Products / Case study
Betelgeuse
Productivity
Notes, docs and databases that stay yours.
A block-based workspace where every page is a plain Markdown file in a git repository on your own computer, and your AI agents can read only the pages you choose to share.
- Platforms
- macOS, Windows, Linux
- Status
- Early preview · v0.2
- Built by
- Devian Labs, in-house
- Stack
- Rust, Tauri 2, React 19, TipTap
01The problem
“Your knowledge deserves a home, not a subscription.”
Workspaces like Notion keep your knowledge in a proprietary database, behind an account and a subscription. Getting it out means an export ritual, and what comes out is rarely what went in.
AI makes it worse. Agents are most useful when they can read your notes, but most tools give them everything or nothing. There was no way to say: this page, not that one.
02What we built
The product.
A block editor
Type / for headings, to-dos, callouts, tables, columns, toggles and code. Wikilinks, backlinks, covers, tabs and a command palette.
Databases
Table, board and calendar views over pages, with properties and relations.
History and sync
Auto-commits as you write, per-page history with restore, and sync to GitHub, GitLab or any git remote.
AI on your terms
Claude, Cursor or any MCP client can search, read and update notes. You choose which pages they see.
Import
Bring in a Notion export or an Obsidian vault, databases and all.
03Under the hood
The engineering we own.
- 01
Markdown and git as the database
A shared Rust engine, betelgeuse-core, reads and writes pages, frontmatter, databases, links and trash as plain files. It auto-commits after a few idle seconds and syncs with the system's own git credentials.
- 02
A permissioned MCP server
Eleven tools, from search_notes to query_database. Visibility is enforced on every one of them, including listings, search, backlinks, history and database rows, and hiding a page hides its sub-pages too.
- 03
Every agent edit is a commit
Each change an agent makes lands as its own git commit, so you can review it or undo it. Commit messages for hidden pages say "private page", so the git log never leaks their titles.
- 04
High-fidelity Notion import
Rebuilds Notion databases with their property types and views, keeps icons, covers, colours, toggles and columns, and downloads remote images so every page is fully local.
- 05
One engine, every shell
The core crate is shared by the desktop app and a mobile shell for iOS and Android that is in progress.
04Key decisions
Files over databases
Pages are Markdown files in a folder you own. Open them in any editor, any time, even if Betelgeuse disappears.
Agents see only what you share
A workspace policy chooses between "everything except hidden pages" and "only shared pages", and the server enforces it.
Free and open source
MIT licensed. Sponsorship funds signed builds.
05Where it is today
Early preview · v0.2
Betelgeuse is an early preview for macOS, Windows and Linux. Builds aren't code-signed yet, so the first launch asks you to confirm.
Up next
For your project
Need something like Betelgeuse?
The team and the engineering behind Betelgeuse are available for client projects and long-term partnerships.
Desktop apps
Native apps for macOS, Windows and Linux with Tauri and Rust: small, fast and auto-updating.
AI agents and MCP
MCP servers, agent tooling and LLM features with structured output, built with permissions in mind.
Backends and APIs
APIs, auth, databases, sync engines, security rules and edge workers, designed to be secure and cheap to run.
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