Fahh Editor docs

A desktop code editor built on Tauri 2, Rust, React 18 and Monaco. It plays fahh.mp3 when a language server reports an error, at most once per cooldown window.

Status in v0.5.0

Quick start

Prerequisites

Clone, install, run

git clone https://github.com/Arnav1771/fahh-ide.git
cd fahh-ide
pnpm install
pnpm tauri dev      # Vite on :1420, compiles Rust, opens the window

The front end on its own

Useful for UI work. The interface loads in a normal browser, but anything that calls the Rust backend (files, terminal, Git, language servers) will not work there.

pnpm dev            # http://localhost:1420
pnpm build          # type-check and bundle to dist/
pnpm test           # Vitest unit tests

Two processes, one contract

The Rust backend owns the operating system: files, processes, language servers, Git. The React front end owns the interface. They talk over Tauri IPC: the front end calls commands with invoke(), and the backend pushes events the front end receives with listen(). The shared payload types live in src/lib/types.ts, which the Rust structs follow.

┌───────────────────────────────────────────────────────────────┐
│ Front end: the system web view (WebView2 / WebKit)            │
│ React 18 · TypeScript · Monaco · Zustand · Tailwind · xterm   │
│   FileTree   EditorPane + TabBar   Terminal   Run   Git   AI  │
│   LspBridge (no UI) ── diagnostics → markers → sound          │
├────────────────────── invoke() ↓   ↑ events ───────────────────┤
│ Back end: Tauri 2, Rust                                       │
│   workspace  editor  terminal  runner  git  formatter         │
│   lsp_client  debugger  installer  plugin  state              │
│   error_detector ── emits fahh://error                        │
└───────────────────────────────────────────────────────────────┘
              file system · processes · language servers

Module reference

Rust: src-tauri/src/

TypeScript: src/

From diagnostic to sound

The whole path, in order. You can watch steps 3 to 5 happen in the simulator.

1. The language server publishes. lsp_client.rs relays textDocument/publishDiagnostics to the window as lsp://message.
2. LspBridge draws. The diagnostics become Monaco markers. An empty list clears the file.
3. Is any of them an error? Severity 1, or a missing severity, which the LSP specification says to treat as the most severe. Warnings, information and hints stop here.
4. Is the cooldown ready? One module-level cooldown for the life of the app. A refused call does not extend the window.
5. trigger_error_sound. The command reaches ErrorDetector, which applies the same cooldown on the Rust side and emits fahh://error.
6. fahh.ts plays. The buffer decoded at start-up goes to an AudioBufferSourceNode, so there is no loading delay.

Tauri commands

All 39 are registered in src-tauri/src/lib.rs, grouped here by the module that implements them.

Events

Emitted by Rust, received in the front end with listen() from @tauri-apps/api/event.

~/.fahh/config.json

Created on first run and safe to edit by hand. Every field is optional.

{
  "sfx_cooldown_secs": 3,
  "installed_tools": ["gh"],
  "last_workspace": "/path/to/project",
  "theme": null
}

Environment variables

The installer wizard

Open it from the gear button at the bottom of the activity bar. It checks which tools are already on your PATH, then runs the install command you choose on your own machine, with progress streamed as it goes.

The wizard also offers one AI coding assistant's command-line tool, installed with npm.

Building and packaging

pnpm tauri build                 # all bundle targets for this OS
cd src-tauri && cargo test       # Rust unit tests
cargo clippy --all-targets -- -D warnings   # the CI lint gate

Bundles land in src-tauri/target/release/bundle/. The v0.5.0 release was built into:

App identifier com.fahh.editor, default window 1400 × 900. Everything runs locally; there is no server and no account.