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PopNx MCPMCP servers for people who use AI · explained in plain words

402xAgent

by withgrokbotversion 0.59.10i★ –iRuns in the cloud
Registry nameio.github.withgrokbot/verified-catalog

Install

Overview

Description from the maker (original English)

Check an x402 endpoint before your agent pays: pay, skip or recheck, with Ed25519-signed receipts.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Install

Pick the AI app you use, then copy the settings.

Before you install

You need

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

  1. Open Settings → Connectors
  2. Press Add custom connector
  3. Paste the address below and press Add
  4. If it asks you to sign in, sign in with the maker
SettingsConnectors1+ Add2https://…3
https://api.402xagent.com/mcp

Run this in your terminal

claude mcp add --transport http verified-catalog https://api.402xagent.com/mcp

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "verified-catalog": {
      "url": "https://api.402xagent.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "verified-catalog": {
      "type": "http",
      "url": "https://api.402xagent.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

  1. Open ChatGPT on the web → Settings → Connectors (Apps)
  2. Press Create or Add (some plans need Developer mode under Advanced first)
  3. Paste the address below, give it a name and save
  4. If it asks you to sign in, sign in with the maker
SettingsConnectors1+ Create2https://…3
https://api.402xagent.com/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 6, 2026. The maker wrote them, not us; we show them as plain text.

  • search_catalog

    Browse or keyword-search the verified catalog of pay-per-call (x402) agent services. Use it when you don't know the task name or want to see what exists; use lookup to rank endpoints for a known task at a max price, and get_service for one id's full record. Read-only. No auth or

  • get_service

    Fetch the complete catalog record for one known service id (e.g. from search_catalog or lookup results). Use search_catalog to find ids and lookup to rank services for a task; get_service has no per-call receipts, so for receipts with tx and Basescan links call lookup with endpoi

  • lookup

    Rank x402 endpoints for a known task at or under a price: "which endpoint should I pay for task X at <= $Y?". Prefer it over search_catalog (keyword browsing, unranked) and get_service (one id's raw record). No auth or API key. Calls the hosted lookup service as client=vc-mcp; al

  • get_overnight_cos_pack

    Buy and download the Overnight Chief of Staff Setup Pack ($9 USDC on Base via x402): 5 ready-to-paste bot prompts, an HTML morning-briefing template, and a PDF setup guide. Always paid — no free quota. Call without PAYMENT-SIGNATURE to receive payment requirements and the HTTP en

  • get_receipt

    Free: read a public 402xAgent receipt. Give id (sc-... from endpoint_spot_check's receipt_id, or a 10-hex crawl id) or url (latest live + crawl receipt for that URL). Receipts hold the listing URL, the live 402 terms, verdict, reason, reason_code, confidence, history summary, tim

  • endpoint_spot_check

    Decision-shaped 402xAgent check of a public URL (private, loopback and link-local addresses blocked on every redirect hop) for an x402 PAYMENT-REQUIRED / 402 challenge. Every answer has reason_code (stable code) and confidence (high|medium|low); rules: https://402xagent.com/rules

  • payment_status

    After you pay an x402 endpoint (Base USDC, EIP-3009 exact): did the payment land, and is it safe to sign a new one? Give payment_payload (the base64 PAYMENT-SIGNATURE you sent), or tx_hash, or from + nonce (+ valid_before). Returns status landed|not_landed|pending|canceled|unknow

  • x402_hygiene

    Free x402 hygiene score for an endpoint you run: {score, grade, deductions[{code, points, fix}]} from normal unpaid requests (never pays, never sends bad params). 20 per day per network, cached 24 h. Grades are returned only to you.

  • discover

    Free discovery of x402 pay-per-call endpoints from 402xAgent's weekly crawl. Returns up to 20 endpoints matching the words in q (URL or source list), each with the verified (quoted) price, network, last_checked, stale flag, verdict pay|skip|recheck with its reason, and a receipt.

  • endpoint_report

    Paid ($0.05 USDC on Base via x402, no free tier): the exact committed snapshots behind endpoint_spot_check's locked teasers: which payment terms changed in the last 30 days, when, from what to what, and the full hygiene checks. Pass the url and the commitment_ref from the free an

  • page_to_markdown

    Fetch one public web page and return clean, LLM-ready Markdown of its main content (no nav, footers, ads or cookie banners; absolute links; tables kept) plus title, description, links, word_count and token_estimate. Respects robots.txt; skips login walls, paywalls and 401/403 pag

  • pdf_tables

    Extract the tables (CSV, JSON, Markdown) and per-page text from one PDF at a public URL. Digital PDFs ~97% cell accuracy; scanned pages (OCR) ~80%. Priced per page via x402 USDC on Base: $0.005/page with ocr=never, $0.015/page with ocr=auto. Charged only if every page succeeds. M

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified with the GitHub account withgrokbot, which owns the repo

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • ✓ Pass

    Endpoint responds

    Responded in 90 ms (HTTP 200)

  • – Not applicable

    Sign-in with OAuth

    No sign-in needed

  • ✓ Pass

    No hidden instructions in tool descriptions

    Read 12 tool descriptions and found no hidden instructions to the AI

Compared with others in Otheri

  • More stars than 0% of the other 32686 servers in this category
  • Published to the registry more recently than 90% of the other 32686 servers in this category
  • Basic checks equal to or better than 100% of the other 32686 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is 402xAgent safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.59.10) reached the registry 3 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Spec Driven Development, Remote Desktop Commander, Microsoft Exchange Online MCP

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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Runs on your computer★ 440MITUpdated 14 months ago
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Remote Desktop Commander

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Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.

Runs in the cloud★ 211Updated 2 days ago
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Exchange Online admin for MSPs: forwarding audits, EWS posture and offboarding, no PowerShell

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Verified Pay-Per-Call Catalog

A static, machine-readable catalog of pay-per-call (x402) services for AI agents, with factual results of our own automated checks. Published by @402xAgent.

Discover (verdict-filtered index). GET https://api.402xagent.com/v1/discover?q= &verdict=pay|skip|recheck&limit= searches 122,891 x402 endpoints from our Oct 20, 2026 crawl. This isn't a plain directory: every result comes with a pay, skip or recheck verdict, a skip reason, the price quoted in the endpoint's live 402 response during our crawl, the network, and an ed25519-signed receipt. Results are facts from an unpaid crawl probe, not endorsements. A pay whose terms are older than 7 days comes back as recheck (reason_code terms_stale), so run the free check (each result's check_url, or the MCP tool endpoint_spot_check) right before you pay. Also available as the MCP tool discover at https://api.402xagent.com/mcp. — withgrokbot

Try it in one line

Which x402 web-search endpoint delivered on our last paid calls, at $0.01 or less? No key; 5 free lookups per client per UTC day:

curl -s "https://api.402xagent.com/v1/lookup?task=web-search&max_price=0.01&ref=via-readme"
const r = await (await fetch("https://api.402xagent.com/v1/lookup?task=web-search&max_price=0.01&ref=via-readme")).json();

Results are sorted by known-answer pass rate over our last paid calls, then price, each with its Base settlement receipts. Other tasks: /v1/tasks. Optional client= ; ref only says where you found the link.

Pricing

  • 5 free lookups per client per UTC day. The client is your client value when you send one, otherwise a salted hash of your IP (raw IPs are never stored). The counter resets at 00:00 UTC. Only /v1/lookup is metered; /v1/tasks, /openapi.json and the static catalog files stay free.
  • After that, $0.02 USDC on Base per lookup via [x402](https://github.com/coinbase/x402). The lookup answers HTTP 402 with a v2 PAYMENT-REQUIRED header (exact scheme, eip155:8453, USDC, payTo 0x37cfCC8a29e9ff9458902B29E31E42dc7B718674). Retry with a PAYMENT-SIGNATURE (or X-PAYMENT) header; the payment is verified and settled through the public PayAI x402 facilitator, and the settlement tx comes back in the PAYMENT-RESPONSE header and the response's access block.
  • Payment never changes results, sort order or listings. It buys query access only. Free, paid and exempt lookups run the same code on the same data and get identical results; no seller can pay for placement, and no check result or known-answer outcome depends on who paid. Every lookup response repeats this in payment_policy.

Remote MCP server (free)

https://api.402xagent.com/mcp (Streamable HTTP, stateless JSON-RPC, no key). Same 3 tools and results as mcp/server.py: search_catalog, get_service and lookup. lookup uses the client name vc-mcp, so it shares that client's 5 free lookups per UTC day; after that it reports the 402 and does not pay. Registry name: io.github.withgrokbot/verified-catalog (server.json).

Always-paid endpoint (x402)

GET https://api.402xagent.com/v1/lookup/paid?task=web-search&max_price=0.01 takes the same parameters and returns the same result as /v1/lookup, for $0.02 USDC on Base per call with no free quota. Its 402 carries x402 Bazaar discovery metadata (extensions.bazaar); it is also listed in /openapi.json (x-payment-info) and /.well-known/x402. Bad parameters get a 400 before anything is settled.

Products

Paid digital downloads sold via the same Worker over x402 (always paid; free lookup quota and SELF_CLIENTS do not apply):

  • Overnight Chief of Staff Setup Pack — $9 USDC on Base. GET https://api.402xagent.com/v1/products/overnight-cos-pack (or MCP tool get_overnight_cos_pack). Unpaid calls return HTTP 402 with Bazaar discovery metadata. After payment: prompts, HTML morning-briefing template, and PDF guide.

Files

  • index.html, services/ .html, methodology.html: the site (no JavaScript, no requests to other hosts)
  • catalog.json, services/ .json, llms.txt, .well-known/agent-card.json: machine-readable
  • data/services.json: the seed listings (source and retrieval date on each), data/site.json: brand/repo settings
  • results/latest.json, results/history.jsonl, results/raw/ / .json, results/spend_ledger.json: check results and evidence
  • scripts/run_checks.py: run checks (free/dry-run by default) and rebuild; scripts/build_site.py: rebuild only
  • data/quality_tests.json, scripts/quality.py: known-answer tests run on every paid call (pass/fail; broken services are "facts only")
  • receipts.json: every paid call (time, charged, settlement tx with Basescan link, delivered, known-answer result)
  • worker/: reliability lookup, a Cloudflare Worker (GET /v1/lookup?task=web-search&max_price=0.01&n=5) that reads catalog.json and receipts.json from this site and counts distinct clients (see worker/README.md)
  • mcp/server.py: small stdio MCP server with search_catalog, get_service (read catalog.json) and lookup (calls the Worker); the Worker serves the same tools remotely at /mcp
  • server.json: official MCP Registry entry (remote server)
  • scripts/demand_weekly.py: weekly count of distinct lookup clients -> results/demand_weekly.json
  • .github/workflows/daily.yml: daily free checks and commit

Run

python3 scripts/run_checks.py            # free checks, no payment (default)

python3 scripts/build_site.py # rebuild pages from data/ and results/ python3 tests/run_tests.py # acceptance tests (Node 18+ for the Worker tests)

Paid checks exist but are off by default. They need --pay, a wallet file outside this folder (--wallet), and pip install -r scripts/requirements-pay.txt. Hard caps: $0.10 per call, $1.00 per UTC day, $20.00 lifetime; only USDC "exact" on Base is ever signed.

We publish facts only, no grades. We hold no customer funds and are not a party to any seller transaction; lookup fees after the free tier go to our own wallet. To contest a result, open a GitHub issue (see methodology.html#contest).

License

MIT, see LICENSE.

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