What this is
MCP (Model Context Protocol) is an open standard that lets AI assistants call external tools. Once the server is connected you don't type numbers into a calculator — the assistant asks for them in the conversation, runs the calculation and explains the answer.
The server is public, needs no login and only calculates: nothing is stored, your numbers go nowhere.
Server address: https://vibetec.eu/mcp — Streamable HTTP, no authentication.
Machine-readable description: /.well-known/mcp/server-card.json
Two tools
calculate_card_fees— Compares six Estonian providers — Nets, SumUp, Revolut Business, LHV, Swedbank, Freepay + Elavon — against your turnover, channels, card mix and transaction sizes. Returns cost per €100 of turnover, total, fixed vs variable cost and coverage, cheapest first.list_card_fee_providers— The price table behind the calculation: each provider's percentage per card type, per-transaction fee, monthly fee, hardware, assumptions and sources with the as-of date. So the assistant can say where a number comes from, not just what it is.
How to connect
One address, each client its own way. No authentication is required — if a client asks, choose “None”.
Claude (claude.ai)
- Settings → Connectors → “Add custom connector”
- Name: vibetec card fees · URL: https://vibetec.eu/mcp
- Save and enable the connector in a conversation
Claude Code
claude mcp add vibetec-card-fees --transport http https://vibetec.eu/mcpCodex CLI
codex mcp add vibetec-card-fees --url https://vibetec.eu/mcpChatGPT
- Settings → Connectors → Advanced → enable “Developer mode” (Plus, Pro or Business)
- Connectors → “Create” → name and URL https://vibetec.eu/mcp, authentication: No authentication
Cursor
{ "mcpServers": { "vibetec-card-fees": { "url": "https://vibetec.eu/mcp" } } }In ~/.cursor/mcp.json (or the project's .cursor/mcp.json).
Try asking
- “My café takes €30,000 a year by card, average purchase €8, all at the counter. Which provider is cheapest?”
- “Online shop, €5,000 a month, a fifth on commercial cards. How far apart are a 1.5% blended rate and the Freepay contract?”
- “Show me where Revolut's number comes from and what the assumption is.”
What this is not
Prices are defaults as of 4 September 2026: public price lists, and for Nets, LHV and Freepay the actual quote given to a small merchant. Your contract may differ — on the tool page you can overwrite every number yourself; via MCP not yet.
The answer is informational, not a quote. Refunds, chargebacks, currency conversion and VAT on fees are excluded.
Calculator in the browser · Post: why and how the calculator came about