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

# Rerank v4.0 Fast

> Cohere latency-focused multilingual relevance ranking model.

Cohere latency-focused multilingual relevance ranking model.

## Model Information

| Field      | Description      |
| ---------- | ---------------- |
| `model`    | rerank-v4.0-fast |
| `context`  | 32,768 tokens    |
| `endpoint` | POST /v1/rerank  |

Context and output sizes describe the model specification. Effective request limits, availability, and billing depend on the MixRoute route.

## Capabilities and Usage

* Reranks supplied documents against a query; it does not generate answers or embeddings.
* The context limit applies to a query/document pair. Retrieve candidates first, then use top\_n to select the most relevant results.
* results\[].index maps back to the original documents array. Use that index instead of assuming document text is returned.

## Request Example

Set `MIXROUTE_API_KEY` before making the request.

```bash theme={null}
curl --request POST "https://api.mixroute.ai/v1/rerank" \
  --header "Authorization: Bearer $MIXROUTE_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "rerank-v4.0-fast",
  "query": "API documentation",
  "documents": [
    "An API reference for developers.",
    "A recipe for soup."
  ],
  "top_n": 1
}'
```

## Request Fields

| Field       | Description                                                                  |
| ----------- | ---------------------------------------------------------------------------- |
| `model`     | Required. Use the exact model ID above.                                      |
| `query`     | Required query text.                                                         |
| `documents` | Required array of document strings.                                          |
| `top_n`     | Optional number of results to return; no more than the number of candidates. |

Complete request format: [rerank](/en/api-reference/endpoint/rerank).