# Create chat

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

> Answers one turn of a conversation with four things: the model's `reply`, the `actions` the server executed on the caller's behalf, the `ops` the client must apply itself, and the `conversationId` the turn was recorded under.

`POST /v1/agent/chat`

> [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/chat`   |
| **Method**    | `POST`                                 |
| **Operation** | `post_agent_chat`                      |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY` |

Answers one turn of a conversation with four things: the model's `reply`, the `actions` the server executed on the caller's behalf, the `ops` the client must apply itself, and the `conversationId` the turn was recorded under.

The split between actions and ops is the rule most easily got wrong. A tool call is executed HERE only when the chosen preset is server-executing AND the tool resolves in the caller's own scope; every other call is handed back as an op for the client to apply to its own graph or UI. A tool that fails still comes back as an action, carrying its error rather than failing the round.

`preset` selects the system prompt and the tool set (`capability` is a legacy alias for it); an unknown one is refused. `conversationId` continues an existing thread, and its absence starts one. A validated principal with a non-empty org is required — the org is the sole authority for both persistence and tool scope, and is NEVER read from the body.

A completion refused for the caller's own reason — 402 insufficient balance, 429, 403 — is relayed with its own status and body verbatim, so the real billing message reaches the client instead of an opaque gateway error. Only a genuine upstream fault becomes a 502.

## Request

The document declares no body for `POST /v1/agent/chat`. 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_chat`, 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 chat create
```

**SDK**

**.ts**

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

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

**.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_chat()
```

**.go**

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

resp, _, err := client.AgentAPI.PostAgentChat(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_chat(&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).postAgentChat();
```

**HTTP**

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

**MCP**

MCP reaches **agent** through the `agent` tool, which names its 38 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)