# x402 Seller Conformance Roster

> x402 Seller Conformance Roster is a paid API for AI agents from www.blockchainiq.co, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns a daily-ranked list of the top 1,000 x402 protocol sellers graded A–F by automated conformance probes covering uptime, schema validity, payment terms, and usage metrics.

## Facts

- Endpoint: GET https://www.blockchainiq.co/api/x402/v1/x402-market?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-seller-conformance-roster-abb48e4a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_djOVZSoJlvlKssxzeChIk

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-seller-conformance-roster-abb48e4a
```

Example prompt: Before my agent pays any x402 endpoint, pull the Blockchain IQ x402 conformance roster and show me the top sellers graded A or B so I only route payments to protocol-compliant endpoints.

## When to prefer this

Use this endpoint when an AI agent needs to screen or rank x402 protocol sellers before committing payments, when you want an independent daily conformance audit rather than self-reported seller metadata, or when you need a single parameterless call to get a full ranked leaderboard of live x402 endpoints with uptime and schema validity already scored.

## Known failure modes

- Probe data over 48 hours old — endpoint returns an error or empty payload rather than stale data
- Network or server error returning a non-200 status
- Empty or truncated seller list if the daily probe has not yet completed
- Payment failure (x402 $0.02 USDC not settled) resulting in a 402 response with payment instructions

## How this service works

Parameter-free: the Blockchain IQ x402 Conformance Index in one call. The top 1,000 x402 sellers ranked by an A to F grade from our own daily unpaid probe of their listed endpoints: valid HTTP 402, x402 v2, payment terms, schema, 7-day uptime, price range, 30-day payers and calls, with method and sources. Dated each day; never sold when the probe is over 48 hours old. Use to screen endpoints for protocol conformance before an agent pays. JSON, no API key. $0.02 per call. Blockchain IQ.

## Output

A JSON array of up to 1,000 x402 seller records, each containing: seller endpoint URL, conformance grade (A–F), HTTP 402 validity, x402 v2 compliance flag, payment terms and schema status, 7-day uptime percentage, price range, 30-day payer count, 30-day call count, probe method, data sources, and the probe date. The dataset is only served when the underlying probe is less than 48 hours old.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-seller-conformance-roster-abb48e4a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.blockchainiq.co](https://www.zero.xyz/host/www.blockchainiq.co/llms.txt)