diff --git a/docs/cli.md b/docs/cli.md
index 9052841..1fb66c8 100644
--- a/docs/cli.md
+++ b/docs/cli.md
@@ -9,7 +9,7 @@ For the minimal end-to-end invocation, see the [README](../README.md).
 
 ```text
 notarius help
-notarius run <pipeline-id> --input path/to/source.json [--config path/to/config.yml] [--only lane-a,lane-b] [--output-dir path] [--diagnostics-dir path] [--llm-profile id] [--resume] [--session-id id] [--reference selector=path] [--without-reference selector]
+notarius run <pipeline-id> --input path/to/source.json [--config path/to/config.yml] [--only lane-a,lane-b] [--chunk_cache auto|bypass|refresh] [--output-dir path] [--diagnostics-dir path] [--llm-profile id] [--resume] [--session-id id] [--reference selector=path] [--without-reference selector]
 notarius config validate [--config path/to/config.yml] [--pipeline pipeline-id] [--only lane-a,lane-b]
 notarius pipelines list [--config path/to/config.yml] [--json]
 ```
@@ -31,6 +31,12 @@ Flags:
   comma-separated and must be non-empty.
 - `--resume`: request checkpoint reuse for this invocation. See
   [Operations](operations.md#checkpoints) for prerequisites and reuse behavior.
+- `--chunk_cache auto|bypass|refresh`: select chunk-plan reuse for this
+  invocation. `auto` reuses a valid plan by canonical source digest, `bypass`
+  performs no plan-cache I/O, and `refresh` regenerates and replaces a valid
+  plan only after chunk validation succeeds. See
+  [Configuration](config.md#workspace) for the persistent setting, precedence,
+  and cache-root selection.
 - `--output-dir path`: output root. Defaults to `./notarius-output`.
 - `--diagnostics-dir path`: diagnostics work directory override for this
   invocation. It does not change the workspace directory.
@@ -125,6 +131,24 @@ go run ./cmd/notarius run dnd-session \
   --resume
 ```
 
+Use `refresh` when intentionally replacing the cached plan for the same source:
+
+```sh
+go run ./cmd/notarius run dnd-session \
+  --config examples/dnd-spells.config.yml \
+  --input examples/seriatim-minimal-transcript.json \
+  --chunk_cache refresh
+```
+
+Use `bypass` for a one-off run that must not inspect or create plan-cache state:
+
+```sh
+go run ./cmd/notarius run dnd-session \
+  --config examples/dnd-spells.config.yml \
+  --input examples/seriatim-minimal-transcript.json \
+  --chunk_cache bypass
+```
+
 For checkpoint behavior, durable output, diagnostics, retention, and failure
 inspection, see [Operations](operations.md).
 
diff --git a/docs/config.md b/docs/config.md
index 03412dc..818461b 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -48,6 +48,8 @@ Built-in defaults:
 - `workspace.diagnostics.enabled`: `true`
 - `workspace.resume.enabled`: `false`
 - `workspace.debug.enabled`: `false`
+- `workspace.chunk_cache.mode`: `auto`
+- `workspace.chunk_cache.directory`: unset
 
 No pipelines are built in. A run requires a configured pipeline.
 
@@ -97,6 +99,8 @@ These environment variables are applied after the config file:
 - `NOTARIUS_WORKSPACE_RESUME_ENABLED`: boolean resume checkpointing
   enablement.
 - `NOTARIUS_WORKSPACE_DEBUG_ENABLED`: boolean debug artifact enablement.
+- `NOTARIUS_WORKSPACE_CHUNK_CACHE_MODE`: chunk-plan cache mode.
+- `NOTARIUS_WORKSPACE_CHUNK_CACHE_DIR`: chunk-plan cache root.
 - `NOTARIUS_WORK_DIR`: deprecated diagnostics work directory compatibility
   override.
 - `NOTARIUS_DIAGNOSTICS_RETENTION`: deprecated diagnostics retention
@@ -344,11 +348,35 @@ casts still must be present in the source transcript.
 - `directory`: optional workspace root for Notarius-owned local state.
 - `resume.enabled`: boolean resume checkpointing setting.
 - `debug.enabled`: boolean debug artifact setting.
+- `chunk_cache.mode`: persistent chunk-plan cache mode: `auto`, `bypass`, or
+  `refresh`. The default is `auto`.
+- `chunk_cache.directory`: optional chunk-plan cache root. This value is the
+  root itself; Notarius does not append `chunk-plans` to it.
 - `diagnostics`: optional diagnostics settings defined below.
 
-`workspace.resume.enabled` and `workspace.debug.enabled` are independent.
-Enabling one does not enable the other. For directory layout, state lifecycle,
-permissions, and sensitive content, see [Operations](operations.md).
+`workspace.resume.enabled`, `workspace.debug.enabled`, and
+`workspace.chunk_cache` are independent. `workspace.directory` does not affect
+chunk-plan placement. For directory layout, state lifecycle, permissions, and
+sensitive content, see [Operations](operations.md).
+
+`chunk_cache.mode` accepts only `auto`, `bypass`, and `refresh`. In `auto`, a
+valid source-addressed plan is reused and a missing or invalid record is
+regenerated and published after chunk validation. `bypass` neither reads nor
+writes plan-cache state. `refresh` always generates a new plan and publishes it
+only after validation succeeds.
+
+Configuration values are applied in file then environment order; an explicit
+`--chunk_cache` CLI value has highest precedence for the mode. The cache root
+is selected from environment, file, then the per-user default; there is no CLI
+root override. Every supplied value is parsed strictly even when a higher
+precedence value wins, so malformed configuration is still an error.
+
+When `chunk_cache.directory` is unset, the root is
+`<os.UserCacheDir>/notarius/chunk-plans`. On Unix this is ordinarily
+`$XDG_CACHE_HOME/notarius/chunk-plans` when `XDG_CACHE_HOME` is an absolute
+path, or `$HOME/.cache/notarius/chunk-plans` when it is unset. A relative
+`XDG_CACHE_HOME` is rejected by `os.UserCacheDir`; Notarius reports that as a
+configuration error and does not fall back to another directory.
 
 ## Diagnostics
 
@@ -390,6 +418,7 @@ Configuration validation checks:
 - supported stage-worker keys and an effective extract worker count in the
   inclusive range `1..concurrency.total_llm`;
 - supported diagnostics retention and non-empty work directory;
+- a supported chunk-cache mode and a chunk-cache directory without NUL bytes;
 - stale removed fields such as `llm_profiles`.
 
 Pipeline resolution additionally checks:
diff --git a/docs/integrations/json-output.md b/docs/integrations/json-output.md
index 572351b..a04c7e4 100644
--- a/docs/integrations/json-output.md
+++ b/docs/integrations/json-output.md
@@ -91,6 +91,16 @@ The manifest fields are:
   identity;
 - `input_module`, `chunker`, `extractors`, `merger`, `normalizer`, and
   `output_encoder`: resolved module keys;
+- `chunk_plan`: payload-free provenance for the effective chunk plan. `mode`
+  is the effective cache mode; `action` is `reused`, `generated`,
+  `refreshed`, or `bypassed` when a plan was materialized. `requested_module`
+  is the current pipeline chunker, while `producer_input_module`,
+  `producer_module`, `producer_llm_profile`, `producer_references`,
+  `producer_metadata`, `source_digest`, `plan_digest`, `plan_schema_version`,
+  and `created_at` describe the stored or generated producer when available.
+  A cached plan can therefore identify a producer different from the requested
+  module. This object never embeds ranges, units, annotations, prompts,
+  responses, or reference content;
 - `module_metadata` and `artifact_lanes`: module and per-lane provenance,
   including prompt and response-schema provenance when provided;
 - `validator_chains`: resolved validation points and validators;
@@ -115,6 +125,10 @@ references.
 `validation_status` is `approved` when no outputs were rejected and `rejected`
 when one or more outputs were rejected.
 
+Producer warnings and the current run's chunk-validation warnings remain in
+`warnings.json`. The manifest records only provenance and decision summaries;
+empty producer-only values are omitted for compatibility with existing readers.
+
 `validator_chains` records the resolved validator chain for each validation
 point. Entries include stage, lane ID when applicable, module key, and validators
 with key and execution class. Empty chains are recorded with an empty
diff --git a/docs/internal/diagnostics.md b/docs/internal/diagnostics.md
index b7ad032..583f37a 100644
--- a/docs/internal/diagnostics.md
+++ b/docs/internal/diagnostics.md
@@ -22,10 +22,18 @@ constructor.
 
 Typed methods on `RunDirectory` write invocation metadata, redacted effective
 configuration, resolved pipeline/reference data, checkpoint events, source data
-when explicitly requested, manifests, reports, warnings, and error text. The
+when explicitly requested, manifests, reports, warnings, redacted chunk-plan
+summaries, and error text. The
 current filenames and their operator-facing contents are listed in
 [Operations](../operations.md#diagnostics-directory).
 
+The chunk-plan summary records the effective mode, source and candidate
+digests, requested module, lookup decision, materialization action, validation
+decision, and publication decision. Its closed decision values make failures
+and recoverable invalid records inspectable without serializing plan ranges,
+annotations, source content, reference content, prompts, model responses, or
+raw invalid-file bytes.
+
 JSON methods indent their payload and append a newline. All artifact writes use
 a temporary file in the target directory, apply the requested permissions, and
 rename it into place. Artifact resolution accepts only a single relative base
@@ -60,7 +68,8 @@ pipeline results, and the final report. This ordering permits later failures to
 retain the context already established.
 
 Failures before construction have no `RunDirectory`. Later failures write an
-error log, preserve any available partial manifest, and apply a failed-run
+error log, preserve any available partial manifest and chunk-plan summary, and
+apply a failed-run
 retention decision. A diagnostics write failure is itself a command failure so
 the CLI does not report success after losing requested inspection data.
 
diff --git a/docs/internal/modules.md b/docs/internal/modules.md
index 2ae7268..2823998 100644
--- a/docs/internal/modules.md
+++ b/docs/internal/modules.md
@@ -67,34 +67,41 @@ rules are defined in the
 
 ## Chunkers
 
+Chunkers implement `contracts.Chunker.Plan`. A plan identifies ordered source
+unit ranges and may carry optional namespaced JSON annotations; it does not
+contain materialized chunk content. The framework canonicalizes annotations,
+validates ranges against the current source, and materializes chunk IDs,
+indexes, references, content, units, and generic metadata. Annotation
+namespaces remain optional data: generic framework code and downstream modules
+must not require D&D scene annotations or import `dnd/scenes`.
+
 ### `internal/modules/generic/chunk/units`
 
-The generic chunker validates the source document, walks units in configured
-windows, clones each selected unit, and emits deterministic ordered chunk IDs.
-Overlap changes the next window start but never reorders units. It records the
-first and last unit and unit count in chunk metadata, and derives the chunk's
-canonical source reference from those unit references.
+The generic chunker validates the source document and returns ranges over units
+in configured windows. Overlap changes the next window start but never reorders
+units. Framework materialization derives the resulting chunk identity and
+generic metadata from those ranges.
 
 The accepted options and defaults are defined in
 [Configuration](../config.md#implemented-production-modules). Generic
 framework validation canonicalizes the returned unit slices before extraction.
 The chunker decodes its options during construction and retains only the typed
-window settings used by `Chunk`.
+window settings used by `Plan`.
 
 ### `internal/modules/dnd/chunk/scenes`
 
 The scene chunker prepares a structured Scriptorium request from the full
 transcript, session, and optional D&D reference inputs. It validates the model's
 scene boundaries against source-unit IDs and converts them into deterministic
-chunks with canonical source references spanning each scene's units.
-Preparation injects the shared structured LLM client into the chunker; `Chunk`
+plan ranges with optional scene annotations. Preparation injects the shared
+structured LLM client into the chunker; `Plan`
 supplies only the run-specific profile, session, source, references, and
 metadata.
 
 Scene validation requires sequential, contiguous, non-overlapping coverage from
-the first source unit through the last. Each chunk contains JSON scene content
-and module-owned metadata for the scene description, boundaries, confidence,
-participants, and unit count. Boundary caveats become warnings. Malformed
+the first source unit through the last. Scene descriptions, boundaries,
+confidence, and participants are module-owned annotations. Boundary caveats
+become warnings. Malformed
 structured output is returned as an error; there is no fallback chunker.
 
 The package embeds its prompt and response schema and reports their non-secret
diff --git a/docs/internal/overview.md b/docs/internal/overview.md
index d7fd425..ab15e7f 100644
--- a/docs/internal/overview.md
+++ b/docs/internal/overview.md
@@ -35,7 +35,7 @@ normalize continuations that may overlap across lanes.
 | `internal/core/config` | Defaults, YAML parsing, environment overrides, validation, redaction, and effective pipeline resolution. |
 | `internal/core/diagnostics` | Scoped run directories, diagnostics writers, atomic writes, and retention decisions. |
 | `internal/core/source` | Generic source documents, units, chunks, canonical references, lookup, validation, and deterministic source digests. |
-| `internal/core/workspace` | Effective workspace settings, confined paths and writes, checkpoint identity, and checkpoint manifest models. |
+| `internal/core/workspace` | Effective workspace settings, confined paths and writes, and checkpoint identity and manifest models. |
 
 ## Framework Packages
 
@@ -47,6 +47,7 @@ normalize continuations that may overlap across lanes.
 | `internal/framework/llm` | Scriptorium-backed structured completions, prompt/schema registration, scheduling, profile recording, and secret redaction. |
 | `internal/framework/promptfs` | Builds module prompt filesystems from module-owned and caller-provided shared prompt assets. |
 | `internal/framework/checkpoint` | Workspace-backed checkpoint loading, recording, and payload serialization. |
+| `internal/framework/chunkplan` | Source-addressed chunk-plan filesystem storage, envelope validation, and atomic publication. |
 | `internal/framework/debug` | Workspace-backed framework and LLM debug recording. |
 
 Framework contracts provide typed artifact, provenance-wrapper, chunk-validator,
@@ -122,7 +123,8 @@ Implementation details for all production extensions are in
 | --- | --- | --- |
 | Durable output | Output module, pipeline runner, and CLI writer | Return logical consumer files and place them for a run. |
 | Diagnostics | `internal/core/diagnostics` and `internal/cli` | Record redacted invocation, resolution, result, and failure inspection data. |
-| Checkpoints | `internal/framework/checkpoint` and `internal/core/workspace` | Validate and serialize reusable stage outcomes. |
+| Checkpoints | `internal/framework/checkpoint` and `internal/core/workspace` | Validate and serialize reusable extract, merge, and normalize outcomes. |
+| Chunk-plan cache | `internal/framework/chunkplan` and `internal/cli` | Persist and select source-addressed plans before framework materialization. |
 | Debug artifacts | `internal/framework/debug` and pipeline instrumentation | Capture sensitive framework-boundary and LLM-call material. |
 
 Physical layout, retention, recovery, and sensitive-data handling are defined
diff --git a/docs/internal/pipeline.md b/docs/internal/pipeline.md
index ca9b40b..b9cd133 100644
--- a/docs/internal/pipeline.md
+++ b/docs/internal/pipeline.md
@@ -8,7 +8,8 @@ defaults, and selectable keys are defined in
 
 Resolution fixes the selected lanes and all stage bindings; preparation
 constructs every selected implementation before the runner begins source work.
-After serial input parsing and chunking, the runner dispatches extract work to
+After serial input parsing and plan selection or generation, the runner
+materializes chunks and dispatches extract work to
 one bounded run-wide worker pool in chunk-first, lane-second order. Each lane's
 merge and normalize operations remain serial and may overlap other lanes once
 all extracts for that lane are terminal.
@@ -118,7 +119,8 @@ validator context as applicable. It never invokes an operation method.
 `PreparedPipeline` keeps private constructed executors and exposes cloned
 resolved input, chunk, lane, and output identities. `pipeline.RunInput` carries
 that prepared pipeline, raw source input, run identity and timing, optional
-session and profile metadata, and checkpoint/debug collaborators. The runner
+session and profile metadata, a chunk-plan store and mode, and checkpoint/debug
+collaborators. The runner
 parses source bytes through the already constructed input adapter. Later stage
 requests receive the generic source model; extract requests receive
 chunk-scoped input material, while chunk, merge, and normalize requests retain
@@ -151,8 +153,9 @@ The runner:
 1. validates its prepared input;
 2. parses the raw input with the prepared adapter and validates the generic
    source document;
-3. obtains or executes the chunk result;
-4. validates and canonicalizes chunks;
+3. selects a stored plan or executes the configured chunker's `Plan` operation;
+4. canonicalizes and materializes the plan, then validates the resulting
+   chunks;
 5. dispatches extract jobs in source-chunk then resolved-lane order, starting a
    bounded lane continuation when all extracts for that lane are terminal;
 6. invokes the prepared output encoder and validates its logical file results;
@@ -173,6 +176,31 @@ and validators while performing these transitions:
 Module-provided warnings and payload warnings are promoted only from attempts
 whose results are accepted and used.
 
+## Chunk Plans And Reuse
+
+`Chunker.Plan` returns a `source.ChunkPlan`: the canonical source digest,
+ordered unit-ID ranges, and optional plan or range annotations. The framework
+owns plan canonicalization and materialization. It creates the generic chunks
+and therefore owns their IDs, indexes, source references, JSON content, units,
+media type, and generic metadata. Plan and range annotations are independently
+owned raw JSON and become `Chunk.PlanAnnotations` and `Chunk.Annotations`.
+
+In `auto`, the runner looks up the source digest before invoking the chunker. A
+valid hit is materialized and sent through the current run's configured chunk
+validators; it does not invoke the chunk module, consume its retry budget, or
+make a chunk-stage LLM call. A missing, invalid, or unmaterializable record
+generates a candidate. `refresh` generates without lookup; `bypass` generates
+without cache access. Generated plans are published only after the full chunk
+validator chain approves them. A validator rejection is a regular rejected
+pipeline outcome and never replaces a cached plan.
+
+The store is source-addressed, not pipeline-addressed. Changes to pipeline
+configuration, requested chunker, options, references, lanes, validators, or
+LLM profile do not prevent a source-digest hit. The manifest records both the
+currently requested chunker and the effective plan producer. Cache state and
+paths are configured and operated outside the runner; see
+[Configuration](../config.md#workspace) and [Operations](../operations.md).
+
 The extract job channel has the same capacity as the effective extract worker
 count, so dispatch applies backpressure. A fixed continuation executor prevents
 ready or checkpoint-reused lanes from creating one goroutine each. Workers and
@@ -180,19 +208,19 @@ continuations publish lane-local results; the coordinator is the only writer of
 aggregate output and merges those results in resolved lane and source-chunk
 order.
 
-## Chunk Canonicalization
+## Plan Canonicalization And Chunk Materialization
 
-Before lane execution, generic validation requires unique chunk IDs, matching
-source identity, indexes matching returned order, a valid canonical reference,
-non-empty content and media type, and at least one valid source unit per chunk.
-Units may not repeat inside a chunk and must form a contiguous range in
-source-document order. The chunk reference must exactly match the source and
-the first and last unit references.
+Plan canonicalization requires canonical JSON annotations, a matching source
+digest, at least one range, existing ordered boundaries, and increasing range
+starts. Ranges may overlap or leave gaps; a chunker may impose stricter policy.
+Materialization deterministically reconstructs each range from the current
+source document and copies annotations without interpreting their namespaces.
 
-The runner then rebuilds each chunk's unit slice from the source document by
-unit ID. It preserves the canonical reference, content, media type, and cloned
-metadata. The framework permits gaps and overlap between separate
-chunks; stricter coverage policy belongs to the chunk implementation.
+Before lane execution, generic chunk validation checks the materialized chunks'
+identities, order, source references, content, media type, units, and metadata.
+No chunk checkpoint participates in plan selection: plan storage is the only
+chunk-reuse mechanism. Extract, merge, and normalize checkpoints continue to
+use materialized chunk digests as their dependencies.
 
 ## Validation And Retries
 
diff --git a/docs/operations.md b/docs/operations.md
index 026172a..15a8345 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -57,6 +57,10 @@ Implemented diagnostics artifacts:
   binding source, without reference content.
 - `checkpoint-events.json`: checkpoint steps that were reused or executed
   during an explicit resume invocation.
+- `chunk-plan.json`: redacted plan-cache lookup, validation, and publication
+  summary. It contains identifiers and decisions, never source units, plan
+  annotations, reference content, prompts, model responses, or invalid-file
+  bytes.
 - `run-manifest.json`: the same run manifest written to durable output when it
   is available, including top-level module metadata when present.
 - `warnings.json`: warning list.
@@ -64,6 +68,54 @@ Implemented diagnostics artifacts:
 - `error.log`: failure message, written after diagnostics directory creation
   when a run fails.
 
+## Chunk-Plan Cache
+
+The chunk-plan cache is independent of the workspace and checkpoints. Its
+configuration and selection precedence are defined in
+[Configuration](config.md#workspace); the invocation override is documented in
+the [CLI reference](cli.md#run).
+
+When no root is configured, a normal Linux user uses
+`$XDG_CACHE_HOME/notarius/chunk-plans` when `XDG_CACHE_HOME` is a valid absolute
+path, or `$HOME/.cache/notarius/chunk-plans` when it is unset. A relative
+`XDG_CACHE_HOME` is a configuration error. A configured
+`workspace.chunk_cache.directory` is the root itself, not a parent to which
+Notarius adds a suffix.
+
+Each source digest has one file:
+
+```text
+<chunk-plan-root>/<source-sha256-hex>/plan.json
+```
+
+Directories are created with `0700` permissions and plan files with `0600`.
+`auto` reuses a complete valid plan or regenerates an absent or invalid one;
+`refresh` deliberately regenerates; `bypass` performs no cache I/O. A stored
+plan is still validated and materialized against the current source before use,
+and the current run's chunk validators always run. Invalid state is recoverable:
+an `auto` run regenerates and atomically replaces it only after validation
+succeeds. Delete an exact cache root or digest directory only when regeneration
+cost is acceptable.
+
+Publication uses atomic replacement. Concurrent readers observe a complete old
+or new plan, and concurrent writers leave one complete valid winner; there is
+no history, lock protocol, or rollback facility. Do not share a cache root
+between mutually untrusted users because plans can contain source-derived
+structure and annotations.
+
+For a system-wide Linux deployment under a dedicated service account, configure
+and provision a separate restrictive root such as:
+
+```yaml
+workspace:
+  chunk_cache:
+    directory: /var/cache/notarius/chunk-plans
+```
+
+`/var/cache/notarius/chunk-plans` is a recommended configured service root, not
+the unprivileged default. The operator or package installer must create it with
+restrictive service-account ownership and permissions before use.
+
 ## Checkpoints
 
 When checkpoint writing is enabled for a configured workspace, runs write
@@ -158,8 +210,12 @@ failure before a candidate exists has no candidate payload. If the envelope
 cannot be persisted, the run does not retry that module attempt and reports the
 debug failure together with any primary attempt error.
 
-Checkpoint-reused chunk, extract, merge, and normalize work retains the
-stage-level input and output artifacts but has no retry-attempt artifacts
+Chunk-plan candidates, materialized chunks, annotations, and chunk-attempt
+details appear only in these opt-in debug artifacts. They are intentionally not
+included in normal manifests or the `chunk-plan.json` diagnostics summary.
+
+Checkpoint-reused extract, merge, and normalize work retains the stage-level
+input and output artifacts but has no retry-attempt artifacts
 because no module attempt executed. Debug artifacts may contain source
 material, reference material, prompt inputs, model outputs, and other sensitive
 data. Typed artifact
@@ -218,6 +274,10 @@ rm -rf /var/lib/notarius/checkpoints/dnd-session/seriatim-abcdef123456/7890abcd1
 rm -rf /var/lib/notarius/debug/run-1234567890
 ```
 
+Chunk-plan cache entries can likewise be removed by exact digest directory or
+configured root. Removal is recoverable, but the next non-bypass run may need
+to regenerate plans and repeat any chunk-stage LLM work.
+
 Use exact run-directory paths. Avoid broad cleanup commands against parent
 directories unless they are part of your own operational policy.
 
diff --git a/docs/policy/architecture.md b/docs/policy/architecture.md
index 13856f9..656e616 100644
--- a/docs/policy/architecture.md
+++ b/docs/policy/architecture.md
@@ -105,6 +105,14 @@ Stage ownership is explicit:
 - normalize modules reconcile merged output;
 - output modules encode accepted results and run outcomes into logical files.
 
+Chunk modules produce source-addressed chunk plans rather than materialized
+chunks. The framework validates and materializes those plans into the generic
+chunk representation before chunk validation and lane execution. Plan reuse is
+therefore independent of the configured pipeline, module options, references,
+lanes, validators, and LLM profile: the canonical source digest selects the
+plan, while the current run still applies its configured chunk validators to
+the materialized chunks.
+
 The framework owns orchestration and handoff provenance. Modules return logical
 results and warnings; they do not own CLI reporting, workspace paths, durable
 file placement, checkpoints, or diagnostics.
@@ -191,6 +199,12 @@ surfaces with separate ownership:
 - debug artifacts are opt-in inspection data and may contain sensitive source,
   prompt, reference, and model-output content.
 
+Chunk-plan cache state is an additional independent surface. It is keyed only
+by canonical source digest, is not rooted under `workspace.directory`, and is
+not a checkpoint or a diagnostic. A cache record is atomically replaced as one
+complete plan envelope; it has no history, locking, or rollback interface.
+Invalid records are recoverable cache misses rather than pipeline state.
+
 Writes of durable state are atomic where practical. Paths for writes, moves,
 overwrites, and deletion must be narrow and explicit. Cleanup that can lose data
 is opt-in.
diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index 1f8a8bc..f4b817c 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -1,13 +1,12 @@
-# ADR-0005 Staged Implementation Plan
+# ADR-0005 Implementation Record
 
-This document is the executable implementation plan for the target state in
+This document records the completed implementation of the target state in
 [ADR-0005 Feature Roadmap](adr0005.md), governed by
-[ADR-0005](../adr/0005-cache-canonical-chunk-plans-by-source.md). The feature is
-not implemented.
+[ADR-0005](../adr/0005-cache-canonical-chunk-plans-by-source.md).
 
-The audience is an LLM coding agent. Implement the stages in order. Each stage
-is deliberately scoped to finish with a compiling, tested repository and may be
-assigned as one implementation prompt.
+All stages below are complete. The plan remains as historical target-state
+context; current behavior is documented in the canonical references linked from
+[Development](../development.md).
 
 ## Execution Rules
 
@@ -870,7 +869,7 @@ and race checks pass.
 
 ## Stage 8: Publish current-behavior documentation
 
-**Status:** Not started
+**Status:** Complete
 
 ### Objective
 
diff --git a/examples/dnd-spells-production.config.yml b/examples/dnd-spells-production.config.yml
index e3cb08f..b62adef 100644
--- a/examples/dnd-spells-production.config.yml
+++ b/examples/dnd-spells-production.config.yml
@@ -12,6 +12,8 @@ workspace:
     enabled: false
   debug:
     enabled: false
+  chunk_cache:
+    directory: /var/cache/notarius/chunk-plans
 pipelines:
   dnd-session:
     input: seriatim
diff --git a/examples/dnd-spells.config.yml b/examples/dnd-spells.config.yml
index a7b4089..f16309f 100644
--- a/examples/dnd-spells.config.yml
+++ b/examples/dnd-spells.config.yml
@@ -1,4 +1,7 @@
 version: 2
+workspace:
+  chunk_cache:
+    mode: bypass
 pipelines:
   dnd-session:
     input: seriatim