# Create a2a

URL: https://docs.hanzo.ai/docs/openapi/agent/post-agent-a2a

> The A2A server its agent card at /.well-known/agent-card.json names.

`POST /v1/agent/a2a`

> [Agent →](https://docs.hanzo.ai/docs/openapi/agent) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides)

|               |                                        |
| ------------- | -------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/agent/a2a`    |
| **Method**    | `POST`                                 |
| **Operation** | `post_agent_a2a`                       |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY` |

The A2A server its agent card at /.well-known/agent-card.json names. Each SendMessage is a task the default assistant answers with the tools your credential reaches: an agent run like POST /v1/agent/:ref/run, so your balance is authorized before any inference and the flat run fee is charged only when the run succeeds. A request waits for the answer unless configuration.returnImmediately is set; either way the task is kept, and GetTask, ListTasks and CancelTask read and stop your own tasks. A conversation continues by sending the next message with the task's contextId.

Methods: SendMessage, GetTask, ListTasks, CancelTask. Streaming and push notifications answer UnsupportedOperation (-32004) and PushNotificationNotSupported (-32003). The A2A-Version header, when sent, is 1.0. With no credential the answer is 401 with a WWW-Authenticate challenge naming the protected-resource metadata; every other outcome, refusals included, is a JSON-RPC response.

## Request

The document declares no body for `POST /v1/agent/a2a`. The handler is typed in cloud but its shape is not yet emitted, so the fields are not listed here — ask MCP's `describe` for `post_agent_a2a`, which answers from the running route.

## Response

The document declares no response body for this operation. It answers `200` on success and the platform error shape on failure — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo agent a2a
```

**SDK**

**.ts**

```ts
import { Configuration, AgentApi } from 'hanzoai';

const api = new AgentApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postAgentA2a();
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import AgentApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = AgentApi(client).post_agent_a2a()
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.AgentAPI.PostAgentA2a(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, agent_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = agent_api::post_agent_a2a(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.AgentApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new AgentApi(client).postAgentA2a();
```

The method above is the one at the current release of the document. `hanzoai@8.5.914` (npm) and `hanzoai@8.5.914` (PyPI) were generated from an earlier release, where this operation carried a different id, so it spells the method differently — regenerating the clients is what makes the two agree. [SDKs →](https://docs.hanzo.ai/docs/sdks)

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/agent/a2a \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP reaches **agent** through the `agent` tool, which names its 51 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them:

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_agents"
         }
       }
     }'
```

---

[Agent API](https://docs.hanzo.ai/docs/openapi/agent) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)