# Settled x402 Endpoint Liveness & Quote Checker

> Settled x402 Endpoint Liveness & Quote Checker is a paid API for AI agents from settled.justinedwardvolmer.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Probes an x402 HTTP endpoint unpaid to verify it is live, returns its parsed payment quote (price, network, payTo), latency, schema completeness, on-chain payer activity on Base, a quality score, and risk flags — all before you commit to paying.

## Facts

- Endpoint: GET https://settled.justinedwardvolmer.workers.dev/v1/check?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/settled-x402-endpoint-liveness-quote-checker-8fdd1b19
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rOqPZLsVWHAW5FIXJeEMo

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 settled-x402-endpoint-liveness-quote-checker-8fdd1b19
```

Example prompt: Before I pay, can you check whether this x402 endpoint is actually live, what it charges, and whether there are any risk flags I should know about? The URL is https://some-x402-api.example.com/v1/data.

## When to prefer this

Use this endpoint any time you encounter an unfamiliar x402 endpoint and need to verify it is live, understand its cost and payment destination, and assess its trustworthiness before committing funds. Prefer it over blindly calling a paid endpoint, especially when the payTo address or price is unknown. It is also appropriate for periodic liveness checks on x402 endpoints you depend on, or for comparing quality scores across multiple candidates.

## Known failure modes

- Target URL is not reachable or not an x402 endpoint — returns error status and no quote data
- Target endpoint returns malformed 402 headers — schema completeness is flagged as incomplete
- On-chain lookup fails for Base — payer activity field may be absent or null
- Cached result is stale (up to 5 minutes old) — liveness may not reflect instantaneous state
- URL parameter missing or not an absolute HTTPS URL — returns validation error

## How this service works

Live liveness + quote check for any x402 endpoint: probes it unpaid (cached ≤5 min), returns status, latency, parsed price/network/payTo, schema completeness, on-chain payer activity (Base), quality score and risk flags. Call before paying an unfamiliar endpoint.

## Output

Returns liveness status (up/down), measured latency, parsed payment quote (price in USDC, network, payTo address), schema completeness rating, on-chain payer activity on Base, an overall quality score, and any risk flags — all derived from a cached (≤5 min) unpaid probe of the target endpoint.

## 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",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Absolute https URL of the x402 endpoint to check"
      }
     }
    }
   },
   "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/settled-x402-endpoint-liveness-quote-checker-8fdd1b19/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from settled.justinedwardvolmer.workers.dev](https://www.zero.xyz/host/settled.justinedwardvolmer.workers.dev/llms.txt)