# FixLedger Verified Bug Fix Unlock (x402 Pay-on-Proof)

> FixLedger Verified Bug Fix Unlock (x402 Pay-on-Proof) is a paid API for AI agents from fixledger-iota.vercel.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-11-01).

Unlocks a Docker-verified bug fix resolution — including root cause, surgical patch diff, and anti-patterns — for a given error ID after a $0.005 USDC micropayment on Base.

## Facts

- Endpoint: POST https://fixledger-iota.vercel.app/api/x402/unlock?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fixledger-verified-bug-fix-unlock-x402-pay-on-proof-3e5822c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9FVAjK-ApKib26Xlf3ydY

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 fixledger-verified-bug-fix-unlock-x402-pay-on-proof-3e5822c8 -d '<json body>'
```

Example prompt: I got a USDC overpayment error because my code used parseEther instead of parseUnits — can you unlock the verified patch for 'x402-usdc-6-decimals-parseether-overpayment' from FixLedger so I can see the root cause, surgical diff, and anti-patterns?

## When to prefer this

Use this endpoint when you have already identified a specific bug resolution via the free FixLedger Peek endpoint and need the full verified fix details — root cause, surgical patch diff, and anti-patterns — and are willing to pay $0.005 USDC on Base. Prefer this over generic documentation search or LLM-generated fixes when you need a Docker-verified, post-cutoff accurate patch for x402, Base USDC, or related SDK integration errors.

## Known failure modes

- Invalid or unrecognized resolution ID/slug returns an error — always use the free /peek endpoint first to obtain a valid ID
- Payment failure or insufficient USDC balance on Base prevents unlock
- Expired or already-used payment authorization may cause rejection
- Network or Vercel hosting downtime returns 5xx errors

## How this service works

Machine-payable MCP and x402 registry of Docker-verified bug fixes and post-cutoff SDK deltas. Free &lt;50ms Peek-Before-Pay check; $0.005 Pay-on-Proof unlock on Base USDC.

## Output

Returns a JSON object with status UNLOCKED, the resolution slug and title, a detailed root cause string, a Docker-verified unified diff patch ready to apply (under 350 tokens), a list of anti-patterns to avoid, and payment provenance including receipt ID, payment rail, verification type, and Docker-verified pass count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "id"
 ],
 "properties": {
  "id": {
   "type": "string",
   "description": "Resolution UUID or slug returned by free POST /api/x402/peek ($0.00)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "id": {
    "type": "string",
    "examples": [
     "x402-eip3009-base-usdc-domain-version-mismatch",
     "x402-eip3009-nonce-not-bytes32-hex",
     "x402-usdc-6-decimals-parseether-overpayment",
     "x402-cors-expose-headers-payment-required-missing"
    ],
    "required": true,
    "description": "Resolution UUID or slug returned by free POST /api/x402/peek ($0.00). Never guess IDs; peek first."
   }
  },
  "discoverable": true
 },
 "output": {
  "type": "object",
  "required": [
   "status",
   "resolution_id",
   "slug",
   "title",
   "root_cause",
   "surgical_patch",
   "anti_patterns",
   "provenance"
  ],
  "properties": {
   "slug": {
    "type": "string"
   },
   "title": {
    "type": "string"
   },
   "status": {
    "enum": [
     "UNLOCKED"
    ],
    "type": "string"
   },
   "provenance": {
    "type": "object",
    "properties": {
     "receipt_id": {
      "type": "string"
     },
     "payment_rail": {
      "type": "string"
     },
     "verification_type": {
      "type": "string"
     },
     "verified_pass_count": {
      "type": "number"
     }
    }
   },
   "root_cause": {
    "type": "string"
   },
   "anti_patterns": {
    "type": "array",
    "items": {
     "type": "string"
    }
   },
   "resolution_id": {
    "type": "string"
   },
   "surgical_patch": {
    "type": "string",
    "description": "Docker-verified unified diff (<350 tokens) ready to apply."
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fixledger-verified-bug-fix-unlock-x402-pay-on-proof-3e5822c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fixledger-iota.vercel.app](https://www.zero.xyz/host/fixledger-iota.vercel.app/llms.txt)