## Step 6 Goal (from `docs/ver1/ver1.md`)
Implement **minimal observability & operability** so a single operator can quickly diagnose and recover from common failures.

---

## 1) Current-State Assessment (what already exists)

### Already in place
- Central startup logging initialization via `setup_logging()` and `dictConfig` (`src/transcription/config.py`, `src/transcription/app.py`).
- Error taxonomy and `error_id` envelope contract (`src/transcription/errors.py`) aligned with `docs/error_handling.md`.
- Error handling for API and worker includes category + error IDs in some paths (`src/transcription/api/errors.py`, `src/transcription/worker.py`).
- Basic health endpoint `/healthz` (`src/transcription/api/health.py`).
- UI error display already shows actionable message + error reference (`src/transcription/ui/error_presenter.py`).

### Gaps to close for Step 6
1. **Structured logging is inconsistent** (many logs are free-form text with embedded key/value; no enforced schema).
2. **Boundary coverage is incomplete** (UI/service/API/worker don’t all emit consistent operation logs).
3. `/healthz` is very basic; no lightweight readiness/startup diagnostics endpoint/reporting.
4. No concise **operator runbook** yet (start/stop, log interpretation, recovery playbooks).
5. Minimal counters/timings are not yet standardized.

---

## 2) MCP Guidance Incorporated (relevant items)

From `john-stream-mcp`, these are directly applied:

- **`python-logging-dictconfig`**: keep one centralized `dictConfig`, configure once at startup, named loggers in modules.
- **`fastapi-async-sqlalchemy-modernization`**: include observability + health/readiness checks; explicit lifecycle and deterministic startup/shutdown checks.
- **`fastapi-uv-docker`**: keep `/healthz`; add practical readiness/ops checks for deployment clarity.
- **`pytesting`**: deterministic tests, concise structure, validation lanes (`collect-only`, `unit`, `not external`, full).
- **`pydantic-settings`**: keep typed settings as single source for logging/health behavior flags.
- **`nicegui` + `nicegui-ui-customization`**: preserve clear, actionable user-facing error feedback and non-blocking UI flows.
- **`zensical-docs`**: produce focused, navigable operator docs.

(Other MCP resources were reviewed but are not core to Step 6 implementation scope.)

---

## 3) Detailed Implementation Plan for Step 6

## Workstream A — Structured Logging Contract

### A1. Define a canonical log event schema
Create a project log schema (doc + code-level constants) with required keys:
- `timestamp` (UTC)
- `level`
- `logger`
- `operation`
- `event`
- `error_id` (when error)
- `category` (when error)
- `exception_type` (when error)
- `job_id`, `document_id` (when relevant)
- optional: `duration_ms`, `retry_count`, `status`

### A2. Standardize log emission helpers
Add small logging helpers (or adapter utilities) to reduce drift:
- `log_operation_start(...)`
- `log_operation_success(...)`
- `log_operation_error(...)`

Keep this minimal and avoid heavy observability frameworks.

### A3. Update formatter to structured output
Use `dictConfig` to emit either:
- JSON lines (preferred for structure), or
- strict key-value line format with fixed fields.

**Recommendation:** JSON lines to satisfy “structured logging” unambiguously while still simple.

---

## Workstream B — Boundary-by-Boundary Instrumentation

### B1. API boundary (`src/transcription/api/*`)
- Add request-level operation logs for key routes (`upload.submit`, `jobs.list`, `jobs.get`, etc.).
- Ensure API exception handler logs always include `error_id`, `category`, `operation`, `exception_type`.

### B2. Service boundary (`src/transcription/services/*`)
- Add operation logs around:
  - upload validation/persist,
  - transcription orchestration,
  - revision add/accept,
  - search/export.
- Add timing (`duration_ms`) for high-value operations only.

### B3. Worker boundary (`src/transcription/worker.py`)
- Standardize all worker log events to schema.
- Ensure retry logs include: `retriable`, `retry_count`, `max_retries`, `backoff_seconds`.
- Ensure terminal failure logs include error contract fields.

### B4. UI boundary (`src/transcription/ui/*`)
- Keep user-safe UI messages as-is.
- Add backend/UI logger events for user-triggered failures (operation + error_id + category) so UI-visible errors correlate to server logs.

---

## Workstream C — Health, Readiness, Startup Operability

### C1. Keep `/healthz` lightweight
- Return “process is running” status quickly.

### C2. Add lightweight `/readyz`
Include small checks:
- DB connectivity ping.
- Worker thread alive check.
- Optional prompt directory existence check.

Return structured status payload with per-check pass/fail.

### C3. Startup self-check summary log
At startup, emit one concise ops summary event:
- environment
- schema validation result
- worker started
- directories checked
- bootstrap/migration mode flags

---

## Workstream D — Minimal Counters & Timings

Add only high-value diagnostics:
1. `worker_jobs_processed_total`
2. `worker_jobs_failed_total`
3. `worker_retries_total`
4. `transcription_duration_ms` (per job)
5. `upload_persist_duration_ms` (per upload path)

Implementation can be log-derived counters (no external metrics backend required).

---

## Workstream E — Operator Runbook

Create concise runbook doc (recommended: `docs/ver1/ver1-step6-operator-runbook.md`) with:

1. **Start/Stop**
   - local `uv` run mode
   - docker compose mode (if applicable)

2. **Where logs are**
   - stdout, docker logs commands, filtering by `error_id` / `operation`.

3. **Common failure patterns → recovery**
   - provider timeout
   - auth denied
   - missing prompt dir
   - DB unavailable
   - job stuck/failed with retry exhausted

4. **Recovery procedures**
   - restart sequence
   - verify health/readiness
   - when to requeue/re-upload

5. **Escalation artifacts**
   - capture timestamp + error_id + operation + job_id/document_id

Also update `README.md` with short links to the runbook.

---

## Workstream F — Verification & Quality Gates

### Tests to add/update
- `tests/api/test_health.py`
  - `/healthz` baseline
  - `/readyz` pass/fail behavior
- `tests/api/test_error_responses.py` / `tests/api/test_routes.py`
  - logs include `error_id/category/operation` on failures
- `tests/services/test_worker.py`
  - retry/failure log fields + timing presence
- `tests/ui/*`
  - ensure UI error correlation path includes operation/ref id behavior

### Validation commands (per MCP pytest guidance)
- `uv run pytest --collect-only -q`
- `uv run pytest -m unit -q`
- `uv run pytest -m "not external" -q`
- `uv run pytest -q`

---

## 4) Traceability to Governing Docs

- **`docs/ver1/ver1.md` Step 6:** all 5 implementation bullets covered.
- **`docs/error_handling.md`:** logging contract fields and error taxonomy continuity enforced.
- **`docs/architecture.md`:** respects modular boundaries, in-process worker model, low-complexity ops.
- **`docs/requirements.md`:**
  - REQ-8 (startup logging/config centralization) strengthened,
  - REQ-5 (status visibility) improved operationally,
  - REQ-7 lifecycle ownership observability improved.
- **`docs/intent.md`:** keeps operation simple for personal-scale archival workflow.

---

## 5) Suggested Execution Order (low risk)

1. Logging schema + formatter + helpers  
2. Worker/API instrumentation (highest value)  
3. Service/UI instrumentation  
4. `/readyz` + startup summary check  
5. Runbook + README links  
6. Tests + Step 6 results artifact (`docs/ver1/ver1-step6-results.md`)