# Create rerank

URL: https://docs.hanzo.ai/docs/openapi/ai/post-rerank

> Implements POST /v1/rerank (Cohere/Jina-compatible).

`POST /v1/rerank`

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|               |                                        |
| ------------- | -------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/rerank`       |
| **Method**    | `POST`                                 |
| **Operation** | `post_rerank`                          |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY` |

Implements POST /v1/rerank (Cohere/Jina-compatible).

Body: {"model": "...", "query": "...", "documents": \["...", ...]|\[{"text":"..."}],

"top\_n"?: int, "return\_documents"?: bool}

Response: {"object":"list","model":...,"results":\[{"index","relevance\_score","document"?}],"usage":{...}}

Backend selection is provider-driven (one endpoint, one contract):

- If the model routes to a native rerank provider (Jina/Cohere/Voyage) the
  request is proxied to that provider's /rerank endpoint.
- Otherwise scores are computed as a real bi-encoder ranking: embed the
  query and documents through the resolved embedding model and rank by
  cosine similarity. No rerank-specific key required.

## Request

The document declares no body for `POST /v1/rerank`. The handler is typed in cloud but its shape is not yet emitted, so the fields are not listed here — ask MCP's `describe` for `post_rerank`, which answers from the running route.

## Response

| Status | Body       | Meaning                                             |
| ------ | ---------- | --------------------------------------------------- |
| `200`  | ai.Ranking | Success.                                            |
| `401`  | —          | No credential, or one this service does not accept. |
| `403`  | —          | A valid credential that may not do this.            |

`200` body — 9 fields.

| Field                       | In   | Type            | Always | Description |
| --------------------------- | ---- | --------------- | ------ | ----------- |
| `model`                     | body | string          | —      |             |
| `object`                    | body | string          | —      |             |
| `results`                   | body | ai.RankedDoc\[] | —      |             |
| `results[].document`        | body | ai.RankedText   | —      |             |
| `results[].document.text`   | body | string          | —      |             |
| `results[].index`           | body | integer         | —      |             |
| `results[].relevance_score` | body | number          | —      |             |
| `usage`                     | body | ai.RankUsage    | —      |             |
| `usage.total_tokens`        | body | integer         | —      |             |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo rerank create
```

**SDK**

**.ts**

```ts
import { Configuration, AiApi } from 'hanzoai';

const api = new AiApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postRerank();
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import AiApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = AiApi(client).post_rerank()
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.AiAPI.PostRerank(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, ai_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = ai_api::post_rerank(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.AiApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new AiApi(client).postRerank();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/rerank \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP declares no tool for **ai** — `tools/list` on `https://api.hanzo.ai/v1/mcp` names the products it does reach. Use HTTP or an SDK.

---

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