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.
License
MIT
