PithiaPrivacy
Pithia is built so there is nothing to collect. This page says exactly what touches a server and why.
The website
pithia.io is served by Firebase Hosting. Like any web server it records the IP address, user agent, and requested URL of each visit in server logs kept by Google under the Firebase terms. The site sets no cookies and runs no analytics scripts.
The app
Pithia stores your bookmarks, history, scripts, rules, and settings on your Mac only. It has no account system and sends no usage data. If you turn on update checks, the app requests one small file from pithia.io, which exposes your IP address and the app version to the same server logs. Websites you visit see what they would see from any WebKit browser; the request blocker exists so you can limit that.
Passwords
Saved passwords live in your Mac's Keychain, protected by macOS. Pithia never uploads them.