ADR-0001: Electron over Tauri

Status: Superseded by ADR-0009 — Web-first Hercules Studio Date: 2026-08-14

Superseded 2026-10-06. This ADR is kept for history. Its decision was never executed: the Electron project never reached a successful npm install, and seven of its eight views were placeholders. More importantly, its core premise — that Studio needed a native shell for filesystem access, process spawning and C# execution — no longer holds, because those responsibilities moved into the agent (DotnetFileBasedExecutor, the documented supervisor (Studio / systemd / watcher) restart protocol, A2A discovery, SqliteWorkflowDefinitionStore). See ADR-0009 for the full analysis.

Two details below are now known to be wrong and should not be reused as arguments:

• “better-sqlite3 requires a native Node addon build” — Tauri ships an official SQLite plugin. This is not a real discriminator.
• “PWA / web-only: Cannot access FS, tray, notifications, process spawning” — the agent now provides process supervision and C# execution server-side, and notifications have a Web API. Only an interactive PTY and a tray icon genuinely remain desktop-only.

Context

Hercules Studio needs a desktop shell that can:

• Run a full IDE-like UI (Monaco, xterm.js, Vue Flow)
• Access local file system and spawn processes
• Bundle complex dependencies (better-sqlite3 native addon)
• Target Windows x64 first
• Support auto-updater

Two main options: Electron and Tauri.

Decision

Choose Electron.

Rationale

• JS team experience: No Rust experience in team; Electron = pure JS/TS
• Native addons: better-sqlite3 requires native Node addon build; Electron has mature tooling (electron-rebuild)
• Monaco integration: Monaco is designed for Electron/browser; proven in VS Code
• Windows focus: Electron + electron-builder has best Windows NSIS/MSI support
• Auto-updater: electron-updater + GitHub Releases is mature
• Ecosystem: AnythingLLM, Flowise, VS Code, Cursor all use Electron — proven pattern
• Size (~150MB): acceptable for IDE product

Consequences

• Larger bundle (~150MB vs Tauri ~5MB)
• Higher memory (Chromium per window)
• Must follow Electron security best practices (contextIsolation, sandbox, CSP)

Alternatives considered

• Tauri 2.0: Lighter, safer, but Rust IPC barrier + OS webview inconsistencies + native addon complexity for better-sqlite3. Revisit if size becomes critical.
• PWA / web-only: Cannot access FS, tray, notifications, process spawning. Not suitable for IDE.