Most expense trackers want you to leave whatever you're doing, open another app, and tap through a form. By the time you've logged the coffee you've already lost the thread. I wanted the logging to disappear into a conversation I was already having.

ExpenseFN is an MCP server that plugs straight into Claude. You say 'I spent twelve dollars on lunch' or 'add my paycheck' in plain English, and it records the expense or credit, files it under a category, and answers questions back the same way: what did I spend on food this month, what's my net balance, summarize my week.

It exposes eight tools to the model, add_expense, add_credit, list_expenses, list_credits, edit_expense, delete_expense, net_balance, and summarize, plus a categories resource, so Claude can run the full create, read, update, delete loop over your finances entirely through chat.

Under the hood it's deliberately small: Python over SQLite with separate expense and credit tables for clean accounting and a zero-config, file-based store. It runs locally or as a remote connector on fastmcp.app, so you can drop the endpoint into Claude Desktop and start logging in a minute.