Mcp

P2Flux MCP — let your AI assistant pay for web content

Some websites ask AI assistants to pay a few cents to read an article or use their data. This gives your assistant a small wallet on your own computer and lets it pay those sites for you — never more than the limits you set. P2Flux never holds your money or your key.

Claude Desktop (no technical knowledge needed)

1. Download p2flux.mcpb and double-click it. Claude Desktop asks you to install it.
2. In the form, leave Money on test the first time, and set your limits (default: 0.50 USDC per page, 5 USDC per day).
3. Ask Claude: "Set up my P2Flux wallet." Claude shows the wallet's address and how to add money.
   • Test: free test money from https://faucet.circle.com (choose Base Sepolia).
   • Real money: in the Coinbase app choose Send → USDC → Base network and paste the address. Send a small amount. Treat it like cash in a pocket.
4. Use it: "Find articles about soup recipes I can buy", "Read this page: https://…", "How much have I spent?"

If the computer is lost, the wallet on it is lost. Keep small amounts.

Claude Code, Cursor and other MCP clients

claude mcp add p2flux -e P2FLUX_NETWORK=test -- npx -y @p2flux/mcp

What it does, and does not

• Pays pages that ask with HTTP 402 (the x402 standard) in USDC on Base. Nothing else.
• Checks the price against your limits before signing, and signs exactly that price. A site that changes the price between the check and the payment gets nothing.
• Keeps a spending log on your computer; the daily limit survives restarts.
• Money put aside at a site and not used comes back when you ask ("take my unused balance at that site back") once 0.10 USDC of it was used or after a day without use, and on its own after a week without use when it is 0.50 USDC or more.
• Your limits are a budget: inside it (default 0.50 USDC per payment, 5 USDC a day) payments go through on their own. Above it, your app asks YOU in a dialog - the assistant cannot answer it - with the amount, the site and what the site says it sells; nothing is paid unless you confirm, and never more than P2FLUX_MAX_CONFIRMED (default 1000 USDC). Apps that cannot show such a dialog refuse the payment instead.
• Some sites sell a period instead of one page - for example a tipster's subscription for 30 days, at the price people pay for it. The site answers with an access token, which is kept on your computer for that site only and sent back to it, so later pages there are read without paying until it expires. check_price shows what the site says a payment buys.
• The key is in one file only you can read. It is never sent anywhere, and no tool can reveal it - so nothing an assistant reads on the web can talk it into giving the key away. To move the wallet elsewhere, run npx -p @p2flux/mcp p2flux-mcp export-key in a terminal yourself.
• ChatGPT and the claude.ai website cannot run a program on your computer. For them there is the remote server below: no wallet is kept anywhere; you approve each payment in your own browser wallet.

Development

npm install && npm test          # unit testsnpm run buildnode test/live.mjs               # live on Base Sepolia (see the file)npx @anthropic-ai/mcpb pack . p2flux.mcpb

ChatGPT and claude.ai (remote server)

p2flux-mcp-remote is the same idea for assistants that only connect to servers on the internet. It holds no wallet, no balance and no history, and needs no login. Tools: find_paid_content, check_price, request_paid_page, get_paid_page.

1. The assistant asks for a paid page. It gets a link, and shows it to you.
2. You open the link. The page shows the amount, the page and the seller's address. You approve in your own wallet (Coinbase Wallet, MetaMask…): one signature for exactly that amount, no network fee.
3. The page is paid and fetched at once; the assistant reads it.

Only sites paid through P2Flux can be paid, only in USDC on Base, and never more than P2FLUX_REMOTE_MAX_PRICE (default 1000 USDC). Above P2FLUX_REMOTE_CONFIRM_ABOVE (default 5 USDC) - a subscription, say - the person is asked twice: the assistant must first ask them and pass their budget as max_price, and the approval page shows the amount and what the site says it sells, with a box to tick before the wallet opens. P2FLUX_REMOTE_SECRET (32+ characters) seals access tokens to their site across restarts. The server reads only public https websites.

P2FLUX_PUBLIC_URL=https://agent.example.com P2FLUX_NETWORK=test PORT=8787 npx -p @p2flux/mcp p2flux-mcp-remote

Put it behind https (nginx) with P2FLUX_TRUST_PROXY=1, then add https://agent.example.com/mcp as a custom connector in claude.ai or ChatGPT (developer mode), authentication: none.

Limits today: a browser wallet extension is needed (no WalletConnect / phone wallets yet); one approval per page (no prepaid balance).