Context

Build the agent messaging layer on top of the message bus. This provides the higher-level API that agents use to communicate, including channel subscriptions, direct messages, and structured message formats per spec section 5.3.

Acceptance Criteria

• Agents can subscribe to named channels
• Agents can publish messages to channels
• Direct agent-to-agent messaging supported
• Message format follows spec 5.3 (sender, recipient, type, payload, timestamp, etc.)
• Message types implemented: task_update, question, announcement, status_change, escalation
• Priority levels for messages (low, normal, high, urgent)
• Agent message handler/callback system (agents register handlers for message types)
• Comprehensive unit tests (>80% coverage)

Dependencies

• Depends on message bus (Evaluate and implement message bus (asyncio queues vs external broker) #8)

Design Spec Reference

• Section 5.3 — Message Format
• Section 5.1 — Communication Patterns