# x402 Bazaar Rank – Change Detection Services

> x402 Bazaar Rank – Change Detection Services is a paid API for AI agents from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-15).

Returns a ranked list of x402 services tagged 'change-detection', ordered by real 30-day call volume and unique paying wallets, with a signed snapshot receipt.

## Facts

- Endpoint: GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/in-change-detection?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-bazaar-rank-change-detection-services-9e260b4b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jzB1EacE3TAigOY6dG2pc

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-bazaar-rank-change-detection-services-9e260b4b
```

Example prompt: Show me the top change-detection services on the x402 market right now, ranked by how many unique paying wallets used them in the last 30 days.

## When to prefer this

Use this endpoint when you need a curated, usage-verified ranked list of change-detection services specifically from the x402 pay-per-call ecosystem, backed by real on-chain payment data from the last 30 days. Prefer this over generic API directories when you want services that have demonstrated actual paying adoption on Base/EVM networks and need a signed snapshot receipt for auditability.

## Known failure modes

- No services indexed under 'change-detection' tag — returns empty services array with count 0
- Payment not completed — 402 response requiring x402 payment header
- Worker timeout if index is large — partial or error response
- Stale snapshot if index hasn't refreshed — generatedAt timestamp may be hours old
- Invalid or malformed request properties — may return 400 or empty result

## How this service works

An open index of the machine-to-machine (agent) economy. x402 routes: ranked discovery over the live x402 service market, every indexed service scored by real 30-day calls and paying-wallet bounds, with a receipt naming the snapshot hash and scoring revision. /economy routes, for Tempo MPP, Virtuals ACP, Olas, Masumi, ERC-8004 agent registries, Solana agent registries, Base agent contracts and MCP servers (Official MCP Registry): each protocol's published figures (agent or server counts, transactions or payment events; payers and USD volume only where the source publishes them: payers for x402 and Tempo MPP, USD volume for x402 and Virtuals ACP), each with its unit, window and source; units differ, so totals are not summed. L402 and per-service MPP listings are not covered.

## Output

A JSON object containing the total count of matched services, the query parameters used (ranking operation, limit, tag filter), the route, a list of ranked services each with name, network, 30-day call count, price in USD, resource URL, and unique payers; plus metadata fields indicating who declared the index, the snapshot generation timestamp, and a receipt with snapshot hash and scoring revision.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 25,
  "query": {
   "by": "payers",
   "op": "top",
   "limit": 25,
   "where": {
    "tag": "change-detection"
   }
  },
  "route": "/in-change-detection",
  "matched": 359,
  "services": [
   {
    "name": "forecast api",
    "network": "eip155:8453",
    "calls30d": 310,
    "priceUsd": 0.01,
    "resource": "https://api.example.com/forecast",
    "payers30d": 42
   }
  ],
  "declaredBy": "agent",
  "generatedAt": "2026-09-17T12:00:00.000Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-bazaar-rank-change-detection-services-9e260b4b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev](https://www.zero.xyz/host/x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/llms.txt)