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

# Unknown tool_use_id

> A tool_outputs payload references a tool_use_id that is not on the latest assistant turn.

**HTTP status:** 400

## Error message

```
tool_use_id(s) not found on latest assistant turn: {ids}
```

## When this error occurs

`POST /agents/conversations/{id}/runs` with `payload.kind = tool_outputs` was called, and at
least one of the `outputs[].tool_use_id` values does not match any `tool_use` block on the
conversation's latest assistant turn.

Common causes:

* Hand-edited or copy-pasted `tool_use_id` with a typo.
* Resuming an old `requires_action` run after the conversation has already advanced past it
  (the latest assistant turn is now different).
* Posting `tool_outputs` to a conversation whose previous run terminated as `completed` rather
  than `requires_action` (in which case there's nothing pending).

## How to fix

1. `GET /agents/runs/{run_id}` for the run that returned `requires_action`. Use the
   `pending_tool_calls[].tool_use_id` values from there verbatim.
2. If you've lost the run id, walk back via
   `GET /agents/conversations/{id}/messages?since=0` and look for the latest assistant turn —
   the `tool_use` blocks within carry the ids you need.
3. Refetch the conversation's `version` and pass it as `expected_version` to avoid posting onto
   a stale head.