# Internal Overview

This document is the implemented component map for Narratio. Normative system
boundaries and dependency direction belong in
[Architecture](../policy/architecture.md). User and operator contracts belong
in the [CLI](../cli.md), [Configuration](../config.md),
[Operations](../operations.md), and [Troubleshooting](../troubleshooting.md).
Externally observable tool and format contracts belong under
[Integrations](../integrations/).

## Execution Path

```text
cmd/narratio -> internal/app -> configuration and production composition
             -> internal/stage -> adapters and external systems
             -> manifests and artifact resolution -> durable local/remote output
```

The executable delegates process behavior to the application boundary. The
application resolves configuration, composes concrete collaborators, acquires
session safety controls, and runs commands. Pipeline commands execute the
canonical stage sequence through adapter interfaces, while manifests record
progress and artifact services resolve durable inputs and outputs.

## Components

| Area | Implemented owners | Responsibility |
| --- | --- | --- |
| Executable | `cmd/narratio` | Process entry, standard stream wiring, argument handoff, and exit status. |
| Application orchestration | `internal/app` | Command dispatch, configuration selection, secret-file environment loading, production composition, session locking, planning, execution, restore, cleanup gates, and user-facing reporting. |
| Configuration | `internal/config` | Strict YAML loading, discovery, defaults, normalization, session templating, and validation. |
| Pipeline stages | `internal/stage` | Canonical stage registry, shared stage contract, execution dependencies, and implemented stage behavior. |
| External boundaries | `internal/adapters`, `internal/audio` | WhisperX HTTP, downstream subprocesses, notification, object storage, and S3 audio materialization behind Narratio contracts. |
| Manifests | `internal/manifest` | Durable session progress, invocation audit state, stage transitions, validation, and atomic persistence. |
| Artifacts and paths | `internal/artifacts`, `internal/pathsafe` | Artifact identities and resolution, local and remote path/key models, current-state discovery, and confined relative destinations. |
| Previous-session cache | `internal/previouscache` | Deterministic planning and materialization requirements for configured previous-session inputs. |
| Artifact policy | `internal/artifactpolicy` | Source and destination policy, configured artifact identity validation, and publish destination safety. |
| Shared models and file operations | `internal/artifactmodel`, `internal/contracts`, [`internal/fileops`](fileops.md) | Transcript and artifact data contracts plus durable single-file replacement helpers; unsupported directory syncing is reported explicitly. |
| Logging | `internal/logging` | Application logger construction and shared structured logging behavior. |

The application boundary composes concrete implementations. Stages depend on
Narratio-level contracts; external transport and SDK details remain in
adapters. The normative rules for these relationships remain in
[Architecture](../policy/architecture.md).

## Pipeline Stage Set

The implemented canonical order is:

1. [`prepare`](stage-prepare.md)
2. [`transcribe`](stage-transcribe.md)
3. [`merge`](stage-merge.md)
4. [`polish`](stage-polish.md)
5. [`normalize`](stage-normalize.md)
6. [`trim`](stage-trim.md)
7. [`extract`](stage-extract.md)
8. [`render`](stage-render.md)
9. [`analyze`](stage-analyze.md)
10. [`publish`](stage-publish.md)
11. `notify` (placeholder)

`notify` currently has optional notifier call behavior and no persisted pipeline
outputs; its default collaborator is a no-op sender. The focused stage
documents own implementation mechanics. The
[CLI](../cli.md) and [Operations](../operations.md) own user-visible invocation
and execution semantics.

## Focused Documentation

- [Adapter Internals](adapters.md): external adapter boundaries, composition,
  failure behavior, and test surfaces.
- [Artifact Internals](artifacts.md): source identities, runtime catalog,
  resolution, previous requirements, and current-state helpers.
- [Manifest Internals](manifest.md): session and run records, persistence, and
  execution transitions.
- [Storage Internals](storage.md): object-store interface and S3 behavior.
- [Workspace Internals](workspace.md): local layout, locking, and cleanup
  guardrails.
- [Restore Internals](command-restore.md): discovery, planning, execution, and
  reporting.
- [`prepare`](stage-prepare.md)
- [`transcribe`](stage-transcribe.md)
- [`merge`](stage-merge.md)
- [`polish`](stage-polish.md)
- [`normalize`](stage-normalize.md)
- [`trim`](stage-trim.md)
- [`extract`](stage-extract.md)
- [`render`](stage-render.md)
- [`analyze`](stage-analyze.md)
- [`publish`](stage-publish.md)

Use this map to find an owner, then read its focused documentation and tests
before changing behavior.

The stage registry is implemented in `internal/stage/placeholders.go` and its
ordering is protected by `internal/app/planner_test.go`. Cross-invocation skip,
force, failure, and invalidation behavior is exercised in
`internal/app/runner_test.go` and `internal/app/run_stage_test.go`.