# x402 Doctor (remote · x402-doctor.onrender.com)

Check x402 endpoints like a paying agent: diagnose, fix plans, pre-payment checks. Free quick check.

- Trust score: 64/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-25

## Components

- remote · `x402-doctor.onrender.com`: 64/100 (this document), [markdown](https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor.md), [page](https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor)

## Channel facts

- Endpoint: `https://x402-doctor.onrender.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-09-25.

- **Endpoint Security**: 57/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 4 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 76/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 625 tokens (~156/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

**Unverified: 1 category.** A category scored 0 because we could not verify it: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.

## Install

### How do I install the x402 Doctor MCP server?

x402 Doctor is a hosted endpoint at https://x402-doctor.onrender.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http fizzl13-x402-doctor 'https://x402-doctor.onrender.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "fizzl13-x402-doctor": {
      "url": "https://x402-doctor.onrender.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "fizzl13-x402-doctor": {
      "type": "http",
      "url": "https://x402-doctor.onrender.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.fizzl13-x402-doctor]
url = "https://x402-doctor.onrender.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "fizzl13-x402-doctor": {
      "type": "remote",
      "url": "https://x402-doctor.onrender.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add fizzl13-x402-doctor --url 'https://x402-doctor.onrender.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  fizzl13-x402-doctor:
    url: "https://x402-doctor.onrender.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "fizzl13-x402-doctor": {
      "Transport": "http",
      "Url": "https://x402-doctor.onrender.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add fizzl13-x402-doctor -t streamable-http -u 'https://x402-doctor.onrender.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "fizzl13-x402-doctor": {
      "type": "http",
      "url": "https://x402-doctor.onrender.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-25 (score 64)

First indexed and scored.

## MCP tools (4)

### `x402_quick_check` (~135 tokens)

Quick x402 endpoint check (free)

Free: does this x402 endpoint work for a paying agent? Returns pass, warn or fail with the number of problems and the top three. Limited to 10 calls per hour. For every check use x402_diagnose ($0.01); for code changes x402_fix ($0.05); before paying someone else's endpoint x402_preflight ($0.001).

Input parameters:

- `method` (string): HTTP method of the paid route (default: GET, then POST)
- `url` (string, required): The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid

### `x402_diagnose` (~151 tokens)

Diagnose an x402 endpoint ($0.01 via x402)

Paid ($0.01 USDC via x402 on Base or Solana): diagnose an x402 endpoint the way a paying agent would, without paying it: the 402 challenge format, every accepts[] option, the resource URL, Solana settlement readiness, which wallets can pay, Bazaar/OpenAPI discovery and the browser paywall. Returns every check with pass/warn/fail and a fix hint. Same as GET /api/v1/diagnose.

Input parameters:

- `method` (string): HTTP method of the paid route (default: GET, then POST)
- `url` (string, required): The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid

### `x402_preflight` (~197 tokens)

Check an x402 endpoint before paying it ($0.001 via x402)

Paid ($0.001 USDC via x402 on Base or Solana): call this before your agent pays an x402 endpoint. Returns go, caution or no_go, the recommended payment option, and why: payment would fail, over your budget (max_usd), price above what is advertised, not HTTPS, unknown token, its 30-day track record. Never pays the endpoint. Same as GET /api/v1/preflight.

Input parameters:

- `max_usd` (number): Your budget per call in USD, e.g. 0.05
- `method` (string): HTTP method of the paid route (default: GET, then POST)
- `network` (string): CAIP-2 network you want to pay on, e.g. eip155:8453
- `url` (string, required): The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid

### `x402_fix` (~142 tokens)

Fix plan for an x402 endpoint ($0.05 via x402)

Paid ($0.05 USDC via x402 on Base or Solana): diagnoses your x402 endpoint, then returns per problem the concrete change as code for your stack (express, next, hono, node, python, generic), filled in with your own payTo, amount, network and route. Same as GET /api/v1/fix.

Input parameters:

- `method` (string): HTTP method of the paid route (default: GET, then POST)
- `stack` (string): Your server stack (default: detected)
- `url` (string, required): The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor#diagnostics

## Score history

- 2026-09-25: 64

## Common questions

### What is the x402 Doctor MCP server?

x402 Doctor is an MCP server listed in the public MCP registry as io.github.Fizzl13/x402-doctor. Check x402 endpoints like a paying agent: diagnose, fix plans, pre-payment checks. Free quick check. This page covers its hosted endpoint (https://x402-doctor.onrender.com/mcp).

### Is the x402 Doctor MCP server safe to use?

x402 Doctor scores 64 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the x402 Doctor MCP server expose?

x402 Doctor exposes 4 tools: x402_quick_check, x402_diagnose, x402_preflight, x402_fix. Their descriptions and schemas cost roughly 625 tokens of context every time the server is loaded.

### Does the x402 Doctor MCP server require authentication?

No. We connected to x402 Doctor without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the x402 Doctor MCP server still maintained?

x402 Doctor is still listed as active in the MCP registry. We last reached this channel on 25 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://x402-doctor.onrender.com/mcp
- Repository: https://github.com/Fizzl13/x402-doctor
- Website: https://x402-doctor.onrender.com/
- Changelog RSS feed: https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor.xml
- Changelog JSON feed: https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor.json
- HTML version of this page: https://verifymcp.io/servers/fizzl13-x402-doctor/x402-doctor