The file is yours

One file, and you can copy it

Your accounts are a SQLite file. You can copy it, back it up, put it on a stick, open and read it with standard tools, without asking anybody for permission.

That is the whole argument in its shortest form. No export you have to request, no format only one vendor understands, no subscription that has to keep running for you to reach your own figures.

SQLite is not an exotic side road here. The Library of Congress recommends it as a long-term archival format, and the odds of it still being readable in ten years are better than for any proprietary accounting format.

No outbound connection

TILL fetches nothing from the internet on its own and sends nothing there. No telemetry, no crash reports, no call home at startup.

Precisely, because the imprecise version would be worse than none here: till serve does open a socket. It has to, because that is how the Studio and the MCP server talk. It listens on localhost, behind a guard that rejects requests from outside. Anyone who looks will see that listener, and we would like them to find this paragraph when they do.

An AI agent you connect is the one case where data can leave your machine, because a cloud model sees what you give it. You make that connection, not TILL, and you decide what the agent may do.

Posted entries stay put

A posted entry is never edited and never deleted. A correction is a reversing entry: the mistake stays visible, the correction stands next to it, and both carry their date.

Posting is also idempotent. The same operation triggered twice posts once. That sounds like a detail and it is the precondition for letting an agent post at all: a dropped connection and a retry must not produce doubled figures.

For proportion, because this sentence is often written too large: append-only bookkeeping is good practice and the basis on which a third party can form a reliable judgement under OR Art. 958 Abs. 1. It is not written into the law as a rule in those words, and we do not claim it is.

What TILL does not protect you from

This list is here because a security page without one is a marketing page.

From your own machine

Anyone with access to your device has access to the file. TILL does not encrypt it on top. Disk encryption and a locked screen are your job.

From data loss

A file on one machine is one copy. Without a backup, a failed drive is the end of your books. TILL does not take backups for you.

From an agent you allow too much

You choose which model to connect and what it may do. What you show it, its provider sees. The audit trail shows you afterwards what happened; it does not prevent it.

From wrong numbers

Immutability means nobody quietly changes an entry. It does not mean the entry was right. You still have to check.

From your retention duty

The ten years under OR Art. 958f are owed by you, not by the software. TILL gives you the form for it and does not take the duty off you.

How to report a vulnerability

Write to security@tillbooks.ch. The address is read. TILL is pre-alpha and has no bug bounty programme, and we are not claiming response times nobody keeps.