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x402 Doctor – Fix Endpoint
x402
x402 Doctor – Fix Endpoint is a paid API for AI agents from x402-doctor.onrender.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-10).
Diagnoses an x402-protected HTTP endpoint and returns concrete, stack-specific code fixes for every detected problem, pre-filled with the caller's own payTo, amount, network, and route.
Price / call$0.05
Success—
StatusUnknown
How this service works
The fix for your x402 endpoint: diagnoses it, then returns per problem the concrete change as code for your stack (Express, Next.js, Hono or raw HTTP), filled in with your own payTo, amount, network and route.
Output
Returns an overall status (pass/warn/fail), a summary, the detected stack, and an array of fixes — each with a title, severity, explanation of why it's a problem, numbered steps to resolve it, ready-to-paste code snippets in the caller's framework, verification checks, and any unfixed issues that couldn't be auto-remediated.
Example use cases
Fix broken Express x402 payment wall
“My Express.js x402 endpoint at https://api.myapp.com/gated isn't responding correctly to payment challenges. Can you diagnose it and give me the exact code snippets to fix it?”
Debug Next.js x402 route implementation
“I built a Next.js API route at https://nextapp.vercel.app/api/premium with x402 but clients can't pay — diagnose what's wrong and show me the corrected Next.js code to fix each issue.”
Validate Hono x402 middleware setup
“Check my Hono x402 endpoint at https://hono-app.workers.dev/paid and tell me everything that's misconfigured, with working Hono code snippets I can paste in to fix each problem.”
Technical details
Endpoint
GEThttps://x402-doctor.onrender.com/api/v1/fix?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you already know your x402 endpoint URL and want actionable, code-level fixes rather than just a diagnosis report. It goes beyond the sibling /diagnose endpoint by generating concrete, copy-paste code snippets tailored to your specific framework (Express, Next.js, Hono, or raw HTTP), pre-filled with your actual payTo address, amount, network, and route — saving significant manual debugging time.
Side effects
- URL is not publicly reachable — endpoint returns connection error
- Provided URL is not an x402 endpoint at all — no 402 response detected
- Stack auto-detection fails if no identifying headers are present — caller should specify stack explicitly
- Endpoint requires authentication before returning 402 — doctor cannot probe it
- Transient Render.com cold-start latency on first call
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"url": "https://x402-doctor.onrender.com/demo/broken",
"fixes": [
{
"why": "x402 amounts are integer strings in the smallest unit.",
"code": [
{
"label": "Option field",
"stack": "generic",
"snippet": "\"amount\": \"10000\"",
"language": "json"
}
],
"steps": [
"Use price: \"$0.01\" instead of an amount."
],
"title": "Amount \"0.01\" → \"10000\" ($0.01)",
"checks": [
"accepts[0]-amount"
],
"recipe": "amount",
"verify": "Run x402 Doctor again.",
"severity": "warn"
}
],
"stack": {
"id": "express",
"name": "Express (@x402/express)",
"detected_from": "x-powered-by: Express"
},
"overall": "fail",
"summary": "1 fix (0 blocking), for Express (@x402/express).",
"unfixed": []
}
}Tags
x402
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