☀ A slimmed-down Obsidian

The markdown editor for git users.

Live preview, wikilinks, backlinks, properties, and full-text search over plain .md files in your repo. Diff your edits against HEAD, step through history, collaborate through commits. No sync service.

Download for macOS, Windows & Linux See what's inside

Launch it from anywhere: sunstone ./my-notes

Open any folder. No vault required.

No vault to create, import, or convert into. Point Sunstone at any directory of markdown and start editing: sunstone ./docs.

Files stay plain .md on disk. Nothing gets indexed into a database you can't grep. Close the app and you're left with a folder of markdown.

Built for the Open Knowledge Format

Sunstone implements Google's Open Knowledge Format, an open standard for markdown bundles that humans and agents read the same way.

OKF is markdown with YAML frontmatter and wikilinks. If you can cat a file you can read it; if you can git clone you can ship it. Nothing to migrate.

Everything you'd install plugins for, built in.

Open a folder and all of it works.

Live preview

Obsidian-style hybrid editing. Inactive lines render styled, the cursor line shows raw markup. Highlighted code, task lists, interactive GFM tables.

Wikilinks & backlinks

Follow links between concepts. The backlinks panel lists every concept that links to the one you're reading.

Properties panel

Edit frontmatter as typed fields: scalars, lists, tags. Complex YAML round-trips verbatim.

Full-text search

Search every concept with snippet results. A fuzzy quick-nav palette jumps to any concept by name.

Margin annotations

Select text and add a margin comment. Stored as CriticMarkup in the file, so feedback travels in git and any tool can read it.

Tiling workspace

Split the editor into columns and tiles to view several concepts side by side. The layout persists across restarts.

Review changes

Toggle a diff of the working tree against HEAD, or step back through history. Word edits render as CriticMarkup track-changes.

Export as PDF

Render the open concept to a print preview and save it as PDF on macOS and Windows.

Light + dark theming

A warm amber palette that follows the OS color scheme. An outline panel and tag browser keep large bundles navigable.

Your repo is the sync layer.

A bundle is just a git repository. On the desktop, toggle Review to see your working tree diffed against HEAD as inline track-changes, and step back through history commit by commit.

For collaboration, run the server in git-synced mode. Every save is a commit, and a sync loop fetches, rebases, and pushes against your origin. Several people edit the same bundle. It isn't realtime; concurrent work reconciles through rebase, and a conflicting edit is forked beside the original instead of silently overwritten.

Sync state is git state. Anything the editor did, you can inspect, revert, or bisect from the command line.

See Sunstone Web

$ git log --oneline docs/
a41f2c9 web: edit concepts/rollout-plan.md (dana)
7be03d1 web: edit concepts/rollout-plan.md (jonas)
f19c884 sync: rebase onto origin/main
c02a7de desktop edits, reviewed against HEAD
918bb3a agent pass over the architecture docs

Leave feedback right in the margin.

Select text in editing or reading mode and choose Add comment. The span is highlighted, a comment icon sits in the gutter, and hovering shows the note.

On disk it's plain {==text==}{>>note<<} CriticMarkup. Comments live in the .md file and travel in git, which makes them useful for reviewing an agent's generated docs before the next pass.

Explore all features

Margin comments on an implementation plan in light mode

Margin comments on an implementation plan in dark mode

Ships as a Docker image

Run it as a web server. Edit as a team.

Sunstone Web serves any bundle in the browser, with the same explorer, backlinks, tags, outline, and full-text search as the desktop app, plus authenticated editing. Every save is a git commit, so a team works on one bundle and reconciles through git. External pushes reach every open browser over SSE.

Read the deploy docs