Prompt-injection check (x402) MCP Server

by onrender-prompt-injection-check Your server? Claim it

not responding

Prompt-injection check (x402) is listed as active in the registry but did not answer our last check. It exposes 7 tools.

Prompt-injection check and safe web fetch for agents, with evidence spans. $0.005 per item, x402.

Uptime history 15 days of history · worst day 0%

15 days agonow

0.0%

Uptime 24h

0 of 91 checks

Tools

read from the server

227 ms

Response time

average over 24h

open, no key

Access

streamable-http

What changed 9

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 25 October 2026. No other catalogue keeps this.

25 Oct 4 tools appeared check_skill_pack, try_check_prompt_injection, try_check_skill_pack and 1 more

25 Oct a tool changed version3 times that day

25 Oct 2 tool descriptions were rewritten check_prompt_injection, fetch_and_check

and 2 more, back to 25 October 2026

Prompt-injection check (x402) does not always answer

Over the last week it answered 0.0% of our checks. We check every 15 minutes, so you hear about the next outage within the hour — not from your users.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 13 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add prompt-injection-check --transport http https://prompt-injection-check.onrender.com/mcp

Settings → Connectors → Add custom connector, then paste this address

https://prompt-injection-check.onrender.com/mcp

~/.codex/config.toml

[mcp_servers.prompt-injection-check]
url = "https://prompt-injection-check.onrender.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "prompt-injection-check": {
      "url": "https://prompt-injection-check.onrender.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "prompt-injection-check": {
      "type": "http",
      "url": "https://prompt-injection-check.onrender.com/mcp"
    }
  }
}

Available tools 7

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

try

try_check_prompt_injection

Free, no payment. Same check and same output as check_prompt_injection for 1 text of at most 4000 characters, plus a trial object with remaining_today and how to upgrade. 3 free calls per source per UTC day, shared with try_fetch_and_check and POST https://prompt-injection-check.onrender.com/try/check; after that the tool returns an error with the paid route.

try_check_skill_pack

Free, no payment. Same report and output as check_skill_pack for 1 pack (files or url), plus a trial object. 3 free calls per source per UTC day, shared with the other try_ tools; after that the tool returns an error with the paid route.

try_fetch_and_check

Free, no payment. Same fetcher, safety rules and output as fetch_and_check for 1 public https URL, plus a trial object. 3 free calls per source per UTC day, shared with try_check_prompt_injection; failed fetches also use a call.

and

fetch_and_check

Fetch 1 to 10 public https pages in one call. Per URL: status, final_url, title, clean markdown, verdict (safe, suspicious, injection), intents, evidence spans (offsets into the markdown or the raw HTML for hidden content) and safe_markdown with flagged sentences removed. robots.txt is respected. Fetch plus check in one call. Free trial with your own URL: try_fetch_and_check. Costs $0.005 USDC per URL fetched successfully on Base via x402; failed URLs are free. The first call without payment returns the payment requirements for the URLs that were fetched; pay with an x402-capable MCP client (_meta['x402/payment']) or POST https://prompt-injection-check.onrender.com/fetch-check.

prompt

check_prompt_injection

Check untrusted texts or URLs for prompt injection before your agent reads them. Per item: verdict (safe, suspicious, injection), score, intents, a one-sentence human_summary and evidence spans with code point, UTF-8 byte and UTF-16 offsets. Hidden HTML and invisible characters are weighed. Deterministic rules for EN, with override and agent-addressed phrases also in NL and DE; a clean verdict is not a guarantee. Try it free first with try_check_prompt_injection (3 calls a day). Costs $0.005 USDC per item on Base via x402: the first call without payment returns the payment requirements; pay with an x402-capable MCP client (_meta['x402/payment']) or call POST https://prompt-injection-check.onrender.com/check over HTTP x402.

selftest

selftest

Free. Replays the published known-answer set v1.2 (24 cases) and returns score and sha256, so you can verify the detector before paying.

skill

check_skill_pack

Static permission report for an agent skill pack. Send files (a list of {path, content}, up to 30) or one public https url to a raw file. Per finding, with file and line: network destinations, files and paths read/written/deleted (~/.ssh, ~/.aws, .env, browser profiles, wallets), secrets and env vars read, shell commands and installs (curl|sh, sudo, rm -rf), and instructions aimed at the agent the buyer did not ask for (plus hidden and base64 text). Returns a risk level and a plain summary of what the pack can do with the human's accounts. Deterministic, no code run; not a guarantee. Try free first with try_check_skill_pack. $0.01 USDC per pack on Base via x402: the first call without payment returns the requirements; pay with an x402 MCP client (_meta['x402/payment']) or POST https://prompt-injection-check.onrender.com/skill-check.

Endpoints

URL	Transport	State	Latency	Checked
https://prompt-injection-check.onrender.com/mcp	streamable-http	answering	227 ms	13 min ago

Alternatives to Prompt-injection check (x402)

same job, measured the same way

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Web pages, JavaScript sites and PDFs to clean Markdown for AI agents, prompt injection removed.

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2 tools answering

Feason Context

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Prompt-injection scanner for agents: risk score, categories and spans for text, pages, MCP tools

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LastSearch

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Evidence-backed web research for AI agents with citations and confidence scores.

539 installs/wk local only

Prompt-injection check (x402) — questions

Answers built from our own checks of this server.

What can Prompt-injection check (x402) do?

It exposes 7 tools, read directly from the server on our last check. Among them: check_prompt_injection, check_skill_pack, fetch_and_check, selftest, try_check_prompt_injection, try_check_skill_pack and 1 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Prompt-injection check (x402) working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 0 of 91 checks got a reply (0.0%), average response time 227 ms. The bar chart above shows every period we have measured.

The registry lists Prompt-injection check (x402) as active — why does it not respond?

The official MCP registry stores what the author submitted; it does not verify that the server still runs. We check the endpoint ourselves, and this one does not answer. Catalogues that copy the registry without checking will show it as working.

How do I connect Prompt-injection check (x402)?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Prompt-injection check (x402) need an API key?

No. Prompt-injection check (x402) completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 7 of them are readable on this page. This is what we observed, not what the docs claim.