X402check MCP Server

by x402check Your server? Claim it

answering

X402check is answering right now. Last checked 14 min ago. 1 663 installs a week from npm. It exposes 6 tools.

Preflight before paying any x402 tool (ok|caution|avoid + history). 1 free/wallet; then $0.01 Base.

Installs per day peak 471 · avg 17

a month agotoday

Uptime history 8 days of history

8 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

239 ms

Response time

average over 24h

1 663

Installs / week

npm and PyPI

What changed 13

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 2 November 2026. No other catalogue keeps this.

4 Nov a tool description was rewritten preflight_check

2 Nov 5 tool descriptions were rewritten7 times that day compare_tools, preflight_batch, preflight_check and 2 more

2 Nov 2 tools appeared deep_check, watch_tool

2 Nov a tool changed version2 times that day

2 Nov a tool changed the parameters it asks for watch_tool

and 3 more, back to 2 November 2026

Nothing serious here today

Today is the operative word: we check X402check every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 14 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add mcp --transport http https://x402check.dev/mcp

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

https://x402check.dev/mcp

~/.codex/config.toml

[mcp_servers.mcp]
url = "https://x402check.dev/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "mcp": {
      "url": "https://x402check.dev/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "mcp": {
      "type": "http",
      "url": "https://x402check.dev/mcp"
    }
  }
}

Available tools 6

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

preflight

preflight_batch

Trust-check up to 25 x402 seller URLs in one request. Charged per URL (N × unit) in a single Exact settlement via MCP _meta payment. Prefer when comparing candidates, picking the cheapest/most reliable, or screening Bazaar search hits before paying any of them.

preflight_check

Preflight an x402 seller URL before settle / PAYMENT-SIGNATURE. Pass the absolute https seller URL. Returns verdict ok|caution|avoid plus that tool's history only (uptime, payToChanges, priceChanges). Use when: about to pay any x402 endpoint; asking is this API a scam; is this endpoint safe or legit; debugging a failing 402; checking uptime; validating payment requirements before signing USDC on Base. Do not pay if verdict=avoid. Charged $0.01 per URL via x402 Exact on this MCP tools/call (params._meta['x402/payment']).

compare

compare_tools

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 via MCP x402 payment.

deep

deep_check

Deeper trust check before paying an x402 endpoint ($0.05 Exact USDC). Runs the same live 402 + history as preflight_check, then repeated probes for payTo/price consistency, a recent public Base USDC-to-payTo transfer sample, Bazaar + 402 Index listing checks, and drift vs last KV history. Does not claim OFAC or wallet simulation. Optional when the base check is not enough signal.

verify

verify_payto

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 via MCP x402 payment.

watch

watch_tool

Subscribe to daily re-checks of one x402 seller URL for 30 days. Alerts your webhook and/or email when payTo, price, network, or availability changes. Fixed $5 USDC Exact (not per-check). Optional after a one-shot preflight when you will revisit the same seller.

Endpoints

URL	Transport	State	Latency	Checked
https://x402check.dev/mcp	streamable-http	answering	261 ms	14 min ago

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same job, measured the same way

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Ticktape

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Deterministic pre-execution verification tools for AI agents with x402 USDC pay-per-call on Base

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Check x402 APIs before paying (pay/caution/avoid); find x402 APIs by real paid usage.

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Lumi Trades: x402 seller checks and test-buys

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Free signed allow/warn/block before paying x402 sellers; test-buys on XRPL, Base and Stellar

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X402check — questions

Answers built from our own checks of this server.

What can X402check do?

It exposes 6 tools, read directly from the server on our last check. Among them: compare_tools, deep_check, preflight_batch, preflight_check, verify_payto, watch_tool. 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 X402check working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 239 ms. The bar chart above shows every period we have measured.

How do I connect X402check?

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 X402check need an API key?

No. X402check completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 6 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is X402check?

It answers our handshake in 239 ms on average, which is faster than 59% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

How many people use X402check?

The npm package x402check-mcp was installed 1 663 times in the last week. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.