# Losbeto x402 Endpoint Auditor

> Losbeto x402 Endpoint Auditor is a paid API for AI agents from markets.losbeto.xyz, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-10).

Audits any x402-enabled HTTP endpoint for spec compliance, payment correctness, and common failure modes by fetching and analyzing its 402 challenge response

## Facts

- Endpoint: GET https://markets.losbeto.xyz/x402-audit?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/losbeto-x402-endpoint-auditor-4baba705
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PW9eEEx5dnTtGOqIRTlTG

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 losbeto-x402-endpoint-auditor-4baba705
```

Example prompt: Audit the x402 endpoint at https://api.example.com/data to check whether it's properly implemented — does it return a valid 402 challenge, correct accepts fields, price floor, and no header or base64 issues that would break paying agents?

## When to prefer this

Use this endpoint when you need to verify that an x402-enabled API is correctly implemented before integrating it, deploying it, or trusting it with real USDC payments. It is especially valuable for catching subtle implementation bugs — oversized headers, unpadded base64, incorrect accepts ordering — that standard HTTP checks miss and that cause silent payment failures in production agents.

## Known failure modes

- Target URL is on an internal/private IP range — request refused
- Target endpoint does not return a 402 response at all — audit flags as non-compliant
- Target endpoint times out — audit cannot complete
- Malformed or unreachable URL — returns error
- Target endpoint returns unexpected content type preventing analysis

## How this service works

OpenAI-compatible LLM gateway at $0.005/call — change base_url, pay in USDC. Plus pay-per-call market data: multi-oracle price consensus, sentiment, forex, equities, commodities, Brazil macro (BCB/B3) and crypto. No API keys, no accounts. USDC on Base, Solana and Algorand via x402.

## Output

A structured audit report covering: HTTP 402 status presence, challenge structure validity, accepts field correctness and ordering, price floor declaration, discovery extension compliance, and known failure modes such as oversized headers, unpadded base64, and accepts ordering that diverts settlement away from facilitators

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Public http/https URL to fetch (internal/private ranges refused)"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "example": {
     "type": "object",
     "description": "Will this x402 endpoint survive a real paying agent — or quietly eat its payment? Audit any endpoint (?url=https://target/path) against the x402 v2 spec: 402 status, challenge structure, accepts fields, price floor, discovery extension — plus failure modes learned the hard way operating a live paid node: oversized headers that abort Node clients, unpadded base64 that breaks strict..."
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/losbeto-x402-endpoint-auditor-4baba705/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from markets.losbeto.xyz](https://www.zero.xyz/host/markets.losbeto.xyz/llms.txt)