# Create runs

URL: https://docs.hanzo.ai/docs/openapi/flow/post-flow-runs

> Executes one of the caller's workflows synchronously: the graph runs in the flow service and the response carries the run's session and outputs.

`POST /v1/flow/runs`

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

|               |                                        |
| ------------- | -------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/flow/runs`    |
| **Method**    | `POST`                                 |
| **Operation** | `post_flow_runs`                       |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY` |

Executes one of the caller's workflows synchronously: the graph runs in
the flow service and the response carries the run's session and outputs. A
graph whose components fail reports the product's own error. Runs are
bounded by the product's five-minute sync ceiling.

## Request

4 fields, body `application/json` (required).

| Field      | In   | Type   | Required | Description                                                                                                  |
| ---------- | ---- | ------ | -------- | ------------------------------------------------------------------------------------------------------------ |
| `input`    | body | string | —        | Input is the run's chat input value, handed to the graph's input node.                                       |
| `session`  | body | string | —        | Session groups runs into one conversation; the product mints one when absent and returns it in the response. |
| `tweaks`   | body | any    | —        | Tweaks override component fields for this run only (the product's tweaks document), verbatim.                |
| `workflow` | body | string | —        | Workflow is the UUID of the workflow to run.                                                                 |

## Response

| Status    | Body            | Meaning |
| --------- | --------------- | ------- |
| `200`     |                 | ok      |
| `default` | problem-details | refused |

`200` body — 1 field.

| Field    | In   | Type | Always | Description |
| -------- | ---- | ---- | ------ | ----------- |
| `(body)` | body | any  | yes    |             |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo flow runs create
```

**SDK**

**.ts**

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

const api = new FlowApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postFlowRuns({ input: "<input>", session: "<session>" });
```

**.py**

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

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = FlowApi(client).post_flow_runs(input="<input>", session="<session>")
```

**.go**

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

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

**.rs**

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

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

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

**.java**

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

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

var result = new FlowApi(client).postFlowRuns();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/flow/runs \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "input": "<input>",
       "session": "<session>"
     }'
```

**MCP**

MCP reaches **flow** through the `flow` tool, which names its 8 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_flow_runs"
         }
       }
     }'
```

---

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