Files
stack/apps/coordinator
Jason Woltje 698b13330a feat(#152): Implement session rotation (TDD)
Implement session rotation that spawns fresh agents when context reaches
95% threshold.

TDD Process:
1. RED: Write comprehensive tests (all initially fail)
2. GREEN: Implement trigger_rotation method (all tests pass)

Changes:
- Add SessionRotation dataclass to track rotation metrics
- Implement trigger_rotation method in ContextMonitor
- Add 6 new unit tests covering all acceptance criteria

Rotation process:
1. Get current context usage metrics
2. Close current agent session
3. Spawn new agent with same type
4. Transfer next issue to new agent
5. Log rotation event with metrics

Test Results:
- All 47 tests pass (34 context_monitor + 13 context_compaction)
- 97% coverage on context_monitor.py (exceeds 85% requirement)
- 97% coverage on context_compaction.py (exceeds 85% requirement)

Prevents context exhaustion by starting fresh when compaction is insufficient.

Acceptance Criteria (All Met):
✓ Rotation triggered at 95% context threshold
✓ Current session closed cleanly
✓ New agent spawned with same type
✓ Next issue transferred to new agent
✓ Rotation logged with session IDs and context metrics
✓ Unit tests with 85%+ coverage

Fixes #152

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-02-01 20:36:52 -06:00
..

Mosaic Coordinator

FastAPI webhook receiver for Gitea issue events, enabling autonomous task coordination for AI agents.

Overview

The coordinator receives webhook events from Gitea when issues are assigned, unassigned, or closed. It verifies webhook authenticity via HMAC SHA256 signature and routes events to appropriate handlers.

Features

  • HMAC SHA256 signature verification
  • Event routing (assigned, unassigned, closed)
  • AI-powered issue metadata parsing (using Anthropic Sonnet)
  • Context estimation and agent assignment
  • Dependency tracking (blocks/blocked_by)
  • Comprehensive logging
  • Health check endpoint
  • Docker containerized
  • 95%+ test coverage

Development

Prerequisites

  • Python 3.11+
  • pip or uv package manager

Setup

# Install dependencies
pip install -e ".[dev]"

# Run tests
pytest

# Run with coverage
pytest --cov=src --cov-report=html

# Type checking
mypy src/

# Linting
ruff check src/

Running locally

# Copy environment template
cp .env.example .env

# Edit .env with your values
# GITEA_WEBHOOK_SECRET, GITEA_URL, ANTHROPIC_API_KEY

# Run server
uvicorn src.main:app --reload --port 8000

API Endpoints

POST /webhook/gitea

Receives Gitea webhook events.

Headers:

  • X-Gitea-Signature: HMAC SHA256 signature of request body

Response:

  • 200 OK: Event processed successfully
  • 401 Unauthorized: Invalid or missing signature
  • 422 Unprocessable Entity: Invalid payload

GET /health

Health check endpoint.

Response:

  • 200 OK: Service is healthy

Environment Variables

Variable Description Required Default
GITEA_WEBHOOK_SECRET Secret for HMAC signature verification Yes -
GITEA_URL Gitea instance URL Yes -
ANTHROPIC_API_KEY Anthropic API key for issue parsing Yes -
LOG_LEVEL Logging level (debug, info, warning, error) No info
HOST Server host No 0.0.0.0
PORT Server port No 8000

Docker

# Build
docker build -t mosaic-coordinator .

# Run
docker run -p 8000:8000 \
  -e GITEA_WEBHOOK_SECRET="your-secret" \
  -e GITEA_URL="https://git.mosaicstack.dev" \
  -e ANTHROPIC_API_KEY="your-anthropic-key" \
  mosaic-coordinator

Testing

# Run all tests
pytest

# Run with coverage (requires 85%+)
pytest --cov=src --cov-report=term-missing

# Run specific test file
pytest tests/test_security.py

# Run with verbose output
pytest -v

Architecture

apps/coordinator/
├── src/
│   ├── main.py             # FastAPI application
│   ├── webhook.py          # Webhook endpoint handlers
│   ├── parser.py           # Issue metadata parser (Anthropic)
│   ├── models.py           # Data models
│   ├── security.py         # HMAC signature verification
│   ├── config.py           # Configuration management
│   └── context_monitor.py  # Context usage monitoring
├── tests/
│   ├── test_security.py
│   ├── test_webhook.py
│   ├── test_parser.py
│   ├── test_context_monitor.py
│   └── conftest.py         # Pytest fixtures
├── pyproject.toml          # Project metadata & dependencies
├── .env.example            # Environment variable template
├── Dockerfile
└── README.md
  • #156 - Create coordinator bot user
  • #157 - Set up webhook receiver endpoint
  • #158 - Implement issue parser
  • #140 - Coordinator architecture