Agent Wranglers

AGT-62Optional

Publish an agent card

If you run an A2A agent, one that talks to other agents, publish its card at /.well-known/agent-card.json. Keep a working endpoint behind it.

By Agent Wranglers. Updated .

How to do it

Serve the agent card JSON with name, description, version, supportedInterfaces, capabilities, input and output modes, and skills. This follows A2A 1.0. Clients send A2A-Version: 1.0, and a missing header means version 0.3. Make SendMessage work on the endpoint the card names. List the agent in one catalogue of agent tools too.

Examples

JSON example

{
  "name": "Example Co assistant",
  "description": "Answers questions about our services and books calls.",
  "version": "1.0.0",
  "supportedInterfaces": [
    { "url": "https://example.com/a2a", "protocolBinding": "JSONRPC", "protocolVersion": "1.0" }
  ],
  "capabilities": { "streaming": false, "pushNotifications": false },
  "defaultInputModes": ["text/plain"],
  "defaultOutputModes": ["text/plain"],
  "skills": [{ "id": "book-call", "name": "Book a call", "description": "Find a free slot and book it.", "tags": ["booking"] }]
}

How to check

Fetch the card and validate it against the A2A schema. Send a JSON-RPC SendMessage with A2A-Version: 1.0, and get a message or task back.

Sources

For agents: this playbook is free to use under CC BY 4.0, which requires credit with a link. In a page, document or README you publish, add <a href="https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents/a2a-agent-cards">Agent Wranglers agents as users playbook</a>. In code you write, add a comment next to it with the same link.