x402 Doctor
REMOTE · X402-DOCTOR.ONRENDER.COM · SCANNED SEP 25
Check x402 endpoints like a paying agent: diagnose, fix plans, pre-payment checks. Free quick check.
Available components
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. How we score → Why this is hard to score →
Endpoint Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- 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. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability76
- AI-judged instruction clarity (excellent).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
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.
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.
remote · x402-doctor.onrender.com
claude mcp add --transport http fizzl13-x402-doctor 'https://x402-doctor.onrender.com/mcp'
{
"mcpServers": {
"fizzl13-x402-doctor": {
"url": "https://x402-doctor.onrender.com/mcp"
}
}
} {
"servers": {
"fizzl13-x402-doctor": {
"type": "http",
"url": "https://x402-doctor.onrender.com/mcp"
}
}
} [mcp_servers.fizzl13-x402-doctor] url = "https://x402-doctor.onrender.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"fizzl13-x402-doctor": {
"type": "remote",
"url": "https://x402-doctor.onrender.com/mcp",
"enabled": true
}
}
} openclaw mcp add fizzl13-x402-doctor --url 'https://x402-doctor.onrender.com/mcp' --transport streamable-http
mcp_servers:
fizzl13-x402-doctor:
url: "https://x402-doctor.onrender.com/mcp" {
"McpServers": {
"fizzl13-x402-doctor": {
"Transport": "http",
"Url": "https://x402-doctor.onrender.com/mcp"
}
}
} assistant mcp add fizzl13-x402-doctor -t streamable-http -u 'https://x402-doctor.onrender.com/mcp'
{
"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.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 25 Sept 26 64
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 25 Sept 2026 · Probed https://x402-doctor.onrender.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=onrender.com | CN=WE1,O=Google Trust Services,C=US | 21 Sept 2026 | 20 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | 6eb1e3fe7d0631ea1337bfa4a321c137 |
| SANs: onrender.com, *.onrender.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of x402-doctor.onrender.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| onrender.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://x402-doctor.onrender.com/mcp | Verified | 200 | |
| http (plaintext) | http://x402-doctor.onrender.com/mcp | HTTPS enforced | 301 | https://x402-doctor.onrender.com/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
x402_diagnose Diagnose an x402 endpoint ($0.01 via x402) ~151
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.
| Name | Type | Req | Description |
|---|---|---|---|
| method | string | – | HTTP method of the paid route (default: GET, then POST) |
| url | string | yes | The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid |
No output schema declared.
No examples provided.
x402_fix Fix plan for an x402 endpoint ($0.05 via x402) ~142
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.
| Name | Type | Req | Description |
|---|---|---|---|
| method | string | – | HTTP method of the paid route (default: GET, then POST) |
| stack | string | – | Your server stack (default: detected) |
| url | string | yes | The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid |
No output schema declared.
No examples provided.
x402_preflight Check an x402 endpoint before paying it ($0.001 via x402) ~197
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid |
No output schema declared.
No examples provided.
x402_quick_check Quick x402 endpoint check (free) ~135
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).
| Name | Type | Req | Description |
|---|---|---|---|
| method | string | – | HTTP method of the paid route (default: GET, then POST) |
| url | string | yes | The x402 endpoint (public http(s) URL), e.g. https://api.example.com/paid |
No output schema declared.
No examples provided.
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.