TypeAssist uses a low-level keyboard hook to see what you type in other apps. A system-wide autocorrect can't work any other way, and that hook is also why some antivirus products flag it. Here is what actually happens:

• No network access. The source has no networking code at all (no System.Net, no sockets, no HTTP). Nothing you type ever leaves your PC.
• No full text is stored. It saves only single words and word pairs with a count, to personalise suggestions.
• Everything stays in %AppData%\TypeAssist on your own PC (user_words.tsv, user_next.tsv, never_correct.txt, settings.ini). "Forget learned words…" in the tray menu deletes it, and you can turn learning off.
• Password fields are ignored. Nothing is corrected or learned there.
• No installer and no admin rights. The only registry write is the optional "Start with Windows" entry under HKCU\Software\Microsoft\Windows\CurrentVersion\Run.

If you'd rather not trust a binary, read the code and build it yourself with build.bat. It uses the C# compiler that ships with Windows.

Please report security issues privately through GitHub Security Advisories, not in a public issue.