
+```yaml
+session_id: "{{ session_id }}"
+previous_session_id: "{{ previous_session_id }}"
+inputs:
+  audio_dir: ./audio
+```
+
+```bash
+narratio run --config /path/to/pipeline.yml --campaign ./campaign.yml --session ./session.yml --session-id 2026-05-03 --previous-session-id 2026-04-26
 ```
 
 ## 6. Production-oriented config
@@ -113,6 +154,9 @@ archive:
     - source: narratio.artifact.session_recap
       dest: artifacts/session_recap.md
       required: true
+  locks:
+    - source: narratio.artifact.session_recap
+      reason: Final recap was manually edited.
 
 whisperx:
   transcribe_url: "https://transcription.example.com/transcribe"
@@ -127,14 +171,18 @@ scriptorium:
         transcript:
           source: narratio.transcript.trimmed
           required: true
+        previous_recap:
+          source: narratio.previous_session.artifact.session_recap
+          required: false
 ```
 
 Operational notes:
 
 - archive promotion is explicit and source-based via `archive.promote_artifacts`.
 - `source` is required; `dest` is optional and derived when omitted.
+- `archive.locks` skips top-level promotion overwrites for locked sources while preserving run-local uploads.
 - Narratio does not auto-promote all generated analyze artifacts.
-- `restore` reads the same config/session inputs and restore scope is bounded by committed archive current state.
+- `restore` reads the same config/campaign/session inputs and restore scope is bounded by committed archive current state.
 
 ## 7. Full pipeline reference
 
@@ -161,6 +209,9 @@ Operational notes:
 | `pipeline.archive.promote_artifacts[].source` | string | Yes (per rule) | none |
 | `pipeline.archive.promote_artifacts[].dest` | string | No | derived from source |
 | `pipeline.archive.promote_artifacts[].required` | bool | No | `true` |
+| `pipeline.archive.locks[]` | list | No | empty |
+| `pipeline.archive.locks[].source` | string | Yes (per lock) | none |
+| `pipeline.archive.locks[].reason` | string | No | empty |
 | `pipeline.whisperx.transcribe_url` | string | Yes | none |
 | `pipeline.whisperx.language` | string | No | `en` |
 | `pipeline.whisperx.timeout` | duration string | No | `30m` |
@@ -243,13 +294,14 @@ Scriptorium artifact-key and dependency rules:
 
 Allowed `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source` values:
 
-- `previous_session_artifact`
+- `narratio.previous_session.artifact.<configured_artifact_key>`
 - `narratio.transcript.merged`
 - `narratio.transcript.polished`
 - `narratio.transcript.full`
 - `narratio.transcript.trimmed`
 - `narratio.bounds.session`
 - `narratio.artifact.<configured_artifact_key>`
+- `previous_session_artifact` (legacy path-based source; uses `inputs.<key>.path`)
 
 `pipeline.archive.promote_artifacts[].source` values:
 
@@ -260,6 +312,8 @@ Allowed `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source` values:
 - `narratio.bounds.session`
 - `narratio.artifact.<configured_artifact_key>`
 
+`pipeline.archive.locks[].source` accepts the same source values as `pipeline.archive.promote_artifacts[].source`.
+
 Archive promotion destination rules:
 
 - `dest` must be a clean relative path (not absolute, no traversal).
@@ -269,25 +323,47 @@ Archive promotion destination rules:
   - configured sources derive from `pipeline.scriptorium.artifacts.<name>.output_path`;
   - derivation failure is a config validation error.
 
+Archive lock rules:
+
+- locks are source-based and do not accept `dest`.
+- duplicate lock sources are rejected.
+- locked promotions are recorded as intentional skips in archive metadata.
+- locked required promotions do not fail archive by default.
+- ordinary `--force` reruns do not override locks.
+
 Restore-related implications:
 
 - restore remote identity requires archive S3 identity to resolve (`pipeline.storage.s3.bucket` and session prefix derivation inputs).
-- restore scope considers only committed current state and durable paths (`manifest.json`, `transcripts/**`, `artifacts/**`, optional `audio/**`).
+- restore scope considers committed current state and durable paths (`manifest.json`, `transcripts/**`, `artifacts/**`, `previous/**`, optional `audio/**`).
 
-## 8. Full session reference
+## 8. Full campaign reference
+
+| Path | Type | Required | Default |
+| --- | --- | --- | --- |
+| `campaign.campaign` | string | Yes | none |
+| `campaign.inputs.speakers_file` | string | Yes | none |
+| `campaign.inputs.autocorrect_file` | string | Yes | none |
+| `campaign.inputs.glossary_file` | string | Yes | none |
+
+Campaign input paths may be absolute or relative. Relative paths resolve from the directory containing `campaign.yml`.
+
+## 9. Full session reference
 
 | Path | Type | Required | Default |
 | --- | --- | --- | --- |
 | `session.session_id` | string | Yes | none |
-| `session.campaign` | string | Yes | none |
+| `session.previous_session_id` | string | No | empty |
+| `session.campaign` | string | No | `campaign.campaign` |
 | `session.date` | string | No | empty |
 | `session.title` | string | No | empty |
 | `session.inputs.audio_dir` | string | Conditional | empty |
 | `session.inputs.audio_files[]` | list[string] | Conditional | empty |
 | `session.inputs.audio_s3.prefix` | string | Conditional | none |
-| `session.inputs.speakers_file` | string | Yes | none |
-| `session.inputs.autocorrect_file` | string | Yes | none |
-| `session.inputs.glossary_file` | string | Yes | none |
+| `session.inputs.speakers_file` | string | No | `campaign.inputs.speakers_file` |
+| `session.inputs.autocorrect_file` | string | No | `campaign.inputs.autocorrect_file` |
+| `session.inputs.glossary_file` | string | No | `campaign.inputs.glossary_file` |
+
+Session input paths may be absolute or relative. Relative audio paths and session-level stable input overrides resolve from the directory containing `session.yml`. If both `campaign.yml` and `session.yml` specify campaign identity, the values must match.
 
 Audio-source rule:
 
@@ -297,7 +373,12 @@ Audio-source rule:
   - `audio_s3.prefix`
 - `audio_s3` cannot be combined with local audio fields.
 
-## 9. Secrets
+Previous-session rule:
+
+- if `session.previous_session_id` is set, it must not equal `session.session_id`.
+- canonical previous-session sources (`narratio.previous_session.artifact.<name>`) are hydrated during `prepare` from archive current state when required by enabled configured artifacts.
+
+## 10. Secrets
 
 Narratio supports filesystem-based secret injection via `pipeline.secrets.env_dir`.
 
@@ -316,13 +397,14 @@ Guidance:
 - do not put secret values directly in YAML.
 - configure env var names in config and provide values via env/secrets files.
 
-## 10. Examples
+## 11. Examples
 
 Maintained examples:
 
 - `examples/pipeline.minimal.yml`
 - `examples/pipeline.production.yml`
 - `examples/pipeline.full.annotated.yml`
+- `examples/campaign.yml`
 - `examples/session.template.yml`
 - `examples/session.local-audio.yml`
 - `examples/session.s3-audio.yml`

docs/internal/artifacts.md

@@ -1,41 +1,36 @@
 # Internal: Artifacts
 
 ## Purpose
-Define Narratio's artifact identity and resolution model for built-in transcript/bounds artifacts and runtime-configured analyze artifacts.
+Define Narratio artifact identity, catalog, and source-resolution behavior for:
+- built-in session artifacts;
+- configured analyze artifacts;
+- canonical previous-session artifact sources.
 
 ## Inputs and outputs
 Inputs:
-- artifact sources from config/runtime (`pipeline.scriptorium.artifacts.*.inputs.*.source`)
-- session paths and optional session manifest stage outputs
-- runtime artifact catalog state for configured artifact sources
+- configured input sources (`pipeline.scriptorium.artifacts.*.inputs.*.source`);
+- session paths and manifest inputs/outputs;
+- runtime catalog state.
 
 Outputs:
-- resolved local artifact path and provenance (`ResolvedSessionArtifact`)
-- runtime catalog entries for planned/executable/available artifacts
-- validation errors for unsupported, missing, or invalid artifact sources
+- resolved artifact path + provenance (`ResolvedSessionArtifact`);
+- runtime catalog entries for built-ins and configured artifacts;
+- requirement sets for canonical previous-session inputs.
+- canonical S3 session, run, current, session config, audio, and promoted artifact keys.
 
 ## Boundaries
 Owns:
-- built-in artifact registry and content validation rules
-- runtime artifact catalog for configured artifact source IDs
-- source resolution behavior for built-in and configured artifact sources
+- built-in source registry and validation;
+- configured artifact catalog identity (`narratio.artifact.<name>`);
+- canonical previous-session source parsing and resolution;
+- previous-session requirement collection (`CollectPreviousArtifactRequirements`).
 
 Does not own:
-- artifact generation (stages produce files)
-- manifest transition policy
-- archive promotion behavior
-
-## Config fields used
-- `pipeline.scriptorium.artifacts.<name>.enabled`
-- `pipeline.scriptorium.artifacts.<name>.output_path`
-- `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source`
-
-## External adapters used
-- none
-
-## State and manifest behavior
-Built-in registry entries:
+- prepare-stage remote hydration;
+- stage success/skip transitions;
+- archive upload orchestration.
 
+## Built-in IDs
 | Artifact ID | Canonical file | Producer stage | Output kind |
 | --- | --- | --- | --- |
 | `narratio.transcript.merged` | `transcripts/merged.json` | `merge` | `transcript_merged` |
@@ -44,44 +39,66 @@ Built-in registry entries:
 | `narratio.transcript.trimmed` | `transcripts/trimmed.json` | `trim` | `transcript_trimmed` |
 | `narratio.bounds.session` | `artifacts/session_bounds.json` | `trim` | `session_bounds` |
 
-Runtime catalog entries include built-ins and configured `narratio.artifact.<name>` sources.
+## Source families
+- built-in: `narratio.transcript.*`, `narratio.bounds.session`
+- configured artifact: `narratio.artifact.<artifact_key>`
+- canonical previous-session artifact: `narratio.previous_session.artifact.<artifact_key>`
 
-Catalog states:
-- `planned`: source is registered and known for this run
-- `executable`: configured artifact is selected for analyze execution
-- `available`: artifact has a usable file path (generated this run or reused from disk)
+## S3 key helpers
+- session prefix: `{root_prefix}/campaigns/{campaign}/sessions/{session_id}/`
+- session config: `{session_prefix}/session.yml`
+- run prefix: `{session_prefix}/runs/{run_id}/`
+- audio prefix: `{session_prefix}/{session.inputs.audio_s3.prefix}`
+- current manifest: `{session_prefix}/current/manifest.json`
+- current run pointer: `{session_prefix}/current/run_id.txt`
 
-Resolution behavior:
-- built-in sources resolve via manifest producer outputs first, then canonical fallback path
-- configured `narratio.artifact.<name>` sources resolve through runtime catalog availability
-- configured source lookup requires catalog context
+## Runtime catalog model
+Catalog entries track:
+- `planned`: source is registered for this run;
+- `executable`: configured artifact is selected for analyze execution;
+- `available`: usable local file exists (generated this run or reused from disk).
 
-Configured artifact provenance values:
+Configured artifact provenance values include:
 - `generated.current_analyze_run`
 - `filesystem.disabled_artifact_output`
 
-Content validation:
-- transcript built-ins: JSON with top-level `segments` array
-- bounds built-in: valid JSON
-- configured artifacts: non-empty text file
+Previous-session canonical provenance values include:
+- `manifest.inputs.previous_cache`
+- `current_session.previous_cache`
 
-## Skip and resume behavior
-- resolver and catalog have no direct skip/resume decisions
-- stage/runner skip-resume behavior consumes catalog/resolver results
+## Resolution behavior
+- Built-ins resolve via manifest producer outputs first, then canonical fallback paths.
+- Configured `narratio.artifact.<name>` sources resolve through catalog availability.
+- Canonical previous-session sources resolve to current-session `previous/` cache candidates derived from configured artifact canonical output paths.
+- Previous-session canonical resolution prefers manifest-recorded input paths when present, then filesystem fallback under `previous/artifacts/**`.
+
+## Previous-session requirement scanning
+`CollectPreviousArtifactRequirements`:
+- scans enabled configured artifacts only;
+- includes canonical previous-session sources only;
+- deduplicates by artifact key;
+- merges required/optional references (`required` wins);
+- records deterministic sorted source locations for diagnostics.
+
+## Validation behavior
+- transcript built-ins: JSON with top-level `segments` array;
+- bounds built-in: valid JSON;
+- configured and previous-session artifact files: non-empty text content.
 
 ## Failure behavior
-- unsupported source -> source validation error
-- known source unavailable -> `ErrSessionArtifactNotFound`
-- configured source without catalog -> resolution error
-- resolved file with invalid content -> validation error
+- unsupported source or malformed canonical previous source: validation/resolution error;
+- known source unavailable: `ErrSessionArtifactNotFound`;
+- configured/previous canonical source without catalog: error;
+- resolved invalid file content: validation error.
 
 ## Tests to inspect before changing
 - `internal/artifacts/artifact_resolver_test.go`
 - `internal/artifacts/catalog_test.go`
+- `internal/artifacts/previous_requirements_test.go`
+- `internal/stage/prepare_previous_test.go`
 - `internal/stage/analyze_test.go`
-- `internal/config/scriptorium_test.go`
 
 ## Architectural invariants
-- built-in IDs are static and registry-backed
-- configured artifact IDs are runtime-derived (`narratio.artifact.<name>`) and catalog-backed
-- built-in/source resolution remains deterministic and validation-gated
+- Built-in source IDs are static.
+- Configured and previous-session source IDs are artifact-key based and validation-gated.
+- Resolution behavior remains deterministic and manifest-aware.

docs/internal/command-restore.md

@@ -1,11 +1,11 @@
 # Internal: Command Restore
 
 ## Purpose
-Define the implemented `narratio restore` command contract: committed remote-state discovery, deterministic planning, safe file installation, conflict policy, and restore reporting.
+Define the implemented `narratio restore` contract: committed remote-state discovery, deterministic plan classification, safe file install semantics, and restore reporting.
 
 ## Inputs and outputs
 Inputs:
-- CLI flags: `--config`, `--session`, `--session-id`, `--dry-run`, `--force`, `--include-audio`.
+- CLI flags: `--config`, `--session`, `--session-id`, `--previous-session-id`, `--dry-run`, `--force`, `--include-audio`.
 - Resolved/validated `pipeline.yml` and `session.yml`.
 - Configured remote object store.
 - Remote committed current-state markers (`current/run_id.txt`, `current/manifest.json`).
@@ -54,6 +54,21 @@ Does not own:
   - existing local manifest is preserved if restored manifest validation/install fails.
 - Non-dry-run report persists summary/action status metadata in `reports/restore-latest.json`.
 
+Restore path scope:
+- includes:
+  - `manifest.json`
+  - `transcripts/**`
+  - `artifacts/**`
+  - `previous/**`
+  - `audio/**` only when `--include-audio` is set
+- excludes:
+  - `runs/**`
+  - `logs/**`
+  - `reports/**`
+  - `config/**`
+  - `inputs/**`
+  - remote `current/**` pointer files as local restore targets
+
 ## Skip and resume behavior
 - Restore does not participate in stage skip/resume decisions.
 - Restore provides durable local state so subsequent stage commands can resume or rerun based on restored manifest state.
@@ -80,7 +95,7 @@ Does not own:
 - `current/run_id.txt` is the remote commit marker; restore must not infer committed state from incidental files.
 - Local path mapping is traversal-safe and constrained to session root.
 - Restore scope is deterministic and path-classified:
-  - include `manifest.json`, `transcripts/**`, `artifacts/**`
+  - include `manifest.json`, `transcripts/**`, `artifacts/**`, `previous/**`
   - include `audio/**` only with `--include-audio`
   - exclude `runs/**`, `logs/**`, `reports/**`, `config/**`, `inputs/**`
 - Command remains standalone; no implicit `run --restore` behavior.

docs/internal/stage-analyze.md

@@ -3,31 +3,36 @@
 ## Purpose
 Execute selected configured Scriptorium artifacts in deterministic dependency order and promote successful outputs to canonical session artifact paths.
 
-## Inputs and Outputs
+## Inputs and outputs
 Inputs:
-- configured artifact definitions from `pipeline.scriptorium.artifacts`
-- selected artifact filter from runtime (`--artifacts`) when provided
-- resolved artifact input sources declared per artifact (`inputs.*.source`)
-- optional previous-session file inputs (`previous_session_artifact`)
+- configured artifact definitions from `pipeline.scriptorium.artifacts`;
+- selected artifact filter (`--artifacts`) when provided;
+- resolved artifact sources from resolver/catalog.
+
+Source types used by analyze:
+- built-ins: `narratio.transcript.*`, `narratio.bounds.session`;
+- configured artifacts: `narratio.artifact.<artifact_key>`;
+- canonical previous-session artifacts: `narratio.previous_session.artifact.<artifact_key>`;
+- legacy path-based previous-session source: `previous_session_artifact` (uses `inputs.*.path`).
 
 Outputs:
-- one promoted output file per executed configured artifact at that artifact's configured `output_path`
-- stage metadata containing generated artifact entries and reused disabled-artifact entries
+- promoted configured artifact files at each configured `output_path`;
+- stage metadata (`generated_artifacts`, `reused_artifacts`, selected/order info).
 
 ## Boundaries
 Owns:
-- runtime artifact catalog construction for analyze execution
-- selected-artifact planning and dependency ordering
-- per-artifact input resolution, var resolution, timeout/render-debug resolution
-- Scriptorium run/render invocation for each selected artifact
-- run-local output generation and canonical promotion
+- runtime artifact catalog construction;
+- selected-artifact planning and dependency ordering;
+- per-input resolution and required/optional handling;
+- Scriptorium render/run invocation;
+- run-local output generation and canonical promotion.
 
 Does not own:
-- transcript generation/processing stages
-- archive promotion policy
-- per-artifact resume semantics
+- prepare-time previous-session hydration;
+- object-store access for previous-session sources;
+- archive promotion policy.
 
-## Config Fields Used
+## Config fields used
 - `session.session_id`
 - `session.campaign`
 - `pipeline.workspace.root`
@@ -36,49 +41,41 @@ Does not own:
 - `pipeline.scriptorium.timeout`
 - `pipeline.scriptorium.render_debug`
 - `pipeline.scriptorium.artifacts.<name>.*`
-  - `enabled`
-  - `depends_on`
-  - `prompt_id`
-  - `profile_id`
-  - `timeout`
-  - `output_path`
-  - `render_debug`
-  - `inputs`
-  - `vars`
 
-## External Adapters Used
+## External adapters used
 - Scriptorium adapter:
-  - optional `RenderArtifact` (render debug)
-  - `RunArtifact` (artifact generation)
+  - optional `RenderArtifact` when render-debug is enabled;
+  - `RunArtifact` for artifact generation.
 
-## State and Manifest Behavior
-- If `pipeline.scriptorium` is absent, stage returns success metadata with `skipped=true`.
-- If no artifacts are configured, stage returns success metadata with `skipped=true`.
-- If zero artifacts are executable after `enabled` + `--artifacts` filtering, stage returns success metadata with `skipped=true`.
-- Builds runtime catalog with built-ins and configured artifacts.
-- Non-executable configured artifacts are marked available only when their configured output file exists and is valid on disk.
-- Executes selected configured artifacts in topological order with deterministic tie-breaking.
-- For each generated artifact, records metadata fields including `name`, `source_id`, `output_kind`, `path`, `prompt_id`, `profile_id`, and `provenance`.
-- Reused disabled artifacts are recorded separately in `reused_artifacts` with provenance `filesystem.disabled_artifact_output`.
+## State and manifest behavior
+- If Scriptorium config is absent, or no artifacts are executable after filtering, analyze returns success metadata with `skipped=true`.
+- Builds runtime catalog with built-ins and configured `narratio.artifact.<name>` entries.
+- Non-executable configured artifacts may still be marked available from existing canonical output files.
+- Resolves canonical previous-session sources from local prepared `previous/` cache:
+  - prefers manifest-backed previous input paths when present;
+  - may fall back to current-session `previous/` filesystem paths.
+- Analyze does not call object storage for canonical previous-session source resolution.
+- Required canonical previous-session input missing:
+  - fails with guidance to run `narratio run-stage --force prepare`.
+- Optional missing sources are omitted from adapter input paths.
 
-## Skip and Resume Behavior
+## Skip and resume behavior
 - Runner-level skip applies when analyze is already `succeeded` and `--force` is not set.
-- Analyze remains stage-scoped for resume/skip; there is no per-artifact resume state.
-- `--artifacts` filters which configured artifacts are executable when analyze runs; it does not imply `--force`.
+- Analyze is stage-scoped for resume; no per-artifact manifest resume state.
+- `--artifacts` filters executable artifacts but does not imply force rerun.
 
-## Failure Behavior
-- Fails on invalid dependency ordering, unavailable required configured inputs, invalid built-in input prerequisites, render/run adapter failures, validation-failed adapter results, or missing/empty outputs.
-- Required configured dependency missing from catalog availability fails clearly before invocation.
-- Optional missing inputs are omitted.
+## Failure behavior
+- Fails on dependency-order violations, missing required inputs, resolver validation failures, adapter errors, and missing/empty generated outputs.
+- Required unavailable configured artifact source (`narratio.artifact.<name>`) fails before invocation.
+- Required canonical previous-session source fails with prepare-rerun guidance.
 
-## Tests to Inspect Before Changing
+## Tests to inspect before changing
 - `internal/stage/analyze_test.go`
 - `internal/artifacts/catalog_test.go`
 - `internal/artifacts/artifact_resolver_test.go`
-- `internal/adapters/scriptorium/subprocess_test.go`
+- `internal/app/restore_workflow_test.go`
 
-## Architectural Invariants
-- Configured artifacts are identified by `narratio.artifact.<name>` source IDs.
-- Artifact-to-artifact references rely on explicit `depends_on` declarations validated in config.
-- Generated analyze outputs are treated uniformly as Scriptorium artifacts.
-- Successful outputs must exist and be non-empty before promotion.
+## Architectural invariants
+- Canonical previous-session behavior is local-cache only during analyze.
+- Generated outputs are validated and promoted before stage success is recorded.
+- Resolver/catalog decisions stay deterministic and validation-gated.

docs/internal/stage-archive.md

@@ -1,17 +1,20 @@
 # Stage: archive
 
 ## Purpose
-Publish run records and promoted session artifacts to object storage, then atomically advance the remote current pointer.
+Publish durable run/session state to object storage, then atomically advance remote current state.
 
 ## Inputs and Outputs
 Inputs:
 - session manifest and prerequisite stage records
 - run root contents under `runs/{run_id}/`
 - promotion rules with artifact `source` IDs and archive `dest` paths (`archive.promote_artifacts`)
+- source-based promotion locks (`archive.locks`)
+- session-level `previous/**` cache files when present
 
 Outputs:
 - uploaded run files under `{session_prefix}/runs/{run_id}/...`
 - uploaded promoted artifacts under `{session_prefix}/...`
+- uploaded session previous-cache files under `{session_prefix}/previous/...` when present
 - `{session_prefix}/current/manifest.json`
 - `{session_prefix}/current/run_id.txt` written last
 
@@ -21,6 +24,8 @@ Owns:
 - Prerequisite stage success enforcement
 - Run file collection and upload (excluding `audio/`)
 - Promotion rule resolution and upload
+- Promotion lock enforcement
+- Session previous-cache file collection/upload
 - Commit pointer publish order
 
 Does not own:
@@ -31,6 +36,7 @@ Does not own:
 - `pipeline.archive.enabled`
 - `pipeline.archive.upload_run`
 - `pipeline.archive.promote_artifacts`
+- `pipeline.archive.locks`
 - `pipeline.storage.s3.bucket`
 - `pipeline.storage.s3.root_prefix`
 - `pipeline.workspace.root`
@@ -43,8 +49,12 @@ Does not own:
 ## State and Manifest Behavior
 - Requires `prepare`, `transcribe`, `merge`, `polish`, `normalize`, `trim`, and `analyze` status `succeeded`.
 - Resolves bucket/prefix from manifest identity first, then config fallback.
+- Uploads session `previous/**` files as durable session state when the local `previous/` directory exists.
+- Skips top-level promotion uploads for sources listed in `pipeline.archive.locks`; run-local uploads still publish.
 - Writes metadata including:
   - upload counts/paths
+  - `previous_files_uploaded` and `previous_uploaded_paths`
+  - `locked_promotion_count` and `locked_promotions`
   - `current_manifest_key`
   - `current_run_id_key`
   - `current_pointer_written`
@@ -55,7 +65,8 @@ Does not own:
 - Runner-level skip also applies for previously succeeded stage unless forced.
 
 ## Failure Behavior
-- Fails on missing prerequisite success, missing object store when required, missing run root, missing required promotion source, upload failures, or pointer write failures.
+- Fails on missing prerequisite success, missing object store when required, missing run root, missing unlocked required promotion source, upload failures, or pointer write failures.
+- Locked required promotions are intentional skips and do not fail archive.
 - Pointer semantics are fail-safe: `current/run_id.txt` is not written if prior required uploads fail.
 
 ## Tests to Inspect Before Changing
@@ -64,5 +75,7 @@ Does not own:
 
 ## Architectural Invariants
 - Run upload excludes `audio/` subtree.
+- Session `previous/**` is archiveable durable input/provenance state, not run-local output.
+- Ordinary `--force` does not override archive locks.
 - `current/manifest.json` uploads before `current/run_id.txt`.
 - `current/run_id.txt` is the remote publish commit marker.

docs/internal/stage-prepare.md

@@ -1,40 +1,51 @@
 # Stage: prepare
 
 ## Purpose
-Materialize all required session inputs into canonical local workspace paths and record input provenance in the session manifest.
+Materialize canonical current-session input state and provenance before downstream stages run.
 
-## Inputs and Outputs
+Prepare owns:
+- local input file materialization (`inputs/**`);
+- audio input materialization (`audio/**`);
+- previous-session cache hydration (`previous/**`) for canonical previous-session artifact sources.
+
+## Inputs and outputs
 Inputs:
-- `session.yml` (resolved session config)
-- `pipeline.resolved.yml` (materialized from resolved pipeline config)
-- `speakers.yml`
-- `autocorrect.yml`
-- `glossary.yml`
+- resolved config/campaign/session (`pipeline.yml`, `campaign.yml`, `session.yml`);
+- remote session provenance when `session.yml` was loaded from S3;
+- campaign or session input files (`speakers`, `autocorrect`, `glossary`);
 - audio source:
-  - local (`session.inputs.audio_dir` or `session.inputs.audio_files`), or
-  - S3 (`session.inputs.audio_s3.prefix`)
+  - local: `session.inputs.audio_dir` or `session.inputs.audio_files`;
+  - S3: `session.inputs.audio_s3.prefix`;
+- configured enabled Scriptorium artifact inputs (for previous-session requirement scanning);
+- remote previous-session current archive state when previous hydration is required.
 
 Outputs:
-- `inputs/session.yml`
-- `inputs/pipeline.resolved.yml`
-- `inputs/speakers.yml`
-- `inputs/autocorrect.yml`
-- `inputs/glossary.yml`
-- `audio/*.flac` in session workdir
-- `manifest.Inputs` records with checksums and source metadata
+- `inputs/campaign.yml`;
+- `inputs/session.yml`;
+- `inputs/pipeline.resolved.yml`;
+- `inputs/speakers.yml`;
+- `inputs/autocorrect.yml`;
+- `inputs/glossary.yml`;
+- `audio/*.flac` in canonical session `audio/`;
+- optional `previous/manifest.json`;
+- optional `previous/artifacts/**`;
+- deterministic `manifest.Inputs` records with checksums and provenance metadata.
 
 ## Boundaries
 Owns:
-- Input path resolution and validation
-- Local copy/materialization of configs and audio files
-- S3 audio download to run-scoped spool, then copy into work audio dir
+- input path resolution and materialization;
+- S3 audio list/download/copy flow;
+- previous-session artifact requirement collection from enabled configured artifacts;
+- previous cache lifecycle when requirements exist (clear and rehydrate managed `previous/` state).
 
 Does not own:
-- Transcript generation/processing
-- Archive publish behavior
+- transcript or artifact generation;
+- analyze-stage source resolution;
+- archive commit behavior.
 
-## Config Fields Used
+## Config fields used
 - `session.session_id`
+- `session.previous_session_id`
 - `session.campaign`
 - `session.inputs.speakers_file`
 - `session.inputs.autocorrect_file`
@@ -46,29 +57,63 @@ Does not own:
 - `pipeline.spool.root`
 - `pipeline.storage.s3.bucket`
 - `pipeline.storage.s3.root_prefix`
+- `pipeline.scriptorium.artifacts.<name>.enabled`
+- `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source`
+- `pipeline.scriptorium.artifacts.<name>.inputs.<key>.required`
+- `campaign.campaign`
+- `campaign.inputs.speakers_file`
+- `campaign.inputs.autocorrect_file`
+- `campaign.inputs.glossary_file`
 
-## External Adapters Used
-- Object storage backend (`env.ObjectStore`) for S3 audio list/download when `audio_s3` is configured.
+## External adapters used
+- `storage.ObjectStore` for:
+  - S3 audio listing/downloads;
+  - previous-session current pointer/manifest/artifact object checks and downloads.
 
-## State and Manifest Behavior
+## State and manifest behavior
 - Ensures workspace layout exists.
-- Writes resolved config and input files to canonical `inputs/` paths.
-- Records all prepared inputs into `manifest.Inputs` (sorted deterministically by kind/path).
-- For S3 audio, records `S3Bucket`, `S3Key`, `S3Size`, `S3ETag`, and `SpoolPath` in each audio input record.
+- Materializes canonical input files and audio files.
+- Records `inputs/session.yml` provenance as local `session_config` or remote `session_config.s3`.
+- Resolves campaign-provided stable input paths relative to `campaign.yml`.
+- Resolves session-provided stable input overrides relative to `session.yml`.
+- Scans enabled configured artifact inputs for canonical sources:
+  - `narratio.previous_session.artifact.<artifact_key>`
+- If one or more canonical previous-session requirements exist:
+  - clears managed `previous/` state;
+  - hydrates required/optional previous artifacts from the configured previous session’s committed archive current state;
+  - writes `previous/manifest.json` and hydrated `previous/artifacts/**`;
+  - records hydrated previous inputs in `manifest.Inputs` with source `previous_session_archive.current`.
+- If no canonical previous-session requirements exist, prepare does not manage `previous/`.
+- `manifest.Inputs` is sorted deterministically by `(kind, path)`.
 
-## Skip and Resume Behavior
-- Runner-level skip applies when stage already `succeeded` and `--force` is not set.
-- Stage itself is deterministic/idempotent for unchanged inputs (`copyFileIfChanged`, `writeBytesIfChanged`).
+## Required and optional previous-session behavior
+- `previous_session_id` unset:
+  - if any referenced previous artifact is required: fail;
+  - if all referenced previous artifacts are optional: continue and omit them.
+- Previous session archive current pointer or manifest missing:
+  - if any referenced previous artifact is required: fail;
+  - if all referenced previous artifacts are optional: continue and omit missing ones.
+- Missing required previous artifact object: fail.
+- Missing optional previous artifact object: omit.
+- Downloaded previous artifacts must validate as non-empty files.
 
-## Failure Behavior
-- Fails on missing required files, invalid audio source combinations, no discoverable `.flac` files, duplicate audio basenames, missing object store for S3 mode, or S3 list/download failures.
+## Skip and resume behavior
+- Runner-level skip remains authoritative:
+  - if `prepare` already succeeded and run is not forced, `prepare` does not run and no hydration/download occurs.
+- If `prepare` runs (including with `--force`), it owns managed `previous/` state for canonical previous-session inputs.
 
-## Tests to Inspect Before Changing
+## Failure behavior
+- Fails on missing required input files, invalid audio-source combinations, empty/duplicate audio inputs, missing object store for S3 modes, and remote access/download/validation errors.
+- For required canonical previous-session inputs, analyze-time missing-input guidance is to rerun:
+  - `narratio run-stage --force prepare`
+
+## Tests to inspect before changing
 - `internal/stage/prepare_test.go`
-- `internal/app/session_cli_test.go`
-- `internal/config/load_validate_test.go`
+- `internal/stage/prepare_previous_test.go`
+- `internal/artifacts/previous_requirements_test.go`
+- `internal/app/runner_test.go`
 
-## Architectural Invariants
+## Architectural invariants
 - `audio_dir`/`audio_files` and `audio_s3` are mutually exclusive.
-- Audio files must be `.flac`.
-- Canonical `inputs/*` and `audio/*` paths are the durable source for downstream stages.
+- Storage keys are computed by callers using archive/path helpers; storage adapter receives explicit keys.
+- `prepare` is the only stage that hydrates canonical previous-session cache state.

docs/internal/storage.md

@@ -6,7 +6,7 @@ Document Narratio's remote storage backend contracts and implementations under `
 ## Inputs and outputs
 Inputs:
 - Resolved storage config (`pipeline.storage.*`).
-- Bucket-relative object keys and local file paths from stage/app orchestration.
+- Bucket-relative object keys and local file paths from app/stage orchestration.
 
 Outputs:
 - Listed/downloaded/uploaded object metadata (`ObjectInfo`).
@@ -57,6 +57,7 @@ Implementations:
 - `S3Backend` constructor fails when required bucket is missing or AWS client setup fails.
 - CRUD operations return contextual errors (including not-found behavior via `Exists`).
 - Key normalization is applied before operations (`\\` to `/`, leading slash trimmed).
+- Remote session loading uses `List` to find the exact `session.yml` key and `Download` to materialize it to a local temp file.
 
 ## Tests to inspect before changing
 - `internal/adapters/storage/factory_test.go`

docs/internal/workspace.md

@@ -17,7 +17,8 @@ Outputs:
 
 ## Boundaries
 Owns:
-- Session-level path layout (`inputs/`, `audio/`, `transcripts/`, `artifacts/`, `reports/`, `logs/`, `config/`, `current/`, `runs/`)
+- Session-level path layout (`inputs/`, `audio/`, `transcripts/`, `artifacts/`, `reports/`, `logs/`, `config/`, `current/`, `runs/`, `previous/`)
+  - `previous/manifest.json` and `previous/artifacts/**` are reserved for prepared previous-session state
 - Run-local stage sandbox layout under `runs/{run_id}/{stage}/`
 - Session lock acquisition/release (`.lock`)
 
@@ -65,4 +66,5 @@ None directly in this subsystem. Stages may use object storage adapters and then
 - Session root is campaign-aware: `{workspace.root}/work/{campaign}/{session_id}`.
 - Run roots are always nested: `runs/{run_id}` under the session root.
 - Run-local output promotion must end in canonical session paths.
+- `previous/**` is session-durable state and must not be treated as run-local output scratch state.
 - Cleanup only targets run-scoped directories and must never delete configured root directories.

docs/operations.md

@@ -6,19 +6,21 @@ For field-level configuration, see [docs/config.md](./config.md). For full comma
 
 ## Normal workflow (S3-first path)
 
-1. Upload session `.flac` files to object storage under the configured session audio prefix.
-2. Run Narratio:
+1. Upload `session.yml` to the configured session prefix, or keep a local `session.yml` available.
+2. Upload session `.flac` files to object storage under the configured session audio prefix.
+3. Run Narratio:
 
 ```bash
 narratio run --session-id 2026-04-04
 ```
 
-3. Read success output:
+4. Read success output:
 - `narratio run: session <session_id>; executed=<n> skipped=<n>; manifest=<path>`
 - use `manifest=<path>` with `status` for inspection.
 
 Notes:
-- default config/session discovery applies unless `--config` and `--session` are passed.
+- default config/campaign/session discovery applies unless `--config`, `--campaign`, and `--session` are passed.
+- when local `session.yml` discovery misses, `--session-id` loads remote `session.yml` from `{root_prefix}/campaigns/{campaign}/sessions/{session_id}/session.yml`.
 - S3 audio mode requires `session.inputs.audio_s3.prefix` and valid object-store access.
 
 ## Restore workflow
@@ -48,7 +50,7 @@ Restore source-of-truth:
 - remote current manifest: `current/manifest.json`
 
 Restore default scope:
-- includes `manifest.json`, `transcripts/**`, `artifacts/**`
+- includes `manifest.json`, `transcripts/**`, `artifacts/**`, `previous/**`
 - includes `audio/**` only with `--include-audio`
 - excludes `runs/**`, `logs/**`, `reports/**`, `config/**`, `inputs/**`, and `current/**` (except remote `current/manifest.json` as source)
 
@@ -61,12 +63,14 @@ Primary state:
 - `manifest.json`: session-level stage state.
 - `runs/{run_id}/manifest.json`: invocation-level state.
 - `.lock`: session lock while a modifying command is active.
+- `inputs/campaign.yml`, `inputs/session.yml`, and `inputs/pipeline.resolved.yml`: materialized config inputs for the run.
 
 Canonical session directories:
 - `inputs/`
 - `audio/`
 - `transcripts/`
 - `artifacts/`
+- `previous/`
 - `reports/`
 - `logs/`
 - `config/`
@@ -99,6 +103,12 @@ Configured artifact source reuse:
 - accepted on `run`, `resume`, and `run-stage analyze`.
 - filters analyze execution only; does not force stage rerun.
 
+Canonical previous-session input behavior:
+- canonical sources use `narratio.previous_session.artifact.<artifact_key>`.
+- these inputs are hydrated by `prepare`, not `analyze`.
+- if analyze fails due to missing canonical previous cache, rerun:
+  - `narratio run-stage --session-id <id> --force prepare`
+
 ## Remote archive layout and publish contract
 
 When archive is enabled and run upload is enabled, archive publishes under:
@@ -122,6 +132,8 @@ Archive promotion is explicit and source-based:
 - missing required promotion sources fail archive stage.
 - missing optional promotion sources are skipped.
 - invalid resolved artifacts fail archive stage.
+- `archive.locks` skips top-level promotion overwrites for locked sources while run-local uploads still publish.
+- locked required promotions are treated as intentional successful skips and are recorded in archive metadata.
 
 ## Resume, retry, restore, and safe rerun behavior
 
@@ -139,6 +151,7 @@ Restore conflict policy:
 
 Forced reruns:
 - force-rerunning an upstream succeeded stage marks downstream succeeded stages as `stale`.
+- ordinary `--force` does not override archive locks.
 
 Safe rerun pattern:
 1. rerun the changed stage with `--force`.

docs/roadmap/remote.md

@@ -0,0 +1,318 @@
+# Roadmap: Campaign State, Remote Sessions, and Archive Locks
+
+## Purpose
+
+This roadmap tracks implementation work for three related feature areas:
+
+1. `campaign.yml` configuration for stable campaign-level inputs.
+2. Remote `session.yml` loading from the existing S3 object-store backend.
+3. Logical archive locks that prevent selected top-level transcript/artifact promotions from overwriting curated archive state while still preserving run-local outputs.
+
+Treat future sections of this document as an implementation plan, not as current behavior. Keep planned behavior under `docs/roadmap/` until each item is implemented and canonical docs are updated.
+
+## Current Code Facts
+
+The current codebase already settles several design choices:
+
+- CLI commands use short noun flags: `--config`, `--session`, `--session-id`, `--previous-session-id`, `--force`, and `--artifacts`.
+- `run-stage` uses flags before the positional stage name, for example:
+
+      narratio run-stage --session ./session.yml prepare
+
+- `session.yml` is represented by `config.SessionConfig` and currently owns `session_id`, `previous_session_id`, `campaign`, `date`, `title`, and `inputs`.
+- Strict YAML decoding is already implemented with `yaml.Decoder.KnownFields(true)`.
+- Local session discovery is already ordered as `./session.yml`, `/usr/local/etc/narratio/session.yml`, then `/etc/narratio/session.yml`.
+- The canonical S3 session prefix is already:
+
+      {root_prefix}/campaigns/{campaign}/sessions/{session_id}/
+
+- Archive promotion is already source-based through `archive.promote_artifacts[].source`, with destination derivation and validation in `internal/config`.
+- Storage adapters receive bucket-relative keys and do not infer campaign, session, run, or root-prefix semantics.
+
+## Guardrails
+
+Keep Narratio explicit and stage-driven. Do not introduce a generic workflow engine, broad config language, or stage behavior that reaches through adapter boundaries.
+
+Implementation must preserve these constraints:
+
+- Keep storage details behind `internal/adapters/storage`.
+- Compute session, campaign, archive, and remote config keys in app/artifact/path helpers, not inside storage implementations.
+- Use centralized path helpers in `internal/artifacts` or the established local path model.
+- Preserve manifest-driven resume and stage status semantics.
+- Keep strict YAML decoding for `pipeline.yml`, `campaign.yml`, and `session.yml`.
+- Keep raw secrets out of configs, manifests, logs, generated configs, archive metadata, and roadmap examples.
+- Update canonical user-facing docs only after behavior is implemented.
+
+## Phase 1: Add `campaign.yml` (implemented)
+
+Add campaign-level configuration for stable campaign identity and stable input files. Do not add remote campaign loading in this phase.
+
+### CLI and Discovery
+
+Add `--campaign <path>` to `run`, `plan`, `resume`, `run-stage`, and `restore`.
+
+Examples:
+
+      narratio run --campaign ./campaign.yml --session ./session.yml
+      narratio plan --campaign ./campaign.yml --session ./session.yml
+      narratio resume --campaign ./campaign.yml --session ./session.yml
+      narratio run-stage --campaign ./campaign.yml --session ./session.yml prepare
+      narratio restore --campaign ./campaign.yml --session ./session.yml
+
+Campaign config discovery order:
+
+1. explicit `--campaign <path>`;
+2. `./campaign.yml`;
+3. `/usr/local/etc/narratio/campaign.yml`;
+4. `/etc/narratio/campaign.yml`.
+
+Implement this in the same style as `resolvePipelineConfigPath` and `resolveSessionConfigPath`. Add default path constants and a search-path variable in `internal/config/defaults.go`.
+
+### Config Shape
+
+Initial `campaign.yml` fields:
+
+      campaign: icewind-dale
+      inputs:
+        speakers_file: ./speakers.yml
+        autocorrect_file: ./autocorrect.yml
+        glossary_file: ./glossary.yml
+
+Do not add speculative campaign artifact defaults, prompt defaults, or title conventions in the first implementation.
+
+### Merge Behavior
+
+Add `CampaignConfig` and keep the final stage-facing config explicit.
+
+Required behavior:
+
+- `pipeline.yml` remains host/runtime configuration.
+- `campaign.yml` supplies campaign identity and stable input file defaults.
+- `session.yml` remains the source for `session_id`, `previous_session_id`, `date`, `title`, and audio input.
+- Campaign-level `speakers_file`, `autocorrect_file`, and `glossary_file` fill missing session-level stable input fields.
+- Session-level stable input fields override campaign-level stable input fields.
+- If both `campaign.yml` and `session.yml` specify `campaign`, the values must match.
+- The resolved session must satisfy the existing session validation rules before stages run.
+- Unknown fields in `campaign.yml` fail strict decode.
+
+Path resolution must preserve source-file locality:
+
+- campaign-provided stable input paths resolve relative to `campaign.yml`;
+- session-provided stable input overrides resolve relative to `session.yml`;
+- absolute paths keep existing behavior.
+
+Track enough provenance in the resolved config or prepare inputs so `prepare` can copy the correct source files without guessing which file supplied each path.
+
+### Prepare Behavior
+
+Update `prepare` to materialize the resolved campaign/session inputs into canonical session input paths:
+
+      inputs/campaign.yml
+      inputs/session.yml
+      inputs/pipeline.resolved.yml
+      inputs/speakers.yml
+      inputs/autocorrect.yml
+      inputs/glossary.yml
+
+Continue recording deterministic `manifest.Inputs` records with checksums. If a prepared input came from `campaign.yml`, record source/provenance using the existing manifest input fields where practical; add narrow metadata only if the existing fields cannot describe it.
+
+## Phase 2: Load Remote `session.yml` (implemented)
+
+Support running with no local session file when a remote session file exists under the canonical session prefix.
+
+### Preconditions
+
+Build this phase after `campaign.yml`, because campaign identity is required to compute the remote session key. Do not infer campaign identity from object-store listing.
+
+### Loading Precedence
+
+Session loading order:
+
+1. If `--session <path>` is supplied, load that local file.
+2. If `--session` is omitted, use existing local discovery: `./session.yml`, `/usr/local/etc/narratio/session.yml`, `/etc/narratio/session.yml`.
+3. If no local session file is found, `--session-id` is present, storage is configured, and campaign identity is resolved, load remote `session.yml`.
+4. If no local or remote session can be loaded, fail with a message that lists the local search paths and the remote key that was attempted when applicable.
+
+Do not make remote loading mask local discovery. Existing local discovery remains the local fallback before remote is attempted. Once remote loading is attempted, a missing remote object, storage init error, or malformed remote YAML fails clearly because no local session was available.
+
+### Remote Key Layout
+
+Use the existing canonical S3 layout:
+
+      session prefix: {root_prefix}/campaigns/{campaign}/sessions/{session_id}/
+      session file:   {session_prefix}/session.yml
+      audio prefix:   {session_prefix}/{session.inputs.audio_s3.prefix}
+
+Add a centralized helper near `internal/artifacts/s3_keys.go`:
+
+      S3SessionConfigKey(sessionPrefix string) string
+
+The helper should return `{session_prefix}/session.yml` using the same key normalization style as `S3CurrentManifestKey`, `S3CurrentRunPointerKey`, and `S3PromotedArtifactKey`.
+
+### Decode, Template, and Provenance
+
+Remote `session.yml` uses the same template variables and mismatch checks as local sessions:
+
+- `{{session_id}}`
+- `{{ session_id }}`
+- `{{previous_session_id}}`
+- `{{ previous_session_id }}`
+
+Decode remote session YAML with strict known-field validation. Reuse the current session template/render/decode path by adding a byte/string-based loader rather than duplicating YAML decode logic.
+
+When `prepare` materializes a remote session into `inputs/session.yml`, record that it came from S3. Preserve useful non-secret provenance when available:
+
+- bucket;
+- key;
+- ETag;
+- size;
+- local checksum;
+- downloaded temp/materialized path.
+
+## Phase 3: Add Logical Archive Locks (implemented)
+
+Narratio supports source-based archive locks under `pipeline.archive.locks`. The promotion system is source-based; destination-based locks are not supported.
+
+### Config Shape
+
+Lock entries:
+
+      archive:
+        locks:
+          - source: narratio.transcript.polished
+            reason: Human-reviewed transcript; do not overwrite automatically.
+          - source: narratio.artifact.session_recap
+            reason: Final recap was manually edited.
+
+Validation rules:
+
+- `source` is required.
+- `source` must be a built-in source ID or configured `narratio.artifact.<key>` accepted by the same source validation used for `promote_artifacts`.
+- `reason` is optional and non-secret.
+- duplicate lock sources fail validation.
+- lock entries do not support `dest` in the first implementation; unknown fields already fail strict decode.
+
+### Archive Behavior
+
+Archive continues uploading complete run-local outputs under `runs/{run_id}/`.
+
+Promotion behavior:
+
+1. Resolve promotion source and destination using existing source-based promotion logic.
+2. If the promotion source is unlocked, upload the top-level promoted object normally.
+3. If the promotion source is locked, skip only the top-level promotion overwrite.
+4. Treat locked required promotions as intentional successful skips by default.
+5. Continue archive commit when all run-local uploads and all non-locked required promotions succeed.
+6. Upload `current/manifest.json` and `current/run_id.txt` in the existing order, with `current/run_id.txt` last.
+
+Ordinary `--force` does not override locks. A lock-break override remains out of scope.
+
+### Metadata
+
+Archive records locked promotion skips in archive metadata/reporting so operators can distinguish missing optional promotions from lock-protected promotions.
+
+Include:
+
+- source ID;
+- destination relative path and remote key;
+- reason;
+- local resolved path;
+- resolved provenance;
+- whether the original promotion rule was required.
+
+Keep existing metadata such as `promoted_paths`, `skipped_optional_promotions`, `current_manifest_key`, `current_run_id_key`, and `current_pointer_written`.
+
+## Phase 4: Future Operator Helpers
+
+These commands are future work only. Do not implement them with the first campaign, remote-session, or lock changes.
+
+Potential helper shapes:
+
+      narratio session validate --session-id 2026-06-07
+      narratio session init --session-id 2026-06-07 --title "The Black Cabin"
+      narratio status --session-id 2026-06-07
+      narratio locks --session-id 2026-06-07
+      narratio lock narratio.artifact.session_recap --session-id 2026-06-07
+      narratio unlock narratio.artifact.session_recap --session-id 2026-06-07
+
+Potential behavior:
+
+- validate remote session config;
+- check audio object availability;
+- inspect committed remote current state;
+- list promoted transcripts/artifacts;
+- list archive lock status;
+- initialize a remote session skeleton;
+- publish or sync campaign assets.
+
+## Implementation Sequence
+
+Use small, reviewable commits.
+
+1. Campaign config types and discovery:
+   add `CampaignConfig`, strict loading, defaults/search paths, `--campaign` flags, and config/app tests.
+2. Campaign/session merge:
+   implement resolved stable input merge, path provenance, validation, and prepare materialization.
+3. Campaign docs after implementation:
+   update canonical docs and examples only for implemented behavior.
+4. Remote session key and loader:
+   add `S3SessionConfigKey`, byte/string session loading, remote download through `ObjectStore`, and app-level precedence tests.
+5. Remote session prepare provenance:
+   materialize downloaded session config and record S3 provenance.
+6. Remote session docs after implementation:
+   update canonical docs and examples only after behavior exists.
+7. Archive lock config:
+   add lock config structs, strict decode coverage, source validation, and duplicate detection.
+8. Archive lock enforcement:
+   skip locked top-level promotions, preserve run-local uploads, record lock metadata, and protect commit ordering.
+9. Final sweep:
+   run focused tests, then `go test ./...`; verify planned behavior remains only in roadmap docs until implemented.
+
+## Test Plan
+
+Add focused coverage in these packages:
+
+- `internal/config`: campaign load, strict decode, discovery constants, merge validation, campaign/session mismatch, lock validation, duplicate lock rejection.
+- `internal/app`: `--campaign` parsing on `run`, `plan`, `resume`, `run-stage`, and `restore`; campaign discovery; explicit `--session` precedence; local discovery before remote; remote session fallback when local discovery misses.
+- `internal/artifacts`: `S3SessionConfigKey`; canonical session prefix compatibility; source ID validation for lock sources.
+- `internal/stage/prepare`: campaign/session stable input materialization; campaign-relative and session-relative path resolution; remote session provenance in `manifest.Inputs`.
+- `internal/stage/archive`: locked required promotion succeeds as skipped; unlocked promotion uploads; run-local outputs upload when top-level promotion is locked; `--force` does not break locks; `current/run_id.txt` remains the last upload.
+- `internal/adapters/storage`: fake object key normalization and remote session download expectations.
+
+Run at least:
+
+      go test ./internal/config -v
+      go test ./internal/app -run TestExecute -v
+      go test ./internal/artifacts -v
+      go test ./internal/stage -run 'Prepare|Archive' -v
+      go test ./internal/adapters/storage -v
+      go test ./...
+
+Use fake storage for remote-session and archive-lock behavior. Ordinary tests must not require live S3.
+
+## Documentation Updates After Implementation
+
+After each phase is implemented, update only docs for behavior that exists.
+
+Likely files:
+
+- `docs/config.md`
+- `docs/cli.md`
+- `docs/operations.md`
+- `docs/internal/stage-prepare.md`
+- `docs/internal/stage-archive.md`
+- `docs/internal/storage.md`
+- `docs/internal/artifacts.md`
+- relevant examples under `examples/`
+
+Do not document remote campaign loading, helper commands, or lock override flags as current behavior until implemented.
+
+## Remaining Open Decisions
+
+The codebase resolves the campaign flag name, campaign discovery order, remote session layout, local-vs-remote session precedence, source-based archive lock model, and locked required promotion policy.
+
+Remaining decisions:
+
+1. Whether `campaign.yml` should eventually be loadable from S3. Do not implement remote campaign loading in the first phase.
+2. Whether a future explicit lock override command or flag is needed. Do not make ordinary `--force` break locks.
+3. Whether future helper commands should be top-level commands or subcommands. Keep them out of the first implementation.

docs/roadmap/restore.md

@@ -1,715 +0,0 @@
-# Roadmap: `narratio restore` Subcommand
-
-## Status
-
-Implemented through Step 8. This document remains as roadmap and design history for the restore feature, and as the home for future restore-related ideas (for example `run --restore`).
-
-## Summary
-
-Add a new `narratio restore` subcommand that hydrates a local session workspace from the current committed remote archive state.
-
-The primary operator workflow is:
-
-```bash
-narratio restore --session-id 2026-04-04
-narratio run-stage --force analyze
-```
-
-This should allow a new machine with no local workspace state to restore the durable session manifest, transcripts, and generated artifacts from S3, then generate new Scriptorium artifacts without re-running transcription, merge, normalize, polish, or trim.
-
-This is intentionally a separate command. Do not fold this behavior into the `prepare` stage. The existing `prepare` stage should remain focused on materializing configured local/S3 inputs for a pipeline run.
-
-## Goals
-
-- Add a first-class `narratio restore` command.
-- Restore the current committed remote session state into the canonical local session workspace.
-- Use the existing object storage adapter boundary.
-- Preserve archive commit semantics: only restore from a remote state that has a valid current commit marker.
-- Restore durable session-level outputs needed for downstream stages, especially `analyze`.
-- Provide safe conflict behavior by default.
-- Support `--dry-run`, `--force`, and `--include-audio`.
-- Keep the implementation explicit, testable, and narrow.
-
-## Non-goals
-
-- Do not make `restore` a pipeline stage.
-- Do not change the `prepare` stage behavior as part of this work.
-- Do not add implicit restore behavior to `narratio run` in this implementation.
-- Do not restore historical run-local sandboxes by default.
-- Do not implement a generic remote synchronization engine.
-- Do not implement bidirectional sync.
-- Do not delete local files merely because they are absent remotely.
-- Do not merge remote and local manifests in the first implementation.
-- Do not require live S3 for the ordinary unit test suite.
-
-## Future work explicitly out of scope
-
-A future change may add:
-
-```bash
-narratio run --restore
-```
-
-That future flag should run `narratio restore` before starting the normal pipeline. Mention this as future work in roadmap/docs if useful, but do not implement it now.
-
-## Existing architecture to preserve
-
-### `prepare` remains input materialization
-
-The `prepare` stage currently materializes required session inputs into canonical local workspace paths and records input provenance. It owns local copying/materialization of config and audio inputs, including S3 audio download when `session.inputs.audio_s3.prefix` is configured. It does not own transcript generation/processing or archive publish behavior.
-
-`restore` should not be implemented by expanding `prepare`. It should be an app-level command that reuses shared helpers where appropriate.
-
-### Workspace model
-
-The local durable session workspace is campaign-aware:
-
-```text
-{workspace.root}/work/{campaign}/{session_id}/
-```
-
-It contains durable session paths such as:
-
-```text
-manifest.json
-inputs/
-audio/
-transcripts/
-artifacts/
-reports/
-logs/
-config/
-current/
-runs/
-```
-
-Run-local sandboxes live below:
-
-```text
-runs/{run_id}/
-```
-
-Restore should target durable session-level paths, not old run-local stage sandboxes.
-
-### Storage boundary
-
-The storage adapter owns object-store primitives only: `List`, `Download`, `Upload`, and `Exists`.
-
-The storage adapter must not infer root prefixes, campaign names, session IDs, run IDs, or archive layout. Restore code must construct full bucket-relative keys before calling storage.
-
-### Archive commit boundary
-
-A remote run is current only after the archive stage has uploaded the run record, promoted outputs, `current/manifest.json`, and finally `current/run_id.txt`.
-
-`current/run_id.txt` is the final remote commit marker and must be written last.
-
-Restore must not treat incomplete, skipped, failed, or uncommitted archive attempts as current remote state.
-
-## User-facing command
-
-Add:
-
-```bash
-narratio restore [flags]
-```
-
-The command should use the same configuration/session discovery conventions as `run`, `plan`, `resume`, and `run-stage` where practical:
-
-```bash
-narratio restore --config /path/to/pipeline.yml --session ./session.yml --session-id 2026-04-04
-```
-
-Required effective inputs:
-
-- resolved pipeline config;
-- resolved session config;
-- `session.campaign`;
-- `session.session_id`;
-- configured remote storage backend.
-
-Supported flags:
-
-```text
---config <path>       Existing pipeline config path behavior.
---session <path>      Existing session config path behavior.
---session-id <value>  Existing session template behavior.
---dry-run             Plan restore actions without writing local files.
---force               Overwrite conflicting local files with remote files.
---include-audio       Include archived session-level audio files.
-```
-
-Do not add `--restore` to `run` in this implementation.
-
-## Default restore scope
-
-By default, restore:
-
-1. Validates and reads the current remote commit marker.
-2. Downloads the current remote manifest into the local session manifest path.
-3. Downloads durable transcript files.
-4. Downloads durable generated artifact files.
-
-Default included remote/local durable paths:
-
-```text
-manifest.json                 from remote current manifest
-transcripts/**
-artifacts/**
-```
-
-Default excluded paths:
-
-```text
-audio/**                      unless --include-audio is passed
-runs/**                       always excluded for this implementation
-logs/**                       excluded for this implementation
-reports/**                    excluded for this implementation unless needed for current manifest validation
-config/**                     excluded for this implementation
-inputs/**                     excluded for this implementation
-current/**                    remote control metadata only; do not mirror blindly
-```
-
-If the existing archive implementation stores promoted files in a different remote layout, use the existing archive/path helpers and current archive semantics rather than inventing a parallel layout.
-
-## Remote state discovery
-
-Implement restore around the current committed archive state.
-
-Expected algorithm:
-
-1. Resolve pipeline/session config.
-2. Ensure storage is configured.
-3. Ensure local workspace layout exists.
-4. Acquire the session lock.
-5. Build the remote session archive prefix using the same helpers/policy used by archive code.
-6. Check for the remote `current/run_id.txt` commit marker.
-7. Read the committed run ID.
-8. Download `current/manifest.json` to a temporary file.
-9. Validate that the manifest is parseable and belongs to the requested campaign/session.
-10. Build a restore plan from the committed remote state.
-11. Execute the restore plan unless `--dry-run` is set.
-12. Emit a concise summary.
-
-Important: `current/run_id.txt` is the commit marker. Do not restore from a remote session prefix merely because files exist under `transcripts/` or `artifacts/`.
-
-## Restore planning
-
-Create a planning layer before writing files.
-
-A restore plan entry should include at least:
-
-```go
-type RestoreAction struct {
-    Kind        RestoreActionKind
-    RemoteKey   string
-    LocalPath   string
-    Size        int64
-    ETag        string
-    ExistsLocal bool
-    SameLocal   bool
-    Conflict    bool
-    Reason      string
-}
-```
-
-Suggested action kinds:
-
-```text
-download
-skip_same
-skip_missing_optional
-conflict
-```
-
-The restore planner should be deterministic:
-
-- sort remote objects by key;
-- sort planned actions by local path or stable restore priority;
-- write/report stable output for tests.
-
-## Conflict and overwrite policy
-
-Default behavior should be safe.
-
-For each planned file:
-
-```text
-local absent:
-  download
-
-local present and same as remote:
-  skip
-
-local present and different:
-  conflict; fail restore unless --force is set
-
---force:
-  overwrite local conflicting files with remote versions
-
---dry-run:
-  do not write any files; report what would happen
-```
-
-The first implementation may use size and checksum/hash comparison where available. If remote ETag cannot be treated as a content hash, compare by downloading to a temporary file and hashing locally before deciding whether a local file is the same. Prefer correctness over assuming provider-specific ETag semantics.
-
-Do not delete local files that are not present remotely.
-
-## File writing and transactionality
-
-Restore should avoid partial writes.
-
-Implementation requirements:
-
-- download each remote object to a temporary file under the session workspace or OS temp dir;
-- validate downloaded content where possible before replacing local files;
-- create parent directories as needed;
-- atomically rename/copy into place only after successful download;
-- do not overwrite local files unless `--force` is set;
-- if a later file fails, preserve already-restored files but return a failure summary;
-- never corrupt an existing local manifest on failed manifest download/parse.
-
-Manifest restore is especially sensitive:
-
-- download remote `current/manifest.json` to a temporary file;
-- parse and validate it;
-- if no local manifest exists, install it;
-- if a local manifest exists and is equivalent, skip;
-- if a local manifest exists and differs, fail unless `--force` is set;
-- with `--force`, replace the local manifest with the remote manifest after validation;
-- do not attempt a manifest merge in the initial implementation.
-
-## Manifest semantics
-
-`restore` is not a pipeline run and should not mark stages as running/succeeded/failed.
-
-The restored remote manifest becomes the local session manifest. That is what allows a subsequent command such as:
-
-```bash
-narratio run-stage --force analyze
-```
-
-to see existing upstream stage state and canonical durable outputs.
-
-Do not create a new run manifest for `restore`.
-
-It is acceptable to write a restore diagnostic report outside the manifest, for example:
-
-```text
-reports/restore-latest.json
-```
-
-or a timestamped report, if that pattern fits the existing codebase. The report must not contain secrets.
-
-## Local workspace locking
-
-`restore` should acquire the same session lock used by ordinary pipeline operations before modifying session workspace state.
-
-If the lock is held, fail fast with the same lock-conflict behavior used elsewhere.
-
-`--dry-run` may still acquire the lock for consistency, but it is acceptable to avoid the lock if the codebase already has a clear read-only command pattern. Prefer safety and simplicity.
-
-## Audio behavior
-
-By default, do not restore audio.
-
-If `--include-audio` is passed:
-
-- restore archived durable session-level audio files only;
-- do not use run-scoped spool paths;
-- do not mutate or delete spool state;
-- do not infer original `session.inputs.audio_s3.prefix` behavior;
-- respect the same conflict/force/dry-run behavior used for transcripts/artifacts.
-
-If the archive does not contain durable audio files, `--include-audio` should report that no archived audio was found rather than failing, unless the final implementation chooses to treat explicit audio restore as required. Prefer non-failure for absent archived audio unless tests or existing archive semantics suggest otherwise.
-
-## Remote object selection
-
-Prefer using manifest/artifact metadata when it reliably identifies durable outputs.
-
-Also support listing committed durable archive prefixes so restore can retrieve all top-level session artifacts that may not yet be fully represented in manifest metadata.
-
-The implementation should inspect existing archive code before choosing the final object-selection method. Do not duplicate archive path construction.
-
-Recommended selection priority:
-
-1. Remote current manifest path.
-2. Durable promoted transcript/artifact outputs recorded in the manifest or archive metadata, if available.
-3. Objects under committed durable `transcripts/` and `artifacts/` archive prefixes.
-4. Objects under durable `audio/` only when `--include-audio` is passed.
-
-Always exclude:
-
-```text
-runs/**
-```
-
-for the first implementation.
-
-## Package and file organization
-
-Expected areas to inspect and update:
-
-```text
-cmd/narratio/
-internal/app/
-internal/adapters/storage/
-internal/artifacts/
-internal/manifest/
-docs/
-examples/
-```
-
-Suggested implementation shape:
-
-```text
-internal/app/restore.go
-internal/app/restore_test.go
-
-internal/archive/restore/
-  planner.go
-  executor.go
-  report.go
-  keys.go
-  *_test.go
-```
-
-The exact package name may vary. Use whatever best fits the existing repository, but keep these boundaries clear:
-
-- `internal/app` owns CLI command handling, config/session loading, lock acquisition, and wiring.
-- Restore planning/execution owns remote key discovery, conflict detection, downloads, and reporting.
-- `internal/adapters/storage` remains a transport boundary only.
-- Workspace/path helpers remain centralized; do not scatter string concatenation.
-
-If the repository already has an `internal/archive` or archive-stage helper package, prefer extending that rather than creating a conflicting package layout.
-
-## CLI output
-
-`narratio restore` should print a concise operator summary.
-
-Example successful output:
-
-```text
-Restored session archive for sample-campaign/2026-04-04
-Remote run: 20260504T031500Z-a1b2c3
-Downloaded: 4
-Skipped unchanged: 2
-Conflicts: 0
-```
-
-Example dry run:
-
-```text
-Restore plan for sample-campaign/2026-04-04
-Remote run: 20260504T031500Z-a1b2c3
-Would download: transcripts/processed.json
-Would download: transcripts/trimmed.json
-Would skip unchanged: artifacts/session_recap.md
-```
-
-Example conflict:
-
-```text
-restore conflict: local artifacts/session_recap.md differs from remote archive; rerun with --force to overwrite
-```
-
-Do not print transcript or artifact content.
-
-## Error behavior
-
-Fail clearly when:
-
-- storage backend is not configured;
-- S3 bucket/config is missing or invalid;
-- remote current commit marker is missing;
-- remote current manifest is missing;
-- remote manifest is invalid;
-- remote manifest does not match requested campaign/session;
-- local file differs from remote and `--force` is not set;
-- a required remote object download fails;
-- a local path would escape the session workspace;
-- a remote key maps to an unsafe local path.
-
-Skip or report non-fatal conditions when:
-
-- optional audio restore finds no archived audio;
-- an included prefix has no objects;
-- a local file already matches the remote file.
-
-## Path safety
-
-Every restored file must map to a safe path under the session root.
-
-Validation rules:
-
-- local restore paths must be relative to the session root;
-- reject absolute paths;
-- reject `..` traversal;
-- reject paths that escape through symlinks if the codebase has symlink-safe path checks;
-- do not restore remote keys directly without mapping/classification;
-- do not mirror arbitrary remote keys.
-
-## Testing plan
-
-Add focused unit tests. Do not require live S3.
-
-### CLI tests
-
-Add or update `internal/app` command tests for:
-
-- `narratio restore --help`;
-- restore accepts `--config`, `--session`, and `--session-id`;
-- restore accepts `--dry-run`;
-- restore accepts `--force`;
-- restore accepts `--include-audio`;
-- restore fails when storage is not configured;
-- restore does not run pipeline stages.
-
-### Restore planner tests
-
-Test:
-
-- missing `current/run_id.txt` fails;
-- missing `current/manifest.json` fails;
-- invalid manifest fails;
-- wrong campaign/session manifest fails;
-- default scope includes manifest/transcripts/artifacts;
-- default scope excludes audio/logs/reports/config/runs;
-- `--include-audio` includes durable audio;
-- run-local keys are excluded;
-- keys are sorted deterministically;
-- unsafe remote-to-local paths are rejected.
-
-### Conflict policy tests
-
-Test:
-
-- absent local file downloads;
-- matching local file skips;
-- differing local file conflicts by default;
-- `--force` overwrites conflicts;
-- `--dry-run` writes nothing;
-- partial failure does not corrupt an existing local manifest.
-
-### Storage/fake tests
-
-Use fake storage to simulate:
-
-- object listing;
-- object download;
-- missing objects;
-- download failures;
-- metadata/ETag behavior.
-
-### Workspace/lock tests
-
-Test:
-
-- session layout is created before restore;
-- session lock conflict fails;
-- restored files land under the expected campaign/session workspace;
-- no files are written outside the session root.
-
-### Follow-up command workflow test
-
-Add at least one test that simulates:
-
-```bash
-narratio restore --session-id 2026-04-04
-narratio run-stage --force analyze
-```
-
-The test does not need to run real Scriptorium. Use existing fake/stub behavior to verify that restored transcripts and manifest state are sufficient for analyze-stage input resolution.
-
-## Documentation updates when implemented
-
-When the feature is implemented, update current-behavior docs:
-
-```text
-docs/cli.md
-docs/operations.md
-docs/internal/storage.md or docs/internal/archive/restore.md
-```
-
-If the documentation set does not yet have an internal restore document, add one consistent with the existing internal-doc style:
-
-```text
-docs/internal/command-restore.md
-```
-
-or:
-
-```text
-docs/internal/archive-restore.md
-```
-
-Do not document future `narratio run --restore` behavior outside `docs/roadmap/` until implemented.
-
-## Implementation phases
-
-### Phase 1: Audit existing archive and path helpers (completed)
-
-Before coding behavior, inspect:
-
-```text
-internal/app/
-internal/stage/archive*
-internal/adapters/storage/
-internal/artifacts/
-internal/manifest/
-docs/internal/stage-archive.md, if present
-```
-
-Determine:
-
-- exact remote archive key layout;
-- how root prefix/campaign/session are modeled;
-- how current commit marker keys are built;
-- how current manifest is uploaded;
-- where promoted outputs are uploaded;
-- whether helper functions already exist for remote archive keys;
-- whether local workspace path helpers can safely map restore destinations.
-
-Deliverable:
-
-- small code comments or internal helper selection;
-- no large behavior change yet unless required by tests.
-
-### Phase 2: Add CLI surface and command wiring (completed)
-
-Add `narratio restore` command parsing.
-
-Wire flags:
-
-```text
---config
---session
---session-id
---dry-run
---force
---include-audio
-```
-
-Use the existing config/session load path where practical.
-
-Deliverable:
-
-- command exists;
-- help output is sensible;
-- command validates basic inputs;
-- command returns a clear “not yet implemented” or calls an empty planner if phased commits are desired;
-- CLI tests pass.
-
-### Phase 3: Implement remote current-state discovery (completed)
-
-Add restore code that:
-
-- creates an object store from resolved config;
-- builds remote current marker key;
-- reads `current/run_id.txt`;
-- reads/downloads `current/manifest.json`;
-- validates manifest identity;
-- returns remote current-state metadata.
-
-Deliverable:
-
-- fake-storage tests for current-state discovery;
-- no local file writes beyond temporary files.
-
-### Phase 4: Implement restore planning (completed)
-
-Build deterministic restore plans for default scope and `--include-audio`.
-
-Deliverable:
-
-- plan lists manifest, transcript, artifact files;
-- plan excludes run-local data;
-- plan detects local same/conflict/missing states;
-- dry-run output works;
-- no real file overwrite yet except temp comparisons as needed.
-
-### Phase 5: Implement restore execution (completed)
-
-Execute the plan safely:
-
-- create directories;
-- download to temporary files;
-- validate content where practical;
-- atomically install files;
-- enforce default conflict failure;
-- support `--force`;
-- preserve existing manifest unless safe to replace.
-
-Deliverable:
-
-- restore works end-to-end against fake storage;
-- failures are clear and do not corrupt existing local manifest.
-
-### Phase 6: Add restore report and operator summary (completed)
-
-Add concise stdout summary and optional JSON restore report if consistent with project diagnostics.
-
-Deliverable:
-
-- user-friendly output;
-- durable diagnostic report if implemented;
-- no content leakage.
-
-### Phase 7: Workflow integration test (completed)
-
-Add a test for restoring a previous session and then forcing `analyze`.
-
-Deliverable:
-
-- restored manifest/transcripts/artifacts are sufficient for analyze input resolution;
-- no upstream stages rerun;
-- no reliance on live subprocesses or S3.
-
-### Phase 8: Documentation update (completed)
-
-Once implemented, update current-behavior docs and internal command docs.
-
-Also leave future `narratio run --restore` in roadmap only.
-
-## Definition of done
-
-The feature is complete when:
-
-- `narratio restore` exists and is documented.
-- It uses the same config/session discovery semantics as other commands where practical.
-- It requires configured remote storage.
-- It restores only from a committed current archive state.
-- It restores the current manifest, transcripts, and artifacts by default.
-- It restores audio only with `--include-audio`.
-- It excludes run-local sandboxes.
-- It fails on local/remote conflicts by default.
-- `--force` overwrites conflicts.
-- `--dry-run` writes nothing.
-- It uses fake storage in tests.
-- It does not change `prepare` behavior.
-- It does not implement `narratio run --restore`.
-- It avoids AWS SDK leakage outside the storage adapter.
-- It uses centralized path/key helpers rather than scattered string concatenation.
-- `go test ./...` passes.
-
-## Suggested test commands
-
-Run focused tests first:
-
-```bash
-go test ./internal/app -run TestExecute -v
-go test ./internal/adapters/storage -v
-go test ./internal/artifacts -v
-go test ./internal/manifest -v
-```
-
-Then run the full suite:
-
-```bash
-go test ./...
-```
-
-## Suggested commit message
-
-```text
-Add restore subcommand roadmap
-```

examples/campaign.yml

@@ -0,0 +1,5 @@
+campaign: sample-campaign
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml

examples/pipeline.full.annotated.yml

@@ -133,9 +133,7 @@ scriptorium:
           source: narratio.transcript.trimmed
           required: true
         previous_recap:
-          source: previous_session_artifact
-          artifact: session_recap
-          path: ""
+          source: narratio.previous_session.artifact.session_recap
           required: false
       vars:
         session_id: true

examples/pipeline.production.yml

@@ -81,8 +81,7 @@ scriptorium:
           source: narratio.transcript.trimmed
           required: true
         previous_recap:
-          source: previous_session_artifact
-          artifact: session_recap
+          source: narratio.previous_session.artifact.session_recap
           required: false
       vars:
         session_id: true

examples/session.local-audio.yml

@@ -1,9 +1,5 @@
 session_id: 2026-05-03
-campaign: sample-campaign
 date: 2026-05-03
 title: Sample Session
 inputs:
   audio_dir: ./audio
-  speakers_file: ./examples/speakers.yml
-  autocorrect_file: ./examples/autocorrect.yml
-  glossary_file: ./examples/glossary.yml

examples/session.s3-audio.yml

@@ -1,10 +1,6 @@
 session_id: 2026-05-03
-campaign: sample-campaign
 date: 2026-05-03
 title: Sample Session
 inputs:
   audio_s3:
     prefix: audio/
-  speakers_file: ./examples/speakers.yml
-  autocorrect_file: ./examples/autocorrect.yml
-  glossary_file: ./examples/glossary.yml

examples/session.template.yml

@@ -1,7 +1,3 @@
 session_id: "{{ session_id }}"
-campaign: sample-campaign
 inputs:
   audio_dir: ./audio
-  speakers_file: ./examples/speakers.yml
-  autocorrect_file: ./examples/autocorrect.yml
-  glossary_file: ./examples/glossary.yml

internal/adapters/storage/fake_test.go

@@ -56,7 +56,7 @@ func TestFakeBackendDownload(t *testing.T) {
 	fake.SeedObject(FakeObject{Key: "audio/a.flac", Data: []byte("audio-a")})
 
 	dst := filepath.Join(t.TempDir(), "nested", "a.flac")
-	if err := fake.Download(context.Background(), "audio/a.flac", dst); err != nil {
+	if err := fake.Download(context.Background(), `audio\a.flac`, dst); err != nil {
 		t.Fatalf("Download() error = %v", err)
 	}
 	data, err := os.ReadFile(dst)

internal/app/analyze_artifacts_commands_test.go

@@ -14,12 +14,12 @@ import (
 
 func TestExecuteRunStageArtifactsNonAnalyzeFails(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
 	code := Execute(
-		[]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "--artifacts", "session_recap", "polish"},
+		[]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--artifacts", "session_recap", "polish"},
 		&stdout,
 		&stderr,
 	)
@@ -33,12 +33,12 @@ func TestExecuteRunStageArtifactsNonAnalyzeFails(t *testing.T) {
 
 func TestExecuteUnknownArtifactsFailValidation(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
 	code := Execute(
-		[]string{"run", "--config", pipelinePath, "--session", sessionPath, "--artifacts", "unknown_artifact"},
+		[]string{"run", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--artifacts", "unknown_artifact"},
 		&stdout,
 		&stderr,
 	)
@@ -52,7 +52,7 @@ func TestExecuteUnknownArtifactsFailValidation(t *testing.T) {
 
 func TestRunStageArtifactsDoesNotImplyForce(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -65,7 +65,7 @@ func TestRunStageArtifactsDoesNotImplyForce(t *testing.T) {
 	var out bytes.Buffer
 	err := RunStage(
 		context.Background(),
-		[]string{"--config", pipelinePath, "--session", sessionPath, "--artifacts", "session_recap,session_recap", "analyze"},
+		[]string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--artifacts", "session_recap,session_recap", "analyze"},
 		&out,
 	)
 	if err != nil {
@@ -78,7 +78,7 @@ func TestRunStageArtifactsDoesNotImplyForce(t *testing.T) {
 
 func TestResumeArtifactsWithSucceededAnalyzeSkipsUnlessForced(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -93,7 +93,7 @@ func TestResumeArtifactsWithSucceededAnalyzeSkipsUnlessForced(t *testing.T) {
 	var out bytes.Buffer
 	err := Resume(
 		context.Background(),
-		[]string{"--config", pipelinePath, "--session", sessionPath, "--artifacts", "session_recap"},
+		[]string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--artifacts", "session_recap"},
 		&out,
 	)
 	if err != nil {
@@ -104,10 +104,10 @@ func TestResumeArtifactsWithSucceededAnalyzeSkipsUnlessForced(t *testing.T) {
 	}
 }
 
-func writeValidConfigFilesWithScriptoriumArtifacts(t *testing.T, workspaceRoot string) (string, string) {
+func writeValidConfigFilesWithScriptoriumArtifacts(t *testing.T, workspaceRoot string) (string, string, string) {
 	t.Helper()
 
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	f, err := os.OpenFile(pipelinePath, os.O_APPEND|os.O_WRONLY, 0)
 	if err != nil {
 		t.Fatalf("open pipeline config for append: %v", err)
@@ -136,5 +136,5 @@ scriptorium:
 	if _, err := f.WriteString(extra); err != nil {
 		t.Fatalf("append scriptorium config: %v", err)
 	}
-	return pipelinePath, sessionPath
+	return pipelinePath, campaignPath, sessionPath
 }

internal/app/campaign_config_path.go

@@ -0,0 +1,49 @@
+package app
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+func resolveCampaignConfigPath(flagValue string) (string, error) {
+	return resolveCampaignConfigPathWithCandidates(flagValue, config.DefaultCampaignConfigSearchPaths)
+}
+
+func resolveCampaignConfigPathWithCandidates(flagValue string, candidates []string) (string, error) {
+	if explicit := strings.TrimSpace(flagValue); explicit != "" {
+		return explicit, nil
+	}
+
+	ordered := make([]string, 0, len(candidates))
+	for _, raw := range candidates {
+		path := strings.TrimSpace(raw)
+		if path == "" {
+			continue
+		}
+		ordered = append(ordered, path)
+		info, err := os.Stat(path)
+		if err == nil {
+			if info.IsDir() {
+				continue
+			}
+			return filepath.Clean(path), nil
+		}
+		if errors.Is(err, os.ErrNotExist) {
+			continue
+		}
+		return "", fmt.Errorf("check default campaign config %q: %w", path, err)
+	}
+
+	if len(ordered) == 0 {
+		return "", fmt.Errorf("no campaign config path provided and no default locations configured")
+	}
+	return "", fmt.Errorf(
+		"no campaign config path provided and no default campaign config found; searched: %s; pass --campaign to use an explicit path",
+		strings.Join(ordered, ", "),
+	)
+}

internal/app/campaign_config_path_test.go

@@ -0,0 +1,49 @@
+package app
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestResolveCampaignConfigPathExplicitWins(t *testing.T) {
+	explicit := filepath.Join(t.TempDir(), "custom-campaign.yml")
+	got, err := resolveCampaignConfigPathWithCandidates(explicit, []string{filepath.Join(t.TempDir(), "campaign.yml")})
+	if err != nil {
+		t.Fatalf("resolveCampaignConfigPathWithCandidates() error = %v", err)
+	}
+	if got != explicit {
+		t.Fatalf("path = %q, want explicit path %q", got, explicit)
+	}
+}
+
+func TestResolveCampaignConfigPathUsesFirstExistingDefault(t *testing.T) {
+	dir := t.TempDir()
+	missing := filepath.Join(dir, "missing.yml")
+	found := filepath.Join(dir, "campaign.yml")
+	if err := os.WriteFile(found, []byte("campaign: sample-campaign\n"), 0o644); err != nil {
+		t.Fatalf("write campaign.yml: %v", err)
+	}
+
+	got, err := resolveCampaignConfigPathWithCandidates("", []string{missing, found})
+	if err != nil {
+		t.Fatalf("resolveCampaignConfigPathWithCandidates() error = %v", err)
+	}
+	if got != filepath.Clean(found) {
+		t.Fatalf("path = %q, want %q", got, filepath.Clean(found))
+	}
+}
+
+func TestResolveCampaignConfigPathErrorIncludesSearchedPaths(t *testing.T) {
+	_, err := resolveCampaignConfigPathWithCandidates("", []string{"./campaign.yml", "/usr/local/etc/narratio/campaign.yml", "/etc/narratio/campaign.yml"})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "searched") {
+		t.Fatalf("error = %q, want searched paths", err.Error())
+	}
+	if !strings.Contains(err.Error(), "pass --campaign") {
+		t.Fatalf("error = %q, want explicit-campaign guidance", err.Error())
+	}
+}

internal/app/commands_test.go

@@ -24,7 +24,7 @@ func TestExecuteValidCommands(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
 	manifestPath := writeManifestPathForExecute(t)
 
 	cases := []struct {
@@ -32,11 +32,11 @@ func TestExecuteValidCommands(t *testing.T) {
 		args    []string
 		wantOut string
 	}{
-		{name: "run", args: []string{"run", "--config", pipelinePath, "--session", sessionPath}, wantOut: "narratio run: session 2026-05-03; executed=9 skipped=0; manifest="},
-		{name: "plan", args: []string{"plan", "--config", pipelinePath, "--session", sessionPath}, wantOut: "prepare: skip\ntranscribe: skip\nmerge: skip\npolish: skip\nnormalize: skip\ntrim: skip\nanalyze: skip\narchive: skip\nnotify: skip"},
+		{name: "run", args: []string{"run", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, wantOut: "narratio run: session 2026-05-03; executed=9 skipped=0; manifest="},
+		{name: "plan", args: []string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, wantOut: "prepare: skip\ntranscribe: skip\nmerge: skip\npolish: skip\nnormalize: skip\ntrim: skip\nanalyze: skip\narchive: skip\nnotify: skip"},
 		{name: "status", args: []string{"status", "--manifest", manifestPath}, wantOut: "session_id: 2026-05-03"},
-		{name: "resume", args: []string{"resume", "--config", pipelinePath, "--session", sessionPath}, wantOut: "narratio resume: session 2026-05-03 has no remaining stages"},
-		{name: "run-stage", args: []string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "polish"}, wantOut: "narratio run-stage: stage=polish executed=0 skipped=1 force=false; manifest="},
+		{name: "resume", args: []string{"resume", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, wantOut: "narratio resume: session 2026-05-03 has no remaining stages"},
+		{name: "run-stage", args: []string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "polish"}, wantOut: "narratio run-stage: stage=polish executed=0 skipped=1 force=false; manifest="},
 	}
 
 	for _, tc := range cases {
@@ -94,12 +94,12 @@ func TestExecuteMissingRequiredFlags(t *testing.T) {
 
 func TestExecuteRunStageUnknownFails(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, "https://example.com/transcribe")
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, "https://example.com/transcribe")
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
 
-	code := Execute([]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "unknown"}, &stdout, &stderr)
+	code := Execute([]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "unknown"}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -110,14 +110,14 @@ func TestExecuteRunStageUnknownFails(t *testing.T) {
 
 func TestExecuteRunStageNormalizeIsAccepted(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, "https://example.com/transcribe")
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, "https://example.com/transcribe")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "processed.json"), `{"segments":[{"id":1}]}`)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
 
-	code := Execute([]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "normalize"}, &stdout, &stderr)
+	code := Execute([]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "normalize"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -136,19 +136,19 @@ func TestExecuteRunStageTranscribeUsesConfiguredWhisperXServer(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
 
-	code := Execute([]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "prepare"}, &stdout, &stderr)
+	code := Execute([]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "prepare"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("prepare exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
 	stdout.Reset()
 	stderr.Reset()
 
-	code = Execute([]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "--force", "transcribe"}, &stdout, &stderr)
+	code = Execute([]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force", "transcribe"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("transcribe exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -188,6 +188,7 @@ func TestExecuteRunStagePolishLoadsCredentialFromSecretsDir(t *testing.T) {
 	t.Setenv("GO_WANT_APP_AUDITA_HELPER", "1")
 
 	pipelinePath := filepath.Join(configDir, "pipeline.yml")
+	campaignPath := writeAppTestCampaignConfig(t, configDir)
 	sessionPath := filepath.Join(configDir, "session.yml")
 	pipelineYAML := `workspace:
   root: ` + workspaceRoot + `
@@ -239,7 +240,7 @@ inputs:
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"run-stage", "--config", pipelinePath, "--session", sessionPath, "--force", "polish"}, &stdout, &stderr)
+	code := Execute([]string{"run-stage", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force", "polish"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -252,6 +253,7 @@ func TestExecuteRunFailsWhenConfiguredSecretsDirMissing(t *testing.T) {
 	workspaceRoot := t.TempDir()
 	configDir := t.TempDir()
 	pipelinePath := filepath.Join(configDir, "pipeline.yml")
+	campaignPath := writeAppTestCampaignConfig(t, configDir)
 	sessionPath := filepath.Join(configDir, "session.yml")
 
 	pipelineYAML := `workspace:
@@ -288,7 +290,7 @@ inputs:
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"run", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"run", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -305,11 +307,14 @@ func TestExecuteUsesDefaultPipelineConfigPathWhenConfigFlagOmitted(t *testing.T)
 	}))
 	defer srv.Close()
 
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
 	originalDefaults := append([]string(nil), config.DefaultPipelineConfigSearchPaths...)
+	originalCampaignDefaults := append([]string(nil), config.DefaultCampaignConfigSearchPaths...)
 	config.DefaultPipelineConfigSearchPaths = []string{pipelinePath}
+	config.DefaultCampaignConfigSearchPaths = []string{campaignPath}
 	defer func() {
 		config.DefaultPipelineConfigSearchPaths = originalDefaults
+		config.DefaultCampaignConfigSearchPaths = originalCampaignDefaults
 	}()
 
 	var stdout bytes.Buffer
@@ -323,6 +328,33 @@ func TestExecuteUsesDefaultPipelineConfigPathWhenConfigFlagOmitted(t *testing.T)
 	}
 }
 
+func TestExecuteMissingCampaignConfigReportsSearchedPaths(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, _, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	missingCampaignPath := filepath.Join(t.TempDir(), "campaign.yml")
+	originalCampaignDefaults := append([]string(nil), config.DefaultCampaignConfigSearchPaths...)
+	config.DefaultCampaignConfigSearchPaths = []string{missingCampaignPath}
+	defer func() {
+		config.DefaultCampaignConfigSearchPaths = originalCampaignDefaults
+	}()
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"run", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	if code == 0 {
+		t.Fatal("exit code = 0, want non-zero")
+	}
+	if stdout.Len() != 0 {
+		t.Fatalf("stdout = %q, want empty", stdout.String())
+	}
+	if !strings.Contains(stderr.String(), "no campaign config path provided and no default campaign config found; searched:") {
+		t.Fatalf("stderr = %q, want campaign discovery failure", stderr.String())
+	}
+	if !strings.Contains(stderr.String(), "pass --campaign") {
+		t.Fatalf("stderr = %q, want explicit campaign guidance", stderr.String())
+	}
+}
+
 func TestExecuteInvalidCommand(t *testing.T) {
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
@@ -359,11 +391,12 @@ func TestExecuteMissingCommand(t *testing.T) {
 	}
 }
 
-func writeValidConfigFiles(t *testing.T, workspaceRoot string, transcribeURL ...string) (string, string) {
+func writeValidConfigFiles(t *testing.T, workspaceRoot string, transcribeURL ...string) (string, string, string) {
 	t.Helper()
 
 	dir := t.TempDir()
 	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	campaignPath := filepath.Join(dir, "campaign.yml")
 	sessionPath := filepath.Join(dir, "session.yml")
 	url := "https://example.com/transcribe"
 	if len(transcribeURL) > 0 && strings.TrimSpace(transcribeURL[0]) != "" {
@@ -407,9 +440,11 @@ notification:
 `
 
 	sessionYAML := `session_id: 2026-05-03
-campaign: sample-campaign
 inputs:
   audio_dir: ./audio
+`
+	campaignYAML := `campaign: sample-campaign
+inputs:
   speakers_file: ./speakers.yml
   autocorrect_file: ./autocorrect.yml
   glossary_file: ./glossary.yml
@@ -418,6 +453,9 @@ inputs:
 	if err := os.WriteFile(pipelinePath, []byte(pipelineYAML), 0o644); err != nil {
 		t.Fatalf("write pipeline config: %v", err)
 	}
+	if err := os.WriteFile(campaignPath, []byte(campaignYAML), 0o644); err != nil {
+		t.Fatalf("write campaign config: %v", err)
+	}
 	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
 		t.Fatalf("write session config: %v", err)
 	}
@@ -427,7 +465,22 @@ inputs:
 	mustWriteTestFile(t, filepath.Join(dir, "glossary.yml"), "[]\n")
 	mustWriteTestFile(t, filepath.Join(dir, "audio", "alice.flac"), "audio-bytes")
 
-	return pipelinePath, sessionPath
+	return pipelinePath, campaignPath, sessionPath
+}
+
+func writeAppTestCampaignConfig(t *testing.T, dir string) string {
+	t.Helper()
+	campaignPath := filepath.Join(dir, "campaign.yml")
+	campaignYAML := `campaign: sample-campaign
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(campaignPath, []byte(campaignYAML), 0o644); err != nil {
+		t.Fatalf("write campaign.yml: %v", err)
+	}
+	return campaignPath
 }
 
 func writeManifestPathForExecute(t *testing.T) string {

internal/app/config_loader.go

@@ -0,0 +1,133 @@
+package app
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
+	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+func loadCommandConfig(ctx context.Context, pipelineFlag, campaignFlag, sessionFlag string, sessionOpts config.SessionLoadOptions) (*config.Config, error) {
+	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelineFlag)
+	if err != nil {
+		return nil, err
+	}
+	resolvedCampaignPath, err := resolveCampaignConfigPath(campaignFlag)
+	if err != nil {
+		return nil, err
+	}
+
+	if explicitSession := strings.TrimSpace(sessionFlag); explicitSession != "" {
+		return config.LoadWithSessionOptions(resolvedPipelinePath, resolvedCampaignPath, explicitSession, sessionOpts)
+	}
+
+	discoveredSession, err := discoverSessionConfigPathWithCandidates(config.DefaultSessionConfigSearchPaths)
+	if err != nil {
+		return nil, err
+	}
+	if discoveredSession.Path != "" {
+		return config.LoadWithSessionOptions(resolvedPipelinePath, resolvedCampaignPath, discoveredSession.Path, sessionOpts)
+	}
+
+	pipelineCfg, err := config.LoadPipeline(resolvedPipelinePath)
+	if err != nil {
+		return nil, err
+	}
+	campaignCfg, err := config.LoadCampaign(resolvedCampaignPath)
+	if err != nil {
+		return nil, err
+	}
+
+	sessionID := strings.TrimSpace(sessionOpts.SessionID)
+	if sessionID == "" {
+		return nil, missingSessionConfigError(discoveredSession.Searched, "remote session loading requires --session-id")
+	}
+
+	sessionPrefix := artifacts.S3SessionPrefix(pipelineCfg.Storage.S3.RootPrefix, campaignCfg.Campaign, sessionID)
+	remoteKey := artifacts.S3SessionConfigKey(sessionPrefix)
+	partialCfg := &config.Config{
+		Pipeline:     pipelineCfg,
+		Campaign:     campaignCfg,
+		PipelinePath: resolvedPipelinePath,
+		CampaignPath: resolvedCampaignPath,
+	}
+	store, err := newObjectStoreFromConfigFn(ctx, partialCfg)
+	if err != nil {
+		return nil, missingSessionConfigError(discoveredSession.Searched, fmt.Sprintf("remote session %q unavailable: %v", remoteKey, err))
+	}
+
+	sessionInfo, err := findRemoteSessionConfig(ctx, store, sessionPrefix, remoteKey)
+	if err != nil {
+		return nil, missingSessionConfigError(discoveredSession.Searched, err.Error())
+	}
+	sessionTempPath, err := downloadRemoteSessionConfig(ctx, store, remoteKey)
+	if err != nil {
+		return nil, missingSessionConfigError(discoveredSession.Searched, fmt.Sprintf("remote session %q download failed: %v", remoteKey, err))
+	}
+	sessionBytes, err := os.ReadFile(sessionTempPath)
+	if err != nil {
+		return nil, fmt.Errorf("read downloaded remote session %q: %w", sessionTempPath, err)
+	}
+	sessionCfg, err := config.LoadSessionBytesWithOptions("s3://"+s3BucketName(pipelineCfg)+"/"+remoteKey, sessionBytes, sessionOpts)
+	if err != nil {
+		return nil, err
+	}
+
+	return config.Resolve(
+		resolvedPipelinePath,
+		pipelineCfg,
+		resolvedCampaignPath,
+		campaignCfg,
+		sessionTempPath,
+		sessionCfg,
+		config.SessionSource{
+			Source:    "session_config.s3",
+			LocalPath: sessionTempPath,
+			S3Bucket:  s3BucketName(pipelineCfg),
+			S3Key:     remoteKey,
+			S3Size:    sessionInfo.Size,
+			S3ETag:    sessionInfo.ETag,
+			SpoolPath: sessionTempPath,
+		},
+	)
+}
+
+func findRemoteSessionConfig(ctx context.Context, store storage.ObjectStore, sessionPrefix, remoteKey string) (storage.ObjectInfo, error) {
+	objects, err := store.List(ctx, sessionPrefix)
+	if err != nil {
+		return storage.ObjectInfo{}, fmt.Errorf("remote session %q list failed: %w", remoteKey, err)
+	}
+	for _, obj := range objects {
+		if obj.Key == remoteKey {
+			return obj, nil
+		}
+	}
+	return storage.ObjectInfo{}, fmt.Errorf("remote session %q not found", remoteKey)
+}
+
+func downloadRemoteSessionConfig(ctx context.Context, store storage.ObjectStore, remoteKey string) (string, error) {
+	f, err := os.CreateTemp("", "narratio-session-*.yml")
+	if err != nil {
+		return "", fmt.Errorf("create temp file: %w", err)
+	}
+	path := f.Name()
+	if err := f.Close(); err != nil {
+		return "", fmt.Errorf("close temp file %q: %w", path, err)
+	}
+	if err := store.Download(ctx, remoteKey, path); err != nil {
+		return "", err
+	}
+	return filepath.Clean(path), nil
+}
+
+func s3BucketName(cfg *config.PipelineConfig) string {
+	if cfg == nil || cfg.Storage.S3 == nil {
+		return ""
+	}
+	return strings.TrimSpace(cfg.Storage.S3.Bucket)
+}

internal/app/plan.go

@@ -20,12 +20,16 @@ func Plan(ctx context.Context, args []string, out io.Writer) error {
 	fs.SetOutput(io.Discard)
 
 	var pipelinePath string
+	var campaignPath string
 	var sessionPath string
 	var sessionID string
+	var previousSessionID string
 	var force bool
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml (optional; defaults searched)")
+	fs.StringVar(&campaignPath, "campaign", "", "path to campaign.yml (optional; defaults searched)")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&sessionID, "session-id", "", "session identifier for session.yml templates")
+	fs.StringVar(&previousSessionID, "previous-session-id", "", "previous session identifier for session.yml templates")
 	fs.BoolVar(&force, "force", false, "force stage execution (reserved for future behavior)")
 
 	if err := fs.Parse(args); err != nil {
@@ -34,17 +38,9 @@ func Plan(ctx context.Context, args []string, out io.Writer) error {
 	if fs.NArg() != 0 {
 		return fmt.Errorf("plan: unexpected positional arguments")
 	}
-	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelinePath)
-	if err != nil {
-		return fmt.Errorf("plan: %w", err)
-	}
-	resolvedSessionPath, err := resolveSessionConfigPath(sessionPath)
-	if err != nil {
-		return fmt.Errorf("plan: %w", err)
-	}
-
-	cfg, err := config.LoadWithSessionOptions(resolvedPipelinePath, resolvedSessionPath, config.SessionLoadOptions{
-		SessionID: sessionID,
+	cfg, err := loadCommandConfig(ctx, pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{
+		SessionID:         sessionID,
+		PreviousSessionID: previousSessionID,
 	})
 	if err != nil {
 		return fmt.Errorf("plan: %w", err)

internal/app/plan_test.go

@@ -15,10 +15,10 @@ import (
 
 func TestPlanCreatesAndReusesWorkdir(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	var out bytes.Buffer
-	args := []string{"--config", pipelinePath, "--session", sessionPath}
+	args := []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}
 
 	if err := Plan(context.Background(), args, &out); err != nil {
 		t.Fatalf("first Plan() error = %v", err)
@@ -62,7 +62,7 @@ func TestPlanCreatesAndReusesWorkdir(t *testing.T) {
 
 func TestPlanShowsRunAndSkipFromManifest(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -74,7 +74,7 @@ func TestPlanShowsRunAndSkipFromManifest(t *testing.T) {
 	}
 
 	var out bytes.Buffer
-	if err := Plan(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath}, &out); err != nil {
+	if err := Plan(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &out); err != nil {
 		t.Fatalf("Plan() error = %v", err)
 	}
 	got := out.String()
@@ -93,6 +93,7 @@ func TestPlanFailsWhenConfiguredSecretsDirMissing(t *testing.T) {
 	workspaceRoot := t.TempDir()
 	configDir := t.TempDir()
 	pipelinePath := filepath.Join(configDir, "pipeline.yml")
+	campaignPath := writeAppTestCampaignConfig(t, configDir)
 	sessionPath := filepath.Join(configDir, "session.yml")
 
 	pipelineYAML := `workspace:
@@ -128,7 +129,7 @@ inputs:
 	}
 
 	var out bytes.Buffer
-	err := Plan(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath}, &out)
+	err := Plan(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &out)
 	if err == nil {
 		t.Fatal("expected error, got nil")
 	}

internal/app/post_archive_cleanup_test.go

@@ -82,6 +82,7 @@ func TestPostArchiveCleanupWorkdirOnly(t *testing.T) {
 
 	assertExists(t, cfg.Pipeline.Workspace.Root)
 	assertExists(t, seed.otherRunDir)
+	assertExists(t, seed.previousCachePath)
 	assertMissing(t, seed.runWorkDir)
 	assertExists(t, seed.spoolAudioDir)
 }
@@ -98,6 +99,7 @@ func TestPostArchiveCleanupBothPolicies(t *testing.T) {
 	assertMissing(t, seed.spoolAudioDir)
 	assertMissing(t, seed.runWorkDir)
 	assertExists(t, seed.otherRunDir)
+	assertExists(t, seed.previousCachePath)
 }
 
 func TestPostArchiveCleanupNotRunWhenArchiveFails(t *testing.T) {
@@ -256,11 +258,12 @@ func TestPostArchiveCleanupNotRunWhenCurrentPointerUploadFails(t *testing.T) {
 }
 
 type cleanupSeed struct {
-	runWorkDir       string
-	otherRunDir      string
-	spoolAudioDir    string
-	localSourceAudio string
-	sessionPrefix    string
+	runWorkDir        string
+	otherRunDir       string
+	spoolAudioDir     string
+	localSourceAudio  string
+	previousCachePath string
+	sessionPrefix     string
 }
 
 func cleanupFixtureConfig(t *testing.T) (*config.Config, cleanupSeed) {
@@ -274,11 +277,18 @@ func cleanupFixtureConfig(t *testing.T) (*config.Config, cleanupSeed) {
 	runWorkDir := artifacts.SessionRunRootForCampaign(cfg.Pipeline.Workspace.Root, cfg.Session.Campaign, cfg.Session.SessionID, runID)
 	otherRunDir := artifacts.SessionRunRootForCampaign(cfg.Pipeline.Workspace.Root, cfg.Session.Campaign, cfg.Session.SessionID, "20260516T010204Z-5e6f7a8b")
 	spoolAudioDir := artifacts.SessionSpoolAudioDir(cfg.Pipeline.Spool.Root, cfg.Session.Campaign, cfg.Session.SessionID, runID)
+	previousCachePath := artifacts.SessionPreviousArtifactPathForCampaign(
+		cfg.Pipeline.Workspace.Root,
+		cfg.Session.Campaign,
+		cfg.Session.SessionID,
+		"session_recap.md",
+	)
 
 	mustWriteFile(t, filepath.Join(runWorkDir, "manifest.json"), "{}\n")
 	mustWriteFile(t, filepath.Join(runWorkDir, "logs", "stage.log"), "log\n")
 	mustWriteFile(t, filepath.Join(otherRunDir, "logs", "stage.log"), "other\n")
 	mustWriteFile(t, filepath.Join(spoolAudioDir, "speaker.flac"), "flac\n")
+	mustWriteFile(t, previousCachePath, "# previous recap\n")
 
 	localSourceAudio := filepath.Join(filepath.Dir(cfg.SessionPath), "audio", "alice.flac")
 	mustWriteFile(t, localSourceAudio, "source\n")
@@ -301,11 +311,12 @@ func cleanupFixtureConfig(t *testing.T) (*config.Config, cleanupSeed) {
 	}
 
 	return cfg, cleanupSeed{
-		runWorkDir:       runWorkDir,
-		otherRunDir:      otherRunDir,
-		spoolAudioDir:    spoolAudioDir,
-		localSourceAudio: localSourceAudio,
-		sessionPrefix:    seed.S3SessionPrefix,
+		runWorkDir:        runWorkDir,
+		otherRunDir:       otherRunDir,
+		spoolAudioDir:     spoolAudioDir,
+		localSourceAudio:  localSourceAudio,
+		previousCachePath: previousCachePath,
+		sessionPrefix:     seed.S3SessionPrefix,
 	}
 }
 

internal/app/remote_session_test.go

@@ -0,0 +1,204 @@
+package app
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
+	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+func TestExecuteRemoteSessionFallbackLoadsFromObjectStore(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
+	fake := &storage.FakeBackend{}
+	remoteKey := seedRemoteSessionConfig(t, fake, "2026-05-03", `session_id: "{{ session_id }}"
+inputs:
+  audio_s3:
+    prefix: audio/
+`)
+	var storeInitCalls int
+	restoreAppConfigTestGlobals(t, fake, &storeInitCalls, []string{filepath.Join(t.TempDir(), "session.yml")})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	if storeInitCalls != 1 {
+		t.Fatalf("object store init calls = %d, want 1", storeInitCalls)
+	}
+	if !strings.Contains(stdout.String(), "narratio plan: workdir prepared") {
+		t.Fatalf("stdout = %q, want plan output", stdout.String())
+	}
+	if _, ok := fake.Objects[remoteKey]; !ok {
+		t.Fatalf("remote session key %q was not seeded", remoteKey)
+	}
+}
+
+func TestExecuteExplicitLocalSessionPrecedenceSkipsRemote(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	fake := &storage.FakeBackend{}
+	var storeInitCalls int
+	restoreAppConfigTestGlobals(t, fake, &storeInitCalls, []string{filepath.Join(t.TempDir(), "session.yml")})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	if storeInitCalls != 0 {
+		t.Fatalf("object store init calls = %d, want 0", storeInitCalls)
+	}
+}
+
+func TestExecuteLocalSessionDiscoveryPrecedenceSkipsRemote(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	fake := &storage.FakeBackend{}
+	var storeInitCalls int
+	restoreAppConfigTestGlobals(t, fake, &storeInitCalls, config.DefaultSessionConfigSearchPaths)
+
+	originalWD, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("Getwd(): %v", err)
+	}
+	if err := os.Chdir(filepath.Dir(sessionPath)); err != nil {
+		t.Fatalf("Chdir(%q): %v", filepath.Dir(sessionPath), err)
+	}
+	t.Cleanup(func() { _ = os.Chdir(originalWD) })
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	if storeInitCalls != 0 {
+		t.Fatalf("object store init calls = %d, want 0", storeInitCalls)
+	}
+}
+
+func TestExecuteRemoteSessionMissingObjectFailsClearly(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
+	fake := &storage.FakeBackend{}
+	var storeInitCalls int
+	missingSessionPath := filepath.Join(t.TempDir(), "session.yml")
+	restoreAppConfigTestGlobals(t, fake, &storeInitCalls, []string{missingSessionPath})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code == 0 {
+		t.Fatal("exit code = 0, want non-zero")
+	}
+	if !strings.Contains(stderr.String(), "remote session") || !strings.Contains(stderr.String(), "session.yml") || !strings.Contains(stderr.String(), "not found") {
+		t.Fatalf("stderr = %q, want remote session not found context", stderr.String())
+	}
+	if !strings.Contains(stderr.String(), missingSessionPath) {
+		t.Fatalf("stderr = %q, want local searched path", stderr.String())
+	}
+}
+
+func TestExecuteRemoteSessionRequiresSessionID(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
+	var storeInitCalls int
+	restoreAppConfigTestGlobals(t, &storage.FakeBackend{}, &storeInitCalls, []string{filepath.Join(t.TempDir(), "session.yml")})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath}, &stdout, &stderr)
+	if code == 0 {
+		t.Fatal("exit code = 0, want non-zero")
+	}
+	if !strings.Contains(stderr.String(), "remote session loading requires --session-id") {
+		t.Fatalf("stderr = %q, want session-id guidance", stderr.String())
+	}
+	if storeInitCalls != 0 {
+		t.Fatalf("object store init calls = %d, want 0", storeInitCalls)
+	}
+}
+
+func TestExecuteRemoteSessionStorageInitErrorFailsClearly(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
+	origStoreFn := newObjectStoreFromConfigFn
+	origSessionDefaults := append([]string(nil), config.DefaultSessionConfigSearchPaths...)
+	config.DefaultSessionConfigSearchPaths = []string{filepath.Join(t.TempDir(), "session.yml")}
+	newObjectStoreFromConfigFn = func(context.Context, *config.Config) (storage.ObjectStore, error) {
+		return nil, errors.New("storage unavailable")
+	}
+	t.Cleanup(func() {
+		newObjectStoreFromConfigFn = origStoreFn
+		config.DefaultSessionConfigSearchPaths = origSessionDefaults
+	})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code == 0 {
+		t.Fatal("exit code = 0, want non-zero")
+	}
+	if !strings.Contains(stderr.String(), "storage unavailable") || !strings.Contains(stderr.String(), "remote session") {
+		t.Fatalf("stderr = %q, want remote storage context", stderr.String())
+	}
+}
+
+func TestExecuteRemoteSessionMalformedYAMLFailsStrictDecode(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, _ := writeValidConfigFiles(t, workspaceRoot)
+	fake := &storage.FakeBackend{}
+	seedRemoteSessionConfig(t, fake, "2026-05-03", "session_id: 2026-05-03\nunknown: true\n")
+	var storeInitCalls int
+	restoreAppConfigTestGlobals(t, fake, &storeInitCalls, []string{filepath.Join(t.TempDir(), "session.yml")})
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"plan", "--config", pipelinePath, "--campaign", campaignPath, "--session-id", "2026-05-03"}, &stdout, &stderr)
+	if code == 0 {
+		t.Fatal("exit code = 0, want non-zero")
+	}
+	if !strings.Contains(stderr.String(), "strict decode failed") {
+		t.Fatalf("stderr = %q, want strict decode context", stderr.String())
+	}
+}
+
+func restoreAppConfigTestGlobals(t *testing.T, fake *storage.FakeBackend, storeInitCalls *int, sessionDefaults []string) {
+	t.Helper()
+	origStoreFn := newObjectStoreFromConfigFn
+	origSessionDefaults := append([]string(nil), config.DefaultSessionConfigSearchPaths...)
+	config.DefaultSessionConfigSearchPaths = append([]string(nil), sessionDefaults...)
+	newObjectStoreFromConfigFn = func(context.Context, *config.Config) (storage.ObjectStore, error) {
+		if storeInitCalls != nil {
+			(*storeInitCalls)++
+		}
+		return fake, nil
+	}
+	t.Cleanup(func() {
+		newObjectStoreFromConfigFn = origStoreFn
+		config.DefaultSessionConfigSearchPaths = origSessionDefaults
+	})
+}
+
+func seedRemoteSessionConfig(t *testing.T, fake *storage.FakeBackend, sessionID, content string) string {
+	t.Helper()
+	sessionPrefix := artifacts.S3SessionPrefix("dnd", "sample-campaign", sessionID)
+	remoteKey := artifacts.S3SessionConfigKey(sessionPrefix)
+	fake.SeedObject(storage.FakeObject{
+		Key:  remoteKey,
+		Data: []byte(content),
+		ETag: "remote-session-etag",
+	})
+	return remoteKey
+}

internal/app/restore.go

@@ -26,19 +26,23 @@ func Restore(ctx context.Context, args []string, out io.Writer) error {
 	fs.SetOutput(out)
 
 	var pipelinePath string
+	var campaignPath string
 	var sessionPath string
 	var sessionID string
+	var previousSessionID string
 	var dryRun bool
 	var force bool
 	var includeAudio bool
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml (optional; defaults searched)")
+	fs.StringVar(&campaignPath, "campaign", "", "path to campaign.yml (optional; defaults searched)")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&sessionID, "session-id", "", "session identifier for session.yml templates")
+	fs.StringVar(&previousSessionID, "previous-session-id", "", "previous session identifier for session.yml templates")
 	fs.BoolVar(&dryRun, "dry-run", false, "plan restore actions without writing local files")
 	fs.BoolVar(&force, "force", false, "overwrite local conflicts with remote state")
 	fs.BoolVar(&includeAudio, "include-audio", false, "include archived session-level audio objects")
 	fs.Usage = func() {
-		_, _ = fmt.Fprintln(out, "Usage: narratio restore [--config <path>] [--session <path>] [--session-id <value>] [--dry-run] [--force] [--include-audio]")
+		_, _ = fmt.Fprintln(out, "Usage: narratio restore [--config <path>] [--campaign <path>] [--session <path>] [--session-id <value>] [--previous-session-id <value>] [--dry-run] [--force] [--include-audio]")
 		_, _ = fmt.Fprintln(out)
 		_, _ = fmt.Fprintln(out, "Flags:")
 		fs.PrintDefaults()
@@ -53,17 +57,9 @@ func Restore(ctx context.Context, args []string, out io.Writer) error {
 	if fs.NArg() != 0 {
 		return fmt.Errorf("restore: unexpected positional arguments")
 	}
-	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelinePath)
-	if err != nil {
-		return fmt.Errorf("restore: %w", err)
-	}
-	resolvedSessionPath, err := resolveSessionConfigPath(sessionPath)
-	if err != nil {
-		return fmt.Errorf("restore: %w", err)
-	}
-
-	cfg, err := config.LoadWithSessionOptions(resolvedPipelinePath, resolvedSessionPath, config.SessionLoadOptions{
-		SessionID: sessionID,
+	cfg, err := loadCommandConfig(ctx, pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{
+		SessionID:         sessionID,
+		PreviousSessionID: previousSessionID,
 	})
 	if err != nil {
 		return fmt.Errorf("restore: %w", err)

internal/app/restore_execution_test.go

@@ -18,10 +18,10 @@ import (
 
 func TestExecuteRestoreNonDryRunRestoresDurableFiles(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, manifestKey, runIDKey := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, manifestKey, runIDKey := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, sessionPrefix+"transcripts/full.json", []byte(`{"segments":[1,2,3]}`))
 	seedRestoreObject(fake, sessionPrefix+"artifacts/session_recap.md", []byte("# recap\n"))
 	seedRestoreObject(fake, sessionPrefix+"audio/alice.flac", []byte("remote-audio"))
@@ -32,7 +32,7 @@ func TestExecuteRestoreNonDryRunRestoresDurableFiles(t *testing.T) {
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -64,17 +64,17 @@ func TestExecuteRestoreNonDryRunRestoresDurableFiles(t *testing.T) {
 
 func TestExecuteRestoreIncludeAudioRestoresAudio(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, sessionPrefix+"audio/alice.flac", []byte("remote-audio"))
 
 	restoreWithStoreAndRealPhases(t, fake)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath, "--include-audio"}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--include-audio"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -87,12 +87,39 @@ func TestExecuteRestoreIncludeAudioRestoresAudio(t *testing.T) {
 	}
 }
 
-func TestExecuteRestoreConflictWithoutForceDoesNotOverwrite(t *testing.T) {
+func TestExecuteRestoreRestoresPreviousCacheWhenPresent(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
+	seedRestoreObject(fake, sessionPrefix+"previous/manifest.json", []byte(`{"session_id":"2026-04-26"}`))
+	seedRestoreObject(fake, sessionPrefix+"previous/artifacts/session_recap.md", []byte("# previous recap\n"))
+
+	restoreWithStoreAndRealPhases(t, fake)
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+
+	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
+	mustReadEquals(t, filepath.Join(sessionRoot, "previous", "manifest.json"), `{"session_id":"2026-04-26"}`)
+	mustReadEquals(t, filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md"), "# previous recap\n")
+	report := mustReadRestoreReport(t, filepath.Join(sessionRoot, "reports", "restore-latest.json"))
+	if report.Execution.Downloaded != 3 {
+		t.Fatalf("report execution.downloaded = %d, want 3", report.Execution.Downloaded)
+	}
+}
+
+func TestExecuteRestoreConflictWithoutForceDoesNotOverwrite(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+
+	fake := &storage.FakeBackend{}
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, sessionPrefix+"transcripts/full.json", []byte("remote-transcript"))
 
 	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
@@ -102,7 +129,7 @@ func TestExecuteRestoreConflictWithoutForceDoesNotOverwrite(t *testing.T) {
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -121,10 +148,10 @@ func TestExecuteRestoreConflictWithoutForceDoesNotOverwrite(t *testing.T) {
 
 func TestExecuteRestoreForceOverwritesDifferingFile(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, sessionPrefix+"transcripts/full.json", []byte("remote-transcript"))
 
 	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
@@ -134,7 +161,7 @@ func TestExecuteRestoreForceOverwritesDifferingFile(t *testing.T) {
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath, "--force"}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -145,12 +172,34 @@ func TestExecuteRestoreForceOverwritesDifferingFile(t *testing.T) {
 	}
 }
 
-func TestExecuteRestoreLockConflictFailsAndWritesNothing(t *testing.T) {
+func TestExecuteRestoreForceOverwritesDifferingPreviousCacheFile(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
+	seedRestoreObject(fake, sessionPrefix+"previous/artifacts/session_recap.md", []byte("# remote previous recap\n"))
+
+	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
+	mustWriteTestFile(t, filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md"), "# local previous recap\n")
+
+	restoreWithStoreAndRealPhases(t, fake)
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	mustReadEquals(t, filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md"), "# remote previous recap\n")
+}
+
+func TestExecuteRestoreLockConflictFailsAndWritesNothing(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+
+	fake := &storage.FakeBackend{}
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, sessionPrefix+"transcripts/full.json", []byte("remote-transcript"))
 
 	store := artifacts.NewLocalStore(workspaceRoot)
@@ -164,7 +213,7 @@ func TestExecuteRestoreLockConflictFailsAndWritesNothing(t *testing.T) {
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -180,10 +229,10 @@ func TestExecuteRestoreLockConflictFailsAndWritesNothing(t *testing.T) {
 
 func TestExecuteRestoreInvalidManifestDoesNotCorruptExistingManifest(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	base := &storage.FakeBackend{}
-	cfg, sessionPrefix, manifestKey, _ := seedRestoreCommittedState(t, base, pipelinePath, sessionPath)
+	cfg, sessionPrefix, manifestKey, _ := seedRestoreCommittedState(t, base, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(base, sessionPrefix+"transcripts/full.json", []byte("remote-transcript"))
 
 	toggled := &stagedManifestDownloadStore{
@@ -211,7 +260,7 @@ func TestExecuteRestoreInvalidManifestDoesNotCorruptExistingManifest(t *testing.
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath, "--force"}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force"}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -295,9 +344,9 @@ func restoreWithStoreAndRealPhases(t *testing.T, objectStore storage.ObjectStore
 	executeRestorePlanFn = executeRestorePlan
 }
 
-func seedRestoreCommittedState(t *testing.T, fake *storage.FakeBackend, pipelinePath, sessionPath string) (*config.Config, string, string, string) {
+func seedRestoreCommittedState(t *testing.T, fake *storage.FakeBackend, pipelinePath, campaignPath, sessionPath string) (*config.Config, string, string, string) {
 	t.Helper()
-	cfg, err := config.LoadWithSessionOptions(pipelinePath, sessionPath, config.SessionLoadOptions{})
+	cfg, err := config.LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{})
 	if err != nil {
 		t.Fatalf("LoadWithSessionOptions() error = %v", err)
 	}

internal/app/restore_plan.go

@@ -194,6 +194,9 @@ func restoreLocalRelativePathForKey(sessionPrefix, currentManifestKey, key strin
 	if cleanRel == config.PathArtifactsDirSegment || strings.HasPrefix(cleanRel, config.PathArtifactsDirSegment+"/") {
 		return cleanRel, true, nil
 	}
+	if cleanRel == config.PathPreviousDirSegment || strings.HasPrefix(cleanRel, config.PathPreviousDirSegment+"/") {
+		return cleanRel, true, nil
+	}
 	if includeAudio && (cleanRel == config.PathAudioDirSegment || strings.HasPrefix(cleanRel, config.PathAudioDirSegment+"/")) {
 		return cleanRel, true, nil
 	}

internal/app/restore_plan_test.go

@@ -58,6 +58,27 @@ func TestRestorePlanIncludeAudio(t *testing.T) {
 	}
 }
 
+func TestRestorePlanIncludesPreviousCacheByDefault(t *testing.T) {
+	cfg := restorePlanConfig(t)
+	current := restorePlanCurrentState(t, cfg)
+	store := &storage.FakeBackend{}
+
+	seedRestoreObject(store, current.CurrentManifestKey, []byte(`{"session_id":"2026-05-03"}`))
+	seedRestoreObject(store, current.SessionPrefix+"previous/manifest.json", []byte(`{"session_id":"2026-04-26"}`))
+	seedRestoreObject(store, current.SessionPrefix+"previous/artifacts/session_recap.md", []byte("# previous recap\n"))
+
+	plan, err := buildRestorePlan(context.Background(), cfg, current, store, RestorePlanOptions{})
+	if err != nil {
+		t.Fatalf("buildRestorePlan() error = %v", err)
+	}
+
+	got := actionRelPaths(plan.Actions)
+	want := []string{"manifest.json", "previous/artifacts/session_recap.md", "previous/manifest.json"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("action local paths = %#v, want %#v", got, want)
+	}
+}
+
 func TestRestorePlanClassifiesSameAndConflict(t *testing.T) {
 	cfg := restorePlanConfig(t)
 	current := restorePlanCurrentState(t, cfg)

internal/app/restore_test.go

@@ -32,6 +32,9 @@ func TestExecuteRestoreHelp(t *testing.T) {
 	if !strings.Contains(out, "--include-audio") {
 		t.Fatalf("stdout = %q, want --include-audio flag", out)
 	}
+	if !strings.Contains(out, "--campaign") {
+		t.Fatalf("stdout = %q, want --campaign flag", out)
+	}
 }
 
 func TestExecuteRestoreRecognizedAndReturnsNYI(t *testing.T) {
@@ -70,7 +73,7 @@ func TestExecuteRestoreRecognizedAndReturnsNYI(t *testing.T) {
 	}
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
@@ -78,6 +81,7 @@ func TestExecuteRestoreRecognizedAndReturnsNYI(t *testing.T) {
 		[]string{
 			"restore",
 			"--config", pipelinePath,
+			"--campaign", campaignPath,
 			"--session", sessionPath,
 			"--session-id", "2026-05-03",
 			"--dry-run",
@@ -116,11 +120,11 @@ func TestExecuteRestoreRecognizedAndReturnsNYI(t *testing.T) {
 
 func TestExecuteRestoreRejectsUnexpectedPositionalArguments(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath, "extra"}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "extra"}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -138,11 +142,11 @@ func TestExecuteRestoreFailsWhenStorageBackendNotConfigured(t *testing.T) {
 	})
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeRestoreConfigWithoutStorage(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeRestoreConfigWithoutStorage(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -166,11 +170,11 @@ func TestExecuteRestoreDiscoveryErrorSurfaced(t *testing.T) {
 	}
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -208,7 +212,7 @@ func TestExecuteRestoreLoadsSecretsBeforeObjectStoreInit(t *testing.T) {
 	restoreEnv(secretKeyEnv)
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	secretsDir := filepath.Join(t.TempDir(), "secrets")
 	mustWriteTestFile(t, filepath.Join(secretsDir, accessKeyEnv), "test-access-key-id\n")
 	mustWriteTestFile(t, filepath.Join(secretsDir, secretKeyEnv), "test-secret-key\n")
@@ -261,6 +265,7 @@ func TestExecuteRestoreLoadsSecretsBeforeObjectStoreInit(t *testing.T) {
 		[]string{
 			"restore",
 			"--config", pipelinePath,
+			"--campaign", campaignPath,
 			"--session", sessionPath,
 			"--session-id", "2026-05-03",
 			"--dry-run",
@@ -307,10 +312,10 @@ func TestExecuteRestoreNonDryRunConflictFailsBeforeNYI(t *testing.T) {
 	}
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &stdout, &stderr)
 	if code == 0 {
 		t.Fatal("exit code = 0, want non-zero")
 	}
@@ -359,10 +364,10 @@ func TestExecuteRestoreNonDryRunForceExecutesPlan(t *testing.T) {
 	}
 
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
-	code := Execute([]string{"restore", "--config", pipelinePath, "--session", sessionPath, "--force"}, &stdout, &stderr)
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force"}, &stdout, &stderr)
 	if code != 0 {
 		t.Fatalf("exit code = %d, want 0; stderr=%q", code, stderr.String())
 	}
@@ -374,11 +379,12 @@ func TestExecuteRestoreNonDryRunForceExecutesPlan(t *testing.T) {
 	}
 }
 
-func writeRestoreConfigWithoutStorage(t *testing.T, workspaceRoot string) (string, string) {
+func writeRestoreConfigWithoutStorage(t *testing.T, workspaceRoot string) (string, string, string) {
 	t.Helper()
 
 	dir := t.TempDir()
 	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	campaignPath := writeAppTestCampaignConfig(t, dir)
 	sessionPath := filepath.Join(dir, "session.yml")
 
 	pipelineYAML := `workspace:
@@ -405,5 +411,5 @@ inputs:
 	mustWriteTestFile(t, filepath.Join(dir, "glossary.yml"), "[]\n")
 	mustWriteTestFile(t, filepath.Join(dir, "audio", "alice.flac"), "audio-bytes")
 
-	return pipelinePath, sessionPath
+	return pipelinePath, campaignPath, sessionPath
 }

internal/app/restore_workflow_test.go

@@ -19,10 +19,10 @@ import (
 
 func TestRestoreThenRunStageForceAnalyzeUsesRestoredDurableState(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFilesWithScriptoriumArtifacts(t, workspaceRoot)
 
 	fake := &storage.FakeBackend{}
-	cfg, sessionPrefix, manifestKey, runIDKey := seedRestoreCommittedState(t, fake, pipelinePath, sessionPath)
+	cfg, sessionPrefix, manifestKey, runIDKey := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
 	seedRestoreObject(fake, runIDKey, []byte("20260519T010203Z-a1b2c3d4\n"))
 	seedRestoreObject(fake, manifestKey, restoreWorkflowManifestJSON(t, cfg.Session.SessionID, cfg.Session.Campaign))
 	seedRestoreObject(fake, sessionPrefix+"transcripts/full.json", []byte(`{"segments":[1,2,3]}`+"\n"))
@@ -48,6 +48,7 @@ func TestRestoreThenRunStageForceAnalyzeUsesRestoredDurableState(t *testing.T) {
 		[]string{
 			"restore",
 			"--config", pipelinePath,
+			"--campaign", campaignPath,
 			"--session", sessionPath,
 			"--session-id", cfg.Session.SessionID,
 		},
@@ -86,6 +87,7 @@ func TestRestoreThenRunStageForceAnalyzeUsesRestoredDurableState(t *testing.T) {
 		[]string{
 			"run-stage",
 			"--config", pipelinePath,
+			"--campaign", campaignPath,
 			"--session", sessionPath,
 			"--session-id", cfg.Session.SessionID,
 			"--force",
@@ -155,6 +157,118 @@ func TestRestoreThenRunStageForceAnalyzeUsesRestoredDurableState(t *testing.T) {
 	}
 }
 
+func TestRestoreThenAnalyzeUsesRestoredPreviousCacheWithoutObjectStore(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	appendRestoreWorkflowScriptoriumConfig(t, pipelinePath, `
+scriptorium:
+  binary: scriptorium
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        transcript:
+          source: narratio.transcript.trimmed
+          required: true
+        previous_recap:
+          source: narratio.previous_session.artifact.session_recap
+          required: true
+`)
+
+	fakeStore := &storage.FakeBackend{}
+	cfg, sessionPrefix, manifestKey, runIDKey := seedRestoreCommittedState(t, fakeStore, pipelinePath, campaignPath, sessionPath)
+	seedRestoreObject(fakeStore, runIDKey, []byte("20260519T010203Z-a1b2c3d4\n"))
+	seedRestoreObject(fakeStore, manifestKey, restoreWorkflowManifestJSON(t, cfg.Session.SessionID, cfg.Session.Campaign))
+	seedRestoreObject(fakeStore, sessionPrefix+"transcripts/trimmed.json", []byte(`{"segments":[]}`+"\n"))
+	seedRestoreObject(fakeStore, sessionPrefix+"previous/manifest.json", []byte(`{"session_id":"2026-04-26"}`))
+	seedRestoreObject(fakeStore, sessionPrefix+"previous/artifacts/session_recap.md", []byte("# previous recap\n"))
+
+	restoreWithStoreAndRealPhases(t, fakeStore)
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	restoreCode := Execute(
+		[]string{
+			"restore",
+			"--config", pipelinePath,
+			"--campaign", campaignPath,
+			"--session", sessionPath,
+			"--session-id", cfg.Session.SessionID,
+		},
+		&stdout,
+		&stderr,
+	)
+	if restoreCode != 0 {
+		t.Fatalf("restore exit code = %d, want 0; stderr=%q", restoreCode, stderr.String())
+	}
+	if stderr.Len() != 0 {
+		t.Fatalf("restore stderr = %q, want empty", stderr.String())
+	}
+
+	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
+	mustReadEquals(t, filepath.Join(sessionRoot, "transcripts", "trimmed.json"), `{"segments":[]}`+"\n")
+	mustReadEquals(t, filepath.Join(sessionRoot, "previous", "manifest.json"), `{"session_id":"2026-04-26"}`)
+	mustReadEquals(t, filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md"), "# previous recap\n")
+
+	scriptoriumFake := &scriptorium.FakeRunner{}
+	origExecuteStagesFn := executeStagesFn
+	origObjectStoreFn := newObjectStoreFromConfigFn
+	objectStoreConstructed := false
+	t.Cleanup(func() {
+		executeStagesFn = origExecuteStagesFn
+		newObjectStoreFromConfigFn = origObjectStoreFn
+	})
+	executeStagesFn = func(ctx context.Context, cfg *config.Config, stages []stage.Stage, opts RunOptions) (*RunSummary, error) {
+		if opts.Env == nil {
+			opts.Env = &Env{}
+		}
+		opts.Env.Scriptorium = scriptoriumFake
+		return executeStages(ctx, cfg, stages, opts)
+	}
+	newObjectStoreFromConfigFn = func(context.Context, *config.Config) (storage.ObjectStore, error) {
+		objectStoreConstructed = true
+		return nil, context.Canceled
+	}
+
+	stdout.Reset()
+	stderr.Reset()
+	runStageCode := Execute(
+		[]string{
+			"run-stage",
+			"--config", pipelinePath,
+			"--campaign", campaignPath,
+			"--session", sessionPath,
+			"--session-id", cfg.Session.SessionID,
+			"--force",
+			"--artifacts", "session_recap",
+			"analyze",
+		},
+		&stdout,
+		&stderr,
+	)
+	if runStageCode != 0 {
+		t.Fatalf("run-stage exit code = %d, want 0; stderr=%q", runStageCode, stderr.String())
+	}
+	if stderr.Len() != 0 {
+		t.Fatalf("run-stage stderr = %q, want empty", stderr.String())
+	}
+	if objectStoreConstructed {
+		t.Fatal("analyze run-stage should not construct object store for previous-session input resolution")
+	}
+	if len(scriptoriumFake.RunRequests) != 1 {
+		t.Fatalf("scriptorium run requests = %d, want 1", len(scriptoriumFake.RunRequests))
+	}
+	req := scriptoriumFake.RunRequests[0]
+	if got := req.InputPaths["transcript"]; got != filepath.Join(sessionRoot, "transcripts", "trimmed.json") {
+		t.Fatalf("transcript input = %q, want trimmed transcript path", got)
+	}
+	if got := req.InputPaths["previous_recap"]; got != filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md") {
+		t.Fatalf("previous_recap input = %q, want restored previous cache path", got)
+	}
+}
+
 func restoreWorkflowManifestJSON(t *testing.T, sessionID, campaign string) []byte {
 	t.Helper()
 	store := &manifest.LocalStore{}
@@ -176,3 +290,15 @@ func restoreWorkflowManifestJSON(t *testing.T, sessionID, campaign string) []byt
 	}
 	return data
 }
+
+func appendRestoreWorkflowScriptoriumConfig(t *testing.T, pipelinePath, extra string) {
+	t.Helper()
+	f, err := os.OpenFile(pipelinePath, os.O_APPEND|os.O_WRONLY, 0)
+	if err != nil {
+		t.Fatalf("open pipeline config for append: %v", err)
+	}
+	defer f.Close()
+	if _, err := f.WriteString(extra); err != nil {
+		t.Fatalf("append pipeline config: %v", err)
+	}
+}

internal/app/resume.go

@@ -17,13 +17,17 @@ func Resume(ctx context.Context, args []string, out io.Writer) error {
 	fs.SetOutput(io.Discard)
 
 	var pipelinePath string
+	var campaignPath string
 	var sessionPath string
 	var sessionID string
+	var previousSessionID string
 	var force bool
 	var selectedArtifacts artifactSelectionFlag
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml (optional; defaults searched)")
+	fs.StringVar(&campaignPath, "campaign", "", "path to campaign.yml (optional; defaults searched)")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&sessionID, "session-id", "", "session identifier for session.yml templates")
+	fs.StringVar(&previousSessionID, "previous-session-id", "", "previous session identifier for session.yml templates")
 	fs.BoolVar(&force, "force", false, "force stage execution")
 	fs.Var(&selectedArtifacts, "artifacts", "artifact names to execute during analyze (comma-separated or repeatable)")
 
@@ -33,17 +37,9 @@ func Resume(ctx context.Context, args []string, out io.Writer) error {
 	if fs.NArg() != 0 {
 		return fmt.Errorf("resume: unexpected positional arguments")
 	}
-	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelinePath)
-	if err != nil {
-		return fmt.Errorf("resume: %w", err)
-	}
-	resolvedSessionPath, err := resolveSessionConfigPath(sessionPath)
-	if err != nil {
-		return fmt.Errorf("resume: %w", err)
-	}
-
-	cfg, err := config.LoadWithSessionOptions(resolvedPipelinePath, resolvedSessionPath, config.SessionLoadOptions{
-		SessionID: sessionID,
+	cfg, err := loadCommandConfig(ctx, pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{
+		SessionID:         sessionID,
+		PreviousSessionID: previousSessionID,
 	})
 	if err != nil {
 		return fmt.Errorf("resume: %w", err)

internal/app/resume_run_stage_test.go

@@ -15,7 +15,7 @@ import (
 
 func TestResumeStartsAfterCompletedStages(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -32,7 +32,7 @@ func TestResumeStartsAfterCompletedStages(t *testing.T) {
 	mustWriteTestFile(t, filepath.Join(workRoot, "inputs", "glossary.yml"), "terms: []\n")
 
 	var out bytes.Buffer
-	err := Resume(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath}, &out)
+	err := Resume(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &out)
 	if err != nil {
 		t.Fatalf("Resume() error = %v", err)
 	}
@@ -51,7 +51,7 @@ func TestResumeStartsAfterCompletedStages(t *testing.T) {
 
 func TestResumeNoRemainingStages(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -64,7 +64,7 @@ func TestResumeNoRemainingStages(t *testing.T) {
 	}
 
 	var out bytes.Buffer
-	err := Resume(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath}, &out)
+	err := Resume(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &out)
 	if err != nil {
 		t.Fatalf("Resume() error = %v", err)
 	}
@@ -80,7 +80,7 @@ func TestResumeForceRerunsSucceeded(t *testing.T) {
 		_, _ = w.Write([]byte(`{"source":"resume-force-test","segments":[{"speaker":"alice"}]}`))
 	}))
 	defer srv.Close()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot, srv.URL)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 
 	store := &manifest.LocalStore{}
@@ -93,7 +93,7 @@ func TestResumeForceRerunsSucceeded(t *testing.T) {
 	}
 
 	var out bytes.Buffer
-	err := Resume(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "--force"}, &out)
+	err := Resume(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force"}, &out)
 	if err != nil {
 		t.Fatalf("Resume() error = %v", err)
 	}
@@ -104,14 +104,14 @@ func TestResumeForceRerunsSucceeded(t *testing.T) {
 
 func TestRunStageExecutesOnlySelectedStage(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "merged.json"), `{"segments":[]}`)
 	mustWriteTestFile(t, filepath.Join(workRoot, "inputs", "glossary.yml"), "terms: []\n")
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "polish"}, &out)
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "polish"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage() error = %v", err)
 	}
@@ -134,7 +134,7 @@ func TestRunStageExecutesOnlySelectedStage(t *testing.T) {
 
 func TestRunStageSkipAndForce(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "merged.json"), `{"segments":[]}`)
@@ -148,7 +148,7 @@ func TestRunStageSkipAndForce(t *testing.T) {
 	}
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "polish"}, &out)
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "polish"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage() error = %v", err)
 	}
@@ -157,7 +157,7 @@ func TestRunStageSkipAndForce(t *testing.T) {
 	}
 
 	out.Reset()
-	err = RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "--force", "polish"}, &out)
+	err = RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force", "polish"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage(force) error = %v", err)
 	}
@@ -168,7 +168,7 @@ func TestRunStageSkipAndForce(t *testing.T) {
 
 func TestRunStageForceMarksDownstreamStaleAndResumeContinuesFromStale(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "merged.json"), `{"segments":[]}`)
@@ -184,7 +184,7 @@ func TestRunStageForceMarksDownstreamStaleAndResumeContinuesFromStale(t *testing
 	}
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "--force", "polish"}, &out)
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--force", "polish"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage(force) error = %v", err)
 	}
@@ -203,7 +203,7 @@ func TestRunStageForceMarksDownstreamStaleAndResumeContinuesFromStale(t *testing
 	}
 
 	out.Reset()
-	err = Resume(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath}, &out)
+	err = Resume(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath}, &out)
 	if err != nil {
 		t.Fatalf("Resume() error = %v", err)
 	}
@@ -214,13 +214,13 @@ func TestRunStageForceMarksDownstreamStaleAndResumeContinuesFromStale(t *testing
 
 func TestRunStageTrimExecutes(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "normalized.json"), `{"segments":[{"id":1},{"id":2}]}`)
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "trim"}, &out)
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "trim"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage(trim) error = %v", err)
 	}
@@ -243,13 +243,13 @@ func TestRunStageTrimExecutes(t *testing.T) {
 
 func TestRunStageNormalizeExecutes(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 	manifestPath := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03", "manifest.json")
 	workRoot := filepath.Join(workspaceRoot, "work", "sample-campaign", "2026-05-03")
 	mustWriteTestFile(t, filepath.Join(workRoot, "transcripts", "processed.json"), `{"segments":[{"id":1},{"id":2}]}`)
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "normalize"}, &out)
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "normalize"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage(normalize) error = %v", err)
 	}

internal/app/run.go

@@ -15,13 +15,17 @@ func Run(ctx context.Context, args []string, out io.Writer) error {
 	fs.SetOutput(io.Discard)
 
 	var pipelinePath string
+	var campaignPath string
 	var sessionPath string
 	var sessionID string
+	var previousSessionID string
 	var force bool
 	var selectedArtifacts artifactSelectionFlag
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml (optional; defaults searched)")
+	fs.StringVar(&campaignPath, "campaign", "", "path to campaign.yml (optional; defaults searched)")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&sessionID, "session-id", "", "session identifier for session.yml templates")
+	fs.StringVar(&previousSessionID, "previous-session-id", "", "previous session identifier for session.yml templates")
 	fs.BoolVar(&force, "force", false, "force stage execution (reserved for future behavior)")
 	fs.Var(&selectedArtifacts, "artifacts", "artifact names to execute during analyze (comma-separated or repeatable)")
 
@@ -31,17 +35,9 @@ func Run(ctx context.Context, args []string, out io.Writer) error {
 	if fs.NArg() != 0 {
 		return fmt.Errorf("run: unexpected positional arguments")
 	}
-	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelinePath)
-	if err != nil {
-		return fmt.Errorf("run: %w", err)
-	}
-	resolvedSessionPath, err := resolveSessionConfigPath(sessionPath)
-	if err != nil {
-		return fmt.Errorf("run: %w", err)
-	}
-
-	cfg, err := config.LoadWithSessionOptions(resolvedPipelinePath, resolvedSessionPath, config.SessionLoadOptions{
-		SessionID: sessionID,
+	cfg, err := loadCommandConfig(ctx, pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{
+		SessionID:         sessionID,
+		PreviousSessionID: previousSessionID,
 	})
 	if err != nil {
 		return fmt.Errorf("run: %w", err)

internal/app/run_stage.go

@@ -15,13 +15,17 @@ func RunStage(ctx context.Context, args []string, out io.Writer) error {
 	fs.SetOutput(io.Discard)
 
 	var pipelinePath string
+	var campaignPath string
 	var sessionPath string
 	var sessionID string
+	var previousSessionID string
 	var force bool
 	var selectedArtifacts artifactSelectionFlag
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml (optional; defaults searched)")
+	fs.StringVar(&campaignPath, "campaign", "", "path to campaign.yml (optional; defaults searched)")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&sessionID, "session-id", "", "session identifier for session.yml templates")
+	fs.StringVar(&previousSessionID, "previous-session-id", "", "previous session identifier for session.yml templates")
 	fs.BoolVar(&force, "force", false, "force stage execution (reserved for future behavior)")
 	fs.Var(&selectedArtifacts, "artifacts", "artifact names to execute during analyze (comma-separated or repeatable)")
 
@@ -44,17 +48,9 @@ func RunStage(ctx context.Context, args []string, out io.Writer) error {
 		return fmt.Errorf("run-stage: %w", err)
 	}
 
-	resolvedPipelinePath, err := resolvePipelineConfigPath(pipelinePath)
-	if err != nil {
-		return fmt.Errorf("run-stage: %w", err)
-	}
-	resolvedSessionPath, err := resolveSessionConfigPath(sessionPath)
-	if err != nil {
-		return fmt.Errorf("run-stage: %w", err)
-	}
-
-	cfg, err := config.LoadWithSessionOptions(resolvedPipelinePath, resolvedSessionPath, config.SessionLoadOptions{
-		SessionID: sessionID,
+	cfg, err := loadCommandConfig(ctx, pipelinePath, campaignPath, sessionPath, config.SessionLoadOptions{
+		SessionID:         sessionID,
+		PreviousSessionID: previousSessionID,
 	})
 	if err != nil {
 		return fmt.Errorf("run-stage: %w", err)

internal/app/runner.go

@@ -555,6 +555,12 @@ func needsObjectStoreForRun(cfg *config.Config, stages []stage.Stage) bool {
 	if cfg.Session.Inputs.AudioS3 != nil && stageRequested("prepare") {
 		return true
 	}
+	if stageRequested("prepare") {
+		requirements := artifacts.CollectPreviousArtifactRequirements(configuredScriptoriumArtifacts(cfg))
+		if len(requirements) > 0 && strings.TrimSpace(cfg.Session.PreviousSessionID) != "" {
+			return true
+		}
+	}
 	if !stageRequested("archive") {
 		return false
 	}
@@ -569,3 +575,10 @@ func needsObjectStoreForRun(cfg *config.Config, stages []stage.Stage) bool {
 	}
 	return true
 }
+
+func configuredScriptoriumArtifacts(cfg *config.Config) map[string]config.ScriptoriumArtifactConfig {
+	if cfg == nil || cfg.Pipeline == nil || cfg.Pipeline.Scriptorium == nil {
+		return nil
+	}
+	return cfg.Pipeline.Scriptorium.Artifacts
+}

internal/app/runner_test.go

@@ -199,6 +199,55 @@ func TestExecuteStagesAnalyzeOutputsPersistAsScriptoriumArtifacts(t *testing.T)
 	}
 }
 
+func TestNeedsObjectStoreForRunPrepareWithPreviousRequirements(t *testing.T) {
+	tests := []struct {
+		name              string
+		previousSessionID string
+		want              bool
+	}{
+		{
+			name:              "previous session configured",
+			previousSessionID: "2026-05-10",
+			want:              true,
+		},
+		{
+			name:              "previous session missing",
+			previousSessionID: "",
+			want:              false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := &config.Config{
+				Pipeline: &config.PipelineConfig{
+					Scriptorium: &config.ScriptoriumConfig{
+						Artifacts: map[string]config.ScriptoriumArtifactConfig{
+							"session_recap": {
+								Enabled: true,
+								Inputs: map[string]config.ScriptoriumInputConfig{
+									"previous_recap": {
+										Source:   "narratio.previous_session.artifact.session_recap",
+										Required: true,
+									},
+								},
+							},
+						},
+					},
+				},
+				Session: &config.SessionConfig{
+					PreviousSessionID: tt.previousSessionID,
+				},
+			}
+
+			got := needsObjectStoreForRun(cfg, []stage.Stage{countingStage{name: "prepare", runs: new(int)}})
+			if got != tt.want {
+				t.Fatalf("needsObjectStoreForRun() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
 func TestExecuteStagesArchiveFailsWhenRequiredRecapPromotionMissingForSelectedArtifacts(t *testing.T) {
 	cfg := testConfig(t)
 	cfg.Pipeline.Storage.S3 = &config.StorageS3Config{
@@ -945,10 +994,12 @@ func testConfig(t *testing.T) *config.Config {
 	workspace := t.TempDir()
 	cfgDir := t.TempDir()
 	sessionPath := filepath.Join(cfgDir, "session.yml")
+	campaignPath := filepath.Join(cfgDir, "campaign.yml")
 	pipelinePath := filepath.Join(cfgDir, "pipeline.yml")
 
 	mustWriteFile(t, pipelinePath, "workspace:\n  root: "+workspace+"\n")
-	mustWriteFile(t, sessionPath, "session_id: 2026-05-03\ncampaign: sample-campaign\n")
+	mustWriteFile(t, campaignPath, "campaign: sample-campaign\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n")
+	mustWriteFile(t, sessionPath, "session_id: 2026-05-03\ncampaign: sample-campaign\ninputs:\n  audio_dir: ./audio\n")
 	mustWriteFile(t, filepath.Join(cfgDir, "speakers.yml"), "alice: alice.flac\n")
 	mustWriteFile(t, filepath.Join(cfgDir, "autocorrect.yml"), "[]\n")
 	mustWriteFile(t, filepath.Join(cfgDir, "glossary.yml"), "[]\n")
@@ -956,8 +1007,27 @@ func testConfig(t *testing.T) *config.Config {
 
 	return &config.Config{
 		Pipeline:     &config.PipelineConfig{Workspace: config.WorkspaceConfig{Root: workspace}},
+		Campaign:     &config.CampaignConfig{Campaign: "sample-campaign"},
 		PipelinePath: pipelinePath,
+		CampaignPath: campaignPath,
 		SessionPath:  sessionPath,
+		StableInputs: config.ResolvedStableInputs{
+			SpeakersFile: config.ResolvedInputFile{
+				Path:       "./speakers.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
+			},
+			AutocorrectFile: config.ResolvedInputFile{
+				Path:       "./autocorrect.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
+			},
+			GlossaryFile: config.ResolvedInputFile{
+				Path:       "./glossary.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
+			},
+		},
 		Session: &config.SessionConfig{
 			SessionID: "2026-05-03",
 			Campaign:  "sample-campaign",
@@ -974,6 +1044,7 @@ func testConfig(t *testing.T) *config.Config {
 func TestBuildDefaultRunnersWithOmittedToolSections(t *testing.T) {
 	dir := t.TempDir()
 	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	campaignPath := filepath.Join(dir, "campaign.yml")
 	sessionPath := filepath.Join(dir, "session.yml")
 	pipelineYAML := `workspace:
   root: ` + t.TempDir() + `
@@ -983,6 +1054,12 @@ analyzer:
   timeout: 20m
 notification:
   timeout: 10s
+`
+	campaignYAML := `campaign: sample-campaign
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
 `
 	sessionYAML := `session_id: 2026-05-03
 campaign: sample-campaign
@@ -993,6 +1070,7 @@ inputs:
   glossary_file: ./glossary.yml
 `
 	mustWriteFile(t, pipelinePath, pipelineYAML)
+	mustWriteFile(t, campaignPath, campaignYAML)
 	mustWriteFile(t, sessionPath, sessionYAML)
 
 	cfg, err := config.Load(pipelinePath, sessionPath)

internal/app/session_cli_test.go

@@ -9,11 +9,12 @@ import (
 	"testing"
 )
 
-func TestPlanUsesDiscoveredSessionTemplateWithSessionID(t *testing.T) {
+func TestPlanUsesDiscoveredSessionTemplateWithSessionIDs(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, _, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	sessionTemplate := `session_id: "{{ session_id }}"
+previous_session_id: "{{ previous_session_id }}"
 campaign: sample-campaign
 inputs:
   audio_dir: ./audio
@@ -36,7 +37,11 @@ inputs:
 	t.Cleanup(func() { _ = os.Chdir(originalWD) })
 
 	var out bytes.Buffer
-	if err := Plan(context.Background(), []string{"--config", pipelinePath, "--session-id", "2026-04-04"}, &out); err != nil {
+	if err := Plan(context.Background(), []string{
+		"--config", pipelinePath,
+		"--session-id", "2026-04-04",
+		"--previous-session-id", "2026-03-28",
+	}, &out); err != nil {
 		t.Fatalf("Plan() error = %v", err)
 	}
 	if !strings.Contains(out.String(), "narratio plan: workdir prepared") {
@@ -46,10 +51,10 @@ inputs:
 
 func TestPlanFailsWhenSessionIDMismatchesConcreteSession(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	var out bytes.Buffer
-	err := Plan(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "--session-id", "2026-04-04"}, &out)
+	err := Plan(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--session-id", "2026-04-04"}, &out)
 	if err == nil {
 		t.Fatal("expected error, got nil")
 	}
@@ -58,12 +63,45 @@ func TestPlanFailsWhenSessionIDMismatchesConcreteSession(t *testing.T) {
 	}
 }
 
-func TestRunStageAcceptsSessionIDFlagAndParsesStageName(t *testing.T) {
+func TestPlanFailsWhenPreviousSessionIDMismatchesConcreteSession(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+
+	sessionYAML := `session_id: 2026-05-03
+previous_session_id: 2026-04-26
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
+		t.Fatalf("write session.yml: %v", err)
+	}
 
 	var out bytes.Buffer
-	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--session", sessionPath, "--session-id", "2026-05-03", "prepare"}, &out)
+	err := Plan(context.Background(), []string{
+		"--config", pipelinePath,
+		"--campaign", campaignPath,
+		"--session", sessionPath,
+		"--session-id", "2026-05-03",
+		"--previous-session-id", "2026-04-25",
+	}, &out)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "previous_session_id mismatch") {
+		t.Fatalf("error = %q, want mismatch context", err.Error())
+	}
+}
+
+func TestRunStageAcceptsSessionIDFlagAndParsesStageName(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+
+	var out bytes.Buffer
+	err := RunStage(context.Background(), []string{"--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--session-id", "2026-05-03", "prepare"}, &out)
 	if err != nil {
 		t.Fatalf("RunStage() error = %v", err)
 	}

internal/app/session_config_path.go

@@ -19,6 +19,22 @@ func resolveSessionConfigPathWithCandidates(flagValue string, candidates []strin
 		return explicit, nil
 	}
 
+	resolved, err := discoverSessionConfigPathWithCandidates(candidates)
+	if err != nil {
+		return "", err
+	}
+	if resolved.Path != "" {
+		return resolved.Path, nil
+	}
+	return "", missingSessionConfigError(resolved.Searched, "")
+}
+
+type sessionConfigDiscovery struct {
+	Path     string
+	Searched []string
+}
+
+func discoverSessionConfigPathWithCandidates(candidates []string) (sessionConfigDiscovery, error) {
 	ordered := make([]string, 0, len(candidates))
 	for _, raw := range candidates {
 		path := strings.TrimSpace(raw)
@@ -31,19 +47,32 @@ func resolveSessionConfigPathWithCandidates(flagValue string, candidates []strin
 			if info.IsDir() {
 				continue
 			}
-			return filepath.Clean(path), nil
+			return sessionConfigDiscovery{Path: filepath.Clean(path), Searched: ordered}, nil
 		}
 		if errors.Is(err, os.ErrNotExist) {
 			continue
 		}
-		return "", fmt.Errorf("check default session config %q: %w", path, err)
+		return sessionConfigDiscovery{}, fmt.Errorf("check default session config %q: %w", path, err)
 	}
 
+	return sessionConfigDiscovery{Searched: ordered}, nil
+}
+
+func missingSessionConfigError(searched []string, remoteDetail string) error {
+	ordered := append([]string(nil), searched...)
 	if len(ordered) == 0 {
-		return "", fmt.Errorf("no session config path provided and no default locations configured")
+		if strings.TrimSpace(remoteDetail) != "" {
+			return fmt.Errorf("no session config path provided and no default locations configured; %s", remoteDetail)
+		}
+		return fmt.Errorf("no session config path provided and no default locations configured")
 	}
-	return "", fmt.Errorf(
-		"no session config path provided and no default session config found; searched: %s; pass --session to use an explicit path",
+	msg := fmt.Sprintf(
+		"no session config path provided and no default session config found; searched: %s",
 		strings.Join(ordered, ", "),
 	)
+	if strings.TrimSpace(remoteDetail) != "" {
+		msg += "; " + strings.TrimSpace(remoteDetail)
+	}
+	msg += "; pass --session to use an explicit path"
+	return fmt.Errorf("%s", msg)
 }

internal/artifacts/artifact_resolver.go

@@ -18,11 +18,15 @@ const (
 	ArtifactTranscriptFull     = "narratio.transcript.full"
 	ArtifactTranscriptTrimmed  = "narratio.transcript.trimmed"
 	ArtifactBoundsSession      = "narratio.bounds.session"
+
+	ArtifactProvenancePreviousCacheManifestInput = "manifest.inputs.previous_cache"
+	ArtifactProvenancePreviousCacheFilesystem    = "current_session.previous_cache"
 )
 
 // ErrSessionArtifactNotFound is returned when no readable artifact exists for a known ID.
 var ErrSessionArtifactNotFound = errors.New("session artifact not found")
 var configuredArtifactSourceRE = regexp.MustCompile(`^narratio\.artifact\.[a-z][a-z0-9_]*$`)
+var previousSessionArtifactSourceRE = regexp.MustCompile(`^narratio\.previous_session\.artifact\.([a-z][a-z0-9_]*)$`)
 
 type artifactContentKind string
 
@@ -118,6 +122,21 @@ func IsConfiguredArtifactSource(source string) bool {
 	return configuredArtifactSourceRE.MatchString(strings.TrimSpace(source))
 }
 
+// IsPreviousSessionArtifactSource returns true when source is narratio.previous_session.artifact.<name>.
+func IsPreviousSessionArtifactSource(source string) bool {
+	_, ok := PreviousSessionArtifactName(source)
+	return ok
+}
+
+// PreviousSessionArtifactName extracts <name> from narratio.previous_session.artifact.<name>.
+func PreviousSessionArtifactName(source string) (string, bool) {
+	matches := previousSessionArtifactSourceRE.FindStringSubmatch(strings.TrimSpace(source))
+	if len(matches) != 2 {
+		return "", false
+	}
+	return matches[1], true
+}
+
 // ResolveSessionArtifact resolves a symbolic source to a readable local session artifact path.
 // Resolution order is manifest producer outputs first, then canonical session path fallback.
 func ResolveSessionArtifact(paths SessionPaths, m *manifest.Manifest, source string) (ResolvedSessionArtifact, error) {
@@ -170,6 +189,9 @@ func ResolveSessionArtifact(paths SessionPaths, m *manifest.Manifest, source str
 // configured narratio.artifact.<name> sources through runtime catalog availability.
 func ResolveSessionArtifactWithCatalog(paths SessionPaths, m *manifest.Manifest, source string, catalog *ArtifactCatalog) (ResolvedSessionArtifact, error) {
 	normalized := strings.TrimSpace(source)
+	if IsPreviousSessionArtifactSource(normalized) {
+		return ResolvePreviousSessionArtifactWithCatalog(paths, m, normalized, catalog)
+	}
 	if !IsConfiguredArtifactSource(normalized) {
 		return ResolveSessionArtifact(paths, m, normalized)
 	}
@@ -195,6 +217,72 @@ func ResolveSessionArtifactWithCatalog(paths SessionPaths, m *manifest.Manifest,
 	}, nil
 }
 
+// ResolvePreviousSessionArtifactWithCatalog resolves one canonical previous-session source id
+// to the prepared current-session previous-cache path.
+func ResolvePreviousSessionArtifactWithCatalog(
+	paths SessionPaths,
+	m *manifest.Manifest,
+	source string,
+	catalog *ArtifactCatalog,
+) (ResolvedSessionArtifact, error) {
+	artifactName, ok := PreviousSessionArtifactName(source)
+	if !ok {
+		return ResolvedSessionArtifact{}, fmt.Errorf("unsupported previous-session artifact source %q", source)
+	}
+	if catalog == nil {
+		return ResolvedSessionArtifact{}, fmt.Errorf("previous-session artifact source %q requires runtime artifact catalog", source)
+	}
+
+	configuredSourceID := ConfiguredArtifactSourceID(artifactName)
+	entry, ok := catalog.Lookup(configuredSourceID)
+	if !ok {
+		return ResolvedSessionArtifact{}, fmt.Errorf("unsupported previous-session artifact source %q", source)
+	}
+	candidates := previousSessionCacheCandidatePaths(paths, entry.CanonicalRelPath)
+	if len(candidates) == 0 {
+		return ResolvedSessionArtifact{}, &SessionArtifactNotFoundError{ArtifactID: source}
+	}
+
+	manifestInputPaths := manifestInputPathSet(paths, m)
+	fallback := ""
+	for _, candidate := range candidates {
+		exists, isDir, statErr := pathExists(candidate)
+		if statErr != nil {
+			return ResolvedSessionArtifact{}, fmt.Errorf("stat %q: %w", candidate, statErr)
+		}
+		if !exists || isDir {
+			continue
+		}
+		if err := validateResolvedContent(candidate, contentText); err != nil {
+			return ResolvedSessionArtifact{}, fmt.Errorf("validate %q: %w", source, err)
+		}
+		if _, ok := manifestInputPaths[candidate]; ok {
+			return ResolvedSessionArtifact{
+				ID:            source,
+				Path:          candidate,
+				ProducerStage: "prepare",
+				OutputKind:    "previous_session_artifact",
+				Provenance:    ArtifactProvenancePreviousCacheManifestInput,
+			}, nil
+		}
+		if fallback == "" {
+			fallback = candidate
+		}
+	}
+
+	if fallback != "" {
+		return ResolvedSessionArtifact{
+			ID:            source,
+			Path:          fallback,
+			ProducerStage: "prepare",
+			OutputKind:    "previous_session_artifact",
+			Provenance:    ArtifactProvenancePreviousCacheFilesystem,
+		}, nil
+	}
+
+	return ResolvedSessionArtifact{}, &SessionArtifactNotFoundError{ArtifactID: source}
+}
+
 func manifestArtifactCandidates(paths SessionPaths, m *manifest.Manifest, spec artifactSpec) []ResolvedSessionArtifact {
 	if m == nil || len(m.Stages) == 0 || spec.ProducerStage == "" || spec.OutputKind == "" {
 		return nil
@@ -243,6 +331,50 @@ func dedupeResolvedArtifacts(values []ResolvedSessionArtifact) []ResolvedSession
 	return out
 }
 
+func previousSessionCacheCandidatePaths(paths SessionPaths, canonicalRelPath string) []string {
+	trimmed := strings.TrimSpace(canonicalRelPath)
+	if trimmed == "" {
+		return nil
+	}
+	normalized := filepath.ToSlash(filepath.Clean(filepath.FromSlash(trimmed)))
+	if normalized == "." || normalized == "" || normalized == ".." || strings.HasPrefix(normalized, "../") || strings.HasPrefix(normalized, "/") {
+		return nil
+	}
+
+	relCandidates := []string{normalized}
+	const artifactsPrefix = "artifacts/"
+	if strings.HasPrefix(normalized, artifactsPrefix) && len(normalized) > len(artifactsPrefix) {
+		relCandidates = append(relCandidates, strings.TrimPrefix(normalized, artifactsPrefix))
+	}
+
+	out := make([]string, 0, len(relCandidates))
+	seen := map[string]struct{}{}
+	for _, rel := range relCandidates {
+		abs := filepath.Clean(SessionPreviousArtifactPath(paths, rel))
+		if _, ok := seen[abs]; ok {
+			continue
+		}
+		seen[abs] = struct{}{}
+		out = append(out, abs)
+	}
+	return out
+}
+
+func manifestInputPathSet(paths SessionPaths, m *manifest.Manifest) map[string]struct{} {
+	if m == nil || len(m.Inputs) == 0 {
+		return nil
+	}
+	out := make(map[string]struct{}, len(m.Inputs))
+	for _, in := range m.Inputs {
+		resolved := filepath.Clean(ResolveSessionLocalPathForRead(paths, in.Path))
+		if strings.TrimSpace(resolved) == "" {
+			continue
+		}
+		out[resolved] = struct{}{}
+	}
+	return out
+}
+
 func pathExists(path string) (exists bool, isDir bool, err error) {
 	info, err := os.Stat(path)
 	if err == nil {

internal/artifacts/artifact_resolver_test.go

@@ -45,6 +45,58 @@ func TestNormalizeSessionArtifactSource(t *testing.T) {
 	}
 }
 
+func TestPreviousSessionArtifactSourceHelpers(t *testing.T) {
+	tests := []struct {
+		name      string
+		source    string
+		wantName  string
+		wantMatch bool
+	}{
+		{
+			name:      "valid",
+			source:    "narratio.previous_session.artifact.session_recap",
+			wantName:  "session_recap",
+			wantMatch: true,
+		},
+		{
+			name:      "valid with surrounding whitespace",
+			source:    "  narratio.previous_session.artifact.quest_log  ",
+			wantName:  "quest_log",
+			wantMatch: true,
+		},
+		{
+			name:      "missing name",
+			source:    "narratio.previous_session.artifact.",
+			wantMatch: false,
+		},
+		{
+			name:      "invalid key characters",
+			source:    "narratio.previous_session.artifact.session-recap",
+			wantMatch: false,
+		},
+		{
+			name:      "wrong prefix",
+			source:    "narratio.previous.artifact.session_recap",
+			wantMatch: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			name, ok := PreviousSessionArtifactName(tt.source)
+			if ok != tt.wantMatch {
+				t.Fatalf("PreviousSessionArtifactName(%q) ok = %t, want %t", tt.source, ok, tt.wantMatch)
+			}
+			if name != tt.wantName {
+				t.Fatalf("PreviousSessionArtifactName(%q) name = %q, want %q", tt.source, name, tt.wantName)
+			}
+			if got := IsPreviousSessionArtifactSource(tt.source); got != tt.wantMatch {
+				t.Fatalf("IsPreviousSessionArtifactSource(%q) = %t, want %t", tt.source, got, tt.wantMatch)
+			}
+		})
+	}
+}
+
 func TestResolveSessionArtifactPrefersManifestOutput(t *testing.T) {
 	workspace := t.TempDir()
 	paths := buildSessionPaths(workspace, "campaign", "session")
@@ -266,3 +318,120 @@ func TestResolveSessionArtifactWithCatalogUnsupportedConfiguredSourceFails(t *te
 		t.Fatalf("error = %q, want unsupported artifact source", err.Error())
 	}
 }
+
+func TestResolvePreviousSessionArtifactWithCatalogPrefersManifestInputRecord(t *testing.T) {
+	workspace := t.TempDir()
+	paths := buildSessionPaths(workspace, "campaign", "session")
+
+	manifestBackedPath := SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	fallbackPath := SessionPreviousArtifactPath(paths, "session_recap.md")
+	if err := os.MkdirAll(filepath.Dir(manifestBackedPath), 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.MkdirAll(filepath.Dir(fallbackPath), 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.WriteFile(manifestBackedPath, []byte("recap from manifest input\n"), 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+	if err := os.WriteFile(fallbackPath, []byte("recap fallback\n"), 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	catalog := NewArtifactCatalog()
+	if err := catalog.RegisterConfiguredArtifacts(
+		map[string]ConfiguredArtifactDefinition{
+			"session_recap": {Enabled: true, OutputPath: "artifacts/session_recap.md"},
+		},
+		nil,
+	); err != nil {
+		t.Fatalf("RegisterConfiguredArtifacts() error = %v", err)
+	}
+
+	m := manifest.New("session", time.Now().UTC())
+	m.Inputs = []manifest.InputRecord{
+		{Kind: "previous_artifact", Path: manifestBackedPath},
+	}
+
+	resolved, err := ResolvePreviousSessionArtifactWithCatalog(
+		paths,
+		m,
+		"narratio.previous_session.artifact.session_recap",
+		catalog,
+	)
+	if err != nil {
+		t.Fatalf("ResolvePreviousSessionArtifactWithCatalog() error = %v", err)
+	}
+	if resolved.Path != manifestBackedPath {
+		t.Fatalf("resolved path = %q, want %q", resolved.Path, manifestBackedPath)
+	}
+	if resolved.Provenance != ArtifactProvenancePreviousCacheManifestInput {
+		t.Fatalf("provenance = %q, want %q", resolved.Provenance, ArtifactProvenancePreviousCacheManifestInput)
+	}
+}
+
+func TestResolvePreviousSessionArtifactWithCatalogFallsBackToPreparedCachePath(t *testing.T) {
+	workspace := t.TempDir()
+	paths := buildSessionPaths(workspace, "campaign", "session")
+
+	fallbackPath := SessionPreviousArtifactPath(paths, "session_recap.md")
+	if err := os.MkdirAll(filepath.Dir(fallbackPath), 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.WriteFile(fallbackPath, []byte("recap fallback\n"), 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	catalog := NewArtifactCatalog()
+	if err := catalog.RegisterConfiguredArtifacts(
+		map[string]ConfiguredArtifactDefinition{
+			"session_recap": {Enabled: true, OutputPath: "artifacts/session_recap.md"},
+		},
+		nil,
+	); err != nil {
+		t.Fatalf("RegisterConfiguredArtifacts() error = %v", err)
+	}
+
+	resolved, err := ResolvePreviousSessionArtifactWithCatalog(
+		paths,
+		nil,
+		"narratio.previous_session.artifact.session_recap",
+		catalog,
+	)
+	if err != nil {
+		t.Fatalf("ResolvePreviousSessionArtifactWithCatalog() error = %v", err)
+	}
+	if resolved.Path != fallbackPath {
+		t.Fatalf("resolved path = %q, want %q", resolved.Path, fallbackPath)
+	}
+	if resolved.Provenance != ArtifactProvenancePreviousCacheFilesystem {
+		t.Fatalf("provenance = %q, want %q", resolved.Provenance, ArtifactProvenancePreviousCacheFilesystem)
+	}
+}
+
+func TestResolvePreviousSessionArtifactWithCatalogMissingReturnsTypedError(t *testing.T) {
+	workspace := t.TempDir()
+	paths := buildSessionPaths(workspace, "campaign", "session")
+	catalog := NewArtifactCatalog()
+	if err := catalog.RegisterConfiguredArtifacts(
+		map[string]ConfiguredArtifactDefinition{
+			"session_recap": {Enabled: true, OutputPath: "artifacts/session_recap.md"},
+		},
+		nil,
+	); err != nil {
+		t.Fatalf("RegisterConfiguredArtifacts() error = %v", err)
+	}
+
+	_, err := ResolvePreviousSessionArtifactWithCatalog(
+		paths,
+		nil,
+		"narratio.previous_session.artifact.session_recap",
+		catalog,
+	)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !errors.Is(err, ErrSessionArtifactNotFound) {
+		t.Fatalf("errors.Is(err, ErrSessionArtifactNotFound)=false; err=%v", err)
+	}
+}

internal/artifacts/local.go

@@ -73,6 +73,8 @@ func (s *LocalStore) ensureLayout(paths SessionPaths) (SessionPaths, error) {
 		paths.LogsDir,
 		paths.CurrentDir,
 		paths.RunsDir,
+		paths.PreviousDir,
+		paths.PreviousArtifactsDir,
 	}
 
 	for _, dir := range dirs {

internal/artifacts/local_test.go

@@ -27,10 +27,15 @@ func TestEnsureLayoutCreatesExpectedDirectories(t *testing.T) {
 	checkDirExists(t, paths.LogsDir)
 	checkDirExists(t, paths.CurrentDir)
 	checkDirExists(t, paths.RunsDir)
+	checkDirExists(t, paths.PreviousDir)
+	checkDirExists(t, paths.PreviousArtifactsDir)
 
 	if filepath.Base(paths.ManifestPath) != "manifest.json" {
 		t.Fatalf("ManifestPath = %q, want basename manifest.json", paths.ManifestPath)
 	}
+	if filepath.Base(paths.PreviousManifestPath) != "manifest.json" {
+		t.Fatalf("PreviousManifestPath = %q, want basename manifest.json", paths.PreviousManifestPath)
+	}
 	if filepath.Base(paths.LockPath) != ".lock" {
 		t.Fatalf("LockPath = %q, want basename .lock", paths.LockPath)
 	}

internal/artifacts/paths.go

@@ -23,6 +23,9 @@ type SessionPaths struct {
 	LogsDir               string
 	CurrentDir            string
 	RunsDir               string
+	PreviousDir           string
+	PreviousManifestPath  string
+	PreviousArtifactsDir  string
 	ManifestPath          string
 	LockPath              string
 }
@@ -42,6 +45,29 @@ func SessionRunsDirForCampaign(rootDir, campaign, sessionID string) string {
 	return filepath.Join(SessionWorkDirForCampaign(rootDir, campaign, sessionID), config.PathRunsDirSegment)
 }
 
+// SessionPreviousDirForCampaign returns the canonical previous-session state directory.
+func SessionPreviousDirForCampaign(rootDir, campaign, sessionID string) string {
+	return filepath.Join(SessionWorkDirForCampaign(rootDir, campaign, sessionID), config.PathPreviousDirSegment)
+}
+
+// SessionPreviousManifestPathForCampaign returns the canonical previous-session manifest cache path.
+func SessionPreviousManifestPathForCampaign(rootDir, campaign, sessionID string) string {
+	return filepath.Join(SessionPreviousDirForCampaign(rootDir, campaign, sessionID), config.PathManifestFile)
+}
+
+// SessionPreviousArtifactsDirForCampaign returns the canonical previous-session artifact cache directory.
+func SessionPreviousArtifactsDirForCampaign(rootDir, campaign, sessionID string) string {
+	return filepath.Join(SessionPreviousDirForCampaign(rootDir, campaign, sessionID), config.PathArtifactsDirSegment)
+}
+
+// SessionPreviousArtifactPathForCampaign returns a path under previous/artifacts for one artifact.
+func SessionPreviousArtifactPathForCampaign(rootDir, campaign, sessionID, artifactRelativePath string) string {
+	return filepath.Join(
+		SessionPreviousArtifactsDirForCampaign(rootDir, campaign, sessionID),
+		filepath.FromSlash(artifactRelativePath),
+	)
+}
+
 // SessionRunRootForCampaign returns the canonical run root under runs/{run_id}.
 func SessionRunRootForCampaign(rootDir, campaign, sessionID, runID string) string {
 	return filepath.Join(SessionRunsDirForCampaign(rootDir, campaign, sessionID), runID)
@@ -62,6 +88,26 @@ func SessionSpoolAudioDir(spoolRoot, campaign, sessionID, runID string) string {
 	return filepath.Join(spoolRoot, campaign, sessionID, runID, config.PathAudioDirSegment)
 }
 
+// SessionPreviousDir returns the previous-session state directory for already-resolved session paths.
+func SessionPreviousDir(paths SessionPaths) string {
+	return paths.PreviousDir
+}
+
+// SessionPreviousManifestPath returns the previous-session manifest path for already-resolved session paths.
+func SessionPreviousManifestPath(paths SessionPaths) string {
+	return paths.PreviousManifestPath
+}
+
+// SessionPreviousArtifactsDir returns the previous-session artifact directory for already-resolved session paths.
+func SessionPreviousArtifactsDir(paths SessionPaths) string {
+	return paths.PreviousArtifactsDir
+}
+
+// SessionPreviousArtifactPath returns a path under previous/artifacts for already-resolved session paths.
+func SessionPreviousArtifactPath(paths SessionPaths, artifactRelativePath string) string {
+	return filepath.Join(paths.PreviousArtifactsDir, filepath.FromSlash(artifactRelativePath))
+}
+
 func buildSessionPaths(workspaceRoot, campaign, sessionID string) SessionPaths {
 	root := SessionWorkDirForCampaign(workspaceRoot, campaign, sessionID)
 	return buildSessionPathsFromRoot(workspaceRoot, campaign, sessionID, root)
@@ -84,6 +130,9 @@ func buildSessionPathsFromRoot(workspaceRoot, campaign, sessionID, root string)
 		LogsDir:               filepath.Join(root, config.PathLogsDirSegment),
 		CurrentDir:            filepath.Join(root, config.PathCurrentDirSegment),
 		RunsDir:               filepath.Join(root, config.PathRunsDirSegment),
+		PreviousDir:           filepath.Join(root, config.PathPreviousDirSegment),
+		PreviousManifestPath:  filepath.Join(root, config.PathPreviousDirSegment, config.PathManifestFile),
+		PreviousArtifactsDir:  filepath.Join(root, config.PathPreviousDirSegment, config.PathArtifactsDirSegment),
 		ManifestPath:          filepath.Join(root, config.PathManifestFile),
 		LockPath:              filepath.Join(root, config.PathLockFile),
 	}

internal/artifacts/paths_model_test.go

@@ -49,6 +49,52 @@ func TestSessionRunManifestPathForCampaign(t *testing.T) {
 	}
 }
 
+func TestSessionPreviousPathsForCampaign(t *testing.T) {
+	root := "/tmp/workspace"
+	previousDir := SessionPreviousDirForCampaign(root, "forsaken", "2026-04-19")
+	wantPreviousDir := filepath.Join(root, "work", "forsaken", "2026-04-19", "previous")
+	if previousDir != wantPreviousDir {
+		t.Fatalf("SessionPreviousDirForCampaign() = %q, want %q", previousDir, wantPreviousDir)
+	}
+
+	manifestPath := SessionPreviousManifestPathForCampaign(root, "forsaken", "2026-04-19")
+	wantManifestPath := filepath.Join(root, "work", "forsaken", "2026-04-19", "previous", "manifest.json")
+	if manifestPath != wantManifestPath {
+		t.Fatalf("SessionPreviousManifestPathForCampaign() = %q, want %q", manifestPath, wantManifestPath)
+	}
+
+	artifactsDir := SessionPreviousArtifactsDirForCampaign(root, "forsaken", "2026-04-19")
+	wantArtifactsDir := filepath.Join(root, "work", "forsaken", "2026-04-19", "previous", "artifacts")
+	if artifactsDir != wantArtifactsDir {
+		t.Fatalf("SessionPreviousArtifactsDirForCampaign() = %q, want %q", artifactsDir, wantArtifactsDir)
+	}
+
+	artifactPath := SessionPreviousArtifactPathForCampaign(root, "forsaken", "2026-04-19", "session_recap.md")
+	wantArtifactPath := filepath.Join(root, "work", "forsaken", "2026-04-19", "previous", "artifacts", "session_recap.md")
+	if artifactPath != wantArtifactPath {
+		t.Fatalf("SessionPreviousArtifactPathForCampaign() = %q, want %q", artifactPath, wantArtifactPath)
+	}
+}
+
+func TestSessionPreviousPathsFromSessionPaths(t *testing.T) {
+	paths := buildSessionPaths("/tmp/workspace", "forsaken", "2026-04-19")
+	if got := SessionPreviousDir(paths); got != paths.PreviousDir {
+		t.Fatalf("SessionPreviousDir() = %q, want %q", got, paths.PreviousDir)
+	}
+	if got := SessionPreviousManifestPath(paths); got != paths.PreviousManifestPath {
+		t.Fatalf("SessionPreviousManifestPath() = %q, want %q", got, paths.PreviousManifestPath)
+	}
+	if got := SessionPreviousArtifactsDir(paths); got != paths.PreviousArtifactsDir {
+		t.Fatalf("SessionPreviousArtifactsDir() = %q, want %q", got, paths.PreviousArtifactsDir)
+	}
+
+	got := SessionPreviousArtifactPath(paths, "quest_log.json")
+	want := filepath.Join(paths.PreviousArtifactsDir, "quest_log.json")
+	if got != want {
+		t.Fatalf("SessionPreviousArtifactPath() = %q, want %q", got, want)
+	}
+}
+
 func TestSessionSpoolAudioDir(t *testing.T) {
 	root := "/var/spool/narratio"
 	got := SessionSpoolAudioDir(root, "forsaken", "2026-04-19", "20260515T031522Z-a1b2c3d4")

internal/artifacts/previous_requirements.go

@@ -0,0 +1,112 @@
+package artifacts
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+// PreviousArtifactRequirement describes one previous-session artifact dependency.
+type PreviousArtifactRequirement struct {
+	Name     string
+	Required bool
+	Sources  []string
+}
+
+// CollectPreviousArtifactRequirements scans enabled Scriptorium artifacts and returns
+// deduplicated previous-session artifact requirements in deterministic order.
+func CollectPreviousArtifactRequirements(
+	artifactsCfg map[string]config.ScriptoriumArtifactConfig,
+) []PreviousArtifactRequirement {
+	if len(artifactsCfg) == 0 {
+		return nil
+	}
+
+	artifactNames := sortedScriptoriumArtifactNames(artifactsCfg)
+	byName := map[string]PreviousArtifactRequirement{}
+
+	for _, artifactName := range artifactNames {
+		artifactCfg := artifactsCfg[artifactName]
+		if !artifactCfg.Enabled {
+			continue
+		}
+
+		inputNames := sortedScriptoriumInputKeys(artifactCfg.Inputs)
+		for _, inputName := range inputNames {
+			inputCfg := artifactCfg.Inputs[inputName]
+			previousName, ok := PreviousSessionArtifactName(inputCfg.Source)
+			if !ok {
+				continue
+			}
+
+			location := fmt.Sprintf(
+				"pipeline.scriptorium.artifacts.%s.inputs.%s.source",
+				artifactName,
+				inputName,
+			)
+			requirement := byName[previousName]
+			requirement.Name = previousName
+			requirement.Required = requirement.Required || inputCfg.Required
+			requirement.Sources = append(requirement.Sources, location)
+			byName[previousName] = requirement
+		}
+	}
+
+	if len(byName) == 0 {
+		return nil
+	}
+
+	requirements := make([]PreviousArtifactRequirement, 0, len(byName))
+	for _, requirement := range byName {
+		requirement.Sources = dedupeAndSortStrings(requirement.Sources)
+		requirements = append(requirements, requirement)
+	}
+	sort.Slice(requirements, func(i, j int) bool {
+		return requirements[i].Name < requirements[j].Name
+	})
+	return requirements
+}
+
+func sortedScriptoriumArtifactNames(artifactsCfg map[string]config.ScriptoriumArtifactConfig) []string {
+	names := make([]string, 0, len(artifactsCfg))
+	for name := range artifactsCfg {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
+func sortedScriptoriumInputKeys(inputs map[string]config.ScriptoriumInputConfig) []string {
+	if len(inputs) == 0 {
+		return nil
+	}
+	names := make([]string, 0, len(inputs))
+	for name := range inputs {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
+func dedupeAndSortStrings(values []string) []string {
+	if len(values) == 0 {
+		return nil
+	}
+	seen := map[string]struct{}{}
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		trimmed := strings.TrimSpace(value)
+		if trimmed == "" {
+			continue
+		}
+		if _, ok := seen[trimmed]; ok {
+			continue
+		}
+		seen[trimmed] = struct{}{}
+		out = append(out, trimmed)
+	}
+	sort.Strings(out)
+	return out
+}

internal/artifacts/previous_requirements_test.go

@@ -0,0 +1,190 @@
+package artifacts
+
+import (
+	"reflect"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+func TestCollectPreviousArtifactRequirements(t *testing.T) {
+	tests := []struct {
+		name         string
+		artifactsCfg map[string]config.ScriptoriumArtifactConfig
+		want         []PreviousArtifactRequirement
+	}{
+		{
+			name:         "no artifacts",
+			artifactsCfg: nil,
+			want:         nil,
+		},
+		{
+			name: "no previous inputs",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"session_recap": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"transcript": {Source: "narratio.transcript.trimmed", Required: true},
+					},
+				},
+			},
+			want: nil,
+		},
+		{
+			name: "one optional previous input",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"session_recap": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"previous_recap": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "session_recap",
+					Required: false,
+					Sources:  []string{"pipeline.scriptorium.artifacts.session_recap.inputs.previous_recap.source"},
+				},
+			},
+		},
+		{
+			name: "one required previous input",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"quest_log": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"previous_quest_log": {Source: "narratio.previous_session.artifact.quest_log", Required: true},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "quest_log",
+					Required: true,
+					Sources:  []string{"pipeline.scriptorium.artifacts.quest_log.inputs.previous_quest_log.source"},
+				},
+			},
+		},
+		{
+			name: "duplicate references are deduped",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"a": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"x": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+				"b": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"y": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "session_recap",
+					Required: false,
+					Sources: []string{
+						"pipeline.scriptorium.artifacts.a.inputs.x.source",
+						"pipeline.scriptorium.artifacts.b.inputs.y.source",
+					},
+				},
+			},
+		},
+		{
+			name: "required plus optional reference becomes required",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"a": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"x": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+				"b": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"y": {Source: "narratio.previous_session.artifact.session_recap", Required: true},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "session_recap",
+					Required: true,
+					Sources: []string{
+						"pipeline.scriptorium.artifacts.a.inputs.x.source",
+						"pipeline.scriptorium.artifacts.b.inputs.y.source",
+					},
+				},
+			},
+		},
+		{
+			name: "disabled artifact references are ignored",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"disabled_artifact": {
+					Enabled: false,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"x": {Source: "narratio.previous_session.artifact.session_recap", Required: true},
+					},
+				},
+				"enabled_artifact": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"y": {Source: "narratio.previous_session.artifact.quest_log", Required: false},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "quest_log",
+					Required: false,
+					Sources:  []string{"pipeline.scriptorium.artifacts.enabled_artifact.inputs.y.source"},
+				},
+			},
+		},
+		{
+			name: "deterministic ordering",
+			artifactsCfg: map[string]config.ScriptoriumArtifactConfig{
+				"zz": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"b_input": {Source: "narratio.previous_session.artifact.quest_log", Required: false},
+						"a_input": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+				"aa": {
+					Enabled: true,
+					Inputs: map[string]config.ScriptoriumInputConfig{
+						"c_input": {Source: "narratio.previous_session.artifact.session_recap", Required: false},
+					},
+				},
+			},
+			want: []PreviousArtifactRequirement{
+				{
+					Name:     "quest_log",
+					Required: false,
+					Sources:  []string{"pipeline.scriptorium.artifacts.zz.inputs.b_input.source"},
+				},
+				{
+					Name:     "session_recap",
+					Required: false,
+					Sources: []string{
+						"pipeline.scriptorium.artifacts.aa.inputs.c_input.source",
+						"pipeline.scriptorium.artifacts.zz.inputs.a_input.source",
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := CollectPreviousArtifactRequirements(tt.artifactsCfg)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Fatalf("CollectPreviousArtifactRequirements() = %#v, want %#v", got, tt.want)
+			}
+		})
+	}
+}

internal/artifacts/s3_keys.go

@@ -34,6 +34,12 @@ func S3AudioPrefix(sessionPrefix, audioPrefix string) string {
 	return ensureS3TrailingSlash(key)
 }
 
+// S3SessionConfigKey returns the session config key.
+// Format: {session_prefix}/session.yml
+func S3SessionConfigKey(sessionPrefix string) string {
+	return path.Join(strings.TrimSuffix(cleanS3Key(sessionPrefix), "/"), "session.yml")
+}
+
 // S3CurrentManifestKey returns the current manifest pointer key.
 // Format: {session_prefix}/current/manifest.json
 func S3CurrentManifestKey(sessionPrefix string) string {

internal/artifacts/s3_keys_test.go

@@ -17,6 +17,11 @@ func TestS3KeyConstruction(t *testing.T) {
 		t.Fatalf("audioPrefix = %q", audioPrefix)
 	}
 
+	sessionConfigKey := S3SessionConfigKey(`dnd\campaigns\forsaken\sessions\2026-04-19\`)
+	if sessionConfigKey != "dnd/campaigns/forsaken/sessions/2026-04-19/session.yml" {
+		t.Fatalf("session config key = %q", sessionConfigKey)
+	}
+
 	runPrefix := S3RunPrefix(sessionPrefix, runID)
 	wantRunPrefix := "dnd/campaigns/forsaken/sessions/2026-04-19/runs/" + runID + "/"
 	if runPrefix != wantRunPrefix {

internal/config/campaign_config_test.go

@@ -0,0 +1,138 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestCampaignConfigDefaultSearchOrder(t *testing.T) {
+	want := []string{
+		"./campaign.yml",
+		"/usr/local/etc/narratio/campaign.yml",
+		"/etc/narratio/campaign.yml",
+	}
+	if len(DefaultCampaignConfigSearchPaths) != len(want) {
+		t.Fatalf("DefaultCampaignConfigSearchPaths = %#v, want %#v", DefaultCampaignConfigSearchPaths, want)
+	}
+	for i := range want {
+		if DefaultCampaignConfigSearchPaths[i] != want[i] {
+			t.Fatalf("DefaultCampaignConfigSearchPaths[%d] = %q, want %q", i, DefaultCampaignConfigSearchPaths[i], want[i])
+		}
+	}
+}
+
+func TestCampaignStrictDecodeRejectsUnknownFields(t *testing.T) {
+	pipelinePath, campaignPath, sessionPath := writeCampaignConfigTestFiles(t,
+		"campaign: sample-campaign\nunknown: true\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n",
+		"session_id: 2026-05-03\ninputs:\n  audio_dir: ./audio\n",
+	)
+
+	_, err := LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, SessionLoadOptions{})
+	if err == nil {
+		t.Fatal("expected load error, got nil")
+	}
+	if !strings.Contains(err.Error(), "campaign file") || !strings.Contains(err.Error(), "strict decode failed") {
+		t.Fatalf("error = %q, want campaign strict decode context", err.Error())
+	}
+}
+
+func TestCampaignSessionMergeFillsStableInputs(t *testing.T) {
+	pipelinePath, campaignPath, sessionPath := writeCampaignConfigTestFiles(t,
+		"campaign: sample-campaign\ninputs:\n  speakers_file: ./campaign-speakers.yml\n  autocorrect_file: ./campaign-autocorrect.yml\n  glossary_file: ./campaign-glossary.yml\n",
+		"session_id: 2026-05-03\ninputs:\n  audio_dir: ./audio\n",
+	)
+
+	cfg, err := LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, SessionLoadOptions{})
+	if err != nil {
+		t.Fatalf("LoadWithSessionOptions() error = %v", err)
+	}
+	if err := Validate(cfg); err != nil {
+		t.Fatalf("Validate() error = %v", err)
+	}
+	if cfg.Session.Campaign != "sample-campaign" {
+		t.Fatalf("session campaign = %q, want campaign config value", cfg.Session.Campaign)
+	}
+	assertResolvedStableInput(t, cfg.StableInputs.SpeakersFile, "./campaign-speakers.yml", campaignPath, "campaign_config")
+	assertResolvedStableInput(t, cfg.StableInputs.AutocorrectFile, "./campaign-autocorrect.yml", campaignPath, "campaign_config")
+	assertResolvedStableInput(t, cfg.StableInputs.GlossaryFile, "./campaign-glossary.yml", campaignPath, "campaign_config")
+}
+
+func TestCampaignSessionMergeSessionOverridesStableInputs(t *testing.T) {
+	pipelinePath, campaignPath, sessionPath := writeCampaignConfigTestFiles(t,
+		"campaign: sample-campaign\ninputs:\n  speakers_file: ./campaign-speakers.yml\n  autocorrect_file: ./campaign-autocorrect.yml\n  glossary_file: ./campaign-glossary.yml\n",
+		"session_id: 2026-05-03\ncampaign: sample-campaign\ninputs:\n  audio_dir: ./audio\n  speakers_file: ./session-speakers.yml\n",
+	)
+
+	cfg, err := LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, SessionLoadOptions{})
+	if err != nil {
+		t.Fatalf("LoadWithSessionOptions() error = %v", err)
+	}
+	if err := Validate(cfg); err != nil {
+		t.Fatalf("Validate() error = %v", err)
+	}
+	assertResolvedStableInput(t, cfg.StableInputs.SpeakersFile, "./session-speakers.yml", sessionPath, "session_config")
+	assertResolvedStableInput(t, cfg.StableInputs.AutocorrectFile, "./campaign-autocorrect.yml", campaignPath, "campaign_config")
+	assertResolvedStableInput(t, cfg.StableInputs.GlossaryFile, "./campaign-glossary.yml", campaignPath, "campaign_config")
+}
+
+func TestCampaignSessionMismatchFails(t *testing.T) {
+	pipelinePath, campaignPath, sessionPath := writeCampaignConfigTestFiles(t,
+		"campaign: sample-campaign\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n",
+		"session_id: 2026-05-03\ncampaign: other-campaign\ninputs:\n  audio_dir: ./audio\n",
+	)
+
+	_, err := LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, SessionLoadOptions{})
+	if err == nil {
+		t.Fatal("expected load error, got nil")
+	}
+	if !strings.Contains(err.Error(), "does not match campaign config") {
+		t.Fatalf("error = %q, want campaign mismatch context", err.Error())
+	}
+}
+
+func TestLoadMissingCampaignFileFails(t *testing.T) {
+	pipelinePath, _, sessionPath := writeCampaignConfigTestFiles(t,
+		"campaign: sample-campaign\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n",
+		"session_id: 2026-05-03\ninputs:\n  audio_dir: ./audio\n",
+	)
+	missingCampaignPath := filepath.Join(filepath.Dir(sessionPath), "missing-campaign.yml")
+
+	_, err := LoadWithSessionOptions(pipelinePath, missingCampaignPath, sessionPath, SessionLoadOptions{})
+	if err == nil {
+		t.Fatal("expected load error, got nil")
+	}
+	if !strings.Contains(err.Error(), "load campaign config") {
+		t.Fatalf("error = %q, want campaign load context", err.Error())
+	}
+}
+
+func writeCampaignConfigTestFiles(t *testing.T, campaignYAML, sessionYAML string) (string, string, string) {
+	t.Helper()
+
+	dir := t.TempDir()
+	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	campaignPath := filepath.Join(dir, "campaign.yml")
+	sessionPath := filepath.Join(dir, "session.yml")
+
+	pipelineYAML := "workspace:\n  root: " + filepath.ToSlash(filepath.Join(dir, "work")) + "\nwhisperx:\n  transcribe_url: https://example.com/transcribe\nanalyzer:\n  timeout: 20m\nnotification:\n  timeout: 10s\n"
+	if err := os.WriteFile(pipelinePath, []byte(pipelineYAML), 0o644); err != nil {
+		t.Fatalf("write pipeline.yml: %v", err)
+	}
+	if err := os.WriteFile(campaignPath, []byte(campaignYAML), 0o644); err != nil {
+		t.Fatalf("write campaign.yml: %v", err)
+	}
+	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
+		t.Fatalf("write session.yml: %v", err)
+	}
+
+	return pipelinePath, campaignPath, sessionPath
+}
+
+func assertResolvedStableInput(t *testing.T, got ResolvedInputFile, wantPath, wantConfigPath, wantSource string) {
+	t.Helper()
+	if got.Path != wantPath || got.ConfigPath != wantConfigPath || got.Source != wantSource {
+		t.Fatalf("resolved input = %#v, want path=%q config_path=%q source=%q", got, wantPath, wantConfigPath, wantSource)
+	}
+}

internal/config/config.go

@@ -1,11 +1,17 @@
 package config
 
-// Config is the resolved combined configuration from pipeline.yml and session.yml.
+// Config is the resolved combined configuration from pipeline.yml,
+// campaign.yml, and session.yml.
 type Config struct {
 	Pipeline     *PipelineConfig
+	Campaign     *CampaignConfig
 	Session      *SessionConfig
 	PipelinePath string
+	CampaignPath string
 	SessionPath  string
+
+	StableInputs  ResolvedStableInputs
+	SessionSource SessionSource
 }
 
 // PipelineConfig contains durable pipeline-level settings.
@@ -25,13 +31,27 @@ type PipelineConfig struct {
 	Notification NotificationConfig `yaml:"notification"`
 }
 
+// CampaignConfig contains stable campaign-level identity and input defaults.
+type CampaignConfig struct {
+	Campaign string               `yaml:"campaign"`
+	Inputs   CampaignInputsConfig `yaml:"inputs"`
+}
+
+// CampaignInputsConfig contains stable campaign-level input file references.
+type CampaignInputsConfig struct {
+	SpeakersFile    string `yaml:"speakers_file"`
+	AutocorrectFile string `yaml:"autocorrect_file"`
+	GlossaryFile    string `yaml:"glossary_file"`
+}
+
 // SessionConfig contains per-session inputs and metadata.
 type SessionConfig struct {
-	SessionID string              `yaml:"session_id"`
-	Campaign  string              `yaml:"campaign"`
-	Date      string              `yaml:"date"`
-	Title     string              `yaml:"title"`
-	Inputs    SessionInputsConfig `yaml:"inputs"`
+	SessionID         string              `yaml:"session_id"`
+	PreviousSessionID string              `yaml:"previous_session_id"`
+	Campaign          string              `yaml:"campaign"`
+	Date              string              `yaml:"date"`
+	Title             string              `yaml:"title"`
+	Inputs            SessionInputsConfig `yaml:"inputs"`
 }
 
 // WorkspaceConfig configures local workspace behavior.
@@ -75,6 +95,7 @@ type ArchiveConfig struct {
 	Enabled          *bool                  `yaml:"enabled"`
 	UploadRun        *bool                  `yaml:"upload_run"`
 	PromoteArtifacts []ArchivePromotionRule `yaml:"promote_artifacts"`
+	Locks            []ArchiveLockRule      `yaml:"locks"`
 }
 
 // ArchivePromotionRule configures one artifact promotion mapping.
@@ -84,6 +105,13 @@ type ArchivePromotionRule struct {
 	Required *bool  `yaml:"required"`
 }
 
+// ArchiveLockRule prevents one source-based promotion from overwriting its
+// top-level archive destination.
+type ArchiveLockRule struct {
+	Source string `yaml:"source"`
+	Reason string `yaml:"reason"`
+}
+
 // WhisperXConfig configures WhisperX adapter settings.
 type WhisperXConfig struct {
 	TranscribeURL string `yaml:"transcribe_url"`
@@ -228,3 +256,29 @@ type SessionInputsConfig struct {
 type SessionAudioS3Input struct {
 	Prefix string `yaml:"prefix"`
 }
+
+// ResolvedStableInputs records where stable input file paths came from after
+// campaign/session merge.
+type ResolvedStableInputs struct {
+	SpeakersFile    ResolvedInputFile
+	AutocorrectFile ResolvedInputFile
+	GlossaryFile    ResolvedInputFile
+}
+
+// ResolvedInputFile records one merged config path and its source config file.
+type ResolvedInputFile struct {
+	Path       string
+	ConfigPath string
+	Source     string
+}
+
+// SessionSource records where session.yml came from before materialization.
+type SessionSource struct {
+	Source    string
+	LocalPath string
+	S3Bucket  string
+	S3Key     string
+	S3Size    int64
+	S3ETag    string
+	SpoolPath string
+}

internal/config/defaults.go

@@ -5,6 +5,9 @@ package config
 const (
 	DefaultPipelineConfigPathUsrLocal = "/usr/local/etc/narratio/pipeline.yml"
 	DefaultPipelineConfigPathEtc      = "/etc/narratio/pipeline.yml"
+	DefaultCampaignConfigPathLocal    = "./campaign.yml"
+	DefaultCampaignConfigPathUsrLocal = "/usr/local/etc/narratio/campaign.yml"
+	DefaultCampaignConfigPathEtc      = "/etc/narratio/campaign.yml"
 	DefaultSessionConfigPathLocal     = "./session.yml"
 	DefaultSessionConfigPathUsrLocal  = "/usr/local/etc/narratio/session.yml"
 	DefaultSessionConfigPathEtc       = "/etc/narratio/session.yml"
@@ -56,6 +59,7 @@ const (
 	PathLogsDirSegment       = "logs"
 	PathCurrentDirSegment    = "current"
 	PathRunsDirSegment       = "runs"
+	PathPreviousDirSegment   = "previous"
 	PathManifestFile         = "manifest.json"
 	PathLockFile             = ".lock"
 	PathTranscriptMerged     = "transcripts/merged.json"
@@ -87,6 +91,17 @@ var DefaultPipelineConfigSearchPaths = []string{
 	DefaultPipelineConfigPathEtc,
 }
 
+// DefaultCampaignConfigSearchPaths defines the default search order for
+// campaign.yml when callers do not provide an explicit path.
+//
+// Keep this in a variable so future defaults can be extended without changing
+// call sites.
+var DefaultCampaignConfigSearchPaths = []string{
+	DefaultCampaignConfigPathLocal,
+	DefaultCampaignConfigPathUsrLocal,
+	DefaultCampaignConfigPathEtc,
+}
+
 // DefaultSessionConfigSearchPaths defines the default search order for
 // session.yml when callers do not provide an explicit path.
 //

internal/config/load.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"sort"
 	"strings"
 
 	"gopkg.in/yaml.v3"
@@ -21,6 +22,15 @@ func LoadPipeline(path string) (*PipelineConfig, error) {
 	return &cfg, nil
 }
 
+// LoadCampaign loads campaign configuration from a YAML file with strict field checking.
+func LoadCampaign(path string) (*CampaignConfig, error) {
+	var cfg CampaignConfig
+	if err := decodeStrictYAML("campaign", path, &cfg); err != nil {
+		return nil, fmt.Errorf("load campaign config: %w", err)
+	}
+	return &cfg, nil
+}
+
 // LoadSession loads session configuration from a YAML file with strict field checking.
 func LoadSession(path string) (*SessionConfig, error) {
 	return LoadSessionWithOptions(path, SessionLoadOptions{})
@@ -28,7 +38,8 @@ func LoadSession(path string) (*SessionConfig, error) {
 
 // SessionLoadOptions configures session template rendering behavior.
 type SessionLoadOptions struct {
-	SessionID string
+	SessionID         string
+	PreviousSessionID string
 }
 
 // LoadSessionWithOptions loads session configuration from a YAML file with
@@ -38,53 +49,180 @@ func LoadSessionWithOptions(path string, opts SessionLoadOptions) (*SessionConfi
 	if err != nil {
 		return nil, fmt.Errorf("load session config: session file %q: open: %w", path, err)
 	}
+	return LoadSessionBytesWithOptions(path, sessionBytes, opts)
+}
 
-	rendered, err := renderSessionTemplate(string(sessionBytes), opts)
+// LoadSessionBytesWithOptions loads session configuration from YAML bytes with
+// strict field checking after template rendering.
+func LoadSessionBytesWithOptions(label string, data []byte, opts SessionLoadOptions) (*SessionConfig, error) {
+	rendered, err := renderSessionTemplate(string(data), opts)
 	if err != nil {
 		return nil, fmt.Errorf("load session config: %w", err)
 	}
 
 	var cfg SessionConfig
-	if err := decodeStrictYAMLFromReader("session", path, strings.NewReader(rendered), &cfg); err != nil {
+	if err := decodeStrictYAMLFromReader("session", label, strings.NewReader(rendered), &cfg); err != nil {
 		return nil, fmt.Errorf("load session config: %w", err)
 	}
 	if strings.TrimSpace(opts.SessionID) != "" && strings.TrimSpace(cfg.SessionID) != "" && strings.TrimSpace(cfg.SessionID) != strings.TrimSpace(opts.SessionID) {
 		return nil, fmt.Errorf(
 			"load session config: session file %q: session_id mismatch: --session-id %q does not match rendered session_id %q",
-			path,
+			label,
 			strings.TrimSpace(opts.SessionID),
 			strings.TrimSpace(cfg.SessionID),
 		)
 	}
+	if strings.TrimSpace(opts.PreviousSessionID) != "" &&
+		strings.TrimSpace(cfg.PreviousSessionID) != "" &&
+		strings.TrimSpace(cfg.PreviousSessionID) != strings.TrimSpace(opts.PreviousSessionID) {
+		return nil, fmt.Errorf(
+			"load session config: session file %q: previous_session_id mismatch: --previous-session-id %q does not match rendered previous_session_id %q",
+			label,
+			strings.TrimSpace(opts.PreviousSessionID),
+			strings.TrimSpace(cfg.PreviousSessionID),
+		)
+	}
 	return &cfg, nil
 }
 
-// Load loads and resolves combined pipeline and session configuration.
-func Load(pipelinePath, sessionPath string) (*Config, error) {
-	return LoadWithSessionOptions(pipelinePath, sessionPath, SessionLoadOptions{})
+// Load loads and resolves combined pipeline, campaign, and session configuration.
+// Passing only a session path is supported for package-internal compatibility;
+// in that form campaign.yml is expected next to the session file.
+func Load(pipelinePath string, paths ...string) (*Config, error) {
+	campaignPath, sessionPath, err := campaignSessionPaths(paths...)
+	if err != nil {
+		return nil, err
+	}
+	return LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, SessionLoadOptions{})
 }
 
-// LoadWithSessionOptions loads and resolves combined pipeline and session
-// configuration with session template options.
-func LoadWithSessionOptions(pipelinePath, sessionPath string, sessionOpts SessionLoadOptions) (*Config, error) {
+// LoadWithSessionOptions loads and resolves combined pipeline, campaign, and
+// session configuration with session template options.
+func LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath string, sessionOpts SessionLoadOptions) (*Config, error) {
 	pipelineCfg, err := LoadPipeline(pipelinePath)
 	if err != nil {
 		return nil, err
 	}
 
+	campaignCfg, err := LoadCampaign(campaignPath)
+	if err != nil {
+		return nil, err
+	}
+
 	sessionCfg, err := LoadSessionWithOptions(sessionPath, sessionOpts)
 	if err != nil {
 		return nil, err
 	}
 
+	return Resolve(pipelinePath, pipelineCfg, campaignPath, campaignCfg, sessionPath, sessionCfg, SessionSource{
+		Source:    "session_config",
+		LocalPath: sessionPath,
+	})
+}
+
+// Resolve builds final stage-facing configuration from already loaded
+// pipeline, campaign, and session documents.
+func Resolve(pipelinePath string, pipelineCfg *PipelineConfig, campaignPath string, campaignCfg *CampaignConfig, sessionPath string, sessionCfg *SessionConfig, sessionSource SessionSource) (*Config, error) {
+	stableInputs, err := mergeCampaignSession(campaignCfg, sessionCfg, campaignPath, sessionPath)
+	if err != nil {
+		return nil, err
+	}
+	if strings.TrimSpace(sessionSource.Source) == "" {
+		sessionSource.Source = "session_config"
+	}
+	if strings.TrimSpace(sessionSource.LocalPath) == "" {
+		sessionSource.LocalPath = sessionPath
+	}
+
 	return &Config{
-		Pipeline:     pipelineCfg,
-		Session:      sessionCfg,
-		PipelinePath: pipelinePath,
-		SessionPath:  sessionPath,
+		Pipeline:      pipelineCfg,
+		Campaign:      campaignCfg,
+		Session:       sessionCfg,
+		PipelinePath:  pipelinePath,
+		CampaignPath:  campaignPath,
+		SessionPath:   sessionPath,
+		StableInputs:  stableInputs,
+		SessionSource: sessionSource,
 	}, nil
 }
 
+func campaignSessionPaths(paths ...string) (campaignPath, sessionPath string, err error) {
+	switch len(paths) {
+	case 1:
+		sessionPath = paths[0]
+		campaignPath = filepath.Join(filepath.Dir(sessionPath), "campaign.yml")
+	case 2:
+		campaignPath = paths[0]
+		sessionPath = paths[1]
+	default:
+		return "", "", fmt.Errorf("load config: expected session path or campaign and session paths")
+	}
+	return campaignPath, sessionPath, nil
+}
+
+func mergeCampaignSession(campaignCfg *CampaignConfig, sessionCfg *SessionConfig, campaignPath, sessionPath string) (ResolvedStableInputs, error) {
+	if campaignCfg == nil {
+		return ResolvedStableInputs{}, fmt.Errorf("campaign config is required")
+	}
+	if sessionCfg == nil {
+		return ResolvedStableInputs{}, fmt.Errorf("session config is required")
+	}
+
+	campaignName := strings.TrimSpace(campaignCfg.Campaign)
+	sessionCampaign := strings.TrimSpace(sessionCfg.Campaign)
+	if sessionCampaign != "" && campaignName != "" && sessionCampaign != campaignName {
+		return ResolvedStableInputs{}, fmt.Errorf(
+			"campaign/session config invalid: session campaign %q does not match campaign config %q",
+			sessionCampaign,
+			campaignName,
+		)
+	}
+	if sessionCampaign == "" {
+		sessionCfg.Campaign = campaignName
+	}
+
+	stable := ResolvedStableInputs{
+		SpeakersFile: selectStableInput(
+			campaignCfg.Inputs.SpeakersFile,
+			sessionCfg.Inputs.SpeakersFile,
+			campaignPath,
+			sessionPath,
+		),
+		AutocorrectFile: selectStableInput(
+			campaignCfg.Inputs.AutocorrectFile,
+			sessionCfg.Inputs.AutocorrectFile,
+			campaignPath,
+			sessionPath,
+		),
+		GlossaryFile: selectStableInput(
+			campaignCfg.Inputs.GlossaryFile,
+			sessionCfg.Inputs.GlossaryFile,
+			campaignPath,
+			sessionPath,
+		),
+	}
+
+	sessionCfg.Inputs.SpeakersFile = stable.SpeakersFile.Path
+	sessionCfg.Inputs.AutocorrectFile = stable.AutocorrectFile.Path
+	sessionCfg.Inputs.GlossaryFile = stable.GlossaryFile.Path
+	return stable, nil
+}
+
+func selectStableInput(campaignValue, sessionValue, campaignPath, sessionPath string) ResolvedInputFile {
+	if strings.TrimSpace(sessionValue) != "" {
+		return ResolvedInputFile{
+			Path:       sessionValue,
+			ConfigPath: sessionPath,
+			Source:     "session_config",
+		}
+	}
+	return ResolvedInputFile{
+		Path:       campaignValue,
+		ConfigPath: campaignPath,
+		Source:     "campaign_config",
+	}
+}
+
 func decodeStrictYAML(kind, path string, out any) error {
 	f, err := os.Open(path)
 	if err != nil {
@@ -114,24 +252,36 @@ var sessionTemplatePattern = regexp.MustCompile(`\{\{\s*([a-zA-Z_][a-zA-Z0-9_]*)
 
 func renderSessionTemplate(content string, opts SessionLoadOptions) (string, error) {
 	sessionID := strings.TrimSpace(opts.SessionID)
+	previousSessionID := strings.TrimSpace(opts.PreviousSessionID)
 	rendered := content
 	if sessionID != "" {
-		rendered = strings.ReplaceAll(rendered, "{{session_id}}", sessionID)
-		rendered = strings.ReplaceAll(rendered, "{{ session_id }}", sessionID)
+		rendered = replaceTemplateVariable(rendered, "session_id", sessionID)
+	}
+	if previousSessionID != "" {
+		rendered = replaceTemplateVariable(rendered, "previous_session_id", previousSessionID)
 	}
 
 	unresolved := sessionTemplatePattern.FindAllStringSubmatch(rendered, -1)
 	if len(unresolved) > 0 {
+		seenVars := map[string]struct{}{}
 		vars := make([]string, 0, len(unresolved))
 		for _, m := range unresolved {
 			if len(m) > 1 {
-				vars = append(vars, m[1])
+				name := m[1]
+				if _, ok := seenVars[name]; ok {
+					continue
+				}
+				seenVars[name] = struct{}{}
+				vars = append(vars, name)
 			}
 		}
+		sort.Strings(vars)
 		if len(vars) > 0 {
+			hints := unresolvedTemplateHints(vars)
 			return "", fmt.Errorf(
-				"session file template rendering failed: unresolved template variable(s): %s; pass --session-id when using {{ session_id }}",
+				"session file template rendering failed: unresolved template variable(s): %s%s",
 				strings.Join(vars, ", "),
+				hints,
 			)
 		}
 		return "", fmt.Errorf("session file template rendering failed: unresolved template placeholders remain")
@@ -140,6 +290,35 @@ func renderSessionTemplate(content string, opts SessionLoadOptions) (string, err
 	return rendered, nil
 }
 
+func replaceTemplateVariable(content, name, value string) string {
+	rendered := strings.ReplaceAll(content, "{{"+name+"}}", value)
+	rendered = strings.ReplaceAll(rendered, "{{ "+name+" }}", value)
+	return rendered
+}
+
+func unresolvedTemplateHints(vars []string) string {
+	seen := map[string]struct{}{}
+	flags := make([]string, 0, 2)
+	for _, name := range vars {
+		switch name {
+		case "session_id":
+			if _, ok := seen["--session-id"]; !ok {
+				seen["--session-id"] = struct{}{}
+				flags = append(flags, "--session-id")
+			}
+		case "previous_session_id":
+			if _, ok := seen["--previous-session-id"]; !ok {
+				seen["--previous-session-id"] = struct{}{}
+				flags = append(flags, "--previous-session-id")
+			}
+		}
+	}
+	if len(flags) == 0 {
+		return ""
+	}
+	return "; pass " + strings.Join(flags, " and ") + " when using those template variable(s)"
+}
+
 func shortName(path, fallback string) string {
 	base := filepath.Base(path)
 	if base == "." || base == string(filepath.Separator) {

internal/config/load_validate_test.go

@@ -187,6 +187,43 @@ inputs:
 `,
 			wantValidate: "session config \"session.yml\" invalid: session.session_id is required",
 		},
+		{
+			name: "valid previous_session_id passes",
+			pipelineYAML: `workspace:
+  root: /tmp/narratio
+whisperx:
+  transcribe_url: https://transcription.ai.rakestrawhome.com/transcribe
+seriatim:
+  binary: seriatim
+`,
+			sessionYAML: `session_id: 2026-05-03
+previous_session_id: 2026-04-26
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`,
+		},
+		{
+			name: "previous_session_id equal to session_id fails",
+			pipelineYAML: `workspace:
+  root: /tmp/narratio
+whisperx:
+  transcribe_url: https://transcription.ai.rakestrawhome.com/transcribe
+seriatim:
+  binary: seriatim
+`,
+			sessionYAML: `session_id: 2026-05-03
+previous_session_id: 2026-05-03
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`,
+			wantValidate: "session config \"session.yml\" invalid: session.previous_session_id must not equal session.session_id",
+		},
 		{
 			name: "missing transcribe_url fails",
 			pipelineYAML: `workspace:
@@ -867,6 +904,7 @@ func TestValidateMissingAudioSource(t *testing.T) {
 				Report:                   boolPtr(true),
 			},
 		},
+		Campaign: &CampaignConfig{Campaign: "sample-campaign"},
 		Session: &SessionConfig{
 			SessionID: "2026-05-03",
 			Campaign:  "sample-campaign",
@@ -926,6 +964,7 @@ func TestExamplesLoadAndValidate(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			pipelinePath := filepath.Join(examplesDir, tt.pipelineFile)
+			campaignPath := filepath.Join(examplesDir, "campaign.yml")
 			sessionPath := filepath.Join(examplesDir, tt.sessionFile)
 
 			var (
@@ -935,7 +974,7 @@ func TestExamplesLoadAndValidate(t *testing.T) {
 			if strings.TrimSpace(tt.sessionOpts.SessionID) == "" {
 				cfg, err = Load(pipelinePath, sessionPath)
 			} else {
-				cfg, err = LoadWithSessionOptions(pipelinePath, sessionPath, tt.sessionOpts)
+				cfg, err = LoadWithSessionOptions(pipelinePath, campaignPath, sessionPath, tt.sessionOpts)
 			}
 			if err != nil {
 				t.Fatalf("load example config error = %v", err)
@@ -964,14 +1003,34 @@ func writeConfigFiles(t *testing.T, pipelineYAML, sessionYAML string) (string, s
 
 	dir := t.TempDir()
 	pipelinePath := filepath.Join(dir, "pipeline.yml")
+	campaignPath := filepath.Join(dir, "campaign.yml")
 	sessionPath := filepath.Join(dir, "session.yml")
 
 	if err := os.WriteFile(pipelinePath, []byte(pipelineYAML), 0o644); err != nil {
 		t.Fatalf("write pipeline.yml: %v", err)
 	}
+	campaignYAML := `campaign: ` + campaignNameFromSessionYAML(sessionYAML) + `
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(campaignPath, []byte(campaignYAML), 0o644); err != nil {
+		t.Fatalf("write campaign.yml: %v", err)
+	}
 	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
 		t.Fatalf("write session.yml: %v", err)
 	}
 
 	return pipelinePath, sessionPath
 }
+
+func campaignNameFromSessionYAML(sessionYAML string) string {
+	for _, line := range strings.Split(sessionYAML, "\n") {
+		trimmed := strings.TrimSpace(line)
+		if strings.HasPrefix(trimmed, "campaign:") {
+			return strings.Trim(strings.TrimSpace(strings.TrimPrefix(trimmed, "campaign:")), `"'`)
+		}
+	}
+	return "sample-campaign"
+}

internal/config/scriptorium_test.go

@@ -116,6 +116,75 @@ func TestScriptoriumLoadAndValidate(t *testing.T) {
         output_kind: session_recap
 `,
 		},
+		{
+			name: "canonical previous-session source is accepted",
+			scriptoriumYAML: `scriptorium:
+  binary: scriptorium
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        transcript:
+          source: narratio.transcript.polished
+          required: true
+        previous_recap:
+          source: narratio.previous_session.artifact.session_recap
+          required: false
+      vars:
+        session_id: true
+        output_kind: session_recap
+`,
+		},
+		{
+			name: "canonical previous-session source missing artifact key fails validation",
+			scriptoriumYAML: `scriptorium:
+  binary: scriptorium
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        previous_recap:
+          source: narratio.previous_session.artifact.
+          required: false
+`,
+			wantValidateErr: `pipeline.scriptorium.artifacts.session_recap.inputs.previous_recap.source "narratio.previous_session.artifact." must reference configured artifact key matching ^[a-z][a-z0-9_]*$`,
+		},
+		{
+			name: "canonical previous-session source invalid artifact key fails validation",
+			scriptoriumYAML: `scriptorium:
+  binary: scriptorium
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        previous_recap:
+          source: narratio.previous_session.artifact.session-recap
+          required: false
+`,
+			wantValidateErr: `pipeline.scriptorium.artifacts.session_recap.inputs.previous_recap.source "narratio.previous_session.artifact.session-recap" must reference configured artifact key matching ^[a-z][a-z0-9_]*$`,
+		},
+		{
+			name: "canonical previous-session source unknown artifact fails validation",
+			scriptoriumYAML: `scriptorium:
+  binary: scriptorium
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        previous_recap:
+          source: narratio.previous_session.artifact.quest_log
+          required: false
+`,
+			wantValidateErr: `pipeline.scriptorium.artifacts.session_recap.inputs.previous_recap.source "narratio.previous_session.artifact.quest_log" references unknown artifact "quest_log"`,
+		},
 		{
 			name: "canonical artifact source is accepted",
 			scriptoriumYAML: `scriptorium:

internal/config/session_template_test.go

@@ -55,6 +55,34 @@ inputs:
 	}
 }
 
+func TestLoadSessionWithOptionsRendersPreviousSessionPlaceholder(t *testing.T) {
+	dir := t.TempDir()
+	sessionPath := filepath.Join(dir, "session.yml")
+	sessionYAML := `session_id: "{{ session_id }}"
+previous_session_id: "{{ previous_session_id }}"
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
+		t.Fatalf("write session.yml: %v", err)
+	}
+
+	cfg, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{
+		SessionID:         "2026-04-04",
+		PreviousSessionID: "2026-03-28",
+	})
+	if err != nil {
+		t.Fatalf("LoadSessionWithOptions() error = %v", err)
+	}
+	if cfg.PreviousSessionID != "2026-03-28" {
+		t.Fatalf("PreviousSessionID = %q, want 2026-03-28", cfg.PreviousSessionID)
+	}
+}
+
 func TestLoadSessionWithOptionsUnresolvedPlaceholderFails(t *testing.T) {
 	dir := t.TempDir()
 	sessionPath := filepath.Join(dir, "session.yml")
@@ -82,6 +110,37 @@ inputs:
 	}
 }
 
+func TestLoadSessionWithOptionsUnresolvedPreviousSessionPlaceholderFails(t *testing.T) {
+	dir := t.TempDir()
+	sessionPath := filepath.Join(dir, "session.yml")
+	sessionYAML := `session_id: 2026-05-03
+previous_session_id: "{{ previous_session_id }}"
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
+		t.Fatalf("write session.yml: %v", err)
+	}
+
+	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "unresolved template variable") {
+		t.Fatalf("error = %q, want unresolved-variable context", err.Error())
+	}
+	if !strings.Contains(err.Error(), "previous_session_id") {
+		t.Fatalf("error = %q, want previous_session_id variable", err.Error())
+	}
+	if !strings.Contains(err.Error(), "--previous-session-id") {
+		t.Fatalf("error = %q, want previous-session-id guidance", err.Error())
+	}
+}
+
 func TestLoadSessionWithOptionsMismatchFails(t *testing.T) {
 	dir := t.TempDir()
 	sessionPath := filepath.Join(dir, "session.yml")
@@ -106,6 +165,34 @@ inputs:
 	}
 }
 
+func TestLoadSessionWithOptionsPreviousSessionMismatchFails(t *testing.T) {
+	dir := t.TempDir()
+	sessionPath := filepath.Join(dir, "session.yml")
+	sessionYAML := `session_id: 2026-05-03
+previous_session_id: 2026-04-26
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`
+	if err := os.WriteFile(sessionPath, []byte(sessionYAML), 0o644); err != nil {
+		t.Fatalf("write session.yml: %v", err)
+	}
+
+	_, err := LoadSessionWithOptions(sessionPath, SessionLoadOptions{
+		SessionID:         "2026-05-03",
+		PreviousSessionID: "2026-04-25",
+	})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "previous_session_id mismatch") {
+		t.Fatalf("error = %q, want mismatch context", err.Error())
+	}
+}
+
 func TestLoadSessionWithOptionsUnknownFieldStillRejectedAfterRendering(t *testing.T) {
 	dir := t.TempDir()
 	sessionPath := filepath.Join(dir, "session.yml")
@@ -154,3 +241,38 @@ inputs:
 		t.Fatalf("SessionID = %q, want 2026-05-03", cfg.SessionID)
 	}
 }
+
+func TestLoadSessionBytesWithOptionsUsesSameTemplateAndStrictDecode(t *testing.T) {
+	sessionYAML := []byte(`session_id: "{{ session_id }}"
+campaign: sample-campaign
+inputs:
+  audio_s3:
+    prefix: audio/
+`)
+
+	cfg, err := LoadSessionBytesWithOptions("s3://bucket/session.yml", sessionYAML, SessionLoadOptions{SessionID: "2026-05-03"})
+	if err != nil {
+		t.Fatalf("LoadSessionBytesWithOptions() error = %v", err)
+	}
+	if cfg.SessionID != "2026-05-03" {
+		t.Fatalf("SessionID = %q, want 2026-05-03", cfg.SessionID)
+	}
+
+	_, err = LoadSessionBytesWithOptions("s3://bucket/session.yml", []byte("session_id: 2026-05-03\nunknown: true\n"), SessionLoadOptions{})
+	if err == nil {
+		t.Fatal("expected strict decode error, got nil")
+	}
+	if !strings.Contains(err.Error(), "strict decode failed") {
+		t.Fatalf("error = %q, want strict decode context", err.Error())
+	}
+}
+
+func TestLoadSessionBytesWithOptionsMismatchFails(t *testing.T) {
+	_, err := LoadSessionBytesWithOptions("s3://bucket/session.yml", []byte("session_id: 2026-05-03\n"), SessionLoadOptions{SessionID: "2026-04-04"})
+	if err == nil {
+		t.Fatal("expected mismatch error, got nil")
+	}
+	if !strings.Contains(err.Error(), "session_id mismatch") {
+		t.Fatalf("error = %q, want mismatch context", err.Error())
+	}
+}

internal/config/storage_archive_test.go

@@ -287,6 +287,100 @@ archive:
 	}
 }
 
+func TestArchiveLockValidation(t *testing.T) {
+	tests := []struct {
+		name        string
+		pipelineYML string
+		wantErr     string
+	}{
+		{
+			name: "valid built in source",
+			pipelineYML: testPipelineBaseYAML + `
+archive:
+  locks:
+    - source: narratio.transcript.trimmed
+      reason: reviewed transcript
+`,
+		},
+		{
+			name: "valid configured source",
+			pipelineYML: testPipelineBaseYAML + `
+scriptorium:
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+archive:
+  locks:
+    - source: narratio.artifact.session_recap
+`,
+		},
+		{
+			name: "missing source rejected",
+			pipelineYML: testPipelineBaseYAML + `
+archive:
+  locks:
+    - reason: no source
+`,
+			wantErr: "pipeline.archive.locks[0].source is required",
+		},
+		{
+			name: "invalid source rejected",
+			pipelineYML: testPipelineBaseYAML + `
+archive:
+  locks:
+    - source: narratio.unknown
+`,
+			wantErr: "pipeline.archive.locks[0].source \"narratio.unknown\" is unsupported",
+		},
+		{
+			name: "duplicate source rejected",
+			pipelineYML: testPipelineBaseYAML + `
+archive:
+  locks:
+    - source: narratio.transcript.trimmed
+    - source: " narratio.transcript.trimmed "
+`,
+			wantErr: "duplicates another archive lock source",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pipelinePath, sessionPath := writeConfigFiles(t, tt.pipelineYML, testSessionBaseYAML)
+			cfg, err := Load(pipelinePath, sessionPath)
+			if err != nil {
+				t.Fatalf("Load() error = %v", err)
+			}
+			err = Validate(cfg)
+			if tt.wantErr == "" {
+				if err != nil {
+					t.Fatalf("Validate() error = %v", err)
+				}
+				return
+			}
+			if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
+				t.Fatalf("Validate() error = %v, want to contain %q", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestArchiveLockUnknownFieldFailsStrictDecode(t *testing.T) {
+	pipelineYAML := testPipelineBaseYAML + `
+archive:
+  locks:
+    - source: narratio.transcript.trimmed
+      dest: transcripts/trimmed.json
+`
+	pipelinePath, sessionPath := writeConfigFiles(t, pipelineYAML, testSessionBaseYAML)
+	_, err := Load(pipelinePath, sessionPath)
+	if err == nil || !strings.Contains(err.Error(), "strict decode failed") {
+		t.Fatalf("Load() error = %v, want strict decode failed", err)
+	}
+}
+
 func TestArchiveLegacyFromToFailsStrictDecode(t *testing.T) {
 	pipelineYAML := testPipelineBaseYAML + `
 archive:

internal/config/validate.go

@@ -17,6 +17,9 @@ func Validate(cfg *Config) error {
 	if cfg.Pipeline == nil {
 		return fmt.Errorf("pipeline config is required")
 	}
+	if cfg.Campaign == nil {
+		return fmt.Errorf("campaign config is required")
+	}
 	if cfg.Session == nil {
 		return fmt.Errorf("session config is required")
 	}
@@ -24,6 +27,9 @@ func Validate(cfg *Config) error {
 	if err := validatePipeline(cfg.Pipeline); err != nil {
 		return fmt.Errorf("pipeline config %q invalid: %w", shortName(cfg.PipelinePath, "pipeline.yml"), err)
 	}
+	if err := validateCampaign(cfg.Campaign); err != nil {
+		return fmt.Errorf("campaign config %q invalid: %w", shortName(cfg.CampaignPath, "campaign.yml"), err)
+	}
 	if err := validateSession(cfg.Session); err != nil {
 		return fmt.Errorf("session config %q invalid: %w", shortName(cfg.SessionPath, "session.yml"), err)
 	}
@@ -34,6 +40,16 @@ func Validate(cfg *Config) error {
 	return nil
 }
 
+func validateCampaign(cfg *CampaignConfig) error {
+	if cfg == nil {
+		return fmt.Errorf("campaign config is required")
+	}
+	if strings.TrimSpace(cfg.Campaign) == "" {
+		return fmt.Errorf("campaign.campaign is required")
+	}
+	return nil
+}
+
 func validatePipeline(cfg *PipelineConfig) error {
 	if strings.TrimSpace(cfg.Workspace.Root) == "" {
 		return fmt.Errorf("pipeline.workspace.root is required")
@@ -136,6 +152,23 @@ func validateArchive(cfg *ArchiveConfig, scriptorium *ScriptoriumConfig) error {
 		}
 		seenDest[normalizedDest] = struct{}{}
 	}
+	seenLocks := map[string]struct{}{}
+	for i, item := range cfg.Locks {
+		prefix := fmt.Sprintf("pipeline.archive.locks[%d]", i)
+		source := strings.TrimSpace(item.Source)
+		if source == "" {
+			return fmt.Errorf("%s.source is required", prefix)
+		}
+		if _, err := archiveSourceKnown(source, scriptorium); err != nil {
+			return fmt.Errorf("%s.source %q is unsupported: %w", prefix, item.Source, err)
+		}
+		if _, ok := seenLocks[source]; ok {
+			return fmt.Errorf("%s.source %q duplicates another archive lock source", prefix, source)
+		}
+		seenLocks[source] = struct{}{}
+		cfg.Locks[i].Source = source
+		cfg.Locks[i].Reason = strings.TrimSpace(item.Reason)
+	}
 	return nil
 }
 
@@ -487,8 +520,14 @@ func validateScriptorium(cfg *ScriptoriumConfig) error {
 }
 
 func validateSession(cfg *SessionConfig) error {
-	if strings.TrimSpace(cfg.SessionID) == "" {
-		return fmt.Errorf("session.session_id is required")
+	if err := validateSessionIdentifier("session.session_id", cfg.SessionID, true); err != nil {
+		return err
+	}
+	if err := validateSessionIdentifier("session.previous_session_id", cfg.PreviousSessionID, false); err != nil {
+		return err
+	}
+	if strings.TrimSpace(cfg.PreviousSessionID) != "" && strings.TrimSpace(cfg.PreviousSessionID) == strings.TrimSpace(cfg.SessionID) {
+		return fmt.Errorf("session.previous_session_id must not equal session.session_id")
 	}
 	if strings.TrimSpace(cfg.Campaign) == "" {
 		return fmt.Errorf("session.campaign is required")
@@ -525,6 +564,16 @@ func validateSession(cfg *SessionConfig) error {
 	return nil
 }
 
+func validateSessionIdentifier(fieldName, value string, required bool) error {
+	if strings.TrimSpace(value) == "" {
+		if required {
+			return fmt.Errorf("%s is required", fieldName)
+		}
+		return nil
+	}
+	return nil
+}
+
 func validateCrossConfig(pipeline *PipelineConfig, session *SessionConfig) error {
 	if pipeline == nil || session == nil {
 		return nil
@@ -563,12 +612,38 @@ var windowsAbsPathRE = regexp.MustCompile(`^[A-Za-z]:[\\/].*`)
 var envVarNameRE = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)
 var scriptoriumArtifactKeyRE = regexp.MustCompile(`^[a-z][a-z0-9_]*$`)
 var narratioArtifactSourceRE = regexp.MustCompile(`^narratio\.artifact\.([a-z][a-z0-9_]*)$`)
+var narratioPreviousSessionArtifactSourceRE = regexp.MustCompile(`^narratio\.previous_session\.artifact\.([a-z][a-z0-9_]*)$`)
 
 func validateScriptoriumInputSource(artifactName, inputName, source string, configuredArtifacts map[string]struct{}) (string, error) {
-	if isStaticSupportedScriptoriumInputSource(source) {
+	trimmedSource := strings.TrimSpace(source)
+	if isStaticSupportedScriptoriumInputSource(trimmedSource) {
 		return "", nil
 	}
-	matches := narratioArtifactSourceRE.FindStringSubmatch(source)
+
+	if strings.HasPrefix(trimmedSource, "narratio.previous_session.artifact") {
+		matches := narratioPreviousSessionArtifactSourceRE.FindStringSubmatch(trimmedSource)
+		if len(matches) != 2 {
+			return "", fmt.Errorf(
+				"pipeline.scriptorium.artifacts.%s.inputs.%s.source %q must reference configured artifact key matching ^[a-z][a-z0-9_]*$",
+				artifactName,
+				inputName,
+				source,
+			)
+		}
+		referenced := matches[1]
+		if _, ok := configuredArtifacts[referenced]; !ok {
+			return "", fmt.Errorf(
+				"pipeline.scriptorium.artifacts.%s.inputs.%s.source %q references unknown artifact %q",
+				artifactName,
+				inputName,
+				source,
+				referenced,
+			)
+		}
+		return "", nil
+	}
+
+	matches := narratioArtifactSourceRE.FindStringSubmatch(trimmedSource)
 	if len(matches) != 2 {
 		return "", fmt.Errorf(
 			"pipeline.scriptorium.artifacts.%s.inputs.%s.source %q is unsupported",
@@ -591,7 +666,7 @@ func validateScriptoriumInputSource(artifactName, inputName, source string, conf
 }
 
 func isStaticSupportedScriptoriumInputSource(source string) bool {
-	switch strings.TrimSpace(source) {
+	switch source {
 	case "previous_session_artifact":
 		return true
 	case "narratio.transcript.merged":

internal/stage/analyze.go

@@ -631,6 +631,23 @@ func resolveScriptoriumInput(
 	runtimeCatalog *artifacts.ArtifactCatalog,
 ) (string, bool, *artifacts.ResolvedSessionArtifact, error) {
 	source := strings.TrimSpace(inputCfg.Source)
+	if artifacts.IsPreviousSessionArtifactSource(source) {
+		resolved, err := artifacts.ResolvePreviousSessionArtifactWithCatalog(paths, m, source, runtimeCatalog)
+		if err == nil {
+			copy := resolved
+			return resolved.Path, true, &copy, nil
+		}
+		if errors.Is(err, artifacts.ErrSessionArtifactNotFound) {
+			if inputCfg.Required {
+				return "", false, nil, fmt.Errorf(
+					"required previous-session input source %q is unavailable; run narratio run-stage --force prepare",
+					source,
+				)
+			}
+			return "", false, nil, nil
+		}
+		return "", false, nil, err
+	}
 	switch source {
 	case "previous_session_artifact":
 		if strings.TrimSpace(inputCfg.Path) == "" {

internal/stage/analyze_test.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"gitea.maximumdirect.net/eric/narratio/internal/adapters/scriptorium"
+	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
 	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
 	"gitea.maximumdirect.net/eric/narratio/internal/config"
 	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
@@ -717,6 +718,146 @@ func TestAnalyzeOmitsOptionalMissingConfiguredArtifactInput(t *testing.T) {
 	}
 }
 
+func TestAnalyzeRequiredPreviousSessionArtifactInputGuidesPrepareForce(t *testing.T) {
+	env, m, _ := setupAnalyzeEnv(t)
+
+	sessionRecap := env.Config.Pipeline.Scriptorium.Artifacts["session_recap"]
+	sessionRecap.Inputs["previous_recap"] = config.ScriptoriumInputConfig{
+		Source:   "narratio.previous_session.artifact.session_recap",
+		Required: true,
+	}
+	env.Config.Pipeline.Scriptorium.Artifacts["session_recap"] = sessionRecap
+
+	_, err := (analyzeStage{}).Run(context.Background(), env, m)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "run narratio run-stage --force prepare") {
+		t.Fatalf("error = %q, want guidance to run force prepare", err.Error())
+	}
+}
+
+func TestAnalyzeResolvesCanonicalPreviousSessionArtifactFromManifestInput(t *testing.T) {
+	env, m, fake := setupAnalyzeEnv(t)
+	paths := sessionPathsForEnv(env, m.SessionID)
+	writeAnalyzeFile(t, filepath.Join(paths.TranscriptsDir, "trimmed.json"), `{"segments":[]}`)
+
+	previousPath := artifacts.SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	writeAnalyzeFile(t, previousPath, "previous recap\n")
+	m.Inputs = append(m.Inputs, manifest.InputRecord{
+		Kind: "previous_artifact",
+		Path: previousPath,
+	})
+
+	sessionRecap := env.Config.Pipeline.Scriptorium.Artifacts["session_recap"]
+	sessionRecap.Inputs["previous_recap"] = config.ScriptoriumInputConfig{
+		Source:   "narratio.previous_session.artifact.session_recap",
+		Required: true,
+	}
+	env.Config.Pipeline.Scriptorium.Artifacts["session_recap"] = sessionRecap
+
+	_, err := (analyzeStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	if len(fake.RunRequests) != 1 {
+		t.Fatalf("run requests = %d, want 1", len(fake.RunRequests))
+	}
+	if got := fake.RunRequests[0].InputPaths["previous_recap"]; got != previousPath {
+		t.Fatalf("previous_recap input = %q, want %q", got, previousPath)
+	}
+}
+
+func TestAnalyzeOmitsOptionalMissingCanonicalPreviousSessionArtifact(t *testing.T) {
+	env, m, fake := setupAnalyzeEnv(t)
+	paths := sessionPathsForEnv(env, m.SessionID)
+	writeAnalyzeFile(t, filepath.Join(paths.TranscriptsDir, "trimmed.json"), `{"segments":[]}`)
+
+	sessionRecap := env.Config.Pipeline.Scriptorium.Artifacts["session_recap"]
+	sessionRecap.Inputs["previous_recap"] = config.ScriptoriumInputConfig{
+		Source:   "narratio.previous_session.artifact.session_recap",
+		Required: false,
+	}
+	env.Config.Pipeline.Scriptorium.Artifacts["session_recap"] = sessionRecap
+
+	_, err := (analyzeStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	if len(fake.RunRequests) != 1 {
+		t.Fatalf("run requests = %d, want 1", len(fake.RunRequests))
+	}
+	if _, exists := fake.RunRequests[0].InputPaths["previous_recap"]; exists {
+		t.Fatalf("optional canonical previous_recap should be omitted when unavailable")
+	}
+}
+
+func TestAnalyzeRenderDebugWithCanonicalPreviousSessionInput(t *testing.T) {
+	env, m, fake := setupAnalyzeEnv(t)
+	paths := sessionPathsForEnv(env, m.SessionID)
+	writeAnalyzeFile(t, filepath.Join(paths.TranscriptsDir, "trimmed.json"), `{"segments":[]}`)
+	env.Config.Pipeline.Scriptorium.RenderDebug = true
+
+	previousPath := artifacts.SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	writeAnalyzeFile(t, previousPath, "previous recap\n")
+	m.Inputs = append(m.Inputs, manifest.InputRecord{
+		Kind: "previous_artifact",
+		Path: previousPath,
+	})
+
+	sessionRecap := env.Config.Pipeline.Scriptorium.Artifacts["session_recap"]
+	sessionRecap.Inputs["previous_recap"] = config.ScriptoriumInputConfig{
+		Source:   "narratio.previous_session.artifact.session_recap",
+		Required: true,
+	}
+	env.Config.Pipeline.Scriptorium.Artifacts["session_recap"] = sessionRecap
+
+	_, err := (analyzeStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	if len(fake.RenderRequests) != 1 || len(fake.RunRequests) != 1 {
+		t.Fatalf("render/run requests = %d/%d, want 1/1", len(fake.RenderRequests), len(fake.RunRequests))
+	}
+	if got := fake.RenderRequests[0].InputPaths["previous_recap"]; got != previousPath {
+		t.Fatalf("render previous_recap input = %q, want %q", got, previousPath)
+	}
+	if got := fake.RunRequests[0].InputPaths["previous_recap"]; got != previousPath {
+		t.Fatalf("run previous_recap input = %q, want %q", got, previousPath)
+	}
+}
+
+func TestAnalyzeDoesNotCallObjectStoreForCanonicalPreviousSessionInput(t *testing.T) {
+	env, m, _ := setupAnalyzeEnv(t)
+	paths := sessionPathsForEnv(env, m.SessionID)
+	writeAnalyzeFile(t, filepath.Join(paths.TranscriptsDir, "trimmed.json"), `{"segments":[]}`)
+
+	previousPath := artifacts.SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	writeAnalyzeFile(t, previousPath, "previous recap\n")
+	m.Inputs = append(m.Inputs, manifest.InputRecord{
+		Kind: "previous_artifact",
+		Path: previousPath,
+	})
+
+	sessionRecap := env.Config.Pipeline.Scriptorium.Artifacts["session_recap"]
+	sessionRecap.Inputs["previous_recap"] = config.ScriptoriumInputConfig{
+		Source:   "narratio.previous_session.artifact.session_recap",
+		Required: true,
+	}
+	env.Config.Pipeline.Scriptorium.Artifacts["session_recap"] = sessionRecap
+
+	tracker := &analyzeObjectStoreTracker{}
+	env.ObjectStore = tracker
+
+	_, err := (analyzeStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	if tracker.called {
+		t.Fatal("analyze should not call object store for previous-session input resolution")
+	}
+}
+
 func TestAnalyzeFailsWhenOutputPathMissing(t *testing.T) {
 	env, m, fake := setupAnalyzeEnv(t)
 	paths := sessionPathsForEnv(env, m.SessionID)
@@ -1145,3 +1286,27 @@ func mustArtifactEntryList(t *testing.T, metadata map[string]any, key string) []
 	}
 	return out
 }
+
+type analyzeObjectStoreTracker struct {
+	called bool
+}
+
+func (s *analyzeObjectStoreTracker) List(context.Context, string) ([]storage.ObjectInfo, error) {
+	s.called = true
+	return nil, errors.New("unexpected object store list call")
+}
+
+func (s *analyzeObjectStoreTracker) Download(context.Context, string, string) error {
+	s.called = true
+	return errors.New("unexpected object store download call")
+}
+
+func (s *analyzeObjectStoreTracker) Upload(context.Context, string, string, storage.UploadOptions) (storage.ObjectInfo, error) {
+	s.called = true
+	return storage.ObjectInfo{}, errors.New("unexpected object store upload call")
+}
+
+func (s *analyzeObjectStoreTracker) Exists(context.Context, string) (bool, error) {
+	s.called = true
+	return false, errors.New("unexpected object store exists call")
+}

internal/stage/archive.go

@@ -118,11 +118,22 @@ func (archiveStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		return nil, fmt.Errorf("archive: collect run files: %w", err)
 	}
 	sessionPaths := archiveSessionPaths(env, m)
+	previousFiles, err := collectArchivePreviousFiles(sessionPaths.PreviousDir)
+	if err != nil {
+		return nil, fmt.Errorf("archive: collect previous files: %w", err)
+	}
 	runtimeCatalog, err := buildArchiveRuntimeArtifactCatalog(sessionPaths, env.Config.Pipeline.Scriptorium)
 	if err != nil {
 		return nil, fmt.Errorf("archive: build runtime artifact catalog: %w", err)
 	}
-	promotions, skippedOptional, err := resolveArchivePromotions(sessionPaths, m, runtimeCatalog, env.Config.Pipeline.Archive.PromoteArtifacts)
+	promotions, skippedOptional, lockedPromotions, err := resolveArchivePromotions(
+		sessionPaths,
+		m,
+		runtimeCatalog,
+		env.Config.Pipeline.Archive.PromoteArtifacts,
+		env.Config.Pipeline.Archive.Locks,
+		sessionPrefix,
+	)
 	if err != nil {
 		return nil, fmt.Errorf("archive: resolve promotion rules: %w", err)
 	}
@@ -144,6 +155,15 @@ func (archiveStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		promotedUploaded = append(promotedUploaded, promotion.Dest)
 	}
 
+	previousUploaded := make([]string, 0, len(previousFiles))
+	for _, file := range previousFiles {
+		key := artifacts.S3PromotedArtifactKey(sessionPrefix, file.RelativePath)
+		if _, err := env.ObjectStore.Upload(ctx, file.LocalPath, key, storage.UploadOptions{}); err != nil {
+			return nil, fmt.Errorf("archive: upload previous file %q to %q: %w", file.RelativePath, key, err)
+		}
+		previousUploaded = append(previousUploaded, file.RelativePath)
+	}
+
 	currentManifestKey, currentRunPointerKey := artifacts.ResolveArchiveCurrentStateKeys(sessionPrefix)
 	manifestTempPath, err := writeCurrentManifestSnapshot(m, archiveMetadataPreview(
 		bucket,
@@ -151,7 +171,9 @@ func (archiveStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		sessionPrefix,
 		runUploaded,
 		promotedUploaded,
+		previousUploaded,
 		skippedOptional,
+		lockedPromotions,
 		currentManifestKey,
 	))
 	if err != nil {
@@ -187,7 +209,11 @@ func (archiveStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 			"run_uploaded_paths":          runUploaded,
 			"promoted_files_uploaded":     len(promotedUploaded),
 			"promoted_paths":              promotedUploaded,
+			"previous_files_uploaded":     len(previousUploaded),
+			"previous_uploaded_paths":     previousUploaded,
 			"skipped_optional_promotions": skippedOptional,
+			"locked_promotion_count":      len(lockedPromotions),
+			"locked_promotions":           lockedPromotionMetadata(lockedPromotions),
 			"current_manifest_key":        currentManifestKey,
 			"current_run_id_key":          currentRunPointerKey,
 			"current_pointer_written":     true,
@@ -204,6 +230,16 @@ type archivePromotion struct {
 	Provenance string
 }
 
+type archiveLockedPromotion struct {
+	Source     string
+	Dest       string
+	RemoteKey  string
+	Reason     string
+	Required   bool
+	LocalPath  string
+	Provenance string
+}
+
 func archiveDisabled(env *Env) bool {
 	cfg := env.Config.Pipeline.Archive
 	if cfg == nil {
@@ -303,26 +339,53 @@ func resolveArchivePromotions(
 	m *manifest.Manifest,
 	catalog *artifacts.ArtifactCatalog,
 	rules []config.ArchivePromotionRule,
-) ([]archivePromotion, []string, error) {
+	locks []config.ArchiveLockRule,
+	sessionPrefix string,
+) ([]archivePromotion, []string, []archiveLockedPromotion, error) {
 	out := make([]archivePromotion, 0, len(rules))
 	skippedOptional := make([]string, 0)
+	lockedPromotions := make([]archiveLockedPromotion, 0)
+	lockSet := archiveLockSet(locks)
 	for _, rule := range rules {
 		source := strings.TrimSpace(rule.Source)
 		required := rule.Required == nil || *rule.Required
 		dest, err := resolveArchivePromotionDest(rule, catalog)
 		if err != nil {
-			return nil, nil, fmt.Errorf("source %q: %w", source, err)
+			return nil, nil, nil, fmt.Errorf("source %q: %w", source, err)
 		}
+		lock, locked := lockSet[source]
 		resolved, err := artifacts.ResolveSessionArtifactWithCatalog(paths, m, source, catalog)
 		if err != nil {
+			if locked {
+				lockedPromotions = append(lockedPromotions, archiveLockedPromotion{
+					Source:    source,
+					Dest:      dest,
+					RemoteKey: artifacts.S3PromotedArtifactKey(sessionPrefix, dest),
+					Reason:    strings.TrimSpace(lock.Reason),
+					Required:  required,
+				})
+				continue
+			}
 			if errors.Is(err, artifacts.ErrSessionArtifactNotFound) && !required {
 				skippedOptional = append(skippedOptional, dest)
 				continue
 			}
 			if errors.Is(err, artifacts.ErrSessionArtifactNotFound) {
-				return nil, nil, fmt.Errorf("required promotion source unavailable: %q", source)
+				return nil, nil, nil, fmt.Errorf("required promotion source unavailable: %q", source)
 			}
-			return nil, nil, fmt.Errorf("resolve source %q: %w", source, err)
+			return nil, nil, nil, fmt.Errorf("resolve source %q: %w", source, err)
+		}
+		if locked {
+			lockedPromotions = append(lockedPromotions, archiveLockedPromotion{
+				Source:     source,
+				Dest:       dest,
+				RemoteKey:  artifacts.S3PromotedArtifactKey(sessionPrefix, dest),
+				Reason:     strings.TrimSpace(lock.Reason),
+				Required:   required,
+				LocalPath:  resolved.Path,
+				Provenance: resolved.Provenance,
+			})
+			continue
 		}
 		out = append(out, archivePromotion{
 			Source:     source,
@@ -332,7 +395,21 @@ func resolveArchivePromotions(
 			Provenance: resolved.Provenance,
 		})
 	}
-	return out, skippedOptional, nil
+	return out, skippedOptional, lockedPromotions, nil
+}
+
+func archiveLockSet(locks []config.ArchiveLockRule) map[string]config.ArchiveLockRule {
+	out := make(map[string]config.ArchiveLockRule, len(locks))
+	for _, lock := range locks {
+		source := strings.TrimSpace(lock.Source)
+		if source == "" {
+			continue
+		}
+		lock.Source = source
+		lock.Reason = strings.TrimSpace(lock.Reason)
+		out[source] = lock
+	}
+	return out
 }
 
 func resolveArchivePromotionDest(rule config.ArchivePromotionRule, catalog *artifacts.ArtifactCatalog) (string, error) {
@@ -497,6 +574,51 @@ func collectArchiveRunFiles(runRoot, manifestPath string) ([]archiveUploadFile,
 	return files, nil
 }
 
+func collectArchivePreviousFiles(previousDir string) ([]archiveUploadFile, error) {
+	previousDir = filepath.Clean(strings.TrimSpace(previousDir))
+	if previousDir == "" {
+		return nil, fmt.Errorf("previous directory is required")
+	}
+	info, err := os.Stat(previousDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("stat %q: %w", previousDir, err)
+	}
+	if !info.IsDir() {
+		return nil, fmt.Errorf("previous path %q is not a directory", previousDir)
+	}
+
+	files := make([]archiveUploadFile, 0, 16)
+	err = filepath.WalkDir(previousDir, func(path string, d fs.DirEntry, walkErr error) error {
+		if walkErr != nil {
+			return walkErr
+		}
+		if d.IsDir() {
+			return nil
+		}
+		rel, err := filepath.Rel(previousDir, path)
+		if err != nil {
+			return fmt.Errorf("relative path from %q to %q: %w", previousDir, path, err)
+		}
+		rel = filepath.ToSlash(rel)
+		files = append(files, archiveUploadFile{
+			RelativePath: filepath.ToSlash(filepath.Join(config.PathPreviousDirSegment, rel)),
+			LocalPath:    path,
+		})
+		return nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("walk %q: %w", previousDir, err)
+	}
+
+	sort.Slice(files, func(i, j int) bool {
+		return files[i].RelativePath < files[j].RelativePath
+	})
+	return files, nil
+}
+
 func resolveArchiveRunManifestSource(runRoot string) (string, error) {
 	path := filepath.Join(filepath.Clean(runRoot), "manifest.json")
 	info, err := os.Stat(path)
@@ -600,7 +722,9 @@ func archiveMetadataPreview(
 	bucket, runPrefix, sessionPrefix string,
 	runUploaded []string,
 	promotedUploaded []string,
+	previousUploaded []string,
 	skippedOptional []string,
+	lockedPromotions []archiveLockedPromotion,
 	currentManifestKey string,
 ) map[string]any {
 	return map[string]any{
@@ -612,10 +736,30 @@ func archiveMetadataPreview(
 		"run_uploaded_paths":          append([]string(nil), runUploaded...),
 		"promoted_files_uploaded":     len(promotedUploaded),
 		"promoted_paths":              append([]string(nil), promotedUploaded...),
+		"previous_files_uploaded":     len(previousUploaded),
+		"previous_uploaded_paths":     append([]string(nil), previousUploaded...),
 		"skipped_optional_promotions": append([]string(nil), skippedOptional...),
+		"locked_promotion_count":      len(lockedPromotions),
+		"locked_promotions":           lockedPromotionMetadata(lockedPromotions),
 		"current_manifest_key":        currentManifestKey,
 		"current_run_id_key":          artifacts.S3CurrentRunPointerKey(sessionPrefix),
 		"current_pointer_written":     false,
 		"audio_upload_skipped":        true,
 	}
 }
+
+func lockedPromotionMetadata(locked []archiveLockedPromotion) []map[string]any {
+	out := make([]map[string]any, 0, len(locked))
+	for _, item := range locked {
+		out = append(out, map[string]any{
+			"source":     item.Source,
+			"dest":       item.Dest,
+			"remote_key": item.RemoteKey,
+			"reason":     item.Reason,
+			"required":   item.Required,
+			"local_path": item.LocalPath,
+			"provenance": item.Provenance,
+		})
+	}
+	return out
+}

internal/stage/archive_test.go

@@ -2,6 +2,7 @@ package stage
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"os"
 	"path/filepath"
@@ -130,6 +131,50 @@ func TestArchiveUploadsRunRecordPromotionsAndCurrentPointer(t *testing.T) {
 	if result.Metadata["promoted_files_uploaded"] != 2 {
 		t.Fatalf("metadata promoted_files_uploaded = %#v, want 2", result.Metadata["promoted_files_uploaded"])
 	}
+	if result.Metadata["previous_files_uploaded"] != 0 {
+		t.Fatalf("metadata previous_files_uploaded = %#v, want 0", result.Metadata["previous_files_uploaded"])
+	}
+}
+
+func TestArchiveUploadsPreviousCacheWhenPresent(t *testing.T) {
+	env, m, _ := archiveFixture(t)
+	fake := env.ObjectStore.(*storage.FakeBackend)
+	sessionRoot := artifacts.SessionWorkDirForCampaign(
+		env.Config.Pipeline.Workspace.Root,
+		env.Config.Session.Campaign,
+		env.Config.Session.SessionID,
+	)
+	writeStageTestFile(t, filepath.Join(sessionRoot, "previous", "manifest.json"), "{\"session_id\":\"2026-04-12\"}\n")
+	writeStageTestFile(t, filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md"), "# previous recap\n")
+
+	result, err := archiveStage{}.Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+
+	previousManifestKey := m.S3SessionPrefix + "previous/manifest.json"
+	previousRecapKey := m.S3SessionPrefix + "previous/artifacts/session_recap.md"
+	if _, ok := fake.Objects[previousManifestKey]; !ok {
+		t.Fatalf("missing archived previous manifest key %q", previousManifestKey)
+	}
+	if _, ok := fake.Objects[previousRecapKey]; !ok {
+		t.Fatalf("missing archived previous artifact key %q", previousRecapKey)
+	}
+	if result.Metadata["previous_files_uploaded"] != 2 {
+		t.Fatalf("metadata previous_files_uploaded = %#v, want 2", result.Metadata["previous_files_uploaded"])
+	}
+}
+
+func TestArchiveToleratesMissingPreviousCache(t *testing.T) {
+	env, m, _ := archiveFixture(t)
+
+	result, err := archiveStage{}.Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	if result.Metadata["previous_files_uploaded"] != 0 {
+		t.Fatalf("metadata previous_files_uploaded = %#v, want 0", result.Metadata["previous_files_uploaded"])
+	}
 }
 
 func TestArchiveUsesCustomPromotionRules(t *testing.T) {
@@ -171,6 +216,128 @@ func TestArchiveSkipsOptionalMissingPromotion(t *testing.T) {
 	}
 }
 
+func TestArchiveSkipsLockedRequiredPromotionAndCommits(t *testing.T) {
+	env, m, _ := archiveFixture(t)
+	env.Config.Pipeline.Archive.Locks = []config.ArchiveLockRule{
+		{Source: "narratio.transcript.trimmed", Reason: "human reviewed"},
+	}
+	fake := env.ObjectStore.(*storage.FakeBackend)
+
+	result, err := archiveStage{}.Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+
+	trimmedKey := m.S3SessionPrefix + "transcripts/trimmed.json"
+	if _, ok := fake.Objects[trimmedKey]; ok {
+		t.Fatalf("locked promotion key %q should not be uploaded", trimmedKey)
+	}
+	recapKey := m.S3SessionPrefix + "artifacts/session_recap.md"
+	if _, ok := fake.Objects[recapKey]; !ok {
+		t.Fatalf("unlocked promotion key %q should be uploaded", recapKey)
+	}
+	runTrimmedKey := m.S3RunPrefix + "trim/outputs/transcripts/trimmed.json"
+	if _, ok := fake.Objects[runTrimmedKey]; !ok {
+		t.Fatalf("run-local locked source output %q should still be uploaded", runTrimmedKey)
+	}
+
+	currentRunIDKey := m.S3SessionPrefix + "current/run_id.txt"
+	if len(fake.Uploads) == 0 || fake.Uploads[len(fake.Uploads)-1].Key != currentRunIDKey {
+		t.Fatalf("last upload = %#v, want current run pointer %q", fake.Uploads, currentRunIDKey)
+	}
+
+	if result.Metadata["promoted_files_uploaded"] != 1 {
+		t.Fatalf("metadata promoted_files_uploaded = %#v, want 1", result.Metadata["promoted_files_uploaded"])
+	}
+	if result.Metadata["locked_promotion_count"] != 1 {
+		t.Fatalf("metadata locked_promotion_count = %#v, want 1", result.Metadata["locked_promotion_count"])
+	}
+	locked := result.Metadata["locked_promotions"].([]map[string]any)
+	if len(locked) != 1 {
+		t.Fatalf("locked_promotions = %#v, want one item", locked)
+	}
+	if locked[0]["source"] != "narratio.transcript.trimmed" ||
+		locked[0]["dest"] != "transcripts/trimmed.json" ||
+		locked[0]["remote_key"] != trimmedKey ||
+		locked[0]["reason"] != "human reviewed" ||
+		locked[0]["required"] != true ||
+		locked[0]["local_path"] == "" ||
+		locked[0]["provenance"] == "" {
+		t.Fatalf("locked promotion metadata = %#v", locked[0])
+	}
+
+	currentManifestKey := m.S3SessionPrefix + "current/manifest.json"
+	var current map[string]any
+	if err := json.Unmarshal(fake.Objects[currentManifestKey].Data, &current); err != nil {
+		t.Fatalf("unmarshal current manifest: %v", err)
+	}
+	stages := current["stages"].(map[string]any)
+	archive := stages["archive"].(map[string]any)
+	meta := archive["metadata"].(map[string]any)
+	if meta["locked_promotion_count"] != float64(1) {
+		t.Fatalf("current manifest locked_promotion_count = %#v, want 1", meta["locked_promotion_count"])
+	}
+	items := meta["locked_promotions"].([]any)
+	if len(items) != 1 {
+		t.Fatalf("current manifest locked_promotions = %#v, want one item", items)
+	}
+}
+
+func TestArchiveLockedRequiredMissingPromotionSucceeds(t *testing.T) {
+	env, m, _ := archiveFixture(t)
+	env.Config.Pipeline.Archive.PromoteArtifacts = []config.ArchivePromotionRule{
+		{Source: "narratio.transcript.merged", Dest: "transcripts/merged.json", Required: boolPtr(true)},
+	}
+	env.Config.Pipeline.Archive.Locks = []config.ArchiveLockRule{
+		{Source: "narratio.transcript.merged", Reason: "manual merge is locked"},
+	}
+
+	result, err := archiveStage{}.Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+
+	fake := env.ObjectStore.(*storage.FakeBackend)
+	mergedKey := m.S3SessionPrefix + "transcripts/merged.json"
+	if _, ok := fake.Objects[mergedKey]; ok {
+		t.Fatalf("locked missing promotion key %q should not be uploaded", mergedKey)
+	}
+	if _, ok := fake.Objects[m.S3SessionPrefix+"current/run_id.txt"]; !ok {
+		t.Fatalf("current run pointer should be written for locked missing promotion")
+	}
+	locked := result.Metadata["locked_promotions"].([]map[string]any)
+	if len(locked) != 1 {
+		t.Fatalf("locked_promotions = %#v, want one item", locked)
+	}
+	if locked[0]["local_path"] != "" || locked[0]["provenance"] != "" {
+		t.Fatalf("locked missing promotion metadata = %#v, want empty local path/provenance", locked[0])
+	}
+}
+
+func TestArchiveLockDoesNotOverwriteExistingPromotion(t *testing.T) {
+	env, m, _ := archiveFixture(t)
+	env.Config.Pipeline.Archive.Locks = []config.ArchiveLockRule{
+		{Source: "narratio.transcript.trimmed", Reason: "already published"},
+	}
+	fake := env.ObjectStore.(*storage.FakeBackend)
+	trimmedKey := m.S3SessionPrefix + "transcripts/trimmed.json"
+	fake.SeedObject(storage.FakeObject{Key: trimmedKey, Data: []byte("previously published\n")})
+
+	if _, err := (archiveStage{}).Run(context.Background(), env, m); err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+
+	got := string(fake.Objects[trimmedKey].Data)
+	if got != "previously published\n" {
+		t.Fatalf("locked promotion object contents = %q, want existing object preserved", got)
+	}
+	for _, upload := range fake.Uploads {
+		if upload.Key == trimmedKey {
+			t.Fatalf("locked promotion key %q was uploaded", trimmedKey)
+		}
+	}
+}
+
 func TestArchiveFailsWhenRequiredPromotionMissing(t *testing.T) {
 	env, m, _ := archiveFixture(t)
 	env.Config.Pipeline.Archive.PromoteArtifacts = []config.ArchivePromotionRule{

internal/stage/placeholders_test.go

@@ -30,8 +30,10 @@ func TestStagesReturnExpectedMetadata(t *testing.T) {
 	store := artifacts.NewLocalStore(root)
 	cfgDir := t.TempDir()
 	sessionPath := filepath.Join(cfgDir, "session.yml")
+	campaignPath := filepath.Join(cfgDir, "campaign.yml")
 	pipelinePath := filepath.Join(cfgDir, "pipeline.yml")
 	writeStageTestFile(t, sessionPath, "session_id: 2026-05-03\n")
+	writeStageTestFile(t, campaignPath, "campaign: sample-campaign\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n")
 	writeStageTestFile(t, pipelinePath, "workspace:\n  root: "+root+"\n")
 	writeStageTestFile(t, filepath.Join(cfgDir, "speakers.yml"), "alice: alice.flac\n")
 	writeStageTestFile(t, filepath.Join(cfgDir, "autocorrect.yml"), "[]\n")
@@ -48,7 +50,9 @@ func TestStagesReturnExpectedMetadata(t *testing.T) {
 	env := &Env{
 		Config: &config.Config{
 			SessionPath:  sessionPath,
+			CampaignPath: campaignPath,
 			PipelinePath: pipelinePath,
+			Campaign:     &config.CampaignConfig{Campaign: "sample-campaign"},
 			Pipeline: &config.PipelineConfig{
 				Workspace: config.WorkspaceConfig{Root: root},
 				Storage: config.StorageConfig{
@@ -62,14 +66,28 @@ func TestStagesReturnExpectedMetadata(t *testing.T) {
 					UploadRun: boolPtr(true),
 				},
 			},
+			StableInputs: config.ResolvedStableInputs{
+				SpeakersFile: config.ResolvedInputFile{
+					Path:       "./speakers.yml",
+					ConfigPath: campaignPath,
+					Source:     "campaign_config",
+				},
+				AutocorrectFile: config.ResolvedInputFile{
+					Path:       "./autocorrect.yml",
+					ConfigPath: campaignPath,
+					Source:     "campaign_config",
+				},
+				GlossaryFile: config.ResolvedInputFile{
+					Path:       "./glossary.yml",
+					ConfigPath: campaignPath,
+					Source:     "campaign_config",
+				},
+			},
 			Session: &config.SessionConfig{
 				SessionID: "2026-05-03",
 				Campaign:  "sample-campaign",
 				Inputs: config.SessionInputsConfig{
-					AudioDir:        "./audio",
-					SpeakersFile:    "./speakers.yml",
-					AutocorrectFile: "./autocorrect.yml",
-					GlossaryFile:    "./glossary.yml",
+					AudioDir: "./audio",
 				},
 			},
 		},

internal/stage/prepare.go

@@ -25,6 +25,7 @@ func (prepareStage) Name() string { return "prepare" }
 func (prepareStage) Declares() IODecl {
 	return IODecl{
 		Inputs: []artifacts.Ref{
+			{Kind: "config", Category: "inputs", RelativePath: "campaign.yml"},
 			{Kind: "config", Category: "inputs", RelativePath: "session.yml"},
 			{Kind: "config", Category: "inputs", RelativePath: "pipeline.resolved.yml"},
 			{Kind: "config", Category: "inputs", RelativePath: "speakers.yml"},
@@ -59,21 +60,30 @@ func (prepareStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		return nil, fmt.Errorf("prepare: ensure workdir layout: %w", err)
 	}
 
+	campaignSrc := env.Config.CampaignPath
+	if err := requireFile(campaignSrc, "campaign.yml"); err != nil {
+		return nil, fmt.Errorf("prepare: %w", err)
+	}
+
 	sessionSrc := env.Config.SessionPath
 	if err := requireFile(sessionSrc, "session.yml"); err != nil {
 		return nil, fmt.Errorf("prepare: %w", err)
 	}
 	sessionDir := filepath.Dir(sessionSrc)
 
-	speakersSrc, err := resolvePath(sessionDir, env.Config.Session.Inputs.SpeakersFile)
+	speakersInput := stableInputSource(env.Config.StableInputs.SpeakersFile, env.Config.Session.Inputs.SpeakersFile, sessionSrc)
+	autocorrectInput := stableInputSource(env.Config.StableInputs.AutocorrectFile, env.Config.Session.Inputs.AutocorrectFile, sessionSrc)
+	glossaryInput := stableInputSource(env.Config.StableInputs.GlossaryFile, env.Config.Session.Inputs.GlossaryFile, sessionSrc)
+
+	speakersSrc, err := resolveConfigRelativePath(speakersInput)
 	if err != nil {
 		return nil, fmt.Errorf("prepare: speakers path: %w", err)
 	}
-	autocorrectSrc, err := resolvePath(sessionDir, env.Config.Session.Inputs.AutocorrectFile)
+	autocorrectSrc, err := resolveConfigRelativePath(autocorrectInput)
 	if err != nil {
 		return nil, fmt.Errorf("prepare: autocorrect path: %w", err)
 	}
-	glossarySrc, err := resolvePath(sessionDir, env.Config.Session.Inputs.GlossaryFile)
+	glossarySrc, err := resolveConfigRelativePath(glossaryInput)
 	if err != nil {
 		return nil, fmt.Errorf("prepare: glossary path: %w", err)
 	}
@@ -96,17 +106,44 @@ func (prepareStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		return nil, fmt.Errorf("prepare: resolve audio inputs: %w", err)
 	}
 
-	inputs := make([]manifest.InputRecord, 0, 5+len(resolvedLocalAudio))
+	inputs := make([]manifest.InputRecord, 0, 6+len(resolvedLocalAudio))
 	registerInput := func(kind, path, checksum string) {
 		inputs = append(inputs, manifest.InputRecord{Kind: kind, Path: path, Checksum: checksum})
 	}
+	registerConfigInput := func(kind, path, checksum, source string) {
+		inputs = append(inputs, manifest.InputRecord{Kind: kind, Path: path, Checksum: checksum, Source: source})
+	}
+	registerSessionConfigInput := func(path, checksum string) {
+		source := env.Config.SessionSource
+		if strings.TrimSpace(source.Source) == "" {
+			source.Source = "session_config"
+		}
+		inputs = append(inputs, manifest.InputRecord{
+			Kind:      "session_config",
+			Path:      path,
+			Checksum:  checksum,
+			Source:    source.Source,
+			S3Bucket:  source.S3Bucket,
+			S3Key:     source.S3Key,
+			S3Size:    source.S3Size,
+			S3ETag:    source.S3ETag,
+			SpoolPath: source.SpoolPath,
+		})
+	}
+
+	campaignDst := filepath.Join(paths.InputsDir, "campaign.yml")
+	campaignChecksum, err := copyFileIfChanged(env.ArtifactStore, campaignSrc, campaignDst)
+	if err != nil {
+		return nil, fmt.Errorf("prepare: materialize campaign.yml: %w", err)
+	}
+	registerConfigInput("campaign_config", campaignDst, campaignChecksum, "campaign_config")
 
 	sessionDst := filepath.Join(paths.InputsDir, "session.yml")
 	sessionChecksum, err := copyFileIfChanged(env.ArtifactStore, sessionSrc, sessionDst)
 	if err != nil {
 		return nil, fmt.Errorf("prepare: materialize session.yml: %w", err)
 	}
-	registerInput("session_config", sessionDst, sessionChecksum)
+	registerSessionConfigInput(sessionDst, sessionChecksum)
 
 	pipelineResolvedBytes, err := renderResolvedPipeline(env.Config.Pipeline)
 	if err != nil {
@@ -120,19 +157,20 @@ func (prepareStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 	registerInput("pipeline_resolved", pipelineDst, pipelineChecksum)
 
 	for _, cfgFile := range []struct {
-		kind string
-		src  string
-		dst  string
+		kind   string
+		src    string
+		dst    string
+		source string
 	}{
-		{kind: "speakers", src: speakersSrc, dst: filepath.Join(paths.InputsDir, "speakers.yml")},
-		{kind: "autocorrect", src: autocorrectSrc, dst: filepath.Join(paths.InputsDir, "autocorrect.yml")},
-		{kind: "glossary", src: glossarySrc, dst: filepath.Join(paths.InputsDir, "glossary.yml")},
+		{kind: "speakers", src: speakersSrc, dst: filepath.Join(paths.InputsDir, "speakers.yml"), source: speakersInput.Source},
+		{kind: "autocorrect", src: autocorrectSrc, dst: filepath.Join(paths.InputsDir, "autocorrect.yml"), source: autocorrectInput.Source},
+		{kind: "glossary", src: glossarySrc, dst: filepath.Join(paths.InputsDir, "glossary.yml"), source: glossaryInput.Source},
 	} {
 		checksum, err := copyFileIfChanged(env.ArtifactStore, cfgFile.src, cfgFile.dst)
 		if err != nil {
 			return nil, fmt.Errorf("prepare: materialize %s: %w", cfgFile.kind, err)
 		}
-		registerInput(cfgFile.kind, cfgFile.dst, checksum)
+		registerConfigInput(cfgFile.kind, cfgFile.dst, checksum, cfgFile.source)
 	}
 
 	if useS3Audio {
@@ -145,6 +183,20 @@ func (prepareStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 		}
 	}
 
+	previousRequirements := collectPreparePreviousRequirements(env.Config)
+	var previousHydration *previousSessionHydrationResult
+	if len(previousRequirements) > 0 {
+		if err := clearManagedPreviousState(paths); err != nil {
+			return nil, fmt.Errorf("prepare: clear previous-session cache: %w", err)
+		}
+		hydration, err := hydratePreviousSessionArtifacts(ctx, env, paths, previousRequirements)
+		if err != nil {
+			return nil, fmt.Errorf("prepare: hydrate previous-session artifacts: %w", err)
+		}
+		previousHydration = hydration
+		inputs = append(inputs, hydration.Inputs...)
+	}
+
 	sort.Slice(inputs, func(i, j int) bool {
 		if inputs[i].Kind != inputs[j].Kind {
 			return inputs[i].Kind < inputs[j].Kind
@@ -153,13 +205,27 @@ func (prepareStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*S
 	})
 	m.Inputs = inputs
 
+	metadata := map[string]any{
+		"prepared":             true,
+		"stage":                "prepare",
+		"inputs_count":         len(inputs),
+		"audio_files_resolved": countAudioInputs(inputs),
+	}
+	if len(previousRequirements) > 0 {
+		metadata["previous_requirements_count"] = len(previousRequirements)
+		if previousHydration != nil {
+			metadata["previous_artifacts_hydrated"] = append([]string(nil), previousHydration.Hydrated...)
+			metadata["previous_artifacts_hydrated_count"] = len(previousHydration.Hydrated)
+			metadata["previous_artifacts_missing_optional"] = append([]string(nil), previousHydration.SkippedMissing...)
+			metadata["previous_artifacts_missing_optional_count"] = len(previousHydration.SkippedMissing)
+			if strings.TrimSpace(previousHydration.PreviousRunID) != "" {
+				metadata["previous_session_run_id"] = strings.TrimSpace(previousHydration.PreviousRunID)
+			}
+		}
+	}
+
 	return &StageResult{
-		Metadata: map[string]any{
-			"prepared":             true,
-			"stage":                "prepare",
-			"inputs_count":         len(inputs),
-			"audio_files_resolved": countAudioInputs(inputs),
-		},
+		Metadata: metadata,
 	}, nil
 }
 
@@ -167,6 +233,31 @@ func renderResolvedPipeline(cfg *config.PipelineConfig) ([]byte, error) {
 	return yaml.Marshal(cfg)
 }
 
+func stableInputSource(resolved config.ResolvedInputFile, fallbackPath, fallbackConfigPath string) config.ResolvedInputFile {
+	if strings.TrimSpace(resolved.Path) != "" || strings.TrimSpace(resolved.ConfigPath) != "" || strings.TrimSpace(resolved.Source) != "" {
+		if strings.TrimSpace(resolved.ConfigPath) == "" {
+			resolved.ConfigPath = fallbackConfigPath
+		}
+		if strings.TrimSpace(resolved.Source) == "" {
+			resolved.Source = "session_config"
+		}
+		return resolved
+	}
+	return config.ResolvedInputFile{
+		Path:       fallbackPath,
+		ConfigPath: fallbackConfigPath,
+		Source:     "session_config",
+	}
+}
+
+func resolveConfigRelativePath(input config.ResolvedInputFile) (string, error) {
+	basePath := strings.TrimSpace(input.ConfigPath)
+	if basePath == "" {
+		return "", fmt.Errorf("source config path is required")
+	}
+	return resolvePath(filepath.Dir(basePath), input.Path)
+}
+
 func resolveAudioInputs(sessionDir string, inputs config.SessionInputsConfig) ([]string, bool, error) {
 	hasLocal := strings.TrimSpace(inputs.AudioDir) != "" || len(inputs.AudioFiles) > 0
 	if inputs.AudioS3 != nil {
@@ -354,6 +445,35 @@ func countAudioInputs(inputs []manifest.InputRecord) int {
 	return count
 }
 
+func collectPreparePreviousRequirements(cfg *config.Config) []artifacts.PreviousArtifactRequirement {
+	if cfg == nil || cfg.Pipeline == nil || cfg.Pipeline.Scriptorium == nil {
+		return nil
+	}
+	return artifacts.CollectPreviousArtifactRequirements(cfg.Pipeline.Scriptorium.Artifacts)
+}
+
+func clearManagedPreviousState(paths artifacts.SessionPaths) error {
+	previousDir := filepath.Clean(paths.PreviousDir)
+	sessionRoot := filepath.Clean(paths.Root)
+	if strings.TrimSpace(previousDir) == "" || strings.TrimSpace(sessionRoot) == "" {
+		return fmt.Errorf("previous/session root paths are required")
+	}
+	if previousDir == sessionRoot {
+		return fmt.Errorf("refusing to clear session root as previous cache: %q", previousDir)
+	}
+	prefix := sessionRoot + string(filepath.Separator)
+	if !strings.HasPrefix(previousDir, prefix) {
+		return fmt.Errorf("refusing to clear path outside session root: %q", previousDir)
+	}
+	if filepath.Base(previousDir) != config.PathPreviousDirSegment {
+		return fmt.Errorf("refusing to clear non-previous path %q", previousDir)
+	}
+	if err := os.RemoveAll(previousDir); err != nil {
+		return err
+	}
+	return os.MkdirAll(previousDir, 0o755)
+}
+
 func pathsWorkDirForManifest(env *Env, m *manifest.Manifest, sessionID string) string {
 	if env == nil || env.Config == nil || env.Config.Pipeline == nil || env.Config.Session == nil {
 		return ""

internal/stage/prepare_previous.go

@@ -0,0 +1,475 @@
+package stage
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
+)
+
+const (
+	preparePreviousInputKindManifest = "previous_manifest"
+	preparePreviousInputKindArtifact = "previous_artifact"
+	preparePreviousInputSource       = "previous_session_archive.current"
+)
+
+// previousSessionHydrationResult captures prepare-time previous-session cache materialization.
+type previousSessionHydrationResult struct {
+	Inputs         []manifest.InputRecord
+	Hydrated       []string
+	SkippedMissing []string
+	PreviousRunID  string
+}
+
+func hydratePreviousSessionArtifacts(
+	ctx context.Context,
+	env *Env,
+	paths artifacts.SessionPaths,
+	requirements []artifacts.PreviousArtifactRequirement,
+) (*previousSessionHydrationResult, error) {
+	if len(requirements) == 0 {
+		return &previousSessionHydrationResult{}, nil
+	}
+	if env == nil || env.Config == nil || env.Config.Session == nil || env.Config.Pipeline == nil {
+		return nil, fmt.Errorf("resolved config with session/pipeline is required")
+	}
+	if env.ArtifactStore == nil {
+		return nil, fmt.Errorf("artifact store is required")
+	}
+
+	orderedRequirements := append([]artifacts.PreviousArtifactRequirement(nil), requirements...)
+	sort.Slice(orderedRequirements, func(i, j int) bool {
+		return orderedRequirements[i].Name < orderedRequirements[j].Name
+	})
+
+	requiredNames := requiredPreviousArtifactNames(orderedRequirements)
+	optionalNames := optionalPreviousArtifactNames(orderedRequirements)
+	previousSessionID := strings.TrimSpace(env.Config.Session.PreviousSessionID)
+	if previousSessionID == "" {
+		if len(requiredNames) > 0 {
+			return nil, fmt.Errorf(
+				"previous_session_id is required for required previous-session artifacts: %s",
+				strings.Join(requiredNames, ", "),
+			)
+		}
+		return &previousSessionHydrationResult{SkippedMissing: optionalNames}, nil
+	}
+
+	if env.ObjectStore == nil {
+		return nil, fmt.Errorf("previous-session artifact hydration requires object store backend")
+	}
+	if env.Config.Pipeline.Storage.S3 == nil {
+		return nil, fmt.Errorf("pipeline.storage.s3 configuration is required for previous-session artifact hydration")
+	}
+	campaign := strings.TrimSpace(env.Config.Session.Campaign)
+	if campaign == "" {
+		return nil, fmt.Errorf("session campaign is required for previous-session artifact hydration")
+	}
+	bucket := strings.TrimSpace(env.Config.Pipeline.Storage.S3.Bucket)
+	if bucket == "" {
+		return nil, fmt.Errorf("pipeline.storage.s3.bucket is required for previous-session artifact hydration")
+	}
+
+	previousSessionPrefix := artifacts.S3SessionPrefix(
+		env.Config.Pipeline.Storage.S3.RootPrefix,
+		campaign,
+		previousSessionID,
+	)
+	currentManifestKey, currentRunIDKey := artifacts.ResolveArchiveCurrentStateKeys(previousSessionPrefix)
+
+	result := &previousSessionHydrationResult{}
+
+	runPointerExists, err := env.ObjectStore.Exists(ctx, currentRunIDKey)
+	if err != nil {
+		return nil, fmt.Errorf("check previous-session current run pointer %q: %w", currentRunIDKey, err)
+	}
+	if !runPointerExists {
+		if len(requiredNames) > 0 {
+			return nil, fmt.Errorf("required previous-session artifacts unavailable: remote current run pointer missing: %q", currentRunIDKey)
+		}
+		result.SkippedMissing = optionalNames
+		return result, nil
+	}
+
+	runIDTemp, err := downloadObjectToTempStage(ctx, env.ObjectStore, currentRunIDKey, "narratio-prepare-previous-run-id-*.txt")
+	if err != nil {
+		return nil, fmt.Errorf("download previous-session current run pointer %q: %w", currentRunIDKey, err)
+	}
+	defer func() { _ = os.Remove(runIDTemp) }()
+
+	runIDBytes, err := os.ReadFile(runIDTemp)
+	if err != nil {
+		return nil, fmt.Errorf("read previous-session current run pointer %q: %w", currentRunIDKey, err)
+	}
+	previousRunID := strings.TrimSpace(string(runIDBytes))
+	if previousRunID == "" {
+		return nil, fmt.Errorf("previous-session current run pointer %q is empty", currentRunIDKey)
+	}
+	result.PreviousRunID = previousRunID
+
+	manifestExists, err := env.ObjectStore.Exists(ctx, currentManifestKey)
+	if err != nil {
+		return nil, fmt.Errorf("check previous-session current manifest %q: %w", currentManifestKey, err)
+	}
+	if !manifestExists {
+		if len(requiredNames) > 0 {
+			return nil, fmt.Errorf("required previous-session artifacts unavailable: remote current manifest missing: %q", currentManifestKey)
+		}
+		result.SkippedMissing = optionalNames
+		return result, nil
+	}
+
+	if err := os.MkdirAll(filepath.Dir(paths.PreviousManifestPath), 0o755); err != nil {
+		return nil, fmt.Errorf("create previous manifest directory: %w", err)
+	}
+	if err := env.ObjectStore.Download(ctx, currentManifestKey, paths.PreviousManifestPath); err != nil {
+		return nil, fmt.Errorf("download previous-session current manifest %q: %w", currentManifestKey, err)
+	}
+
+	manifestStore := &manifest.LocalStore{}
+	previousManifest, err := manifestStore.Load(ctx, paths.PreviousManifestPath)
+	if err != nil {
+		return nil, fmt.Errorf("decode downloaded previous-session manifest %q: %w", currentManifestKey, err)
+	}
+	if strings.TrimSpace(previousManifest.SessionID) != previousSessionID {
+		return nil, fmt.Errorf(
+			"previous-session manifest session_id %q does not match configured previous_session_id %q",
+			strings.TrimSpace(previousManifest.SessionID),
+			previousSessionID,
+		)
+	}
+	if strings.TrimSpace(previousManifest.Campaign) != campaign {
+		return nil, fmt.Errorf(
+			"previous-session manifest campaign %q does not match current campaign %q",
+			strings.TrimSpace(previousManifest.Campaign),
+			campaign,
+		)
+	}
+	if strings.TrimSpace(previousManifest.RunID) == "" {
+		return nil, fmt.Errorf("previous-session manifest run_id is required")
+	}
+	if strings.TrimSpace(previousManifest.RunID) != previousRunID {
+		return nil, fmt.Errorf(
+			"previous-session current run pointer %q references run %q but current manifest run_id is %q",
+			currentRunIDKey,
+			previousRunID,
+			strings.TrimSpace(previousManifest.RunID),
+		)
+	}
+
+	manifestChecksum, err := env.ArtifactStore.Checksum(paths.PreviousManifestPath)
+	if err != nil {
+		return nil, fmt.Errorf("checksum downloaded previous-session manifest: %w", err)
+	}
+	result.Inputs = append(result.Inputs, manifest.InputRecord{
+		Kind:     preparePreviousInputKindManifest,
+		Path:     paths.PreviousManifestPath,
+		Checksum: manifestChecksum,
+		Source:   preparePreviousInputSource,
+		S3Bucket: bucket,
+		S3Key:    currentManifestKey,
+	})
+
+	for _, requirement := range orderedRequirements {
+		candidates := previousArtifactRelativePathCandidates(requirement.Name, previousManifest, env.Config)
+		if len(candidates) == 0 {
+			if requirement.Required {
+				return nil, fmt.Errorf(
+					"required previous-session artifact %q is unavailable in previous-session manifest/archive",
+					requirement.Name,
+				)
+			}
+			result.SkippedMissing = append(result.SkippedMissing, requirement.Name)
+			continue
+		}
+
+		selectedRel := ""
+		selectedKey := ""
+		for _, candidate := range candidates {
+			remoteKey := artifacts.S3PromotedArtifactKey(previousSessionPrefix, candidate)
+			exists, err := env.ObjectStore.Exists(ctx, remoteKey)
+			if err != nil {
+				return nil, fmt.Errorf("check previous-session artifact object %q: %w", remoteKey, err)
+			}
+			if !exists {
+				continue
+			}
+			selectedRel = candidate
+			selectedKey = remoteKey
+			break
+		}
+		if selectedRel == "" {
+			if requirement.Required {
+				return nil, fmt.Errorf(
+					"required previous-session artifact %q object missing from archive candidate keys",
+					requirement.Name,
+				)
+			}
+			result.SkippedMissing = append(result.SkippedMissing, requirement.Name)
+			continue
+		}
+
+		localPath := artifacts.SessionPreviousArtifactPath(paths, selectedRel)
+		if err := os.MkdirAll(filepath.Dir(localPath), 0o755); err != nil {
+			return nil, fmt.Errorf("create previous-session artifact directory for %q: %w", localPath, err)
+		}
+		if err := env.ObjectStore.Download(ctx, selectedKey, localPath); err != nil {
+			return nil, fmt.Errorf("download previous-session artifact %q from %q: %w", requirement.Name, selectedKey, err)
+		}
+		if err := requireNonEmptyFile(localPath, "previous-session artifact "+requirement.Name); err != nil {
+			return nil, err
+		}
+		checksum, err := env.ArtifactStore.Checksum(localPath)
+		if err != nil {
+			return nil, fmt.Errorf("checksum previous-session artifact %q: %w", requirement.Name, err)
+		}
+
+		result.Inputs = append(result.Inputs, manifest.InputRecord{
+			Kind:     preparePreviousInputKindArtifact,
+			Path:     localPath,
+			Checksum: checksum,
+			Source:   preparePreviousInputSource,
+			S3Bucket: bucket,
+			S3Key:    selectedKey,
+		})
+		result.Hydrated = append(result.Hydrated, requirement.Name)
+	}
+
+	sort.Strings(result.Hydrated)
+	sort.Strings(result.SkippedMissing)
+	sort.Slice(result.Inputs, func(i, j int) bool {
+		if result.Inputs[i].Kind != result.Inputs[j].Kind {
+			return result.Inputs[i].Kind < result.Inputs[j].Kind
+		}
+		return result.Inputs[i].Path < result.Inputs[j].Path
+	})
+	return result, nil
+}
+
+func requiredPreviousArtifactNames(requirements []artifacts.PreviousArtifactRequirement) []string {
+	names := make([]string, 0, len(requirements))
+	for _, requirement := range requirements {
+		if requirement.Required {
+			names = append(names, strings.TrimSpace(requirement.Name))
+		}
+	}
+	sort.Strings(names)
+	return names
+}
+
+func optionalPreviousArtifactNames(requirements []artifacts.PreviousArtifactRequirement) []string {
+	names := make([]string, 0, len(requirements))
+	for _, requirement := range requirements {
+		if requirement.Required {
+			continue
+		}
+		names = append(names, strings.TrimSpace(requirement.Name))
+	}
+	sort.Strings(names)
+	return names
+}
+
+func previousArtifactRelativePathCandidates(
+	artifactName string,
+	previousManifest *manifest.Manifest,
+	cfg *config.Config,
+) []string {
+	candidates := []string{}
+	appendCandidate := func(v string) {
+		normalized, err := normalizeArchiveRelativePath(v)
+		if err != nil {
+			return
+		}
+		candidates = append(candidates, normalized)
+	}
+
+	sourceID := artifacts.ConfiguredArtifactSourceID(artifactName)
+	if rel, ok := previousManifestArtifactRelativePathBySourceID(previousManifest, sourceID); ok {
+		appendCandidate(rel)
+		base := path.Base(rel)
+		for _, promoted := range previousManifestPromotedPaths(previousManifest) {
+			if path.Base(promoted) == base {
+				appendCandidate(promoted)
+			}
+		}
+	}
+
+	if cfg != nil && cfg.Pipeline != nil && cfg.Pipeline.Scriptorium != nil {
+		if artifactCfg, ok := cfg.Pipeline.Scriptorium.Artifacts[artifactName]; ok {
+			appendCandidate(artifactCfg.OutputPath)
+		}
+	}
+
+	return dedupeOrderedStrings(candidates)
+}
+
+func previousManifestArtifactRelativePathBySourceID(previousManifest *manifest.Manifest, sourceID string) (string, bool) {
+	if previousManifest == nil || len(previousManifest.Stages) == 0 {
+		return "", false
+	}
+	sourceID = strings.TrimSpace(sourceID)
+	if sourceID == "" {
+		return "", false
+	}
+
+	stageNames := make([]string, 0, len(previousManifest.Stages))
+	if _, ok := previousManifest.Stages["analyze"]; ok {
+		stageNames = append(stageNames, "analyze")
+	}
+	for stageName := range previousManifest.Stages {
+		if stageName == "analyze" {
+			continue
+		}
+		stageNames = append(stageNames, stageName)
+	}
+	start := 0
+	if len(stageNames) > 0 && stageNames[0] == "analyze" {
+		start = 1
+	}
+	sort.Strings(stageNames[start:])
+
+	for _, stageName := range stageNames {
+		sr := previousManifest.Stages[stageName]
+		if sr == nil {
+			continue
+		}
+		for _, out := range sr.Outputs {
+			if strings.TrimSpace(out.SourceID) != sourceID {
+				continue
+			}
+			rel, ok := derivePreviousManifestRelativePath(previousManifest, out.LocalPath)
+			if ok {
+				return rel, true
+			}
+		}
+	}
+	return "", false
+}
+
+func derivePreviousManifestRelativePath(previousManifest *manifest.Manifest, localPath string) (string, bool) {
+	trimmed := strings.TrimSpace(localPath)
+	if trimmed == "" {
+		return "", false
+	}
+	if !filepath.IsAbs(trimmed) {
+		normalized, err := normalizeArchiveRelativePath(filepath.ToSlash(trimmed))
+		if err != nil {
+			return "", false
+		}
+		return normalized, true
+	}
+
+	sessionRoot, ok := previousManifestSessionRoot(previousManifest)
+	if !ok {
+		return "", false
+	}
+	rel, err := filepath.Rel(sessionRoot, trimmed)
+	if err != nil {
+		return "", false
+	}
+	normalized, err := normalizeArchiveRelativePath(filepath.ToSlash(rel))
+	if err != nil {
+		return "", false
+	}
+	return normalized, true
+}
+
+func previousManifestSessionRoot(previousManifest *manifest.Manifest) (string, bool) {
+	if previousManifest == nil {
+		return "", false
+	}
+	runRoot := filepath.Clean(strings.TrimSpace(previousManifest.LocalWorkDir))
+	runID := strings.TrimSpace(previousManifest.RunID)
+	if runRoot == "" || runID == "" {
+		return "", false
+	}
+	if filepath.Base(runRoot) != runID {
+		return "", false
+	}
+	runsDir := filepath.Dir(runRoot)
+	if filepath.Base(runsDir) != config.PathRunsDirSegment {
+		return "", false
+	}
+	return filepath.Dir(runsDir), true
+}
+
+func previousManifestPromotedPaths(previousManifest *manifest.Manifest) []string {
+	if previousManifest == nil || len(previousManifest.Stages) == 0 {
+		return nil
+	}
+	sr := previousManifest.Stages["archive"]
+	if sr == nil || sr.Metadata == nil {
+		return nil
+	}
+	raw, ok := sr.Metadata["promoted_paths"]
+	if !ok {
+		return nil
+	}
+	values, ok := raw.([]any)
+	if !ok {
+		return nil
+	}
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		asString, ok := value.(string)
+		if !ok {
+			continue
+		}
+		normalized, err := normalizeArchiveRelativePath(asString)
+		if err != nil {
+			continue
+		}
+		out = append(out, normalized)
+	}
+	return dedupeOrderedStrings(out)
+}
+
+func dedupeOrderedStrings(values []string) []string {
+	if len(values) == 0 {
+		return nil
+	}
+	seen := map[string]struct{}{}
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		trimmed := strings.TrimSpace(value)
+		if trimmed == "" {
+			continue
+		}
+		if _, ok := seen[trimmed]; ok {
+			continue
+		}
+		seen[trimmed] = struct{}{}
+		out = append(out, trimmed)
+	}
+	return out
+}
+
+func downloadObjectToTempStage(
+	ctx context.Context,
+	store interface {
+		Download(context.Context, string, string) error
+	},
+	key, pattern string,
+) (string, error) {
+	tmp, err := os.CreateTemp("", pattern)
+	if err != nil {
+		return "", fmt.Errorf("create temp file: %w", err)
+	}
+	path := tmp.Name()
+	if err := tmp.Close(); err != nil {
+		_ = os.Remove(path)
+		return "", fmt.Errorf("close temp file: %w", err)
+	}
+	if err := store.Download(ctx, key, path); err != nil {
+		_ = os.Remove(path)
+		return "", err
+	}
+	return path, nil
+}

internal/stage/prepare_previous_test.go

@@ -0,0 +1,415 @@
+package stage
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
+	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
+)
+
+func TestHydratePreviousSessionArtifactsDownloadsManifestAndRequiredArtifact(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+	seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeArtifactObject:   true,
+		artifactBody:            "# previous recap\n",
+	})
+
+	result, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err != nil {
+		t.Fatalf("hydratePreviousSessionArtifacts() error = %v", err)
+	}
+	if result == nil {
+		t.Fatal("result is nil")
+	}
+	if len(result.Inputs) != 2 {
+		t.Fatalf("inputs len = %d, want 2", len(result.Inputs))
+	}
+	if !containsString(result.Hydrated, "session_recap") {
+		t.Fatalf("hydrated = %#v, want session_recap", result.Hydrated)
+	}
+	if len(result.SkippedMissing) != 0 {
+		t.Fatalf("skipped missing = %#v, want none", result.SkippedMissing)
+	}
+
+	if _, err := os.Stat(sessionPaths.PreviousManifestPath); err != nil {
+		t.Fatalf("previous manifest missing: %v", err)
+	}
+	recapPath := artifacts.SessionPreviousArtifactPath(sessionPaths, "artifacts/session_recap.md")
+	if _, err := os.Stat(recapPath); err != nil {
+		t.Fatalf("previous artifact missing: %v", err)
+	}
+
+	manifestInput := findInputByKind(result.Inputs, preparePreviousInputKindManifest)
+	if manifestInput == nil {
+		t.Fatalf("missing input kind %q", preparePreviousInputKindManifest)
+	}
+	if manifestInput.Source != preparePreviousInputSource {
+		t.Fatalf("manifest input source = %q, want %q", manifestInput.Source, preparePreviousInputSource)
+	}
+
+	artifactInput := findInputByKind(result.Inputs, preparePreviousInputKindArtifact)
+	if artifactInput == nil {
+		t.Fatalf("missing input kind %q", preparePreviousInputKindArtifact)
+	}
+	if artifactInput.Source != preparePreviousInputSource {
+		t.Fatalf("artifact input source = %q, want %q", artifactInput.Source, preparePreviousInputSource)
+	}
+	if artifactInput.Path != recapPath {
+		t.Fatalf("artifact input path = %q, want %q", artifactInput.Path, recapPath)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsSkipsMissingOptionalArtifact(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: false},
+	}
+	seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeManifestObject:   true,
+		includeArtifactObject:   false,
+	})
+
+	result, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err != nil {
+		t.Fatalf("hydratePreviousSessionArtifacts() error = %v", err)
+	}
+	if result == nil {
+		t.Fatal("result is nil")
+	}
+	if !containsString(result.SkippedMissing, "session_recap") {
+		t.Fatalf("skipped missing = %#v, want session_recap", result.SkippedMissing)
+	}
+	if len(result.Hydrated) != 0 {
+		t.Fatalf("hydrated = %#v, want none", result.Hydrated)
+	}
+	manifestInput := findInputByKind(result.Inputs, preparePreviousInputKindManifest)
+	if manifestInput == nil {
+		t.Fatalf("missing input kind %q", preparePreviousInputKindManifest)
+	}
+	if findInputByKind(result.Inputs, preparePreviousInputKindArtifact) != nil {
+		t.Fatalf("unexpected %q input for missing optional artifact", preparePreviousInputKindArtifact)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsFailsMissingRequiredArtifact(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+	seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeArtifactObject:   false,
+	})
+
+	_, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err == nil || !strings.Contains(err.Error(), "required previous-session artifact") {
+		t.Fatalf("error = %v, want required artifact failure", err)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsFailsRequiredWhenPreviousSessionIDUnset(t *testing.T) {
+	env, sessionPaths, _ := previousHydrationFixture(t)
+	env.Config.Session.PreviousSessionID = ""
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+
+	_, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err == nil || !strings.Contains(err.Error(), "previous_session_id is required") {
+		t.Fatalf("error = %v, want previous_session_id required failure", err)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsOptionalWithNoPreviousSessionID(t *testing.T) {
+	env, sessionPaths, _ := previousHydrationFixture(t)
+	env.Config.Session.PreviousSessionID = ""
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: false},
+	}
+
+	result, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err != nil {
+		t.Fatalf("hydratePreviousSessionArtifacts() error = %v", err)
+	}
+	if result == nil {
+		t.Fatal("result is nil")
+	}
+	if len(result.Inputs) != 0 {
+		t.Fatalf("inputs len = %d, want 0", len(result.Inputs))
+	}
+	if !containsString(result.SkippedMissing, "session_recap") {
+		t.Fatalf("skipped missing = %#v, want session_recap", result.SkippedMissing)
+	}
+	if _, err := os.Stat(sessionPaths.PreviousManifestPath); !os.IsNotExist(err) {
+		t.Fatalf("previous manifest should not be created, stat err = %v", err)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsRespectsCurrentCommitMarker(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+	seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: false,
+		includeArtifactObject:   true,
+		artifactBody:            "# previous recap\n",
+	})
+
+	_, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err == nil || !strings.Contains(err.Error(), "remote current run pointer missing") {
+		t.Fatalf("error = %v, want current run pointer missing failure", err)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsDoesNotUseLocalPreviousWorkspaceState(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+	seed := seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeManifestObject:   true,
+		includeArtifactObject:   false,
+	})
+	// Write a local previous-session workspace file that should be ignored.
+	writeFile(t, filepath.Join(seed.PreviousSessionRoot, "artifacts", "session_recap.md"), "# local stale recap\n")
+
+	_, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err == nil || !strings.Contains(err.Error(), "object missing from archive") {
+		t.Fatalf("error = %v, want remote-object-missing failure", err)
+	}
+}
+
+func TestHydratePreviousSessionArtifactsUsesExplicitStorageKeys(t *testing.T) {
+	env, sessionPaths, fake := previousHydrationFixture(t)
+	requirements := []artifacts.PreviousArtifactRequirement{
+		{Name: "session_recap", Required: true},
+	}
+	seed := seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeArtifactObject:   true,
+		artifactBody:            "# previous recap\n",
+	})
+
+	capture := &preparePreviousCaptureStore{delegate: fake}
+	env.ObjectStore = capture
+
+	_, err := hydratePreviousSessionArtifacts(context.Background(), env, sessionPaths, requirements)
+	if err != nil {
+		t.Fatalf("hydratePreviousSessionArtifacts() error = %v", err)
+	}
+
+	if !containsString(capture.existsKeys, seed.RunPointerKey) {
+		t.Fatalf("exists keys = %#v, want %q", capture.existsKeys, seed.RunPointerKey)
+	}
+	if !containsString(capture.existsKeys, seed.ManifestKey) {
+		t.Fatalf("exists keys = %#v, want %q", capture.existsKeys, seed.ManifestKey)
+	}
+	if !containsString(capture.existsKeys, seed.ArtifactKey) {
+		t.Fatalf("exists keys = %#v, want %q", capture.existsKeys, seed.ArtifactKey)
+	}
+	if !containsString(capture.downloadKeys, seed.RunPointerKey) {
+		t.Fatalf("download keys = %#v, want %q", capture.downloadKeys, seed.RunPointerKey)
+	}
+	if !containsString(capture.downloadKeys, seed.ManifestKey) {
+		t.Fatalf("download keys = %#v, want %q", capture.downloadKeys, seed.ManifestKey)
+	}
+	if !containsString(capture.downloadKeys, seed.ArtifactKey) {
+		t.Fatalf("download keys = %#v, want %q", capture.downloadKeys, seed.ArtifactKey)
+	}
+}
+
+type previousStateSeedResult struct {
+	PreviousSessionPrefix string
+	PreviousSessionRoot   string
+	ManifestKey           string
+	RunPointerKey         string
+	ArtifactKey           string
+}
+
+type previousStateSeedOptions struct {
+	includeRunPointerObject bool
+	includeManifestObject   bool
+	includeArtifactObject   bool
+	artifactBody            string
+}
+
+func seedPreviousCurrentState(
+	t *testing.T,
+	env *Env,
+	fake *storage.FakeBackend,
+	options previousStateSeedOptions,
+) previousStateSeedResult {
+	t.Helper()
+
+	if !options.includeRunPointerObject && !options.includeManifestObject && !options.includeArtifactObject {
+		// Keep default behavior deterministic when caller omits explicit flags.
+		options.includeRunPointerObject = true
+		options.includeManifestObject = true
+	}
+	if options.includeManifestObject == false && options.includeArtifactObject {
+		options.includeManifestObject = true
+	}
+
+	previousSessionID := strings.TrimSpace(env.Config.Session.PreviousSessionID)
+	campaign := strings.TrimSpace(env.Config.Session.Campaign)
+	rootPrefix := strings.TrimSpace(env.Config.Pipeline.Storage.S3.RootPrefix)
+	previousSessionPrefix := artifacts.S3SessionPrefix(rootPrefix, campaign, previousSessionID)
+	manifestKey, runPointerKey := artifacts.ResolveArchiveCurrentStateKeys(previousSessionPrefix)
+
+	previousRunID := "20260510T010203Z-a1b2c3d4"
+	previousSessionRoot := filepath.Join(t.TempDir(), "work", campaign, previousSessionID)
+	artifactLocalPath := filepath.Join(previousSessionRoot, "artifacts", "session_recap.md")
+	previousManifest := buildPreviousManifestForSeed(
+		t,
+		previousSessionID,
+		campaign,
+		previousRunID,
+		filepath.Join(previousSessionRoot, "runs", previousRunID),
+		artifactLocalPath,
+	)
+
+	if options.includeRunPointerObject || (!options.includeRunPointerObject && !options.includeManifestObject && !options.includeArtifactObject) {
+		fake.SeedObject(storage.FakeObject{
+			Key:  runPointerKey,
+			Data: []byte(previousRunID + "\n"),
+		})
+	}
+	if options.includeManifestObject || options.includeArtifactObject {
+		fake.SeedObject(storage.FakeObject{
+			Key:  manifestKey,
+			Data: previousManifest,
+		})
+	}
+
+	artifactKey := artifacts.S3PromotedArtifactKey(previousSessionPrefix, "artifacts/session_recap.md")
+	if options.includeArtifactObject {
+		body := options.artifactBody
+		if body == "" {
+			body = "# previous recap\n"
+		}
+		fake.SeedObject(storage.FakeObject{
+			Key:  artifactKey,
+			Data: []byte(body),
+		})
+	}
+
+	return previousStateSeedResult{
+		PreviousSessionPrefix: previousSessionPrefix,
+		PreviousSessionRoot:   previousSessionRoot,
+		ManifestKey:           manifestKey,
+		RunPointerKey:         runPointerKey,
+		ArtifactKey:           artifactKey,
+	}
+}
+
+func previousHydrationFixture(t *testing.T) (*Env, artifacts.SessionPaths, *storage.FakeBackend) {
+	t.Helper()
+	env, m := setupPrepareEnv(t)
+	env.Config.Session.Campaign = "forsaken"
+	env.Config.Session.PreviousSessionID = "2026-05-10"
+	env.Config.Pipeline.Storage.S3 = &config.StorageS3Config{
+		Bucket:     "my-dnd-archive",
+		RootPrefix: "dnd",
+	}
+	env.Config.Pipeline.Scriptorium = &config.ScriptoriumConfig{
+		Artifacts: map[string]config.ScriptoriumArtifactConfig{
+			"session_recap": {
+				Enabled:    true,
+				OutputPath: "artifacts/session_recap.md",
+			},
+		},
+	}
+	fake := &storage.FakeBackend{}
+	env.ObjectStore = fake
+
+	paths, err := ensureLayoutForEnv(env, m.SessionID)
+	if err != nil {
+		t.Fatalf("ensureLayoutForEnv() error = %v", err)
+	}
+	return env, paths, fake
+}
+
+func buildPreviousManifestForSeed(
+	t *testing.T,
+	sessionID, campaign, runID, runRoot, artifactPath string,
+) []byte {
+	t.Helper()
+	now := time.Date(2026, 5, 19, 22, 0, 0, 0, time.UTC)
+	m := manifest.New(sessionID, now)
+	m.Campaign = campaign
+	m.RunID = runID
+	m.LocalWorkDir = runRoot
+	m.MarkStageSucceeded("analyze", now, []manifest.ArtifactRecord{
+		{
+			Kind:      "scriptorium_artifact",
+			SourceID:  artifacts.ConfiguredArtifactSourceID("session_recap"),
+			LocalPath: artifactPath,
+		},
+	})
+	m.MarkStageSucceeded("archive", now, nil)
+	m.Stages["archive"].Metadata = map[string]any{
+		"promoted_paths": []string{"artifacts/session_recap.md"},
+	}
+	data, err := json.MarshalIndent(m, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal manifest: %v", err)
+	}
+	return append(data, '\n')
+}
+
+type preparePreviousCaptureStore struct {
+	delegate     storage.ObjectStore
+	existsKeys   []string
+	downloadKeys []string
+}
+
+func (s *preparePreviousCaptureStore) List(ctx context.Context, prefix string) ([]storage.ObjectInfo, error) {
+	return s.delegate.List(ctx, prefix)
+}
+
+func (s *preparePreviousCaptureStore) Download(ctx context.Context, key, localPath string) error {
+	s.downloadKeys = append(s.downloadKeys, key)
+	return s.delegate.Download(ctx, key, localPath)
+}
+
+func (s *preparePreviousCaptureStore) Upload(ctx context.Context, localPath, key string, opts storage.UploadOptions) (storage.ObjectInfo, error) {
+	return s.delegate.Upload(ctx, localPath, key, opts)
+}
+
+func (s *preparePreviousCaptureStore) Exists(ctx context.Context, key string) (bool, error) {
+	s.existsKeys = append(s.existsKeys, key)
+	return s.delegate.Exists(ctx, key)
+}
+
+func findInputByKind(inputs []manifest.InputRecord, kind string) *manifest.InputRecord {
+	for i := range inputs {
+		if inputs[i].Kind == kind {
+			return &inputs[i]
+		}
+	}
+	return nil
+}
+
+func containsString(values []string, target string) bool {
+	for _, value := range values {
+		if value == target {
+			return true
+		}
+	}
+	return false
+}

internal/stage/prepare_test.go

@@ -35,6 +35,7 @@ func TestPrepareStageExplicitAudioFiles(t *testing.T) {
 
 	paths := sessionPathsForEnv(env, m.SessionID)
 	for _, p := range []string{
+		filepath.Join(paths.InputsDir, "campaign.yml"),
 		filepath.Join(paths.InputsDir, "session.yml"),
 		filepath.Join(paths.InputsDir, "pipeline.resolved.yml"),
 		filepath.Join(paths.InputsDir, "speakers.yml"),
@@ -48,8 +49,8 @@ func TestPrepareStageExplicitAudioFiles(t *testing.T) {
 		}
 	}
 
-	if len(m.Inputs) != 7 {
-		t.Fatalf("manifest inputs len = %d, want 7", len(m.Inputs))
+	if len(m.Inputs) != 8 {
+		t.Fatalf("manifest inputs len = %d, want 8", len(m.Inputs))
 	}
 	for _, in := range m.Inputs {
 		if in.Checksum == "" {
@@ -151,6 +152,64 @@ func TestPrepareStageIdempotent(t *testing.T) {
 	}
 }
 
+func TestPrepareStageRecordsLocalSessionProvenance(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+
+	if _, err := (prepareStage{}).Run(context.Background(), env, m); err != nil {
+		t.Fatalf("prepare.Run() error = %v", err)
+	}
+	sessionInput := findManifestInput(t, m.Inputs, "session_config")
+	if sessionInput.Source != "session_config" {
+		t.Fatalf("session source = %q, want session_config", sessionInput.Source)
+	}
+	if sessionInput.S3Bucket != "" || sessionInput.S3Key != "" || sessionInput.SpoolPath != "" {
+		t.Fatalf("local session input has unexpected remote provenance: %#v", sessionInput)
+	}
+}
+
+func TestPrepareStageRecordsRemoteSessionProvenance(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	remoteSessionPath := filepath.Join(t.TempDir(), "downloaded-session.yml")
+	writeFile(t, remoteSessionPath, "session_id: 2026-05-03\ninputs:\n  audio_s3:\n    prefix: audio/\n")
+	env.Config.SessionPath = remoteSessionPath
+	env.Config.Session.Inputs.AudioDir = ""
+	env.Config.Session.Inputs.AudioS3 = &config.SessionAudioS3Input{Prefix: "audio/"}
+	env.Config.SessionSource = config.SessionSource{
+		Source:    "session_config.s3",
+		LocalPath: remoteSessionPath,
+		S3Bucket:  "my-dnd-archive",
+		S3Key:     "dnd/campaigns/sample-campaign/sessions/2026-05-03/session.yml",
+		S3Size:    58,
+		S3ETag:    "session-etag",
+		SpoolPath: remoteSessionPath,
+	}
+	env.Config.Pipeline.Spool = config.SpoolConfig{Root: filepath.Join(t.TempDir(), "spool")}
+	env.Config.Pipeline.Storage.S3 = &config.StorageS3Config{Bucket: "my-dnd-archive", RootPrefix: "dnd"}
+	m.RunID = "20260515T031522Z-a1b2c3d4"
+	m.LocalWorkDir = artifacts.SessionRunRootForCampaign(env.Config.Pipeline.Workspace.Root, "sample-campaign", m.SessionID, m.RunID)
+	m.LocalSpoolDir = artifacts.SessionSpoolAudioDir(env.Config.Pipeline.Spool.Root, "sample-campaign", m.SessionID, m.RunID)
+	fake := &storage.FakeBackend{}
+	fake.SeedObject(storage.FakeObject{Key: "dnd/campaigns/sample-campaign/sessions/2026-05-03/audio/alice.flac", Data: []byte("alice")})
+	env.ObjectStore = fake
+
+	if _, err := (prepareStage{}).Run(context.Background(), env, m); err != nil {
+		t.Fatalf("prepare.Run() error = %v", err)
+	}
+	sessionInput := findManifestInput(t, m.Inputs, "session_config")
+	if sessionInput.Source != "session_config.s3" {
+		t.Fatalf("session source = %q, want session_config.s3", sessionInput.Source)
+	}
+	if sessionInput.S3Bucket != "my-dnd-archive" || sessionInput.S3Key != "dnd/campaigns/sample-campaign/sessions/2026-05-03/session.yml" {
+		t.Fatalf("remote session input missing bucket/key: %#v", sessionInput)
+	}
+	if sessionInput.S3Size != 58 || sessionInput.S3ETag != "session-etag" || sessionInput.SpoolPath != remoteSessionPath {
+		t.Fatalf("remote session input missing metadata: %#v", sessionInput)
+	}
+}
+
 func TestPrepareStageS3AudioDownloadAndMaterialization(t *testing.T) {
 	env, m := setupPrepareEnv(t)
 	env.Config.Session.Campaign = "forsaken"
@@ -284,6 +343,188 @@ func TestPrepareStageAudioSourceConflictFails(t *testing.T) {
 	}
 }
 
+func TestPrepareStageWithoutPreviousRequirementsDoesNotTouchPreviousState(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+
+	paths := sessionPathsForEnv(env, m.SessionID)
+	stalePath := filepath.Join(paths.PreviousDir, "stale.txt")
+	writeFile(t, stalePath, "stale")
+
+	_, err := (prepareStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("prepare.Run() error = %v", err)
+	}
+	if _, err := os.Stat(stalePath); err != nil {
+		t.Fatalf("expected previous stale file to remain untouched: %v", err)
+	}
+}
+
+func TestPrepareStageOptionalPreviousArtifactWithoutPreviousSessionIDSucceeds(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+	configurePreparePreviousArtifactSource(env, false)
+	env.Config.Session.PreviousSessionID = ""
+
+	paths := sessionPathsForEnv(env, m.SessionID)
+	writeFile(t, filepath.Join(paths.PreviousArtifactsDir, "stale.txt"), "stale")
+
+	result, err := (prepareStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("prepare.Run() error = %v", err)
+	}
+	if result.Metadata["previous_requirements_count"] != 1 {
+		t.Fatalf("metadata previous_requirements_count = %#v, want 1", result.Metadata["previous_requirements_count"])
+	}
+	if result.Metadata["previous_artifacts_hydrated_count"] != 0 {
+		t.Fatalf("metadata previous_artifacts_hydrated_count = %#v, want 0", result.Metadata["previous_artifacts_hydrated_count"])
+	}
+	if result.Metadata["previous_artifacts_missing_optional_count"] != 1 {
+		t.Fatalf("metadata previous_artifacts_missing_optional_count = %#v, want 1", result.Metadata["previous_artifacts_missing_optional_count"])
+	}
+	if _, err := os.Stat(filepath.Join(paths.PreviousArtifactsDir, "stale.txt")); !os.IsNotExist(err) {
+		t.Fatalf("expected stale previous state to be cleared, stat err = %v", err)
+	}
+	for _, in := range m.Inputs {
+		if in.Kind == preparePreviousInputKindManifest || in.Kind == preparePreviousInputKindArtifact {
+			t.Fatalf("unexpected previous input record: %#v", in)
+		}
+	}
+}
+
+func TestPrepareStageRequiredPreviousArtifactWithoutPreviousSessionIDFails(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+	configurePreparePreviousArtifactSource(env, true)
+	env.Config.Session.PreviousSessionID = ""
+
+	_, err := (prepareStage{}).Run(context.Background(), env, m)
+	if err == nil || !strings.Contains(err.Error(), "previous_session_id is required") {
+		t.Fatalf("error = %v, want previous_session_id required failure", err)
+	}
+}
+
+func TestPrepareStageHydratesRequiredPreviousArtifactAndRecordsInputs(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+	env.Config.Session.Campaign = "forsaken"
+	env.Config.Session.PreviousSessionID = "2026-05-10"
+	env.Config.Pipeline.Storage.S3 = &config.StorageS3Config{Bucket: "my-dnd-archive", RootPrefix: "dnd"}
+	configurePreparePreviousArtifactSource(env, true)
+
+	fake := &storage.FakeBackend{}
+	env.ObjectStore = fake
+	seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeArtifactObject:   true,
+		artifactBody:            "# prior recap\n",
+	})
+
+	paths := sessionPathsForEnv(env, m.SessionID)
+	result, err := (prepareStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("prepare.Run() error = %v", err)
+	}
+
+	if _, err := os.Stat(paths.PreviousManifestPath); err != nil {
+		t.Fatalf("expected previous manifest: %v", err)
+	}
+	recapPath := artifacts.SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	if _, err := os.Stat(recapPath); err != nil {
+		t.Fatalf("expected previous artifact: %v", err)
+	}
+
+	var hasPreviousManifest, hasPreviousArtifact bool
+	for _, in := range m.Inputs {
+		if in.Kind == preparePreviousInputKindManifest {
+			hasPreviousManifest = true
+		}
+		if in.Kind == preparePreviousInputKindArtifact {
+			hasPreviousArtifact = true
+		}
+	}
+	if !hasPreviousManifest || !hasPreviousArtifact {
+		t.Fatalf("manifest inputs missing previous provenance: %#v", m.Inputs)
+	}
+	if result.Metadata["previous_artifacts_hydrated_count"] != 1 {
+		t.Fatalf("metadata previous_artifacts_hydrated_count = %#v, want 1", result.Metadata["previous_artifacts_hydrated_count"])
+	}
+}
+
+func TestPrepareStageRerunOverwritesPreviousCache(t *testing.T) {
+	env, m := setupPrepareEnv(t)
+	root := filepath.Dir(env.Config.SessionPath)
+	writeFile(t, filepath.Join(root, "audio", "a.flac"), "a")
+	env.Config.Session.Inputs.AudioFiles = []string{"./audio/a.flac"}
+	env.Config.Session.Campaign = "forsaken"
+	env.Config.Session.PreviousSessionID = "2026-05-10"
+	env.Config.Pipeline.Storage.S3 = &config.StorageS3Config{Bucket: "my-dnd-archive", RootPrefix: "dnd"}
+	configurePreparePreviousArtifactSource(env, true)
+
+	fake := &storage.FakeBackend{}
+	env.ObjectStore = fake
+	seed := seedPreviousCurrentState(t, env, fake, previousStateSeedOptions{
+		includeRunPointerObject: true,
+		includeArtifactObject:   true,
+		artifactBody:            "# old recap\n",
+	})
+
+	paths := sessionPathsForEnv(env, m.SessionID)
+	if _, err := (prepareStage{}).Run(context.Background(), env, m); err != nil {
+		t.Fatalf("first prepare run error = %v", err)
+	}
+	recapPath := artifacts.SessionPreviousArtifactPath(paths, "artifacts/session_recap.md")
+	firstBytes, err := os.ReadFile(recapPath)
+	if err != nil {
+		t.Fatalf("read first hydrated artifact: %v", err)
+	}
+	if strings.TrimSpace(string(firstBytes)) != "# old recap" {
+		t.Fatalf("first hydrated content = %q, want %q", strings.TrimSpace(string(firstBytes)), "# old recap")
+	}
+
+	writeFile(t, filepath.Join(paths.PreviousArtifactsDir, "stale.txt"), "stale")
+	fake.SeedObject(storage.FakeObject{Key: seed.ArtifactKey, Data: []byte("# new recap\n")})
+
+	if _, err := (prepareStage{}).Run(context.Background(), env, m); err != nil {
+		t.Fatalf("second prepare run error = %v", err)
+	}
+	secondBytes, err := os.ReadFile(recapPath)
+	if err != nil {
+		t.Fatalf("read second hydrated artifact: %v", err)
+	}
+	if strings.TrimSpace(string(secondBytes)) != "# new recap" {
+		t.Fatalf("second hydrated content = %q, want %q", strings.TrimSpace(string(secondBytes)), "# new recap")
+	}
+	if _, err := os.Stat(filepath.Join(paths.PreviousArtifactsDir, "stale.txt")); !os.IsNotExist(err) {
+		t.Fatalf("expected stale previous cache file to be removed, stat err = %v", err)
+	}
+}
+
+func configurePreparePreviousArtifactSource(env *Env, required bool) {
+	env.Config.Pipeline.Scriptorium = &config.ScriptoriumConfig{
+		Artifacts: map[string]config.ScriptoriumArtifactConfig{
+			"session_recap": {
+				Enabled:    true,
+				OutputPath: "artifacts/session_recap.md",
+				Inputs: map[string]config.ScriptoriumInputConfig{
+					"previous_recap": {
+						Source:   "narratio.previous_session.artifact.session_recap",
+						Required: required,
+					},
+				},
+			},
+		},
+	}
+}
+
 func setupPrepareEnv(t *testing.T) (*Env, *manifest.Manifest) {
 	t.Helper()
 	workspace := t.TempDir()
@@ -291,8 +532,15 @@ func setupPrepareEnv(t *testing.T) (*Env, *manifest.Manifest) {
 
 	sessionPath := filepath.Join(cfgDir, "session.yml")
 	pipelinePath := filepath.Join(cfgDir, "pipeline.yml")
+	campaignPath := filepath.Join(cfgDir, "campaign.yml")
 
 	writeFile(t, pipelinePath, "workspace:\n  root: "+workspace+"\n")
+	writeFile(t, campaignPath, `campaign: sample-campaign
+inputs:
+  speakers_file: ./speakers.yml
+  autocorrect_file: ./autocorrect.yml
+  glossary_file: ./glossary.yml
+`)
 	writeFile(t, sessionPath, "session_id: 2026-05-03\n")
 	writeFile(t, filepath.Join(cfgDir, "speakers.yml"), "alice: alice.flac\n")
 	writeFile(t, filepath.Join(cfgDir, "autocorrect.yml"), "[]\n")
@@ -300,16 +548,32 @@ func setupPrepareEnv(t *testing.T) (*Env, *manifest.Manifest) {
 
 	cfg := &config.Config{
 		Pipeline:     &config.PipelineConfig{Workspace: config.WorkspaceConfig{Root: workspace}},
+		Campaign:     &config.CampaignConfig{Campaign: "sample-campaign"},
 		SessionPath:  sessionPath,
+		CampaignPath: campaignPath,
 		PipelinePath: pipelinePath,
 		Session: &config.SessionConfig{
 			SessionID: "2026-05-03",
 			Campaign:  "sample-campaign",
 			Inputs: config.SessionInputsConfig{
-				AudioDir:        "./audio",
-				SpeakersFile:    "./speakers.yml",
-				AutocorrectFile: "./autocorrect.yml",
-				GlossaryFile:    "./glossary.yml",
+				AudioDir: "./audio",
+			},
+		},
+		StableInputs: config.ResolvedStableInputs{
+			SpeakersFile: config.ResolvedInputFile{
+				Path:       "./speakers.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
+			},
+			AutocorrectFile: config.ResolvedInputFile{
+				Path:       "./autocorrect.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
+			},
+			GlossaryFile: config.ResolvedInputFile{
+				Path:       "./glossary.yml",
+				ConfigPath: campaignPath,
+				Source:     "campaign_config",
 			},
 		},
 	}
@@ -337,3 +601,14 @@ func snapshotInputs(inputs []manifest.InputRecord) map[string]string {
 	}
 	return out
 }
+
+func findManifestInput(t *testing.T, inputs []manifest.InputRecord, kind string) manifest.InputRecord {
+	t.Helper()
+	for _, input := range inputs {
+		if input.Kind == kind {
+			return input
+		}
+	}
+	t.Fatalf("manifest input kind %q not found in %#v", kind, inputs)
+	return manifest.InputRecord{}
+}

internal/stage/run_local.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
 	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
 )
 
@@ -99,6 +100,9 @@ func runLocalPathForCanonical(layout runStageLayout, sessionPaths artifacts.Sess
 	if rel == "." || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
 		return "", fmt.Errorf("canonical path %q is outside session root %q", cleanCanonical, sessionPaths.Root)
 	}
+	if rel == config.PathPreviousDirSegment || strings.HasPrefix(rel, config.PathPreviousDirSegment+string(filepath.Separator)) {
+		return cleanCanonical, nil
+	}
 	localPath := filepath.Join(layout.OutputsDir, rel)
 	if err := os.MkdirAll(filepath.Dir(localPath), 0o755); err != nil {
 		return "", fmt.Errorf("create run-local output parent for %q: %w", localPath, err)

internal/stage/run_local_test.go

@@ -33,3 +33,24 @@ func TestRunLocalPathForCanonicalCreatesParentDirectories(t *testing.T) {
 		t.Fatalf("expected run-local parent directory to exist: %v", err)
 	}
 }
+
+func TestRunLocalPathForCanonicalKeepsPreviousStateSessionDurable(t *testing.T) {
+	root := t.TempDir()
+	sessionRoot := filepath.Join(root, "work", "dilfs", "2026-05-17")
+	layout := runStageLayout{
+		Enabled:    true,
+		OutputsDir: filepath.Join(sessionRoot, "runs", "run-1", "prepare", "outputs"),
+	}
+	if err := os.MkdirAll(layout.OutputsDir, 0o755); err != nil {
+		t.Fatalf("mkdir outputs dir: %v", err)
+	}
+
+	canonical := filepath.Join(sessionRoot, "previous", "artifacts", "session_recap.md")
+	got, err := runLocalPathForCanonical(layout, artifacts.SessionPaths{Root: sessionRoot}, canonical)
+	if err != nil {
+		t.Fatalf("runLocalPathForCanonical() error = %v", err)
+	}
+	if got != canonical {
+		t.Fatalf("runLocalPathForCanonical() = %q, want canonical %q", got, canonical)
+	}
+}

internal/stage/transcribe_test.go

@@ -233,8 +233,10 @@ func setupTranscribeEnv(t *testing.T, audioFiles []string) (*Env, *manifest.Mani
 
 	sessionPath := filepath.Join(cfgDir, "session.yml")
 	pipelinePath := filepath.Join(cfgDir, "pipeline.yml")
+	campaignPath := filepath.Join(cfgDir, "campaign.yml")
 	writeFile(t, sessionPath, "session_id: 2026-05-03\ncampaign: sample-campaign\n")
 	writeFile(t, pipelinePath, "workspace:\n  root: "+workspace+"\n")
+	writeFile(t, campaignPath, "campaign: sample-campaign\ninputs:\n  speakers_file: ./speakers.yml\n  autocorrect_file: ./autocorrect.yml\n  glossary_file: ./glossary.yml\n")
 	writeFile(t, filepath.Join(cfgDir, "speakers.yml"), "alice: alice.flac\n")
 	writeFile(t, filepath.Join(cfgDir, "autocorrect.yml"), "[]\n")
 	writeFile(t, filepath.Join(cfgDir, "glossary.yml"), "[]\n")
@@ -243,7 +245,9 @@ func setupTranscribeEnv(t *testing.T, audioFiles []string) (*Env, *manifest.Mani
 	concurrency := 2
 	cfg := &config.Config{
 		PipelinePath: pipelinePath,
+		CampaignPath: campaignPath,
 		SessionPath:  sessionPath,
+		Campaign:     &config.CampaignConfig{Campaign: "sample-campaign"},
 		Pipeline: &config.PipelineConfig{
 			Workspace: config.WorkspaceConfig{Root: workspace},
 			WhisperX: config.WhisperXConfig{
@@ -265,6 +269,11 @@ func setupTranscribeEnv(t *testing.T, audioFiles []string) (*Env, *manifest.Mani
 				GlossaryFile:    "./glossary.yml",
 			},
 		},
+		StableInputs: config.ResolvedStableInputs{
+			SpeakersFile:    config.ResolvedInputFile{Path: "./speakers.yml", ConfigPath: campaignPath, Source: "campaign_config"},
+			AutocorrectFile: config.ResolvedInputFile{Path: "./autocorrect.yml", ConfigPath: campaignPath, Source: "campaign_config"},
+			GlossaryFile:    config.ResolvedInputFile{Path: "./glossary.yml", ConfigPath: campaignPath, Source: "campaign_config"},
+		},
 	}
 
 	env := &Env{