# x402 Service Ranker

> x402 Service Ranker is a paid API for AI agents from x402-zadenworks.zaden-gaming.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-02).

Returns a ranked list of the best x402-enabled services for a given task category, scored by price, usage volume, and recency.

## Facts

- Endpoint: POST https://x402-zadenworks.zaden-gaming.workers.dev/rank?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-service-ranker-5f4278eb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8i-HUvidBx4E7z1i7JWxA

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 x402-service-ranker-5f4278eb -d '<json body>'
```

Example prompt: Can you rank the best x402 services available for web scraping — scored by price, usage volume, and how recently they've been active?

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover and select the best x402-compatible API for a given task at runtime, rather than hardcoding a service. Ideal for agent orchestrators that want to optimize for cost, popularity, or freshness across available x402 services before delegating a subtask.

## Known failure modes

- Unknown or unsupported task category returns empty or error response
- No x402 services indexed for the category yields an empty ranked list
- Stale index data may cause recency scores to be outdated
- Payment failure (insufficient USDC balance) returns 402 Payment Required
- Malformed POST body returns 400 Bad Request

## How this service works

A bundle of pay-per-call x402 resources for AI agents: /rank (best-service lookup by category), /snap (headless-browser screenshot/PDF/HTML), and /read (clean markdown extraction from any URL).

## Output

A ranked list of x402 services matching the requested task category, each scored and ordered by a composite of price competitiveness, usage volume, and recency. Includes service URLs and scoring breakdowns to help agents select the best-fit option.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "category"
 ],
 "properties": {
  "category": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "category",
  "results"
 ],
 "properties": {
  "results": {
   "type": "array",
   "items": {
    "type": "object",
    "properties": {
     "score": {
      "type": "number"
     },
     "calls30d": {
      "type": "number"
     },
     "resource": {
      "type": "string"
     },
     "description": {
      "type": "string"
     },
     "lastCalledAt": {
      "type": [
       "string",
       "null"
      ]
     },
     "uniquePayers30d": {
      "type": "number"
     },
     "cheapestPriceUsd": {
      "type": [
       "number",
       "null"
      ]
     }
    }
   }
  },
  "category": {
   "type": "string"
  },
  "generatedAt": {
   "type": [
    "string",
    "null"
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-service-ranker-5f4278eb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-zadenworks.zaden-gaming.workers.dev](https://www.zero.xyz/host/x402-zadenworks.zaden-gaming.workers.dev/llms.txt)