---
phase: 04-matrix-mvp-shared-agent-context-and-context-management-comma
plan: 03
subsystem: infra
tags: [docker, docker-compose, matrix, uv, lambda-agent-api]
requires:
  - phase: 04-01
    provides: Matrix MVP runtime and environment model
provides:
  - Matrix bot Docker image definition
  - Single-service docker-compose setup for matrix-bot
  - Env template entries for Agent API base URLs and real backend selection
affects: [deployment, matrix, local-dev]
tech-stack:
  added: [Dockerfile, docker-compose]
  patterns: [uv-managed container install with system Python runtime, local path install for lambda_agent_api]
key-files:
  created: [Dockerfile, docker-compose.yml]
  modified: [.env.example]
key-decisions:
  - "Kept compose scoped to matrix-bot only; platform-agent remains external to this stack."
  - "Set UV_PROJECT_ENVIRONMENT=/usr/local so uv-installed dependencies are available to CMD [\"python\", \"-m\", \"adapter.matrix.bot\"]."
patterns-established:
  - "Install project dependencies with uv inside the container, then install lambda_agent_api from external/platform-agent_api via pip --ignore-requires-python."
requirements-completed: [Dockerfile for Matrix bot, docker-compose.yml with matrix-bot service, .env.example updated with AGENT_BASE_URL and MATRIX_PLATFORM_BACKEND]
duration: 6min
completed: 2026-04-17
---

# Phase 4 Plan 03: Matrix Bot Containerization Summary

**Python 3.11 Matrix bot container with uv-managed app dependencies, local lambda_agent_api install bypass, and a single-service compose entrypoint**

## Performance

- **Duration:** 6 min
- **Started:** 2026-04-17T13:01:00Z
- **Completed:** 2026-04-17T13:07:04Z
- **Tasks:** 1
- **Files modified:** 4

## Accomplishments

- Added a root `Dockerfile` for the Matrix bot using `python:3.11-slim`.
- Added `docker-compose.yml` with a single `matrix-bot` service using `env_file: .env`.
- Extended `.env.example` with `AGENT_WS_URL`, `AGENT_BASE_URL`, and `MATRIX_PLATFORM_BACKEND=real`.

## Files Created/Modified

- `Dockerfile` - Builds the Matrix bot image, installs project dependencies with `uv`, and installs `lambda_agent_api` from the local `external/` tree.
- `docker-compose.yml` - Defines the `matrix-bot` service with restart policy and `.env` loading.
- `.env.example` - Documents the agent WebSocket URL, agent HTTP base URL, and real backend selector.

## Decisions Made

- Kept the compose scope limited to the Matrix bot, matching the phase boundary and excluding platform services.
- Added `UV_PROJECT_ENVIRONMENT=/usr/local` as a correctness fix so `uv sync` installs are visible to the final `python` runtime.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 2 - Missing Critical] Ensured uv installs are available to the container runtime**
- **Found during:** Task 1 (Create Dockerfile and docker-compose.yml)
- **Issue:** The plan sketch used `uv sync` plus `CMD ["python", ...]`; by default, `uv sync` would install into a virtual environment that system `python` would not use.
- **Fix:** Set `UV_PROJECT_ENVIRONMENT=/usr/local` in the Dockerfile before running `uv sync`.
- **Files modified:** `Dockerfile`
- **Verification:** Required grep checks passed and the generated compose config remained valid.

---

**Total deviations:** 1 auto-fixed (1 missing critical)
**Impact on plan:** Narrow correctness fix only. No scope expansion.

## Issues Encountered

- `docker compose config` resolved values from the local `.env`, so verification was kept to config rendering and grep-style checks rather than a full image build.

## User Setup Required

- Create `.env` from `.env.example` with real Matrix and agent values before running `docker compose up`.

## Next Phase Readiness

- Matrix bot container packaging is in place and ready for operator-supplied secrets plus an external platform-agent deployment.
- No code changes were made outside the allowed containerization files.

## Verification

- `grep 'python:3.11-slim' Dockerfile`
- `grep 'ignore-requires-python' Dockerfile`
- `grep 'PYTHONPATH=/app' Dockerfile`
- `grep 'adapter.matrix.bot' Dockerfile`
- `grep 'matrix-bot' docker-compose.yml`
- `grep 'env_file' docker-compose.yml`
- `grep 'AGENT_BASE_URL' .env.example`
- `grep 'AGENT_WS_URL' .env.example`
- `grep 'MATRIX_PLATFORM_BACKEND' .env.example`
- `docker compose -f docker-compose.yml config`

## Self-Check: PASSED

- Found `Dockerfile`
- Found `docker-compose.yml`
- Found updated `.env.example`
- Found `.planning/phases/04-matrix-mvp-shared-agent-context-and-context-management-comma/04-03-SUMMARY.md`