# Tell the engine the model and harness behind an agent session (what an MCP server reports): later requests carrying that session in `X-Datanotes-Actor` are journaled with it. Any token may call it.

`POST /datanotes/sessions/identify/` (operation `identify_session`)

## Request body

`application/json`, required

| Property | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `session` | `string` | yes |  |  |
| `model` | `string` | no |  |  |
| `harness` | `string` | no |  |  |

## Responses

| Status | Description | Body |
| --- | --- | --- |
| 200 | Done. | `object` (application/json) |
| 400 | Bad input: the body is not a JSON object, or an argument is unknown, missing or of the wrong type. | `Error` (application/json) |
| 401 | Missing or wrong bearer token. | `Error` (application/json) |
| 500 | Unexpected error. | `Error` (application/json) |

The schemas named here are in [openapi.json](https://datanotes.dev/openapi.json) (`components.schemas`).