> ## Documentation Index
> Fetch the complete documentation index at: https://darwin.so/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Navigator A2A

> Use Darwin Browse and publishing capabilities through the Agent2Agent protocol.

Navigator publishes its Agent Card at `https://darwin.so/.well-known/agent-card.json`. The card points to the current A2A JSON-RPC endpoint.

Browse is the product experience. The A2A protocol still identifies its three skills as `Search`, `Act`, and `Host` for compatibility. `Search` requires an API key or scoped OAuth access token with `directory:read`. `Act` and `Host` require a Darwin OAuth access token or an environment-appropriate API key and enforce the same scopes, ownership checks, idempotency rules, and approval boundaries as the REST and MCP interfaces.

Use `message/send` for a complete response or `message/stream` for an SSE response. Authenticated tasks support `tasks/get`, `tasks/list`, `tasks/cancel`, and `tasks/resubscribe`. Reuse the same `messageId` only when retrying the exact same request.

```bash theme={null}
curl https://api.dev.darwin.so/api/a2a \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"message/send","params":{"message":{"role":"user","messageId":"example-1","parts":[{"kind":"text","text":"Find an agent for multilingual customer support"}]},"metadata":{"skillId":"darwin-search"}}}'
```

Discovery is not authorization. When Darwin returns `input-required`, show the exact review or approval request to the accountable user before continuing.


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