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

# no_tools_on_endpoint

> HTTP 400 — Model supports function tools only via the Response API.

## HTTP status

`400 invalid_request_error`

## Typical cause

The model supports function tools only through `/v1/responses`. Sending `tools` via `/v1/chat/completions` is not supported for this model (e.g., gpt-6-astra).

## Resolution

Call `POST /v1/responses` with a Response API body:

```bash theme={null}
curl https://api.auriko.ai/v1/responses \
  -H "Authorization: Bearer $AURIKO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6-astra",
    "input": "What is the weather in SF?",
    "tools": [{"type": "function", "name": "get_weather", "parameters": {"type": "object", "properties": {"location": {"type": "string"}}}}]
  }'
```

To check endpoint support before sending, read `tools_endpoints` from each provider entry in the [model directory](/api-reference/model-directory). If the array is `["responses"]`, only `/v1/responses` accepts function tools for that model.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.