---
description: Rust backend conventions for Tauri commands and database
globs: src-tauri/src/**/*.rs
alwaysApply: false
---

# Rust Backend Conventions

## Tauri Commands

- All IPC commands live in `commands.rs`, annotated with `#[tauri::command]`
- Commands that need DB access take `State<'_, DbState>`
- Commands that need the app handle take `app: tauri::AppHandle`
- Return `Result<T, String>` — map errors with `.map_err(|e| e.to_string())`
- Register every new command in `lib.rs` → `invoke_handler`

## Database (db.rs)

- `Database` wraps `Mutex<Connection>` for thread safety
- Use `Database::in_memory()` in tests, `Database::new()` in production
- Settings are key-value in the `settings` table; add defaults in `init_tables()`
- FTS5 table `clipboard_fts` syncs via triggers on insert/delete

## macOS-Specific Code

- Gate with `#[cfg(target_os = "macos")]`
- Cursor position: use `core-graphics` crate's `CGEvent` (not Tauri's `cursor_position()` which is window-relative)
- AppleScript for paste simulation: always use `.output()` not `.spawn()` to ensure execution completes