A code editor where every view is a tab you can place anywhere.

Why Kosmos

Most editors dictate where things go. Kosmos lets you treat every view as a tab you can place anywhere, split in any direction, and rearrange freely. Multiple workspaces stay alive in the background so you can context-switch without losing terminals, layouts, or in-progress work.

Platform support

Kosmos only runs on Linux. Windows and macOS are not supported, and support for those platforms is not planned at this time.

Installation

• Debian, Ubuntu, Linux Mint, and Pop!_OS: install the .deb package from the latest release.
• Fedora and openSUSE: install the .rpm package from the latest release.
• Arch Linux and derivatives: install kosmos-bin from the AUR, for example with yay -S kosmos-bin.
• Other distributions: download the AppImage from the latest release, make it executable, and run it.

Project layout

• core/ owns application policy, state transitions, and persistence decisions.
• server/ translates IPC and schedules core commands; it owns the Unix-socket transport.
• desktop/ renders the UI and adapts Electron, Monaco, and other UI libraries through IPC.

Development

• Run the app with ./scripts/run.sh.

• Development builds use an isolated app identity and state database, so they can run alongside an installed Kosmos instance.

• Install desktop dependencies with bun install --cwd desktop --frozen-lockfile.

• Run the full local verification sequence from the repository root:

  bash scripts/check-boundaries.sh
  cargo fmt --all -- --check
   cargo clippy --workspace --all-targets -- -D warnings
   cargo test --workspace
   bun run --cwd desktop check:ipc
   bun run --cwd desktop typecheck
  bun run --cwd desktop test
  bun run --cwd desktop build

• Build production Linux AppImage, deb, and rpm packages with ./scripts/bundle-linux.sh. Artifacts are written to desktop/release/.

• Building the rpm locally requires rpmbuild; install it with sudo pacman -S rpm-tools on Arch Linux, sudo apt-get install rpm on Debian-based systems, or sudo dnf install rpm-build on Fedora.

• The AppImage-based AUR package template lives in aur/kosmos-bin/.

• Bump release metadata with ./scripts/bump-version.sh patch|minor|major|x.y.z.

The Electron main process launches the Rust server as a sidecar process. They communicate over a per-process Unix socket under $XDG_RUNTIME_DIR/kosmos/, while the renderer communicates with Electron main through Electron IPC only. Set KOSMOS_SOCKET to override the socket path.

The Rust server owns the IPC contract. Update generated desktop schema, declaration, and validation artifacts with bun run --cwd desktop generate:ipc; use bun run --cwd desktop check:ipc to verify they are current.

Language tooling

Kosmos manages reviewed, version-pinned language servers and formatters from Settings. Installed standalone formatters take precedence over language-server formatting according to the configured formatter priority; language-server formatting remains the fallback.

• Shift+Alt+F formats the active document.
• Ctrl+T searches workspace symbols.
• Language features include diagnostics, completion, hover, signature help, navigation, references, symbols, colors, rename, and code actions.
• Managed formatters include Prettier, Ruff, and shfmt. Prettier installation requires Node.js 22.6 or newer and npm; Ruff and shfmt use verified native artifacts.
• Format on save is available under Editor settings and defaults to off.

Language tools run with the permissions of the opened workspace. Managed installations live under the Kosmos XDG data directory.

License

MIT - see LICENSE.