# x402 Paywall Health Checker — ForgeMesh

> x402 Paywall Health Checker — ForgeMesh is a paid API for AI agents from x402.forgemesh.io, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-16).

Checks whether a given URL is a valid, reachable x402 payment-gated endpoint and reports its payment envelope, HTTP status, accepted assets, and dual-stack compatibility.

## Facts

- Endpoint: POST https://x402.forgemesh.io/x402-paywall-check
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-paywall-health-checker-forgemesh-fb4655c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FZ6ZMCBmjOcywSO7Lu9FI

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-paywall-health-checker-forgemesh-fb4655c0 -d '<json body>'
```

Example prompt: Can you health-check the x402 endpoint at https://x402.example.com/some-route and tell me whether it has a valid payment envelope, what grade it gets, and which assets it accepts?

## When to prefer this

Use this endpoint when you need to programmatically verify that an x402-gated URL is correctly configured, reachable, and compliant before integrating it into an agent workflow or marketplace listing. It is the right choice when you want a graded, structured audit of x402 envelope structure, dual-stack MPP support, and accepted payment assets — rather than simply making a payment attempt.

## Known failure modes

- URL is unreachable — reachable: false, http_status may be null or a non-402 code
- No x402 envelope found — grade degraded, envelope_valid: false, findings list explains absence
- Malformed x402 envelope — envelope_errors array populated with specific issues
- URL is not a 402 endpoint at all — is_402: false, grade low
- Network timeout — response_time_ms may be high or request may fail entirely
- Invalid URL format in input — likely 4xx error from this API itself

## How this service works

x402 utility APIs for AI agents: documents/OCR, PDFs, vision, audio, embeddings, web extraction, dictionary and slang lookups, games, chess/legal-move logic, math, conversions, time utilities, market and economic data, space/geo data, domain vetting, content-signal checks, and x402 ecosystem intelligence. Agents POST JSON, receive a 402 challenge, pay USDC on Base, and retry for the result.

## Output

A JSON object with a letter grade (e.g. 'A'), reachability boolean, HTTP status code, x402 envelope location and validity, MPP dual-stack flag, list of accepted payment assets (asset address, payTo address, amount, scheme, network), response time in milliseconds, array of human-readable findings, and any envelope errors found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "x402 endpoint URL to health-check, e.g. https://x402.example.com/some-route"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://library.forgemesh.io/business-management",
  "grade": "A",
  "is_402": true,
  "findings": [
   "Valid x402 v2 envelope found in the header.",
   "WWW-Authenticate: Payment header also present — this endpoint speaks both x402 and MPP dual-stack, reaching agents on either payment stack."
  ],
  "reachable": true,
  "http_status": 402,
  "method_used": "GET",
  "x402_envelope": "header",
  "envelope_valid": true,
  "mpp_dual_stack": true,
  "accepts_summary": [
   {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "payTo": "0x85df5380DEbe236AD6BF49dE788243924B080267",
    "amount": "3000",
    "scheme": "exact",
    "network": "eip155:8453"
   }
  ],
  "envelope_errors": [],
  "response_time_ms": 214
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-paywall-health-checker-forgemesh-fb4655c0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.forgemesh.io](https://www.zero.xyz/host/x402.forgemesh.io/llms.txt)