Mast

Desktop cockpit for Sail. Mast connects to your Sail control plane over SSH and gives you the spec board, agent rooms, live agent logs, a terminal into any project container, and a file workbench.

macOS only today. The build is universal, so it runs on Apple Silicon and Intel.

Install

Download Mast_<version>_universal.dmg from the latest release, open it, and drag Mast to your Applications folder.

The app is signed with a Developer ID certificate and notarized by Apple, so it opens on first launch without a Gatekeeper warning.

Mast updates itself. It checks a few seconds after launch, and you can check on demand from the user menu, which also shows the version you are running.

Connecting

Mast is a client, so it needs a Sail control plane to talk to. It reads the same configuration the sail CLI writes:

• ~/.sail/config.yaml gives it the host and the control-plane address. Without that file Mast reports no ~/.sail/config.yaml at startup. Run sail host config first.
• ~/.ssh/config gives it the route. Mast dials the host and follows every ProxyJump in the chain to reach project containers.
• Authentication tries your ssh-agent first, then key files: IdentityFile, the key: in ~/.sail/config.yaml, then the default ~/.ssh/id_*. Run ssh-add if your agent is empty.

Signing in to the control plane is a passkey ceremony. Mast forwards 127.0.0.1:7070 to the devbox, opens your browser at that origin, and captures the session token the login page hands back.

Development

You need Bun 1.3.14, a stable Rust toolchain (edition 2021, 1.77+), and macOS to run or build the app. Typecheck and tests run anywhere Bun does.

bun install
bun run dev        # tauri dev, rebuilding the web bundle first
bun test           # webview DOM + core, happy-dom preload
bun run typecheck  # tsc --noEmit
bun run build      # tauri build

CI runs typecheck, bun test, and cargo test on macos-15 for every pull request. Pushing a mast-v* tag builds, signs, notarizes, and cuts a release.

Layout

src-tauri/         Rust core
  src/ssh.rs       connection, ProxyJump chain, sftp, terminal channels, SSE streams
  src/login.rs     passkey ceremony over a temporary local forward
  src/lib.rs       the commands the webview can call
src/
  mainview/        React 19 UI: board, rooms, terminal, file workbench, updater
  mainview/tauri/  the Tauri transport, invoke plus events
  shared/          Sail API models and RPC types
docs/decisions/    ADR-per-fix records

The Rust core exposes about two dozen commands to the webview: sail_request for the control-plane REST API, stream_open for SSE tails, fs_* for the workbench over sftp, and terminal_* for interactive shells. Terminal rendering is ghostty-web.

License

MIT. See LICENSE.