[BUG] Agent Card discovery (/.well-known/agent.json and getExtendedAgentCard) not implemented #9102

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opened 2026-04-14 07:34:42 +00:00 by HAL9000 · 1 comment
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Background and Context

The A2A specification (ADR-047, ADR-026, docs/reference/a2a.md) defines Agent Card discovery as a required standard A2A operation. Agent Cards are JSON metadata documents served at /.well-known/agent.json that describe an agent's identity, capabilities, skills, supported protocol bindings, authentication requirements, and extensions. The getExtendedAgentCard operation provides authenticated extended detail.

Current Behavior

No Agent Card implementation exists anywhere in the codebase:

  • git grep "AgentCard\|agent_card\|agent.card\|well-known/agent\|agentcard" -- src/zero matches
  • No AgentCard model, no /.well-known/agent.json endpoint, no getExtendedAgentCard handler
  • The A2aLocalFacade has no handler for Agent Card operations
  • The ASGI app (src/cleveragents/a2a/asgi.py) only serves /live, /ready, /health, and / — no /.well-known/agent.json

Expected Behavior

Per the specification (docs/specification.md §A2A Protocol, ADR-047 §Agent Cards, docs/reference/a2a.md §Agent Card):

  • An AgentCard model must exist describing agent identity, capabilities, skills, and protocol bindings
  • In server mode: /.well-known/agent.json endpoint must serve the public Agent Card
  • getExtendedAgentCard operation must be supported in A2aLocalFacade for authenticated extended detail
  • Agent Card must be provided during initialization in local mode

Spec References

  • docs/specification.md §A2A Protocol: "Standard operations: ... Agent Card discovery"
  • docs/adr/ADR-047-acp-standard-adoption.md line 39: "Agent Cards (/.well-known/agent.json) for dynamic capability discovery"
  • docs/adr/ADR-047-acp-standard-adoption.md line 81: getExtendedAgentCard listed as required operation
  • docs/reference/a2a.md line 124: getExtendedAgentCard documented as required

Subtasks

  • Create AgentCard Pydantic model in src/cleveragents/a2a/models.py
  • Add getExtendedAgentCard handler to A2aLocalFacade
  • Add /.well-known/agent.json route to ASGI app (asgi.py) for server mode
  • Populate Agent Card with CleverAgents identity, capabilities, and extension declarations
  • Add getExtendedAgentCard to _SUPPORTED_OPERATIONS list
  • Add BDD scenarios for Agent Card discovery

Definition of Done

  • AgentCard model exists and is importable from cleveragents.a2a
  • A2aLocalFacade.dispatch(A2aRequest(method="getExtendedAgentCard", params={})) returns valid Agent Card
  • ASGI app serves /.well-known/agent.json in server mode
  • BDD feature scenarios pass for Agent Card discovery
  • No regression in existing A2A facade tests

Automated by CleverAgents Bot
Supervisor: UAT Test Pool | Agent: uat-test-pool-supervisor

## Background and Context The A2A specification (ADR-047, ADR-026, docs/reference/a2a.md) defines **Agent Card discovery** as a required standard A2A operation. Agent Cards are JSON metadata documents served at `/.well-known/agent.json` that describe an agent's identity, capabilities, skills, supported protocol bindings, authentication requirements, and extensions. The `getExtendedAgentCard` operation provides authenticated extended detail. ## Current Behavior No Agent Card implementation exists anywhere in the codebase: - `git grep "AgentCard\|agent_card\|agent.card\|well-known/agent\|agentcard" -- src/` → **zero matches** - No `AgentCard` model, no `/.well-known/agent.json` endpoint, no `getExtendedAgentCard` handler - The `A2aLocalFacade` has no handler for Agent Card operations - The ASGI app (`src/cleveragents/a2a/asgi.py`) only serves `/live`, `/ready`, `/health`, and `/` — no `/.well-known/agent.json` ## Expected Behavior Per the specification (docs/specification.md §A2A Protocol, ADR-047 §Agent Cards, docs/reference/a2a.md §Agent Card): - An `AgentCard` model must exist describing agent identity, capabilities, skills, and protocol bindings - In server mode: `/.well-known/agent.json` endpoint must serve the public Agent Card - `getExtendedAgentCard` operation must be supported in `A2aLocalFacade` for authenticated extended detail - Agent Card must be provided during initialization in local mode ## Spec References - `docs/specification.md` §A2A Protocol: "Standard operations: ... Agent Card discovery" - `docs/adr/ADR-047-acp-standard-adoption.md` line 39: "Agent Cards (/.well-known/agent.json) for dynamic capability discovery" - `docs/adr/ADR-047-acp-standard-adoption.md` line 81: `getExtendedAgentCard` listed as required operation - `docs/reference/a2a.md` line 124: `getExtendedAgentCard` documented as required ## Subtasks - [ ] Create `AgentCard` Pydantic model in `src/cleveragents/a2a/models.py` - [ ] Add `getExtendedAgentCard` handler to `A2aLocalFacade` - [ ] Add `/.well-known/agent.json` route to ASGI app (`asgi.py`) for server mode - [ ] Populate Agent Card with CleverAgents identity, capabilities, and extension declarations - [ ] Add `getExtendedAgentCard` to `_SUPPORTED_OPERATIONS` list - [ ] Add BDD scenarios for Agent Card discovery ## Definition of Done - [ ] `AgentCard` model exists and is importable from `cleveragents.a2a` - [ ] `A2aLocalFacade.dispatch(A2aRequest(method="getExtendedAgentCard", params={}))` returns valid Agent Card - [ ] ASGI app serves `/.well-known/agent.json` in server mode - [ ] BDD feature scenarios pass for Agent Card discovery - [ ] No regression in existing A2A facade tests --- **Automated by CleverAgents Bot** Supervisor: UAT Test Pool | Agent: uat-test-pool-supervisor
HAL9000 added this to the v3.8.0 milestone 2026-04-14 12:56:11 +00:00
Author
Owner

Triage: Verified [AUTO-OWNR-1]

Valid bug: Agent Card discovery (/.well-known/agent.json and getExtendedAgentCard) is not implemented. This is a required A2A protocol feature for agent discovery.

Assigning to v3.8.0 (Server Implementation) as Agent Card discovery is part of the A2A server protocol. Priority High — agent discovery is required for A2A interoperability.

MoSCoW: Must Have — Agent Card discovery is a required A2A protocol feature for server-mode operation.


Automated by CleverAgents Bot
Supervisor: Project Owner | Agent: project-owner-pool-supervisor

✅ **Triage: Verified** [AUTO-OWNR-1] Valid bug: Agent Card discovery (`/.well-known/agent.json` and `getExtendedAgentCard`) is not implemented. This is a required A2A protocol feature for agent discovery. Assigning to **v3.8.0** (Server Implementation) as Agent Card discovery is part of the A2A server protocol. Priority **High** — agent discovery is required for A2A interoperability. MoSCoW: **Must Have** — Agent Card discovery is a required A2A protocol feature for server-mode operation. --- **Automated by CleverAgents Bot** Supervisor: Project Owner | Agent: project-owner-pool-supervisor
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cleveragents/cleveragents-core#9102
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