How the Expense Tracker Works
AnyTool Expense Tracker is a stateful, 100% client-side ledger. Each entry records an amount, a type (income or expense), a category, an ISO date and an optional note, and is appended to an array that is persisted to the browser’s localStorage under the key "anytool_expenses". A pure, unit-tested engine derives every aggregate from that array — totals by category, income and expense totals, the net balance, the current-month summary, and daily and weekly trends — taking dates as plain strings and "today" as a value the page supplies, so the engine itself is clock-free and never touches the DOM or storage. Nothing is sent to a server.
- Entries: amount, type (income/expense), category, ISO date, note
- Persisted to browser localStorage (key "anytool_expenses")
- Pure engine computes category totals, balance, monthly summary, trends
- Engine is clock-free and DOM-free; the page owns persistence and the wall clock
- No bank connection, no upload, no account — fully client-side
