# Creator Desk Marketplace Rank API

> Creator Desk Marketplace Rank API is a paid API for AI agents from creator-desk-x402-isolated.onrender.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-12).

Ranks a list of candidate agents or services by multi-criteria scoring (task fit, health, latency, price) and returns an ordered ranking with reason codes.

## Facts

- Endpoint: POST https://creator-desk-x402-isolated.onrender.com/v1/marketplace/rank?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/creator-desk-marketplace-rank-api-1db17294
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a12ZyDLZG_BxLXEf52kIU

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 creator-desk-marketplace-rank-api-1db17294 -d '<json body>'
```

Example prompt: I have three candidate agents — agent-a with task_fit 0.95, health 1.0, latency 180ms and price $0.03; agent-b with task_fit 0.90, health 1.0, latency 120ms and price $0.01; agent-c with task_fit 0.75, health 0.8, latency 90ms and price $0.005 — can you rank them from best to worst for this job?

## When to prefer this

Use this endpoint when you have a set of 2–50 pre-measured agent or service candidates and need a deterministic, multi-criteria ranking to decide which one to invoke next. It is ideal for agent orchestration layers, load balancers, or marketplace routers that already collect task_fit, health, latency, and price metrics and want a normalized priority order with reason codes — without building custom sorting logic.

## Known failure modes

- Fewer than 2 candidates submitted — validation error
- More than 50 candidates submitted — exceeds maxItems limit
- Missing required fields (id, task_fit, health, latency_ms, price_usd) on any candidate — schema validation error
- Values out of range (e.g. health > 1, negative latency) — rejected
- Payment not provided or insufficient — 402 Payment Required
- Service temporarily unavailable on Render free tier — 503 or cold-start timeout

## How this service works

Machine-callable x402-paid utilities for autonomous agents.

## Output

Returns a ranked array of all submitted candidates in order from best to worst, each annotated with their rank position and human-readable reason codes (e.g. BEST_TASK_FIT, FULL_HEALTH, LOWEST_LATENCY, LOWEST_PRICE). Also includes the applied sorting policy, the product_id, version, and a limitations disclaimer noting that rankings are based solely on caller-supplied data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "candidates": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "id",
     "task_fit",
     "health",
     "latency_ms",
     "price_usd"
    ],
    "properties": {
     "id": {
      "type": "string",
      "maxLength": 128,
      "minLength": 1
     },
     "health": {
      "type": "number",
      "maximum": 1,
      "minimum": 0
     },
     "network": {
      "type": "string",
      "maxLength": 128
     },
     "provider": {
      "type": "string",
      "maxLength": 256
     },
     "task_fit": {
      "type": "number",
      "maximum": 1,
      "minimum": 0
     },
     "price_usd": {
      "type": "number",
      "maximum": 100000,
      "minimum": 0
     },
     "latency_ms": {
      "type": "number",
      "maximum": 600000,
      "minimum": 0
     }
    },
    "additionalProperties": false
   },
   "maxItems": 50,
   "minItems": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "policy": [
   "task_fit_desc",
   "health_desc",
   "latency_ms_asc",
   "price_usd_asc",
   "id_asc"
  ],
  "ranking": [
   {
    "id": "agent-a",
    "rank": 1,
    "health": 1,
    "network": "eip155:8453",
    "task_fit": 0.95,
    "price_usd": 0.03,
    "latency_ms": 180,
    "reason_codes": [
     "BEST_TASK_FIT",
     "FULL_HEALTH"
    ]
   },
   {
    "id": "agent-b",
    "rank": 2,
    "health": 1,
    "network": "eip155:8453",
    "task_fit": 0.9,
    "price_usd": 0.01,
    "latency_ms": 120,
    "reason_codes": [
     "FULL_HEALTH",
     "LOWEST_LATENCY",
     "LOWEST_PRICE"
    ]
   }
  ],
  "version": "1.0.0",
  "product_id": "creator_desk_machine_marketplace_rank",
  "limitations": [
   "Ranks only caller-supplied measurements. It does not independently verify identity, reputation, settlement history, availability, or delivery quality."
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/creator-desk-marketplace-rank-api-1db17294/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from creator-desk-x402-isolated.onrender.com](https://www.zero.xyz/host/creator-desk-x402-isolated.onrender.com/llms.txt)