# x402broker Paywall Check — HTTP 402 & MCP Endpoint Compliance Auditor

> x402broker Paywall Check — HTTP 402 & MCP Endpoint Compliance Auditor is a paid API for AI agents from x402broker.com, paid per call via x402 or MPP, $0.01/call, status unknown (last checked 2026-10-20).

Audits a remote agent, MCP, or HTTP URL for JSON-RPC compliance, latency SLA, OpenAPI schema validity, and HTTP 402 payment settlement headers

## Facts

- Endpoint: GET https://x402broker.com/v1/paywall-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402, MPP
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402broker-paywall-check-http-402-mcp-endpoint-compliance-auditor-911ef154
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dnXbehhkLY2zhNDep1Pld

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 x402broker-paywall-check-http-402-mcp-endpoint-compliance-auditor-911ef154
```

Example prompt: Can you audit https://api.myagent.com/v1/tool for HTTP 402 compliance and check whether its JSON-RPC responses and latency SLA are up to spec using a GET request?

## When to prefer this

Choose this endpoint when you need to verify that a remote agent, MCP server, or HTTP API endpoint correctly implements the HTTP 402 payment protocol, JSON-RPC spec, OpenAPI schema, and latency SLAs — especially useful before deploying or integrating a new agent endpoint, debugging a broken paywall, or periodically monitoring compliance of live services

## Known failure modes

- Target URL is unreachable or times out — returns error indicating host is unavailable
- Invalid or malformed URL provided — returns validation error
- Target returns unexpected content type — compliance check may be partial
- Rate limit exceeded — returns 429
- Payment not settled — returns HTTP 402 requiring USDC payment

## How this service works

Audits any remote agent or MCP URL for JSON-RPC compliance, latency SLA, OpenAPI schema, and HTTP 402 settlement headers. (Live x402 v2, IETF MPP & MCP endpoint at https://x402broker.com/v1/paywall-check)

## Output

Returns a structured compliance report covering: JSON-RPC protocol conformance, measured latency against SLA thresholds, OpenAPI schema validity, and presence/correctness of HTTP 402 payment settlement headers for the audited URL

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "minLength": 1,
   "description": "Target A2A, MCP, or x402 service URL to audit for protocol compliance"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402broker-paywall-check-http-402-mcp-endpoint-compliance-auditor-911ef154/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402broker.com](https://www.zero.xyz/host/x402broker.com/llms.txt)