Use Cases

A2A over MQTT is suitable for distributed agent systems that need broker-neutral discovery and reliable request/reply messaging. This page is aligned with the user stories in user-stories/:

• Security OAuth (01-security-oauth.md): discover via MQTT, acquire OAuth token, and send authenticated requests using MQTT User Property a2a-authorization.
• One request, one response (02-request-single-response.md): synchronous request/reply with Response Topic and Correlation Data.
• One request, multiple responses (03-request-multi-response.md): stream task status and artifact updates on reply topic until terminal task state.
• One request, multiple binary artifact responses (04-request-multi-binary-artifact-responses.md): request a2a-artifact-mode=binary and receive chunked binary artifact updates.
• Shared pool dispatch (05-shared-pool-dispatch.md): publish to unit-level pool topic and route follow-up operations using a2a-responder-agent-id and server-generated Task.id.
• Untrusted-broker security profile (06-untrusted-broker-security-profile.md): use a2a-security-profile=ubsp-v1 for end-to-end encrypted request/reply/stream payloads with key discovery and property validation.