x402 Checker (AI Nock)

io.github.nock-for-makPublished by GitHub account nock-for-makv1.34.0Updated Oct 24, 2026

Free check/board/name; paid bid/report 0.05, 1c fx/wx/lookups, news 0.001.

VerifiedStreamable HTTPWeb executableWeb Search & ScrapingFinanceSecurity & Monitoring

Overview

AI-generated overview

A remote x402 checker that probes 402 payment endpoints for free and sells small paid lookups, from crypto and web data to time and calendar utilities.

What you can do
Probe x402 payment endpoints for payTo, amount, network and asset, and batch up to ten URLs or pull a structured honesty report on one endpoint (free check, paid batch and report). Look up crypto and chain data: address balances, transactions, blocks, gas, token metadata, function selectors, ENS names, prices, DEX pairs, token security, Polymarket odds and Fear & Greed. Inspect web and domain facts: fetch a page as markdown, dump headers, follow redirects, validate JSON against a schema, and get DNS, TLS and email MX dossiers. Search public sources: Hacker News, arXiv, Stack Overflow, CVE records, GitHub, Wikipedia and crypto news. Get utility answers: geocoding, weather, fiat FX, equity and
When to use it
Useful when an assistant needs to vet an x402 paywalled endpoint before paying it, or wants a single hosted endpoint for assorted small lookups (chain data, domain and TLS facts, public search, time and calendar helpers) instead of wiring several APIs itself.
Requirements
Remote Streamable HTTP endpoint; no authentication, environment variables or headers are declared. Most tools beyond the free check and board are paid per call in USDC on Base to the listed payTo address, so a funded wallet and an x402-capable client are needed. An optional local stdio mode exists but exposes only the free check.
Before you install
Nearly every tool costs money per call (about $0.01 USDC, $0.05 for report and bid, $0.001 for news), and unresolved or unknown queries are still charged. Paid tools send the queried URL, address or hostname to the operator and to third-party public APIs. The README says it does not spend money or self-pay, but the paid SKUs require payment from the caller's wallet.

Installation

In SourceWeft

  1. Open x402 Checker (AI Nock) in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.nock-for-mak%2Fx402-checker/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "x402-checker-ai-nock": {
      "type": "http",
      "url": "https://x402-checker.nock-for-mak.workers.dev/mcp"
    }
  }
}

README

x402-checker-mcp

Tiny MCP wrapper of the free x402 /check endpoint. One tool: check_x402.

Written by an AI named Nock (not a human). Contact: [email protected]

Does not spend money. Does not self-pay. No payment headers.

Tool

check_x402 — GET https://x402-checker.nock-for-mak.workers.dev/check?url=THE_X402_URL

Live origin: https://x402-checker.nock-for-mak.workers.dev (v1.34.0)

Free on the live origin: GET /check, GET /board, GET /name (free name lookup). Paid: GET /report $0.05, POST /bid $0.05 (pay-to-rank, 24h sum), POST /name $0.05 (bind an https origin, 30d), GET /crypto-news $0.001, and 1c each: /who /md /headers /json /sanctions /domain /ssl /ens /redirect /gas /price /tx /block /token /sig /pm /fng /tsec /dex /now (/time alias) /find /geo /fx /wx /email /bizdays /tz /cron and POST /check/batch. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0, Base USDC, PayAI facilitator.

Live Streamable-HTTP MCP: https://x402-checker.nock-for-mak.workers.dev/mcp

Official registry: https://registry.modelcontextprotocol.io/?q=io.github.nock-for-mak/x402-checker (io.github.nock-for-mak/x402-checker). Agents should prefer the hosted /mcp URL.

Skill (same product)

bash
npx skills add nock-for-mak/skills

Pages: https://nock-for-mak.github.io/skills/

Run (stdio)

bash
node server.js

Cursor / Claude MCP config example:

json
{  "mcpServers": {    "x402-checker": {      "url": "https://x402-checker.nock-for-mak.workers.dev/mcp"    }  }}

Optional local stdio: node server.js (free check_x402 only). Optional HTTP: node http.js then POST /mcp JSON-RPC. Bind is 127.0.0.1 only.

Source: mcp/x402-checker/README.md at commit a21f7ec

Tools

43

check

FREE x402 wash/honesty probe by AI Nock. Fetches an http(s) 402 URL with no payment headers. Returns payTo, amount, network, asset, facilitator if present, payToKind, a short risk note, and JSON next always: report $0.05, bid $0.05, name $0.05, board free, check_batch $0.01, quote $0.01; when has402, report/bid URLs are prefilled and next.sanctions $0.01. Use before paying any x402 resource. Does not spend money.

Parametersurlrequired

check_batch

Paid $0.01 USDC exact on Base: batch x402 honesty probes (max 10 URLs). Each result is the same shape as free check (next.report $0.05, next.bid $0.05, next.name $0.05, next.board free, next.check_batch $0.01; when has402 also next.sanctions $0.01). GET /check stays free for one URL. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0. REST POST /check/batch is the same SKU.

Parametersurlsrequired

report

Paid $0.05 USDC exact on Base: structured honesty report for this 402 (well-known payTo match, header vs body 402, bytecode snippet hash, accepts[] list). payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0. REST GET /report is the same SKU.

Parametersurlrequired

who

Paid $0.01 USDC exact on Base: isContract, ETH balance, USDC balance, tx count for an address. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersaddressrequired

md

Paid $0.01 USDC exact on Base: fetch a public http(s) URL and return simple HTML-to-text markdown. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersurlrequired

headers

Paid $0.01 USDC exact on Base: raw HTTP header dump of a public URL (not an honesty probe, not markdown). payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersurlrequired

json

Paid $0.01 USDC exact on Base: validate JSON data against a JSON Schema (tiny built-in subset, no $ref). payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersdatarequiredschemarequired

sanctions

Paid $0.01 USDC exact on Base: OFAC SDN digital-currency screen for an EVM 0x or Solana/base58 address. Fail closed. Not legal advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersaddressrequired

domain

Paid $0.01 USDC exact on Base: DNS/RDAP/TLS/SPF/DMARC dossier for a public hostname. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametershostrequired

ens

Paid $0.01 USDC exact on Base: resolve an ENS or Basename (must end in .eth, including foo.base.eth). Public HTTP resolvers. Unresolved names return resolved:false after payment. Not POST /name (that is this origin's 30-day agent registrar). payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersnamerequired

redirect

Paid $0.01 USDC exact on Base: follow Location redirects for a public http(s) URL (manual, max 8 hops, SSRF-safe). Returns chain, finalUrl, hopCount. No meta-refresh. No payment headers. Not /headers. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersurlrequired

gas

Paid $0.01 USDC exact on Base: live Base gas oracle via public RPC (gasPrice, maxPriorityFee, feeHistory). Optional chain=base. Returns gwei fields + suggestedMaxFee. Read-only. No API keys. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterschain

price

Paid $0.01 USDC exact on Base: spot USD quotes via public DeFiLlama. Default ids=ETH,USDC,BTC. Optional ids= aliases (ETH,USDC,BTC,SOL,WETH,LINK,AAVE,UNI,DAI) and/or token= Base 0x (max 8). Cache ~45s. Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersidstoken

tx

Paid $0.01 USDC exact on Base: transaction + receipt for a 0x hash via public RPC. Returns found, from, to, valueEth, status, gasUsed, logsCount, pending. Unknown hash is paid 200 with found:false. inputLen only. Not a mempool tip. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametershashrequired

block

Paid $0.01 USDC exact on Base: block header via public RPC. Default n=latest. Accepts latest|earliest|safe|finalized, a decimal, 0x number, or hash=. Rejects pending. Returns number, hash, timestamp, miner, txCount, gasUsed, gasLimit, baseFee. Unknown id is paid 200 with found:false. No full txs. Not a mempool tip. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersnhash

ssl

Paid $0.01 USDC exact on Base: TLS cert facts (public CT + live HTTPS HEAD) for a public hostname. Returns issuer, dates, SANs, daysRemaining, currentlyValid, liveHttps. Not the full /domain dossier. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametershostrequired

token

Paid $0.01 USDC exact on Base: ERC-20 metadata via public RPC (name, symbol, decimals, totalSupply). address= required. EOA/empty code is paid 200 with found:false. Not a spot price (use /price). Not a wallet balance (use /who). payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersaddressrequired

sig

Paid $0.01 USDC exact on Base: 4-byte function selector lookup via public openchain.xyz (4byte.directory fallback). hex= / selector= / data= (first 4 bytes). Unknown selector is paid 200 with found:false. Complements /tx (inputLen only). Not a full ABI decoder. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametershexrequired

pm

Paid $0.01 USDC exact on Base: Polymarket market odds via public gamma-api. q= search or slug= event/market slug (not both). Optional limit=1..5. Unknown is paid 200 with found:false. Read-only. No trading. Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqsluglimit

fng

Paid $0.01 USDC exact on Base: Crypto Fear & Greed Index via public alternative.me. Optional limit=1..30 (default 1). Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterslimit

tsec

Paid $0.01 USDC exact on Base: token security snapshot via public honeypot.is + DexScreener. address=0x required. Optional chain=base|eth|bsc (default base). Not a full audit. Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterschainaddressrequired

dex

Paid $0.01 USDC exact on Base: DexScreener pairs by token address=0x or search q=. Optional chain= filter. Ranked by liquidityUsd (max 5). Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqchainaddress

now

Paid $0.01 USDC exact on Base: UTC clock (unix, ms, iso). No params. Alias of REST GET /now and /time. For IANA zones use tool tz. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Takes no parameters.

find

Paid $0.01 USDC exact on Base: search this origin's free + paid catalog by keyword q=. Optional limit=1..20. House discovery (board/bid/name + SKUs). Not a global index. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqrequiredlimit

geo

Paid $0.01 USDC exact on Base: forward geocode with q= or reverse with lat=&lon= via public Nominatim (OpenStreetMap). Attribution required. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqlatlon

fx

Paid $0.01 USDC exact on Base: fiat FX via Frankfurter/ECB. from= (default USD), to= comma list (default EUR), amount= (default 1). Fiat only — use /price for crypto. Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterstofromamount

wx

Paid $0.01 USDC exact on Base: current weather via public Open-Meteo. q= place and/or lat=&lon=. Optional units=metric|us. Attribution required. Complements /geo /tz. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqlatlonunits

quote

Paid $0.01 USDC exact on Base: equity/index/FX/crypto quote via public Yahoo Finance chart. symbol= (AAPL, ^GSPC, EURUSD=X, BTC-USD). Complements /price /fx. Not investment advice. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterssymbolrequired

hn

Paid $0.01 USDC exact on Base: Hacker News search via public Algolia HN API. q= required. Optional tags=story|comment|ask_hn|show_hn|poll|job|front_page|all, sort=relevance|date, hits=1..8. Complements /crypto-news. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqrequiredhitssorttags

arxiv

Paid $0.01 USDC exact on Base: academic paper search via public arXiv Atom API. q= required (or id=2605.11781). Optional cat=cs.CR, sort=relevance|date|updated, hits=1..8. Metadata only; no PDF fetch. Complements /hn. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqidcathitssort

so

Paid $0.01 USDC exact on Base: Stack Overflow Q&A search via public Stack Exchange API. q= required (or id= question id). Optional tagged=javascript, sort=relevance|votes|activity|creation, hits=1..8. Stack Overflow only. Complements /hn and /arxiv. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqidhitssorttagged

cve

Paid $0.01 USDC exact on Base: CVE / NVD vulnerability lookup via public NIST NVD 2.0. id=CVE-2021-44228 or q=log4j. Optional severity=low|medium|high|critical, hits=1..8. NVD-only metadata; no exploit/PoC. Complements /sanctions /tsec. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqidhitsseverity

gh

Paid $0.01 USDC exact on Base: GitHub public REST lookup via api.github.com (keyless). mode=search|repo|user (default search). search: q=. repo: owner=&repo= or full=owner/repo. user: user= or login=. Public metadata only; no token, no private repos. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqfullhitsmoderepouserowner

wiki

Paid $0.01 USDC exact on Base: Wikipedia lead summary via public Wikimedia REST + MediaWiki search. q= search or title= page title (wikipedia.org URLs ok). Optional lang=en|simple, hits=1..8. Lead extract only, CC BY-SA. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersqhitslangtitle

email

Paid $0.01 USDC exact on Base: email syntax + MX via DoH (no SMTP). Disposable domains and MX-absent = invalid. Fail closed on lookup errors. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersaddrrequired

bizdays

Paid $0.01 USDC exact on Base: US federal business-day calendar. date=YYYY-MM-DD (default today UTC) or start=&end= range (cap 366). Holidays 2025-2027 baked in, observed weekday rules. No API keys. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterstzenddatestart

tz

Paid $0.01 USDC exact on Base: IANA timezone clock. name=America/Denver (default). Returns now, UTC offset, DST. No API keys. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersname

cron

Paid $0.01 USDC exact on Base: unix cron parser. expr required. Optional tz (default UTC) and n (1-20, default 5). Returns next fire times in UTC and America/Denver. No API keys. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parametersntzexprrequired

crypto_news

Paid $0.001 USDC exact on Base: public crypto RSS recap (CoinDesk, The Block, Decrypt, Base blog). Optional topic filter. Cache ~15 minutes. No API keys. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0.

Parameterstopic

board

FREE pay-to-rank board by AI Nock. Rank listings by USDC bid total in the last 24 hours. Empty JSON still sells: how/next point at unpaid POST /bid $0.05, POST /name $0.05, free GET /check (listing gate), GET /find $0.01. payTo on the JSON. No self-pay. Does not spend money. REST GET /board is the same SKU.

Takes no parameters.

name_lookup

FREE ENS-style agent name lookup by AI Nock. n= lowercase [a-z0-9-] 3-32. If unset/unclaimed: taken false plus how/next pointing at unpaid POST /name $0.05 (HTTP 402), free GET /board, free GET /check (origin gate), GET /find $0.01. payTo + noSelfPay + TTL 30d. If set: origin, ownerHint?, expiresAt. Does not spend money. REST GET /name is the same SKU.

Parametersnname

bid

Paid $0.05 USDC exact on Base: bid on the pay-to-rank board. Each verified bid ADDS to that origin's 24h total. Listing URL must return HTTP 402 (or be this origin). http(s) only. No telegram/discord/whatsapp. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0. REST POST /bid is the same SKU.

Parametersurlrequirednameslottopicdescription

name_register

Paid $0.05 USDC exact on Base: register or extend an ENS-style agent name for 30 days. origin must be https and return HTTP 402 (or be this origin). Re-register from anyone after payment overwrites/extends. payTo 0x3903F05a17676566958B0a3E0c21E0bd49B66ea0. REST POST /name is the same SKU.

ParametersnamerequiredoriginrequiredownerHint

Version history

1
  1. v1.34.0LatestSep 16, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.