Shipping a Node.js server as a native desktop app with Tauri and Bun

Description and use

Building a cross‑platform desktop app for a Node server with Tauri and Bun: compile the server to a single executable, bundle it as a sidecar, configure static assets and download handling, and ensure proper process cleanup.

Problem

Users of a small Node.js LAN file‑transfer tool (MeghXL) needed a double‑clickable desktop app for macOS, Windows and Linux that hides the Node runtime.

Outcome

The resulting installers are 28–41 MB, launch a Tauri UI and a Bun‑compiled server, and run without requiring Node. The app handles static files, downloads, drag‑drop, and cleans up orphaned server processes.

Workflow

• 1. Choose Tauri for small bundle size and OS webview.
• 2. Configure Tauri’s externalBin to include the compiled server binary.
• 3. Compile the Node server to a single executable with bun build --compile (cross‑compile per target).
• 4. Ensure all dependencies are pure JavaScript (no .node binaries).
• 5. Name the binary <name>-<triple> matching the Rust host triple.
• 6. Ship static assets as Tauri resources and expose their path via an environment variable (PUBLIC_DIR).
• 7. Handle Tauri quirks: disable native drag‑drop, implement custom download handler, and tie sidecar lifecycle to parent via stdin EOF.
• 8. Build installers for macOS, Windows and Linux separately (Tauri cannot cross‑compile).

Evidence

Tauri resolves sidecars by target triple. The binary must be named <name>-<triple>

Source

Bun won: bun build ./server.js --compile --target=bun-darwin-x64 --outfile meghxl-server-x86_64-apple-darwin

Source