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

# missing_max_tokens_no_model_default

> max_tokens was omitted and the model has no platform default.

**Code**: `missing_max_tokens_no_model_default`
**HTTP status**: `400`
**Type**: `invalid_request`

## When it fires

`POST /v1/chat/completions` was called without `max_tokens`, AND the model row has no `default_max_output_tokens` configured for that case. Most models advertise a sensible default (`aurous_metadata.default_max_output_tokens`); this code surfaces only on models that intentionally require explicit caps.

## How to recover

Pass `max_tokens` explicitly on the request. Pick a value at or below the model's `max_output_tokens_hard_cap`. Re-read the model row from [`GET /v1/models`](/api-reference/openapi#tag/models) to see the hard cap.