A2A Support and Limitations

PromptJang is an outbound A2A adapter for registered targets. It is not an agent discovery network or workflow engine.

Supported

• Agent Card fetched from an HTTPS URL
• A2A v1 HTTP+JSON interface
• Unauthenticated or bearer-token target authentication
• Standard Message with ROLE_USER
• PromptJang event ID reused as stable messageId across retries
• JSON payload stored in a structured data part
• Valid 2xx response containing exactly one Task or Message
• Task ID, context ID, response body, headers, latency, and attempt history retained as delivery evidence

The dashboard says Accepted by A2A agent. A valid acceptance response does not prove the remote task completed.

Excluded from this beta

• JSON-RPC, gRPC, and streaming bindings
• Task polling or completion tracking
• Inbound A2A gateway
• OAuth
• Required Agent Card extensions
• Arbitrary destination URLs
• Fan-out, replies, routing, and workflow construction

Delivery is at least once. PromptJang keeps the same A2A messageId during retries, but remote idempotency is not guaranteed by every A2A agent.