# ForgeSignals x402 Endpoint Verifier

> ForgeSignals x402 Endpoint Verifier is a paid API for AI agents from forgesignals.org, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-13).

Runs pre-flight verification checks on any x402 API endpoint, including liveness, latency, 402 handshake, payment-schema validity, and payee on-chain activity.

## Facts

- Endpoint: POST https://forgesignals.org/verify-x402
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/forgesignals-x402-endpoint-verifier-fed3e0b2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aGWCRCfACwdXeHeQVeq1h

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 forgesignals-x402-endpoint-verifier-fed3e0b2 -d '<json body>'
```

Example prompt: Can you run a full pre-flight check on this x402 endpoint — https://api.example.com/data — and tell me if it's live, whether the 402 handshake works, whether the payment schema is valid, and if the payee wallet has on-chain activity? Use a 7000ms timeout.

## When to prefer this

Choose this endpoint when you need to programmatically validate an x402-protocol API before integrating it into an agent workflow, when debugging a failing x402 payment interaction, or when you need to vet an unknown x402 provider for legitimacy and on-chain activity. Prefer this over manual inspection or generic HTTP health checks because it understands the full x402 handshake sequence, validates the payment schema structure, and cross-checks the payee wallet on-chain — checks that generic ping/liveness tools cannot perform.

## Known failure modes

- Target endpoint is unreachable or times out — verifier reports liveness failure
- timeout_ms outside allowed range (500–10000) causes a parameter validation error
- Target URL is not an x402 endpoint and returns unexpected status codes — handshake check fails
- Payee address is unrecognized or has zero on-chain activity — flagged in results
- Malformed payment schema on target endpoint — schema validation fails with details
- Network error between verifier and target — returns connectivity error

## How this service works

x402 endpoint verification: pre-flight checks for any x402 API - liveness, latency, 402 handshake, payment-schema validity, payee on-chain activity. Fixed price per check.

## Output

Returns a structured report covering: liveness status (is the endpoint reachable), measured latency, result of the 402 handshake (did the endpoint respond correctly to a pre-flight payment request), payment schema validity (are the schema fields correctly formed), and payee on-chain activity (has the declared payment address transacted on-chain).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "x402 endpoint URL to verify"
  },
  "timeout_ms": {
   "type": "number",
   "description": "per-check timeout in ms, 500-10000 (default 5000)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/forgesignals-x402-endpoint-verifier-fed3e0b2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from forgesignals.org](https://www.zero.xyz/host/forgesignals.org/llms.txt)