crosscheck is answering right now. Last checked 7 min ago. 272 installs a week from npm. It exposes 8 tools. Last commit 25 Oct 2026.
Checks for AI agents over x402: review drafts, accept-check handoffs, scan skills before install.
Installs per day
peak 895 · avg 59 · -77% w/w
a month agotoday
Uptime history
39 days of history · worst day 0%
39 days agonow
100.0%
Uptime 24h
91 of 91 checks
8
Tools
read from the server
645 ms
Response time
average over 24h
272
Installs / week
npm and PyPI
What changed 8
Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 26 September 2026. No other catalogue keeps this.
24 Oct
2 tools appeared
sellercheck, sellerwatch
27 Sep
2 tool descriptions were rewritten
check, verify_receipt
27 Sep
2 tools changed the parameters they ask for
check, verify_receipt
26 Sep
a tool appeared
verify_receipt
26 Sep
a tool changed the parameters it asks for
check
What the code does
We read the source, 1 d ago · tools taken from the live server · rules 995398eba69f
Evidence
Things with no honest explanation: a promise that contradicts the code, code that runs at install time while hiding what it does, data leaving the machine.
Hides code and sends data out
[пакет] bin/crosscheck.mjs:47
…sterPolicy(o)}),e}import{createHash as hA,createPublicKey as yA,randomBytes as bA,verify as gA}from"node:crypto";import{readdirSync as xA,readFileSync as wA,statSync as vA}from"node:fs";import{join as EA,relative as AA,sep as SA}from"node:path";Ma();X();yr();Pt();function hx(e){i…
Capabilities
What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.
File ships in the package but is absent from the source
[пакет] bin/crosscheck.mjs:1
этот файл ставится пользователю, но в репозитории его нет
Reads files and sends them to the network
[пакет] bin/crosscheck.mjs:47
…sterPolicy(o)}),e}import{createHash as hA,createPublicKey as yA,randomBytes as bA,verify as gA}from"node:crypto";import{readdirSync as xA,readFileSync as wA,statSync as vA}from"node:fs";import{join as EA,relative as AA,sep as SA}from"node:path";Ma();X();yr();Pt();function hx(e){i…
Long encoded blob in source
[пакет] bin/crosscheck.mjs:43
…e:"amount",type:"uint256"}],outputs:[{type:"bool"}]}]});var yb,bb=R(()=>{yb="0x82ad56cb"});var Hf,gb,xb,Uo,Za=R(()=>{Hf="0x608060405234801561001057600080fd5b5060405161018e38038061018e83398101604081905261002f91610124565b6000808351602085016000f59050803b61004857600080fd5b60008083516…
Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.
We found things in this code
Code changes quietly between releases, and nobody reads the diff of a dependency. We do, on every release — watch crosscheck and you get told the day something new turns up.
Connect this server
Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 7 min ago.
run in your terminal
claude mcp add crosscheck --transport http https://crosscheckapi.com/mcpSettings → Connectors → Add custom connector, then paste this address
https://crosscheckapi.com/mcp~/.codex/config.toml
[mcp_servers.crosscheck]
url = "https://crosscheckapi.com/mcp".cursor/mcp.json
{
"mcpServers": {
"crosscheck": {
"url": "https://crosscheckapi.com/mcp"
}
}
}.vscode/mcp.json
{
"servers": {
"crosscheck": {
"type": "http",
"url": "https://crosscheckapi.com/mcp"
}
}
}Available tools 8
Read directly from the server with tools/list, grouped by what they act on.
If a tool disappears, we record the date.
skillcheck
skillcheck
Security review of a skill or MCP server's files before you install or connect it: read, never run. Free when these exact files were scanned before (looked up by bundle hash); otherwise paid, $0.03 base. Never says safe. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
skillcheck_lookup
Free. The latest skillcheck of an exact bundle, by its bundle_sha256 (SHA-256 of the canonical JSON of the files sorted by path, each as {path, sha256}).
accept
accept
Checks work another agent handed back against the task it was given, before you pay, release escrow, or pass it on. Returns accept, reject, or verify_externally with every requirement judged; counts, required JSON fields, and sums are checked in code. Optional payment_tx is verified on chain. $0.03 base. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
check
check
Independent review of a draft (email, report, summary, PR description) before its human sees it. Returns pass or specific issues with fixes; arithmetic is recomputed in code. With request (what the human asked), it also checks the draft answers that. With sources, each claim is checked against them and quotes are verified; with source_urls or fetch_cited, crosscheck fetches up to 3 web pages itself and checks against those (+$0.01 a page, and a dead link the draft gives fails it). $0.02. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
result
result
Free. Status, verdict, and signed receipt of an earlier paid call that was still running, using the job_id and result_token it returned.
sellercheck
sellercheck
For x402 sellers: one dated report on your own paid resource, by code alone. Does it answer a valid 402 (v1 or v2: price, network, payTo), is it in the x402 Bazaar index, would agent402's router route to it, and how many USDC settlements reached its payTo on Base in 24 hours and 7 days. Nothing is paid to the resource. $0.05. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
sellerwatch
sellerwatch
For x402 sellers: sellercheck every hour for 30 days on one resource, paid once. An alert to your webhook (JSON POST) or ntfy topic only when something changes: the 402 breaks or its price or payTo change, it leaves or rejoins the Bazaar index, agent402's router flips, settlements start, double, or halve, or it is down twice in a row. Returns a public record page to link from your listing. $1. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
verify
verify_receipt
Free. Before trusting work that arrives with a crosscheck receipt, check in code that crosscheck issued it, its signature is valid, what the outcome was, and that it covers exactly the text you were handed. Pass receipt_hash (or the receipt object) plus that text: draft, request, and sources for check, task and deliverable for accept, files for skillcheck, and the verdict if one came with it.
Endpoints
| URL | Transport | State | Latency | Checked |
|---|---|---|---|---|
| https://crosscheckapi.com/mcp | streamable-http | answering | 617 ms | 7 min ago |
Alternatives to crosscheck
same job, measured the same wayThe Agent Forge
by theagentforge
See which AI models fall for traps in real jobs, and check MCP servers or skills before install.
AgentSecurityLens MCP Security Trust Check
by professor2k8
MCP security trust-check for agents before installing MCPs, Skills or tools.
Veragent
by lixiaowww
Check the trust/security score of MCP servers, agents, skills & CLIs before you install them.
tashan
by tashan
Check any MCP server or agent skill before installing: upkeep, real adoption, and OSV advisories.
Agorean
by agorean
The review layer for x402: check a seller's reviews before you pay. Also a marketplace for agents.
Haven
by parvizrahayan
Rest stop for AI agents: check in, reflect, check out. Paid cross-project memory recall via x402.
SKV Network
by skv
Memory + answer checks for AI agents: recall across chats, draft→check→seal, fewer hallucinations.
x402 Triage MCP
by tatelyman
MCP server for no-payment x402 surface triage, 402 Index health checks, and paid review handoff.
crosscheck — questions
Answers built from our own checks of this server.
What can crosscheck do?
It exposes 8 tools, read directly from the server on our last check. Among them: accept, check, result, sellercheck, sellerwatch, skillcheck and 2 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 crosscheck 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 645 ms. The bar chart above shows every period we have measured.
How do I connect crosscheck?
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 crosscheck need an API key?
No. crosscheck completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 8 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is crosscheck?
It answers our handshake in 645 ms on average, which is faster than 16% of all working MCP servers we measure. That is on the slow side — worth knowing if the tool sits inside an interactive loop. The comparison comes from our own checks across the whole registry, every 15 minutes.
How many people use crosscheck?
The npm package crosscheckapi was installed 272 times in the last week. Week over week that is -77%. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.
Is crosscheck open source?
The code is open source: it is published under the MIT licence, written in JavaScript, 1 stars on GitHub and 2 open issues. The licence covers the code in the repository, not the hosted service at crosscheckapi.com, which runs on its operator's own terms.