# list-smith /v1/fix — x402 Route Discovery Repair

> list-smith /v1/fix — x402 Route Discovery Repair is a paid API for AI agents from list-smith-production.up.railway.app, paid per call via x402, $0.5/call, status unknown (last checked 2026-10-29).

Audits and fully repairs an x402 route's Bazaar discovery metadata, returning a validated discovery package (schema, description, OpenAPI snippet, instructions) inferred from a real sample output.

## Facts

- Endpoint: POST https://list-smith-production.up.railway.app/v1/fix?utm_source=zero.xyz
- Price: $0.5/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-v1-fix-x402-route-discovery-repair-758b6187
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iXA5OtJODVI54wT28Qso2

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-v1-fix-x402-route-discovery-repair-758b6187 -d '<json body>'
```

Example prompt: My x402 route at https://myservice.example.com/v1/analyze is invisible in Bazaar — can you repair its discovery metadata? The category is 'data' and here's a real sample response body from it: {"risk_score": 0.87, "label": "high", "token": "0xabc"}

## When to prefer this

Use this endpoint (rather than the sibling /v1/grade diagnosis-only endpoint) when you want both the diagnosis AND a ready-to-paste, validator-approved discovery package in a single call. Ideal when your x402 listing is confirmed hollow, invalid, or invisible in Bazaar and you want immediate remediation rather than just a report. The $0.50 USDC cost is justified by receiving a complete, pre-validated package you can ship immediately.

## Known failure modes

- Invalid or unreachable resource_url — failure field set, no package shipped
- Sample output is unparseable or empty — cannot infer schema, ok=false
- Package fails both x402 SDK validators — endpoint refuses to ship broken package, failure explains why
- Missing required sample_output field — request rejected
- Endpoint cannot infer sufficient schema from a single sample with high variance types

## How this service works

Repair one x402 route's Bazaar discovery metadata in one call. Send a resource URL and one real sample output; get the defect report plus a complete discovery package — full output schema inferred from the sample, a sub-500-char description with a use-when sentence, OpenAPI and well-known snippets, paste-in instructions — that ships only after passing both x402 SDK validators. Use this when your listing is hollow, invalid, or invisible in the Bazaar.

## Output

A JSON object containing: a boolean ok flag, a pre-repair score, an array of defect objects (each with name, severity, and detail), a failure reason if the package could not be produced, and — when ok is true — a full discovery package including the inferred output schema extension (validated by both x402 SDK validators), a sub-500-char description with a use-when sentence, an OpenAPI snippet, a well-known snippet, and paste-in instructions. Also includes notes about inference caveats.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mode": {
   "enum": [
    "full",
    "compact"
   ],
   "type": "string",
   "description": "Optional response mode, default 'full'. 'full' returns the complete package (extension with meta-schema, OpenAPI + well-known snippets, instructions). 'compact' returns the repaired fields only (description, extension info, changes) in a smaller response; the package is validated the same way in both modes."
  },
  "name": {
   "type": "string",
   "description": "Optional display name for the generated description; derived from the URL when omitted."
  },
  "category": {
   "type": "string",
   "description": "Optional category (e.g. token-risk, search, data, media, monitoring) used to phrase the description's use-when sentence."
  },
  "resource_url": {
   "type": "string",
   "description": "Full URL of the x402 resource to repair, e.g. https://service.example.com/v1/endpoint"
  },
  "sample_output": {
   "description": "One real response body from the endpoint (required). The repaired output schema is inferred from this sample only — nothing is invented."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "resource_url",
   "graded_at",
   "ok",
   "failure",
   "score_before",
   "defects",
   "package",
   "notes"
  ],
  "properties": {
   "ok": {
    "type": "boolean"
   },
   "notes": {
    "type": "array",
    "items": {
     "type": "string"
    }
   },
   "defects": {
    "type": "array",
    "items": {
     "type": "object",
     "required": [
      "name",
      "severity",
      "detail"
     ],
     "properties": {
      "name": {
       "type": "string"
      },
      "detail": {
       "type": "string"
      },
      "severity": {
       "enum": [
        "critical",
        "major",
        "minor"
       ],
       "type": "string"
      }
     }
    }
   },
   "failure": {
    "type": [
     "string",
     "null"
    ],
    "description": "Why no package was shipped, when ok is false — an unvalidatable package is never shipped broken"
   },
   "package": {
    "type": [
     "object",
     "null"
    ],
    "required": [
     "inferred_from",
     "description",
     "extension",
     "openapi_snippet",
     "well_known_snippet",
     "instructions",
     "validation"
    ],
    "properties": {
     "extension": {
      "type": "object",
      "description": "The repaired Bazaar discovery extension (passed both SDK validators)"
     },
     "validation": {
      "type": "object",
      "required": [
       "consistency_valid",
       "spec_valid"
      ],
      "properties": {
       "spec_valid": {
        "type": "boolean"
       },
       "consistency_valid": {
        "type": "boolean"
       }
      }
     },
     "description": {
      "type": "string",
      "description": "Under 500 chars, with a use-when sentence"
     },
     "instructions": {
      "type": "string"
     },
     "inferred_from": {
      "type": "string",
      "const": "single_sample"
     },
     "openapi_snippet": {
      "type": "object"
     },
     "well_known_snippet": {
      "type": "object"
     }
    }
   },
   "graded_at": {
    "type": "string"
   },
   "resource_url": {
    "type": "string"
   },
   "score_before": {
    "type": [
     "integer",
     "null"
    ],
    "description": "The /v1/grade score of the listing as found"
   }
  }
 },
 "example": {
  "ok": true,
  "notes": [
   "inferred_from: single_sample — the output schema was inferred from the one sample supplied; review it before shipping, especially arrays (element schemas are merged) and any field whose real type varie
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/list-smith-v1-fix-x402-route-discovery-repair-758b6187/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)