Seller Fees MCP

seller-fees-mcp

A free Model Context Protocol (MCP) server that works out seller fees, payouts and break-even prices for Gumroad, Stripe, PayPal and Etsy (US sellers, USD). Everything runs locally: no API key, no account, no network calls.

Tools

Tool	What it does
fee	Fee and net for one sale. Gumroad direct includes the 2.9% + $0.30 card processing; options discover, high_volume, processing (card/none). PayPal type and international, Stripe extra_pct, Etsy qty, shipping, sales_tax_pct, offsite_ads.
payout	What you keep per sale and in total for units sales.
price_for_target	Lowest price that leaves at least target after fees.
compare	One price across Gumroad direct, Gumroad Discover, Stripe, PayPal (checkout, card, goods) and Etsy, best net first.
platforms	Default rates, options and official source pages.

Default rates are as of Oct 20, 2026. Gumroad direct: 10% + $0.50 plus card processing 2.9% + $0.30 (5% + $0.50 with high_volume); Discover: 30% all-in. Stripe: 2.9% + $0.30. PayPal Checkout: 3.49% + $0.49. Etsy: $0.20 listing, 6.5% transaction, 3% + $0.25 processing. Check each platform's pricing page before relying on a number. Planning estimates only; not tax or accounting advice.

Install

Requires Node.js 18 or newer.

npx

npx -y seller-fees-mcp

From source

git clone https://github.com/NarwhalThePong/seller-fees-mcp.git && cd seller-fees-mcp && npm install && npm test
node src/server.js

Desktop MCP clients

Add to your client's MCP config file:

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

Cursor

Add to ~/.cursor/mcp.json (or .cursor/mcp.json in a project):

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

For a local checkout, use "command": "node", "args": ["/path/to/seller-fees-mcp/src/server.js"].

Example

fee with { "platform": "gumroad", "amount": 19 } returns a fee of $3.25 ($2.40 Gumroad + $0.85 card processing) and a net of $15.75.

Prefer a web page?

• Free Gumroad fee calculator: https://narwhalthepong.github.io/gumroad-license-check/gumroad-fee-calculator.html
• Free PayPal and Stripe fee calculator: https://narwhalthepong.github.io/gumroad-license-check/paypal-stripe-fee-calculator.html
• Free Etsy fee calculator: https://narwhalthepong.github.io/gumroad-license-check/etsy-fee-calculator.html
• Creator Payout Calculator Pro (browser extension, paid): https://paudrudis.gumroad.com/l/ijrzbz

Disclosure: these are our own products. The calculator pages are free; Creator Payout Calculator Pro is a paid product we sell.

Prefer a spreadsheet?

Seller Fee Formulas for Google Sheets, $9: custom functions such as GUMROADFEE, STRIPEFEE, PAYPALFEE and ETSYFEE, plus price solvers for the price you need to keep a target amount, on a whole column at once. Our own paid product (the MCP server stays free).

License

MIT