# x402 Bazaar Rank – In-Headers Services

> x402 Bazaar Rank – In-Headers Services is a paid API for AI agents from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev, paid per call via x402, $0.032/call, status unknown (last checked 2026-10-15).

Returns a ranked list of x402 services tagged 'headers', scored by real 30-day call volume and unique paying wallets, with a snapshot hash and scoring revision receipt.

## Facts

- Endpoint: GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/in-headers?utm_source=zero.xyz
- Price: $0.032/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-in-headers-services-fdd566b7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HDBjepznrR36XcZOxPDWr

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-in-headers-services-fdd566b7
```

Example prompt: Show me the top 25 x402 services tagged 'headers', ranked by unique paying wallets over the last 30 days, and include the snapshot hash so I can verify the scoring revision.

## When to prefer this

Choose this endpoint when you need real usage-backed discovery of x402 services specifically tagged 'headers', rather than static or unverified service directories. It is ideal when you want to rank candidates by actual market demand (paying wallets and call volume) rather than self-reported metrics, and when auditability via snapshot hash matters.

## Known failure modes

- No services indexed under the 'headers' tag — returns empty services array
- Snapshot data stale if indexer has not refreshed — generatedAt timestamp will be old
- Rate limit or payment failure for the $0.032 USDC call — 402 response requiring fresh payment
- Worker cold-start latency on Cloudflare edge causing slower-than-expected response
- Malformed response if scoring revision changes schema without notice

## 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: total matched service count, the query parameters used (ranking by top payers, limit, tag filter), the route, a list of up to 25 services each with name, network, 30-day call count, USD price, resource URL, and 30-day unique payer count, plus metadata fields for who declared the data, a snapshot hash, and a generation timestamp.

## 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": "headers"
   }
  },
  "route": "/in-headers",
  "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-in-headers-services-fdd566b7/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)