a2a-patterns

name	a2a-patterns
description	How gaia exposes/consumes agents over A2A and persists AgentCards for reuse. Use when touching agents/factory.py or agents/registry.py.

A2A in gaia

• A new subagent → an A2A AgentCard (name, description, url, skills). Build it with to_agent_card() in agents/factory.py (schema v0.3).
• registry.py stores specs as JSON in agent_registry/. Before creating an agent, look up an existing key → reuse, don't recreate.
• ADK has native A2A support:
  • Expose a gaia agent with ADK's A2A server helpers.
  • Consume a remote agent by adding it as a sub_agent via its AgentCard URL.
• Stay on A2A v0.3 card schema. Don't invent fields.

Reference links

• A2A protocol: https://a2a-protocol.org/latest/
• ADK + A2A: https://google.github.io/adk-docs/a2a/