Technology

Last updated: 30 October 2026

Short version: TapXpense is local-first. The iPhone app uses on-device storage as the source of truth, supports guest use without an account, and only syncs when you choose to sign in.

Local-First App Data

Expenses, categories, accounts, budgets, subscriptions, and reports are stored locally on your device with SwiftData. The app is designed to keep working when you have no account and no network connection.

Optional Sync

When you sign in with Apple or Google, TapXpense can back up and sync your data through Supabase. Database rows are isolated per user with row-level security so one account cannot read another account's private data.

Fast Logging

Back Tap, widgets, Siri, and Shortcuts are built around App Intents so logging can start outside the app. The goal is to reduce friction at the moment you spend money.

AI Categorisation

Categorisation runs on your iPhone: first a built-in word list, then Apple's on-device model where your iPhone supports Apple Intelligence. From version 1.0.1 there is no cloud fallback, so the phrase you type never leaves the device. (Version 1.0 could send just the typed phrase, for signed-in users, when the iPhone couldn't sort it.) Insights, reports, the Ask chat and receipt reading run on-device too.

Backups

iCloud backup saves a copy to your own iCloud Drive. With a backup password, the copy is encrypted on your iPhone (AES-GCM) before it is saved.

Community Board

Our public feedback board is hosted on UserJot, completely separate from private in-app expense data. Read ideas, submit feedback, vote on requests, and follow items as they move from planned to shipped.