What is Lumen used for?

Lumen is a free, open-source note-taking app that stores notes as markdown files and syncs them with a GitHub repository, built local-first. It is a good fit for personal knowledge management and keeping notes under git version control.

Is Lumen open source?

Yes. Lumen is open source under the MIT licence. Its source code is on GitHub at lumen-notes/lumen and is written mainly in TypeScript.

Yes. Lumen is open source, so the software itself is free to use.

Can I self-host Lumen?

Yes. Lumen can be self-hosted on your own server or infrastructure.

What is Lumen an alternative to?

Lumen is an open-source alternative to Obsidian, Bear and Ulysses. Other open-source alternatives to Obsidian include WitNote, Zettlr and VNote.

Is Lumen actively maintained?

The most recent commit to Lumen was on 25 February 2026. The project has 721 stars on GitHub.

Lumen: open-source alternative to Obsidian, Bear, Ulysses

About Lumen

Lumen is a free, open-source note-taking app written in TypeScript. Instead of keeping notes in a proprietary database, it syncs with markdown files stored in a GitHub repository, so your notes remain plain text files that you own and can read with any other tool.

The repository topics describe it as local-first, personal knowledge management and zettelkasten software that works with git. It is released under the MIT license, and the project site is uselumen.com. The repository README is very brief, so any further detail is best checked on the project site.

Key features

Notes stored as plain markdown files
Sync with a GitHub repository
Local-first note storage
Distraction-free writing interface

Good fit for

→Personal knowledge management
→Keeping notes under git version control

Built with: TypeScript
Tags: note-taking; markdown; local-first; github; pkm; zettelkasten; git

Lumen: questions and answers

What is Lumen used for?: Lumen is a free, open-source note-taking app that stores notes as markdown files and syncs them with a GitHub repository, built local-first. It is a good fit for personal knowledge management and keeping notes under git version control.
Is Lumen open source?: Yes. Lumen is open source under the MIT licence. Its source code is on GitHub at lumen-notes/lumen and is written mainly in TypeScript.
Is Lumen free?: Yes. Lumen is open source, so the software itself is free to use.
Can I self-host Lumen?: Yes. Lumen can be self-hosted on your own server or infrastructure.
What is Lumen an alternative to?: Lumen is an open-source alternative to Obsidian, Bear and Ulysses. Other open-source alternatives to Obsidian include WitNote, Zettlr and VNote.
Is Lumen actively maintained?: The most recent commit to Lumen was on 25 February 2026. The project has 721 stars on GitHub.