> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abstract.inc/llms.txt
> Use this file to discover all available pages before exploring further.

# Handoff

> The optional handoff flag, and why true is refused today.

`handoff` is an optional boolean.
It goes at the top level of a `POST /v1/chat/completions` body, and in the WebSocket's `session.open` message.

| Value | Effect |
| - | - |
| `false`, or absent | The model runs alone. |
| `true` | Refused today. It will let a human operator behind the API take over when a model fails a task. |

The API refuses `true` instead of ignoring it:

| Transport | Refusal |
| - | - |
| `POST /v1/chat/completions` | HTTP 400 with code `handoff_unavailable` |
| WebSocket `session.open` | An `error` message with code `handoff_unavailable` and `closing: false`. Send `session.open` again on the same socket without `handoff`. |

A value that is not a boolean returns `invalid_parameter`.


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