Every small business eventually meets the same wall. The books are essential — the GST you owe, the wages you paid, the invoices still outstanding — and yet they live somewhere you do not control. A subscription lapses, a card is declined, an account is flagged for review, and the ledger you built over years is suddenly on the far side of a paywall. You did the work. Someone else holds the keys.
SAE Books exists because of that wall. It is accounting software built on a single, stubborn premise: the data that runs your business should live on infrastructure you own and can carry. Not rented. Not held hostage. Not switch-off-able by anyone but you.
A ledger that cannot be switched off — because you own the code, host the data, and hold the keys.
API-first, not API-eventually
Most accounting platforms bolt an API on years after the fact, and it shows: half the things you can do in the screens, you cannot do in the API. SAE Books is built the other way around. Every screen is a thin client over a public REST API — the same API your own scripts, integrations and automations call. There is no hidden second system. If the app can do it, your code can do it, because the app is just code calling the same endpoints you can.
For anyone who automates — importing bank feeds, raising invoices from a job system, reconciling on a schedule — that is the difference between a tool you operate and a tool you can build on.
Australian to the core
SAE Books is built for Australian small business, not adapted to it. GST tracking and the BAS worksheet, STP Phase 2 payroll reporting, the standard Australian chart of accounts, PAYG, superannuation — these are built in, not plugins you bolt on and hope stay current. The compliance shape of the country sits inside the product rather than around it.
Double-entry, with an audit trail that does not lie
Underneath the friendly screens is a real double-entry general ledger — debits and credits that must balance, the same discipline an accountant trusts. Every change is written to an immutable audit log: you can see what happened, when, and what it touched. And nothing is ever hostage — full export to CSV, JSON, OFX and a complete database dump is a first-class feature, not a favour. Your numbers are yours to take, any day, in formats you can actually use.
Self-hosted by default, open source by design
The Community edition is free and open source under the AGPLv3. It runs on your server, against your own PostgreSQL database. The paid tiers — Business, Pro, Enterprise — are not a different program; they are runtime flags on the same binary. Self-compile, flip the flag, and run the lot. That is what AGPL means: not a trial, not a teaser, but software you can read, change, host and own outright.
There is a sole-trader bundle too — Cashbook — the same Community engine pre-configured for cash-basis simplicity, free for life. Start there, switch to full accrual with one setting when you outgrow it.
Where it is today — honestly
SAE Books is a young product, and the honest version matters more than the polished one. The Community edition is available now to self-host. The hosted editions are in private beta — access by request while they are hardened. Some advanced features (direct ATO lodgement, bank feeds) are early-access. You can see exactly where things stand on the build log, and you can try the whole product right now in the live demo — real screens, real data, no sign-up.
The one-sentence version
SAE Books is an API-first, self-hosted, open-source accounting ledger for Australian small business — built so that the books that run your business answer to you, and stay yours, no matter who you stop paying.