dev.x402check/mcp
dev.x402check/mcpx402check.devstreamable-httpv0.1.1Scanned
Preflight x402 sellers before pay: ok|caution|avoid + history. Paid per tool.
4 tools: 3 change things and 1 only read.
- Reads private data · 0
- Reads text others write · 4
- Can send data out · 4
- No findings
Anlyon alternative
3 of these tools change something. Run those as governed actions.
Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.
Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.
Import an OpenAPI spec →Tools
Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.
4 tools
Changes things 3Claude Code: ask
preflight_batchTrust-check up to 25 x402 seller URLs in one request.Reads text others writeCan send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe input takes a URL (input.urls): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Trust-check up to 25 x402 seller URLs in one request. Charged per URL (N × unit) in a single Exact settlement. Prefer when comparing candidates, picking the cheapest/most reliable, or screening Bazaar search hits before paying any of them.
Annotations the server declares
- title: Batch x402 trust preflight
- readOnlyHint: true
- openWorldHint: true
- destructiveHint: false
preflight_checkMandatory trust preflight before paying any x402 endpoint.Reads text others writeCan send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Mandatory trust preflight before paying any x402 endpoint. Pass the absolute https seller URL. Returns verdict ok|caution|avoid plus that tool's history only (uptime, payToChanges, priceChanges). Use when: about to settle / PAYMENT-SIGNATURE; asking if an endpoint is safe or legit; debugging a failing 402; checking uptime; validating payment requirements before signing USDC on Base. Do not pay if verdict=avoid. Charged $0.002 per URL via x402 on GET /preflight.
Annotations the server declares
- title: x402 endpoint trust preflight
- readOnlyHint: true
- openWorldHint: true
- destructiveHint: false
verify_paytoVerify the payTo / receiving wallet an x402 seller demands before you sign.Reads text others writeCan send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Verify the payTo / receiving wallet an x402 seller demands before you sign. Same check as preflight_check: live 402 probe + history.payToChanges (wallet rotations) and priceChanges. Use when confirming which Base USDC address you will pay, comparing payTo to an allowlist, or detecting a rug-style wallet swap. Charged per URL.
Annotations the server declares
- title: Verify x402 payTo address
- readOnlyHint: true
- openWorldHint: true
- destructiveHint: false
Only reads 1Show 1 read-only tool
compare_toolsCompare several x402 tools before choosing which to pay.Reads text others writeCan send data outNo findings
Why it is in this group
- The name "compare_tools" says "compare": a word for reading.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- untrusted-inputThe input takes a URL (input.urls), and the tool reads it: it reads web pages, which anyone can write.
- outboundThe input takes a URL (input.urls): a request to a URL can carry data to whoever runs it.
Claude Code: ask, because it is tagged outbound.
Description, as the server wrote it Compare several x402 tools before choosing which to pay. Alias of preflight_batch: returns each URL's verdict, priceUsd, payTo, uptimePct, and drift history so you can pick reliable/cheap candidates and skip avoid. Charged per URL.
Annotations the server declares
- title: Compare x402 seller tools
- readOnlyHint: true
- openWorldHint: true
- destructiveHint: false
This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.
Exfil surface
Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.
No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data.
- Reads private data0
- Reads files, mail, messages, databases, secrets, calendars or repositories.
- Reads text others write4
- Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
- Can send data out4
- Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.
Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.
Findings
Matches of fixed checks, with the text they matched.
No check matched anything in these tool definitions. That is not a safety guarantee.
History
Changes to its tool definitions and to its remote endpoint, newest first.
No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.
Install
Pinned to version 0.1.1. Values in angle brackets are yours to fill in.
claude mcp add --transport http x402check https://x402check.dev/mcpclaude mcp add --transport http x402check https://x402check.dev/mcpRun in a terminal.
Claude Code permissions
Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.
{
"permissions": {
"allow": [],
"ask": [
"mcp__x402check__preflight_check",
"mcp__x402check__verify_payto",
"mcp__x402check__preflight_batch",
"mcp__x402check__compare_tools"
],
"deny": []
}
}Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as x402check. Review it before you use it.
Capability tags behind 4 rules
- mcp__x402check__preflight_check untrusted-input, outbound
- mcp__x402check__verify_payto untrusted-input, outbound
- mcp__x402check__preflight_batch untrusted-input, outbound
- mcp__x402check__compare_tools untrusted-input, outbound
Pin
Keep the decision: fail CI when the tools change, follow every change, or show a badge.
Pin in CI
Fail a build when the tools you reviewed are not the tools the server serves today.
curl -s "https://anlyon.dev/api/v1/servers/dev.x402check/mcp/verify?hash=8c5a2480b40035b9301a32be096817b6b0d5092ce677e3a6740c172413e2adc3" | jq -e '.changed == false'Pinned hash 8c5a2480b400, from Oct 31, 2026, 19:18 UTC.
Watch
Get told when its tools change: a new tool, a new description, a new class.
https://anlyon.dev/servers/dev.x402check/mcp/changes.xmlAn Atom feed. Works in any feed reader or Slack's RSS app.
Badge
[](https://anlyon.dev/servers/dev.x402check/mcp)Source: MCP Registry. Synced Oct 31, 2026, 19:17 UTC.