a2a-integrator

name	a2a-integrator
description	Design an A2A integration between two agents — Agent Card, task schemas, auth, streaming or polling. Use when you need help with a2a integrator.
license	CC-BY-NC-SA-4.0
phase	16
lesson	12
metadata	{"version":"1.0.0","tags":["multi-agent","a2a","protocol","interoperability","google"]}

Given two agent systems that need to interoperate, produce the A2A integration plan: Agent Card contents, task schemas, auth, transport mode.

Produce:

1. Agent Card. Name, version, skills, endpoints, supported modalities (text, structured, image, audio, video), protocol_version, auth declaration.
2. Task schemas per skill. Input JSON schema + artifact JSON schema. Be explicit — clients will validate.
3. Auth choice. Bearer token (OAuth2 or opaque), mTLS, or signed requests. Justify given the threat model (public internet, VPC, mixed).
4. Transport mode. Polling vs SSE streaming vs webhook callbacks. Streaming for long-running or progress-heavy tasks; polling for short tasks.
5. Rate limits. Per-client and per-task limits. Protection from abuse.
6. Idempotency. Strategy for duplicate POST /tasks requests (client-side task-key, server-side deduplication).
7. Failure handling. Task states beyond failed (retriable vs fatal), dead-letter policy, error artifact schema.
8. MCP vs A2A split. If the remote agent uses MCP internally, note which tools are exposed vs kept internal.

Hard rejects:

• Agent Cards without a declared protocol version.
• Task schemas that are free-form text when the use case warrants structure.
• Auth=none on public-internet deployments.

Refusal rules:

• If both agents run in the same process, refuse A2A and recommend direct Python/JS calls. A2A is for cross-system boundaries.
• If latency requirements are sub-100ms round-trip, refuse A2A and recommend direct RPC with a shared schema.
• If the remote agent does not declare an Agent Card, refuse integration and recommend publishing one first.

Output: a one-page integration brief. Close with the Agent Card JSON pasted inline so engineering can drop it into /.well-known/agent.json.