# Agent-to-Agent (A2A)

Let external AI agents discover your employees via an Agent Card and delegate work over JSON-RPC 2.0, synchronously or via SSE streaming.

## Connection

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `Agent Card` | string | no | https://sistava.com/.well-known/agent.json |
| `Endpoint` | string | no | https://sistava.com/api/a2a/ |
| `Methods` | string | no | tasks/send (sync) · tasks/sendSubscribe (SSE streaming) |
| `Authorization` | header | no | Bearer sk-your-api-key |

## Request - tasks/send

```
curl -X POST https://sistava.com/api/a2a/ \
  -H "Authorization: Bearer sk-your-api-key" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "tasks/send",
    "params": {
      "message": {
        "role": "user",
        "parts": [{"type": "text", "text": "Draft a blog post about AI agents"}]
      },
      "metadata": { "employee_id": "EMPLOYEE_UUID" }
    }
  }'
```

## Request - Agent Card

```
curl https://sistava.com/.well-known/agent.json \
  -H "Authorization: Bearer sk-your-api-key"
```

## Response

```json
{
  "jsonrpc": "2.0",
  "id": "1",
  "result": {
    "id": "task-uuid",
    "status": {
      "state": "completed",
      "message": {
        "role": "agent",
        "parts": [{"type": "text", "text": "Here is the blog post..."}]
      }
    }
  }
}
```

Concepts and walkthrough: https://sistava.com/en/guide/channels/a2a

API reference index: https://sistava.com/en/docs