PayPerScreen

Name: PayPerScreen
Author: tonythetiger22

@tonythetiger22MCP server · External

Sanctions, crypto wallet, email and IP screening for agents. Pay per check in USDC via x402.

Sanctions screeningv0.1.1MITJavaScript

Freeno charge per call

How to install

Runs on your machine from its package; the steps are below.

What it does

Reads
Writes
High impact

At most: only reads or looks up information.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally over stdio

This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).

npmpayperscreen-mcpv0.1.1

Run

npx -y payperscreen-mcp

MCP client config

{
  "mcpServers": {
    "payperscreen": {
      "command": "npx",
      "args": [
        "-y",
        "payperscreen-mcp"
      ]
    }
  }
}

README4 min readView on GitHub

Pay-per-check compliance screening over x402. Sanctions names, crypto wallets, emails and IP addresses, paid per request in USDC on Base, Polygon or Arbitrum. No account, no API key, no contract.

Hosted version: payperscreen.com (try it by hand at /try)
API: https://api.payperscreen.com (docs, OpenAPI)
Source: github.com/TonytheTiger22/payperscreen (MIT)
How every check works, and what it doesn't cover: methodology

This repo is the whole thing: the paid API, the website, the case queue and the list ingest. Use the hosted version, or run your own.

What it checks

Endpoint	Price	What it does
`GET /screen?name=`	$0.02	Fuzzy name match against OFAC SDN, UN Consolidated, EU Consolidated and UK Sanctions lists, refreshed daily. Each hit includes record ID, programmes, aliases and a date of birth / nationality / type comparison
`GET /context?name=`	$0.05	The same comparison for the top hit; now included in `/screen`, kept for existing integrations
`GET /screen-address?address=`	$0.02	Exact match against OFAC sanctioned addresses (with the listed party), Tether USDT freezes on Tron, and known hack proceeds. Each source is reported separately
`GET /screen-email?email=`	$0.02	Ten deterministic signals: MX, disposable domain, domain age, certificate history, DNSBL, typo-squat, role account, mailbox probe and more
`GET /screen-ip?ip=`	$0.01	Spamhaus ZEN and Tor exit node check (beta)

No LLM anywhere in the scoring. Every result says which sources it checked.

Calling it

Any x402 client works. The reference client is a single file:

bash

PRIVATE_KEY=0x... node examples/agent-client.mjs screen "Jane Doe"

An unpaid request returns 402 Payment Required with the price; the client signs a USDC payment and retries.

Use it from Claude, Cursor or any MCP client

The mcp/ folder is an MCP server (npx -y payperscreen-mcp) that gives an AI agent screen_name, screen_wallet, check_email and check_ip tools, paying per check from a wallet you configure, with a spending cap. See mcp/README.md.

bash

claude mcp add payperscreen -e PAYPERSCREEN_PRIVATE_KEY=0xYOUR_KEY -- npx -y payperscreen-mcp

Running your own

Two Node services from one repo, plus Postgres:

Service	Entry	Port	What it is
API	`compliance-api.js`	4025	The paid x402 endpoints and list refresh
Site	`payment-agent.js` (`npm start`)	4030	Website, wallet payments, prepaid balance, case queue, admin

bash

npm install
psql "$DATABASE_URL" -f schema.sql
node compliance-api.js        # API
npm start                     # website

API settings

Variable	Needed	Purpose
`DATABASE_URL`	yes	Postgres with the `pg_trgm` extension
`SELLER_ADDRESS`	yes	Wallet that receives payments
`CDP_API_KEY_ID`, `CDP_API_KEY_SECRET`	yes	Coinbase CDP facilitator (settles payments)
`AUTO_REFRESH_LISTS=1`	recommended	Refresh every list daily, starting 60 s after start
`TRONGRID_API_KEY`	optional	Faster USDT-on-Tron freeze sync
`ETH_RPC_URL`, `BASE_RPC_URL`, `ARB_RPC_URL`, `OP_RPC_URL`	optional	Node URLs that serve historical logs (e.g. Infura). Each one set switches on freeze coverage for that chain (USDT and USDC on Ethereum, USDC on Base, Arbitrum, Optimism); unset chains are skipped and not claimed
`PUBLIC_API_URL`	optional	Public URL reported to x402 directories
`TOPUP_MIN_USD`	optional	Minimum prepaid top-up (default 1.25)
`INTERNAL_API_KEY`	recommended	Same random value (32+ characters) on both services. Prepaid-balance checks then come straight off the customer's balance via `/internal/*`, with no second on-chain payment
`SOLANA_PAY_TO`	optional	A Solana address to receive USDC; when set, every paid route also accepts payment on Solana

Site settings

Variable	Needed	Purpose
`COMPLIANCE_API_URL`	yes	Where the API runs
`BUYER_KEY`	yes	Site wallet: pays the API for admin test checks (and for prepaid checks if `INTERNAL_API_KEY` isn't set)
`INTERNAL_API_KEY`	recommended	Same value as on the API; prepaid checks then come off customers' balances directly
`ADMIN_CODE`	yes	Code for `/admin`
`DB_PATH`	yes in production	SQLite file for accounts, cases, balances (put it on a persistent volume)
`CONTACT_EMAIL`, `CONTACT_X`, `CONTACT_FACEBOOK`	optional	Footer contact details
`ANALYTICS_SALT`	optional	Salt for privacy-preserving visitor counts
`BASE_RPC_URL`	optional	Verifies smart-contract wallet sign-ins

Data sources

Source	Licence
OFAC SDN and `sdn_advanced.xml` (US Treasury)	Public domain
UN Security Council Consolidated List	Public
EU Consolidated Financial Sanctions List	Public
UK Sanctions List (FCDO)	Open Government Licence
Stablecoin freezes	Read from the Tether USDT contract's public on-chain events on Tron (Ethereum and Circle USDC chains switch on when an RPC is set, see below)
Known hack proceeds (`data/hack-addresses.json`)	Curated here from FBI notices (public domain) and published incident reports; each incident lists its sources
Crypto address fallback	0xB10C/ofac-sanctioned-digital-currency-addresses, MIT

Not legal advice

A screening result is a lookup against the listed sources, not a compliance decision. "No match" means no match on those lists only. See the methodology for exactly what each check does and doesn't cover.

Contributing

Issues and pull requests are welcome. Most useful right now: new public data sources (each kept as its own labelled result, never folded into "sanctioned"), and corrections to the hack list with a source link.

server.js, shop.js and check.js are early x402 experiments (a demo weather API), kept for reference; they aren't part of PayPerScreen.

Licence

MIT, see LICENSE.

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