# list-smith x402 Route Grader

> list-smith x402 Route Grader is a paid API for AI agents from list-smith-production.up.railway.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-29).

Probes and grades an x402 route's Bazaar discovery metadata, returning a 0-100 score with itemized defects and SDK validator verdicts.

## Facts

- Endpoint: POST https://list-smith-production.up.railway.app/v1/grade?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/list-smith-x402-route-grader-12d7c01b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H-5JPozSRNRqsmIFO-vnl

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 list-smith-x402-route-grader-12d7c01b -d '<json body>'
```

Example prompt: Grade my x402 route at https://service.example.com/v1/endpoint and tell me exactly what's broken — I want the score, every defect with its severity, and whether it's fixable.

## When to prefer this

Choose this endpoint when you operate an x402 route and need a precise, itemized diagnosis of its Bazaar discovery metadata quality before paying for a repair. It is read-only (diagnosis only, no side effects) and returns structured defect data with severities — ideal for automated CI checks or pre-listing audits. Use the sibling /v1/fix endpoint only after reviewing this grade report.

## Known failure modes

- Resource URL unreachable: reachable=false, http_status null, score likely 0
- No x402 challenge found: x402_valid=false, terms.found=false, SDK validation skipped
- Hollow output schema detected: major defect logged, schema_quality.hollow=true, points deducted
- Description over 500 chars: minor defect flagged with detail
- Wrong or invalid asset address: critical defect with specific address mismatch detail
- SDK spec or consistency validation failure: sdk_validation errors array populated
- Malformed input URL: HTTP 400 or unreachable result

## How this service works

Grade one x402 route's Bazaar discovery metadata. Returns the diagnosis only: both x402 SDK validator verdicts, the schema-quality score, itemized defects with severities (hollow output schemas, over-500-char descriptions, wrong asset addresses, failed validation), and a 0-100 grade. Use this when you operate an x402 route and want to know exactly what is broken before paying for the repair.

## Output

Returns a JSON object containing: the 0-100 listing grade, a reachability flag, HTTP status, x402 validity boolean, parsed payment terms (price, network, asset, pay_to, scheme, version), SDK validation results (ran, spec_valid, consistency_valid, errors), schema quality report (score, hollow flag, deductions), an array of itemized defects each with name/severity/detail, a graded_at ISO-8601 timestamp, and a fix_available boolean indicating whether the companion /v1/fix endpoint can repair the route.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "resource_url": {
   "type": "string",
   "description": "Full URL of the x402 resource to grade, e.g. https://service.example.com/v1/endpoint"
  },
  "sample_output": {
   "description": "Optional: one real response body from the endpoint. When supplied, the grade also checks it against the endpoint's published output schema."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "resource_url",
   "graded_at",
   "reachable",
   "http_status",
   "x402_valid",
   "terms",
   "extension_present",
   "sdk_validation",
   "schema_quality",
   "defects",
   "score",
   "fix_available"
  ],
  "properties": {
   "score": {
    "type": "integer",
    "maximum": 100,
    "minimum": 0,
    "description": "Listing grade: 100 (clean) to 0, from the itemized defects"
   },
   "terms": {
    "type": "object",
    "required": [
     "found",
     "price_usdc",
     "amount_units",
     "network",
     "asset",
     "pay_to",
     "scheme",
     "x402_version"
    ],
    "properties": {
     "asset": {
      "type": [
       "string",
       "null"
      ]
     },
     "found": {
      "type": "boolean"
     },
     "pay_to": {
      "type": [
       "string",
       "null"
      ]
     },
     "scheme": {
      "type": [
       "string",
       "null"
      ]
     },
     "network": {
      "type": [
       "string",
       "null"
      ]
     },
     "price_usdc": {
      "type": [
       "string",
       "null"
      ]
     },
     "amount_units": {
      "type": [
       "string",
       "null"
      ]
     },
     "x402_version": {
      "type": [
       "integer",
       "null"
      ]
     }
    }
   },
   "defects": {
    "type": "array",
    "items": {
     "type": "object",
     "required": [
      "name",
      "severity",
      "detail"
     ],
     "properties": {
      "name": {
       "type": "string"
      },
      "detail": {
       "type": "string"
      },
      "severity": {
       "enum": [
        "critical",
        "major",
        "minor"
       ],
       "type": "string"
      }
     }
    }
   },
   "graded_at": {
    "type": "string",
    "description": "ISO-8601 timestamp of the probe"
   },
   "reachable": {
    "type": "boolean"
   },
   "x402_valid": {
    "type": "boolean"
   },
   "http_status": {
    "type": [
     "integer",
     "null"
    ]
   },
   "resource_url": {
    "type": "string"
   },
   "fix_available": {
    "type": "boolean",
    "description": "True when the endpoint presents a valid challenge /v1/fix can repair against"
   },
   "schema_quality": {
    "type": "object",
    "required": [
     "extension_present",
     "hollow",
     "score",
     "deductions"
    ],
    "properties": {
     "score": {
      "type": [
       "integer",
       "null"
      ]
     },
     "hollow": {
      "type": [
       "boolean",
       "nu
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/list-smith-x402-route-grader-12d7c01b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from list-smith-production.up.railway.app](https://www.zero.xyz/host/list-smith-production.up.railway.app/llms.txt)