# Proofline x402 Readiness Check

> Proofline x402 Readiness Check is a paid API for AI agents from proofline-audit.chrismellado.chatgpt.site, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-17).

Inspects a public x402 endpoint's unpaid response to validate its x402 v2 protocol compliance and score its payment-challenge readiness

## Facts

- Endpoint: GET https://proofline-audit.chrismellado.chatgpt.site/api/x402/readiness-check?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/proofline-x402-readiness-check-7a61a42e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b3WgfGvSj0lBKJgapG47K

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 proofline-x402-readiness-check-7a61a42e
```

Example prompt: Can you run a Proofline readiness check on my x402 endpoint at https://myapi.example.com/premium-data to see if the 402 payment challenge is properly configured and get a compliance score?

## When to prefer this

Use this endpoint when you need to programmatically verify that an x402-protected API endpoint is correctly implementing the x402 v2 payment challenge protocol — especially before publishing to a marketplace like Bazaar, debugging a broken payment wall, or automating compliance checks in a CI/CD pipeline. It is purpose-built for x402 protocol validation and provides structured, actionable output (score, verdict, issues, firstRepair) rather than generic HTTP inspection.

## Known failure modes

- Target URL is not publicly reachable — endpoint returns a network error or DNS failure
- Target URL does not return any 402 response — verdict is 'broken' with a low score
- Malformed URL input causes request validation failure
- Target endpoint requires authentication before returning 402, making inspection impossible
- x402 challenge JSON cannot be decoded — challengeDecodes check fails
- Rate limiting or firewall on the target endpoint blocks the inspection probe

## How this service works

Evidence-backed product validation and SaaS conversion audits, including a fixed $250 validation sprint with reproducible, Linear-ready defects.

## Output

Returns a JSON object containing: a 0–100 integer readiness score, a verdict enum ('ready', 'warnings', or 'broken'), a plain-English summary, a breakdown of named compliance checks (e.g. returns402, usesX402v2, challengeDecodes, hasPaymentOption, hasBazaarDiscovery, hasResourceMetadata, hasValidExactOption, paymentChallengeSchemaValid), an array of issues found, the detected product name, and a firstRepair suggestion indicating the highest-priority fix.

## 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",
       "format": "uri",
       "maxLength": 2048,
       "description": "Public HTTPS x402 endpoint to inspect without paying it"
      },
      "method": {
       "enum": [
        "GET",
        "POST"
       ],
       "type": "string",
       "default": "GET"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "product",
      "score",
      "verdict",
      "summary",
      "checks",
      "issues",
      "firstRepair"
     ],
     "properties": {
      "score": {
       "type": "integer",
       "maximum": 100,
       "minimum": 0
      },
      "checks": {
       "type": "object"
      },
      "issues": {
       "type": "array"
      },
      "product": {
       "type": "string"
      },
      "summary": {
       "type": "string"
      },
      "verdict": {
       "enum": [
        "ready",
        "warnings",
        "broken"
       ],
       "type": "string"
      },
      "challenge": {
       "type": "object"
      },
      "firstRepair": {
       "type": "string"
      },
      "limitations": {
       "type": "array"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "score": 100,
  "checks": {
   "returns402": true,
   "usesX402v2": true,
   "challengeDecodes": true,
   "hasPaymentOption": true,
   "hasBazaarDiscovery": true,
   "hasResourceMetadata": true,
   "hasValidExactOption": true,
   "paymentChallengeSchemaValid": true
  },
  "issues": [],
  "product": "Proofline x402 Readiness Check",
  "summary": "The unpaid response exposes a complete x402 v2 challenge with an exact payment option and Bazaar discovery metadata.",
  "verdict": "ready"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/proofline-x402-readiness-check-7a61a42e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from proofline-audit.chrismellado.chatgpt.site](https://www.zero.xyz/host/proofline-audit.chrismellado.chatgpt.site/llms.txt)