A personal or small-business ledger you use for your own tracking (not tax filing) is a genuinely implementable double-entry data model, the same core pattern behind this register's own QuickBooks and Xero entries.
Build it
Effort: a weekendRunning cost: $0/mo to start
Why CanICodeThis says Build it
Accounts (assets, liabilities, income, expense categories) as a simple typed table follow well-documented double-entry bookkeeping
Manually-entered transactions, each affecting two accounts, keep the books balanced by construction
Basic reports (a profit-and-loss statement, a balance sheet) are just grouped sums over a date range
The parts that'll cause problems
Live bank-account sync is a serious integration and security surface — manual CSV import keeps you out of that entirely
Any tax calculation or filing logic carries real financial and legal consequences if wrong — this stays a personal ledger, not tax software
Multi-currency accounting with live exchange rates adds real, separate complexity
How I'd build this
frontend
Astro
database
Turso or SQLite
hosting
Cloudflare Pages
MVP scope
Accounts (assets, liabilities, income, expenses)
Manually-entered double-entry transactions
A profit-and-loss report and a balance sheet
Postpone to v2
CSV import from bank statements
Multi-currency support
Recurring transaction templates
What it actually costs to build
AI agent — with a subscription (Claude Pro/Max, Cursor, etc.)
$0 marginal
AI agent — pay-per-use API, no subscription
$43–$86 one-time
Hosting, once it's running
$0/mo (free tier)
Domain name, if you want your own
~$12/yr
Existing tools solving a similar problem typically run $35–$42/mo — see how they compare below.
The build prompt
Build me a simple bookkeeping ledger, genuinely achievable in a weekend:
1. Accounts (assets, liabilities, income, expense categories) as a simple typed table — well-documented double-entry bookkeeping.
2. Manually-entered double-entry transactions, each affecting two accounts so the books stay balanced by construction.
3. A profit-and-loss report and a balance sheet, computed as grouped sums over the transaction table.
This is a personal ledger, not tax software. Out of scope: bank-statement CSV import (manual entry keeps you out of that integration surface for now), and any tax calculation, which carries real financial and legal consequences if wrong.
