x402 Doctor is an MCP server with 3 tools an agent can call, among them explain_defect, list_checks, probe_x402_endpoint. It answers at https://x402-doctor.tsharpe.workers.dev/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 6 of 6 times since 10 September 2026; the last check, on 19 October 2026, succeeded.
Diagnose x402 seller endpoints: what is wrong with your 402 challenge, and how to fix it.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
explain_defect | Full explanation of one rule by id — what it checks, why it matters, how to fix it, and where the rule came from. Use when you want the reasoning without re-probing. Inputs: id |
list_checks | The whole rule table. Knowing what was NOT checked is part of knowing what a clean result means. |
probe_x402_endpoint | Probe an x402 seller endpoint and report what it observes about it. Performs the handshake a paying client would: GET with no X-PAYMENT header, then checks the 402 challenge against 16 rules. Every finding says whether the rule comes from t Inputs: url |
Every block below points at https://x402-doctor.tsharpe.workers.dev/mcp. Pick your client and copy.
claude mcp add --transport http x402-doctor https://x402-doctor.tsharpe.workers.dev/mcp
{
"mcpServers": {
"x402-doctor": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://x402-doctor.tsharpe.workers.dev/mcp"]
}
}
}{
"mcpServers": {
"x402-doctor": {
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"servers": {
"x402-doctor": {
"type": "http",
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"context_servers": {
"x402-doctor": {
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"mcpServers": {
"x402-doctor": {
"serverUrl": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"mcpServers": {
"x402-doctor": {
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}name: x402 Doctor
version: 0.0.1
schema: v1
mcpServers:
- name: x402 Doctor
type: streamable-http
url: https://x402-doctor.tsharpe.workers.dev/mcp{
"mcpServers": {
"x402-doctor": {
"httpUrl": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"mcpServers": {
"x402-doctor": {
"type": "http",
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}{
"mcpServers": {
"x402-doctor": {
"url": "https://x402-doctor.tsharpe.workers.dev/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fx402-doctor.tsharpe.workers.dev%2Fmcp&type=streamable_http&id=x402-doctor&name=x402%20Doctor
It answered our last check on 19 October 2026 in 130 ms. Over 6 checks since 10 September 2026 it answered 6. Status here comes from Neuronto's own probes, not from the publisher.
3, as returned by the server's own tools/list on 11 September 2026: explain_defect, list_checks, probe_x402_endpoint.
It answered our last check on 19 October 2026 in 130 ms. Over 6 checks since 10 September 2026 it answered 6.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://x402-doctor.tsharpe.workers.dev/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: com.twelvepermissions. Endpoint host: x402-doctor.tsharpe.workers.dev. ARD identifier: urn:air:com.twelvepermissions:mcp:x402-doctor.
First indexed 10 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.