phase: 03-db-api-channel-awareness
plan: "02"
subsystem: api
tags: [fastapi, pgvector, pydantic, python, channel-awareness]

Dependency graph

requires:
- phase: 03-01
provides: channels table in PostgreSQL with channel_id FK column on chunks

provides:
- ingest_file(filepath, channel_id="general") with channel-scoped INSERT
- similarity_search filters by WHERE channel_id = %s
- ask(question, channel_id="general") passes channel_id through
- IngestRequest and QueryRequest Pydantic models with optional channel_id field
- /ingest and /query route handlers pass channel_id to backend functions
- CLI --channel flag on ingest.py

affects:
- 04-channel-crud-api
- 05-ui-redesign

Tech tracking

tech-stack:
added: []
patterns:
- "Optional channel_id parameter defaulting to 'general' for backward compatibility"
- "channel_id threaded from API layer through to SQL WHERE clause"

key-files:
created: []
modified:
- ingest.py
- query.py
- api.py

key-decisions:
- "Default channel_id='general' at every layer (Pydantic, Python functions, SQL) — single source of backward-compat truth"
- "channel_id added as keyword argument (not positional) to avoid breaking existing callers"

patterns-established:
- "channel_id flows: IngestRequest.channel_id -> ingest_file(channel_id) -> INSERT ... channel_id"
- "channel_id flows: QueryRequest.channel_id -> ask(channel_id) -> similarity_search(channel_id) -> WHERE channel_id = %s"

requirements-completed: [DAT-02, DAT-03, DAT-04]

Metrics

duration: 2min
completed: 2026-03-24

Phase 03 Plan 02: Channel-Aware Python Layer Summary

channel_id threaded from FastAPI Pydantic models through ingest_file INSERT and similarity_search WHERE clause, with "general" as backward-compatible default at every layer

Performance

  • Duration: ~2 min
  • Started: 2026-03-24T18:31:00Z
  • Completed: 2026-03-24T18:32:38Z
  • Tasks: 2
  • Files modified: 3

Accomplishments

  • ingest_file() accepts optional channel_id parameter, stores it in the chunks INSERT
  • similarity_search() and ask() filter/scope queries to the specified channel via WHERE clause
  • All three FastAPI models and handlers wired through: backward-compat defaults of "general" at every level
  • CLI ingest.py now accepts --channel flag

Task Commits

Each task was committed atomically:

  1. Task 1: Add channel_id to ingest.py and query.py - cf590f6 (feat)
  2. Task 2: Add channel_id to api.py Pydantic models and route handlers - eca36e3 (feat)

Plan metadata: (docs commit follows)

Files Created/Modified

  • ingest.py - ingest_file signature, INSERT statement, and CLI --channel arg updated
  • query.py - similarity_search signature + WHERE channel_id clause, ask signature + passthrough
  • api.py - IngestRequest and QueryRequest gain optional channel_id field; /ingest and /query pass it through

Decisions Made

  • Default "general" set at every layer independently (not inherited) — no hidden coupling between layers
  • channel_id added as keyword-only argument to avoid breaking any direct callers of ingest_file() or ask()

Deviations from Plan

None - plan executed exactly as written.

Issues Encountered

None.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

  • Python layer fully channel-aware; ready for Phase 04 Channel CRUD API
  • Existing /ingest and /query API calls without channel_id continue to work unchanged (backward compatible)
  • CLI usage with --channel flag available immediately

Self-Check: PASSED

  • ingest.py: FOUND (with channel_id in signature, INSERT, and CLI)
  • query.py: FOUND (with channel_id in similarity_search, WHERE clause, and ask)
  • api.py: FOUND (with channel_id in both Pydantic models and both route handlers)
  • 03-02-SUMMARY.md: FOUND
  • cf590f6: FOUND (Task 1 commit)
  • eca36e3: FOUND (Task 2 commit)

Phase: 03-db-api-channel-awareness
Completed: 2026-03-24