# Sessions

Generation runs can be grouped into a **session** — the same concept as a canvas in the Layer app. Sessions are optional, but useful for organizing runs that belong to one task or user interaction.

## Using sessions

Both forge and workflow execute requests accept two optional fields:

| Field         | Meaning                                 |
| ------------- | --------------------------------------- |
| session\_id   | Add the run to an existing session.     |
| session\_name | Create (or name) a session for the run. |

```jsonc
{
  "model_id": "MODEL_ID",
  "parameters": { "prompt": "a mossy stone golem" },
  "session_name": "Golem concepts"
}
```

Runs created with the same `session_id` are grouped together, and appear together on that session’s canvas in the Layer app. If you omit both fields, the run is created without an explicit session.

## When to use them

* Group the variations you generate for a single prompt or asset.
* Keep an end user’s runs together so they show up as one canvas in-app.
* Give a batch a stable `session_id` so you can reference the whole set later.