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

# Create Completion (Legacy)

> Current production status of the POST /v1/completions compatibility endpoint

> Last updated: 2026-06-06

# Create Completion (Legacy)

```
POST /v1/completions
```

<Warning>
  This is a compatibility endpoint, not the primary recommended path. For new integrations, prefer `/v1/chat/completions` or `/v1/responses`.
</Warning>

## Current Production Status

As of March 23, 2026, Crazyrouter production confirms:

* the route still exists
* a request using the classic example model `gpt-5-mini` returned `503`
* the error code was `model_not_found`
* the message said the model was temporarily unavailable

In practice, this means the endpoint should be treated as legacy-client compatibility only, not as the default path for new work.

***

## Current Recommendation

1. Use [`Chat Completions`](/chat/openai/completions) for new chat-style integrations
2. Use [`Responses`](/chat/responses/overview) when you need GPT-5 reasoning, web search, or newer response shapes
3. Only keep testing `/v1/completions` if you already depend on a legacy client and have confirmed that your legacy model is currently available

***

## Retest Template

If you must verify whether a legacy model still works on this endpoint, first confirm the model ID through [`/v1/models`](/chat/openai/models), then send a minimal request:

```bash theme={null}
curl https://api.crazyrouter.com/v1/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "YOUR_LEGACY_MODEL",
    "prompt": "Say hello in three words.",
    "max_tokens": 16
  }'
```

Observed production error example:

```json theme={null}
{
  "error": {
    "code": "model_not_found",
    "message": "Model gpt-5-mini is temporarily unavailable",
    "type": "new_api_error"
  }
}
```