spec.card

Optional protocol-card metadata. Surfaces information consumers need to talk to the deployed agent - protocol version, endpoint URL, supported input/output modes, and documentation links.

These fields populate the A2A AgentCard the generator serves at /.well-known/agent-card.json. See A2A & the Agent Card for the full ADL → AgentCard mapping.

spec:
  card:
    protocolVersion: "1.0"
    url: https://agents.acme.example/customer-support
    preferredTransport: http+sse
    defaultInputModes:
      - text/plain
      - application/json
    defaultOutputModes:
      - text/plain
    documentationUrl: https://acme.example/docs/customer-support
    iconUrl: https://acme.example/agents/customer-support.png

Fields

Field	Type	Description
protocolVersion	string	The agent-protocol version the deployed instance speaks.
url	string	Where the deployed agent lives.
preferredTransport	string	The transport the agent prefers (e.g. http+sse, grpc).
defaultInputModes	string[]	Media types the agent accepts by default.
defaultOutputModes	string[]	Media types the agent returns by default.
documentationUrl	string	Human-readable documentation for the agent.
iconUrl	string	Display icon for registries and UIs.

All fields are optional. If you don't surface a public card, omit the block entirely - it's purely declarative.