# CortexCloud Rerank

> CortexCloud Rerank is a paid API for AI agents from api.cortexcloud.org, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-13).

Reranks a list of documents or passages by relevance to a query using Cohere (primary) with Jina as fallback, paid per call in USDC via x402.

## Facts

- Endpoint: GET https://api.cortexcloud.org/v1/ml/rerank
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cortexcloud-rerank-ae429ee8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_C1XSZIGw5pl5ZdZiHFlQQ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability cortexcloud-rerank-ae429ee8
```

Example prompt: Rerank these 10 retrieved passages by how relevant they are to the question 'What are the side effects of ibuprofen?' and return them sorted with relevance scores — pay the per-call fee in USDC.

## When to prefer this

Choose this endpoint when you need neural cross-encoder reranking to improve precision of retrieved documents in a RAG or search pipeline, especially when you want no API key management (x402 USDC payment handles auth) and want automatic fallback from Cohere to Jina. Prefer it over embedding-only retrieval when you need a second-stage reranker to boost relevance of your top-k candidates.

## Known failure modes

- Payment not included or insufficient USDC on Base — returns 402 Payment Required
- Upstream Cohere API unavailable and Jina fallback also fails — returns 5xx error
- Empty or malformed document list — returns 400 Bad Request
- Query string missing — reranking cannot proceed without a reference query
- Too many documents exceeding model token limits — truncation or error

## How this service works

Result reranking by relevance (Cohere primary, Jina fallback). x402-paid, USDC on Base.

## Output

An ordered list of the input documents re-sorted by relevance score to the query, with each document assigned a numeric relevance score. The highest-scoring, most semantically relevant documents appear first.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "properties": {
    "body": {
     "type": "object",
     "properties": {}
    }
   }
  },
  "output": {
   "properties": {
    "example": {}
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cortexcloud-rerank-ae429ee8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.cortexcloud.org](https://www.zero.xyz/host/api.cortexcloud.org/llms.txt)