Boncos

Boncos records income and expenses from three sources: my bank's transaction
emails, my crypto exchange accounts, and manual entry for the rest. Everything is
stored in SQLite on the phone. There is no account, no sync, and no server holding
my data.

I have been using it as my only expense tracker for three months.

The name is a joke at my own expense. Boncos is Indonesian for broke, or for
buying something that blows your budget. Naming a money tracking app after the
thing it keeps catching you doing felt about right.

What it does

• Reads bank emails. Gmail API into an LLM into a validated row, filtered to four sender addresses, one month at a time.
• Real time notifications. A Cloud Run relay watches the inbox and pushes a parsed transaction to the phone within seconds of paying, without the app being open.
• Statement reconciliation. Imports the monthly PDF with a deterministic parser and refuses the import unless the opening balance plus every line equals the closing balance.
• Crypto net worth. Reads balances directly from OKX, Bitget, Binance and Bybit with read only keys, including the Earn products that aggregators miss, and prices them in IDR.
• Two legged transfers. Paying a credit card bill moves money between two of my own accounts, so both legs are recorded and neither counts as spending.
• Search and filter. By merchant, category, wallet and month, over the month currently in view.
• Backup and export. Full JSON backup with a replace all restore, plus CSV for spreadsheets. Neither ever contains an API key.

Seeing it work

Three real payments, made on three different channels, appearing on the lock screen seconds later.

Do you open source the app?

For now? no. The repository is a map of one person's bank notifications: which senders the app trusts, and exactly where it is blind. It also only works for one bank, so a fork would be a rewrite.

The reasoning is public instead. It is in the write-up below.