---
title: "Publish an agent card · Agent Wranglers"
url: https://agentwranglers.se/playbook/website/ready-for-ai-agents/a2a-agent-cards
updated: 2026-10-20
licence: "All rights reserved"
---

# Publish an agent card

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Optional
- Chapter: [Ready for AI agents](https://agentwranglers.se/playbook/website/ready-for-ai-agents)
- Rule: 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.
- How: 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.
- 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.

Example:

```json
{
  "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"] }]
}
```

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers website playbook: https://agentwranglers.se/playbook/website/ready-for-ai-agents/a2a-agent-cards`.

- Previous: [Describe your MCP tools honestly](https://agentwranglers.se/playbook/website/ready-for-ai-agents/mcp-and-tool-discovery)
- Next: [List skills agents can learn](https://agentwranglers.se/playbook/website/ready-for-ai-agents/agent-skills-discovery)
- [Ready for AI agents](https://agentwranglers.se/playbook/website/ready-for-ai-agents)