Write together.
Think clearly.

A self-hosted document editor with real-time collaboration and AI that actually edits your writing — not just autocomplete. Your data, your server.

Lumen document editor with collaboration

What you get

Everything a writing team needs

Real-time collaboration

Multiple people, one document — edits merge instantly via Yjs CRDTs. Live cursors show exactly where everyone is. No refreshing, no conflicts.

AI that edits your writing

Select any passage and hit AI: Improve, Shorten, Fix grammar, Change tone, or type a custom instruction. Responses stream token-by-token. You keep control.

Fact-check against the web

Coming soon — the editor will extract your claims, search the web for each one, and flag what's confirmed, disputed, or unverifiable. With source links.

Self-hosted, your data

Docker Compose gets you running in minutes. Postgres, MinIO, and Redis stay on your infrastructure. No SaaS vendor, no data leaving your network.

Two cursors.
One document.

Watch edits land in real time as your teammate types. Yjs CRDTs handle merge conflicts so you never overwrite each other. Works offline too — syncs when you reconnect.

Threaded comments in Lumen

Ready to write?

Free to use. Self-host in minutes with Docker Compose. No card required.

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