penx

What it does

Local-first storage for structured personal data, with optional sync across devices and AI features for organising what accumulates. Two caveats before you commit years of notes to it: development has been quiet since September 2025, and no licence file was found, which means all rights rest with the author rather than the software being free to reuse. Where synced data lands depends on how you configure it.

Summary based on the project's own description. The Japanese page has a fuller beginner guide: setup difficulty, what to prepare, and a step-by-step start.

Screenshots & visuals

Before you start

• Setup difficultyFor advanced users
• Command lineRequired
• API keyRequired
• Sends data onlineYes

Judged automatically from the project's own metadata. Always confirm on the official page.

penx FAQ

Is penx free?

penx itself is free, but it needs an API key for an external AI service. That service charges separately, though some have a free tier.

Do I need to install anything or write code to use penx?

It needs the command line. If you are not comfortable typing commands, expect to get stuck during setup.

Does penx work on a phone?

No. It needs a computer.

Can I use penx commercially?

The project does not state a clear licence, so commercial use cannot be confirmed here. Check the official page or ask the author before using it at work.

How it compares

The conditions that decide whether you can actually use it, side by side.

"Sends data out" means your input is uploaded to someone's server. Pick "No" when the material cannot leave your organisation.

Other writing & notes tools