v0.2.0

clean architecture refactor, performance, resilience, DX/UX

architecture:
- 13 crates with proper domain/application/infrastructure layers
- domain crate: newtypes, ports (Plugin, AppLauncher), constants
- kernel: pure orchestrator
- shared UI state machine (k-launcher-ui-core)
- merged plugin-api into domain as ports module
- granular file structure (no monolithic lib.rs)
- all tests extracted to tests/ directories

features:
- frecency boost in search results
- empty query shows top frecent apps
- append-only frecency log with configurable compaction
- config-driven styling (all colors, sizes, debounce)
- configurable terminal emulator, external plugin timeout
- log rotation with max_log_files
- loading indicator, descriptive placeholder text
- graceful shutdown via iced::exit() + Plugin::shutdown()
- --version flag, panic hook, signal handling (SIGINT/SIGTERM)
- SpawnInTerminal in external plugin protocol

performance:
- ~1500 -> ~50 heap allocs per keystroke
- reused Matcher, Pattern, char buffer across entries
- Arc<str> for shared result fields
- pre-filter before fuzzy matching
- partial sort for top frecent IDs
- cached lowercase names in entries

resilience:
- parking_lot (no mutex poisoning)
- thiserror hierarchy (PluginError, ConfigError, AppError)
- all silent error swallowing replaced with tracing::warn
- config parse errors logged

quality:
- named constants (no magic strings/numbers)
- named types (no anonymous tuples)
- Rgba newtype with validation
- domain newtype validation (debug_assert non-empty)
- man page, LICENSE (MIT), PKGBUILD, example config
- plugin development guide updated
- make check (fmt + clippy + test), make dev (RUST_LOG=debug)

style: format code for better readability in tests and function signatures

fix: update build_entries function signature to ignore frecency parameter

fix(review): bugs, arch violations, design smells

P1 bugs:
- unix_launcher: shell_split respects quoted args (was split_whitespace)
- plugin-host: 5s timeout on external plugin search
- ui: handle engine init panic, wire error state
- ui-egui: read window config instead of always using defaults
- plugin-url: use OpenPath action instead of SpawnProcess+xdg-open

Architecture:
- remove WindowConfig (mirror of WindowCfg); use WindowCfg directly
- remove on_select closure from SearchResult (domain leakage)
- remove LaunchAction::Custom; add Plugin::on_selected + SearchEngine::on_selected
- apps: record frecency via on_selected instead of embedded closure

Design smells:
- frecency: extract decay_factor helper, write outside mutex
- apps: remove cfg(test) cache_path hack; add new_for_test ctor
- apps: stable ResultId using name+exec to prevent collision
- files: stable ResultId using full path instead of index
- plugin-host: remove k-launcher-os-bridge dep (WindowConfig gone)

Update iced dependency in Cargo.toml to disable default features and add additional ones

feat(app): enhance engine initialization with EngineHandle and update run function signature

feat: production hardening (panic isolation, file logging, apps cache)

- Kernel::search wraps each plugin in catch_unwind; panics are logged and return []
- init_logging() adds daily rolling file at ~/.local/share/k-launcher/logs/
- AppsPlugin caches entries to ~/.cache/k-launcher/apps.bin via bincode; stale-while-revalidate on subsequent launches
- 57 tests pass

refactor: remove client module and associated show command logic

fix(app): format code for clarity in update function

chore: update .gitignore and enhance README with compositor setup instructions

chore(docs): remove unused screenshot file

feature/prod-ready (#1)

Reviewed-on: #1

fix(calc): remove ambiguous log alias, use ln/log2/log10 explicitly

fix(calc): fix log/ln naming, cache math context, strengthen sin(pi) test

feat(calc): add math functions (sqrt, sin, cos, etc.) and pi/e constants

refactor(calc): rename preprocess, extend underscore test assertions

feat(calc): strip underscore digit separators

feat: update dependencies for improved compatibility and performance

feat: add plugin-url for URL handling and open in browser functionality

feat: add support for external plugins and enhance plugin management

feat: add Makefile for build, run, and installation commands

feat: add required features for k-launcher-egui and update dependencies

feat: update README and add documentation for installation, configuration, usage, and plugin development

feat: enhance configuration management and UI styling, remove unused theme module

feat: add k-launcher-config crate for configuration management and integrate with existing components

feat: add k-launcher-ui-egui crate for enhanced UI

- Introduced a new crate `k-launcher-ui-egui` to provide a graphical user interface using eframe and egui.
- Updated the workspace configuration in `Cargo.toml` to include the new crate.
- Implemented the main application logic in `src/app.rs`, handling search functionality and user interactions.
- Created a library entry point in `src/lib.rs` to expose the `run` function for launching the UI.
- Modified the `k-launcher` crate to include a new binary target for the egui-based launcher.
- Added a new main file `src/main_egui.rs` to initialize and run the egui UI with the existing kernel and launcher components.

feat: implement OS bridge and enhance app launcher functionality

feat: add FilesPlugin for file searching and integrate into KLauncher

feat: implement frecency tracking for app usage and enhance search functionality

feat: add CmdPlugin for executing terminal commands and update workspace configuration

refactor: update dependencies and improve keyboard event handling in KLauncherApp

refactor: simplify theme usage and enhance AppsPlugin structure

feat: restructure k-launcher workspace and add core functionality

- Updated Cargo.toml to include a new k-launcher crate and reorganized workspace members.
- Introduced a README.md file detailing the project philosophy, architecture, and technical specifications.
- Implemented a new Kernel struct in k-launcher-kernel for managing plugins and search functionality.
- Created a Plugin trait for plugins to implement, allowing for asynchronous search operations.
- Developed k-launcher-ui with an Iced-based UI for user interaction, including search input and result display.
- Added AppsPlugin and CalcPlugin to handle application launching and basic calculations, respectively.
- Established a theme module for UI styling, focusing on an Aero aesthetic.
- Removed unnecessary main.rs files from plugin crates, streamlining the project structure.

Initialize k-launcher project structure with multiple crates and basic configurations

crates/k-launcher-config/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k-launcher-config"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -9,5 +9,11 @@ path = "src/lib.rs"
 
 [dependencies]
 dirs = { workspace = true }
+k-launcher-domain = { workspace = true }
 serde = { workspace = true }
-toml = { workspace = true }
+thiserror = { workspace = true }
+toml = "1.0"
+tracing = { workspace = true }
+
+[dev-dependencies]
+toml = "1.0"

crates/k-launcher-config/src/config.rs

@@ -0,0 +1,14 @@
+use serde::Deserialize;
+
+use crate::types::*;
+
+#[derive(Debug, Clone, Deserialize, Default)]
+#[serde(default)]
+pub struct Config {
+    pub window: WindowCfg,
+    pub appearance: AppearanceCfg,
+    pub search: SearchCfg,
+    pub plugins: PluginsCfg,
+    pub logging: LoggingCfg,
+    pub terminal: TerminalCfg,
+}

crates/k-launcher-config/src/error.rs

@@ -0,0 +1,18 @@
+use std::path::PathBuf;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum ConfigError {
+    #[error("config directory not found")]
+    NoDirFound,
+    #[error("failed to read config at {path}: {source}")]
+    ReadFailed {
+        path: PathBuf,
+        source: std::io::Error,
+    },
+    #[error("failed to parse config at {path}: {source}")]
+    ParseFailed {
+        path: PathBuf,
+        source: toml::de::Error,
+    },
+}

crates/k-launcher-config/src/lib.rs

@@ -1,191 +1,8 @@
-use serde::Deserialize;
+mod config;
+pub mod error;
+mod load;
+mod types;
 
-// RGBA: [r, g, b, a] where r/g/b are 0–255 as f32, a is 0.0–1.0
-pub type Rgba = [f32; 4];
-
-#[derive(Debug, Clone, Deserialize, Default)]
-#[serde(default)]
-pub struct Config {
-    pub window: WindowCfg,
-    pub appearance: AppearanceCfg,
-    pub search: SearchCfg,
-    pub plugins: PluginsCfg,
-}
-
-#[derive(Debug, Clone, Deserialize)]
-#[serde(default)]
-pub struct WindowCfg {
-    pub width: f32,
-    pub height: f32,
-    pub decorations: bool,
-    pub transparent: bool,
-    pub resizable: bool,
-}
-
-impl Default for WindowCfg {
-    fn default() -> Self {
-        Self {
-            width: 600.0,
-            height: 400.0,
-            decorations: false,
-            transparent: true,
-            resizable: false,
-        }
-    }
-}
-
-#[derive(Debug, Clone, Deserialize)]
-#[serde(default)]
-pub struct AppearanceCfg {
-    pub background_rgba: Rgba,
-    pub border_rgba: Rgba,
-    pub border_width: f32,
-    pub border_radius: f32,
-    pub search_font_size: f32,
-    pub title_size: f32,
-    pub desc_size: f32,
-    pub row_radius: f32,
-    pub placeholder: String,
-}
-
-impl Default for AppearanceCfg {
-    fn default() -> Self {
-        Self {
-            background_rgba: [20.0, 20.0, 30.0, 0.9],
-            border_rgba: [229.0, 125.0, 33.0, 1.0],
-            border_width: 1.0,
-            border_radius: 8.0,
-            search_font_size: 18.0,
-            title_size: 15.0,
-            desc_size: 12.0,
-            row_radius: 4.0,
-            placeholder: "Search...".to_string(),
-        }
-    }
-}
-
-#[derive(Debug, Clone, Deserialize)]
-#[serde(default)]
-pub struct SearchCfg {
-    pub max_results: usize,
-}
-
-impl Default for SearchCfg {
-    fn default() -> Self {
-        Self { max_results: 8 }
-    }
-}
-
-#[derive(Debug, Clone, Deserialize, Default)]
-pub struct ExternalPluginCfg {
-    pub name: String,
-    pub path: String,
-    #[serde(default)]
-    pub args: Vec<String>,
-}
-
-#[derive(Debug, Clone, Deserialize)]
-#[serde(default)]
-pub struct PluginsCfg {
-    pub calc: bool,
-    pub cmd: bool,
-    pub files: bool,
-    pub apps: bool,
-    pub external: Vec<ExternalPluginCfg>,
-}
-
-impl Default for PluginsCfg {
-    fn default() -> Self {
-        Self {
-            calc: true,
-            cmd: true,
-            files: true,
-            apps: true,
-            external: vec![],
-        }
-    }
-}
-
-pub fn load() -> Config {
-    let path = dirs::config_dir().map(|d| d.join("k-launcher").join("config.toml"));
-    let Some(path) = path else {
-        return Config::default();
-    };
-    let Ok(content) = std::fs::read_to_string(&path) else {
-        return Config::default();
-    };
-    toml::from_str(&content).unwrap_or_default()
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn default_config_has_sane_values() {
-        let cfg = Config::default();
-        assert_eq!(cfg.search.max_results, 8);
-        assert_eq!(cfg.window.width, 600.0);
-        assert_eq!(cfg.window.height, 400.0);
-        assert!(!cfg.window.decorations);
-        assert!(cfg.window.transparent);
-        assert!(!cfg.window.resizable);
-        assert!(cfg.plugins.calc);
-        assert!(cfg.plugins.apps);
-        assert_eq!(cfg.appearance.search_font_size, 18.0);
-        assert_eq!(cfg.appearance.placeholder, "Search...");
-    }
-
-    #[test]
-    fn parse_partial_toml_uses_defaults() {
-        let toml = "[search]\nmax_results = 5\n";
-        let cfg: Config = toml::from_str(toml).unwrap();
-        assert_eq!(cfg.search.max_results, 5);
-        assert_eq!(cfg.window.width, 600.0);
-        assert_eq!(cfg.appearance.search_font_size, 18.0);
-        assert!(cfg.plugins.apps);
-    }
-
-    #[test]
-    fn parse_full_toml_roundtrip() {
-        let toml = r#"
-[window]
-width = 800.0
-height = 500.0
-decorations = true
-transparent = false
-resizable = true
-
-[appearance]
-background_rgba = [10.0, 10.0, 20.0, 0.8]
-border_rgba = [100.0, 200.0, 255.0, 1.0]
-border_width = 2.0
-border_radius = 12.0
-search_font_size = 20.0
-title_size = 16.0
-desc_size = 13.0
-row_radius = 6.0
-placeholder = "Type here..."
-
-[search]
-max_results = 12
-
-[plugins]
-calc = false
-cmd = true
-files = false
-apps = true
-"#;
-        let cfg: Config = toml::from_str(toml).unwrap();
-        assert_eq!(cfg.window.width, 800.0);
-        assert_eq!(cfg.window.height, 500.0);
-        assert!(cfg.window.decorations);
-        assert!(!cfg.window.transparent);
-        assert_eq!(cfg.appearance.background_rgba, [10.0, 10.0, 20.0, 0.8]);
-        assert_eq!(cfg.appearance.search_font_size, 20.0);
-        assert_eq!(cfg.appearance.placeholder, "Type here...");
-        assert_eq!(cfg.search.max_results, 12);
-        assert!(!cfg.plugins.calc);
-        assert!(!cfg.plugins.files);
-    }
-}
+pub use config::*;
+pub use load::*;
+pub use types::*;

crates/k-launcher-config/src/load.rs

@@ -0,0 +1,25 @@
+use k_launcher_domain::constants::{APP_NAME, CONFIG_FILENAME};
+
+use crate::config::Config;
+use crate::error::ConfigError;
+
+pub fn load() -> Config {
+    match try_load() {
+        Ok(cfg) => cfg,
+        Err(ConfigError::NoDirFound | ConfigError::ReadFailed { .. }) => Config::default(),
+        Err(e @ ConfigError::ParseFailed { .. }) => {
+            tracing::warn!("{e}");
+            Config::default()
+        }
+    }
+}
+
+pub fn try_load() -> Result<Config, ConfigError> {
+    let dir = dirs::config_dir().ok_or(ConfigError::NoDirFound)?;
+    let path = dir.join(APP_NAME).join(CONFIG_FILENAME);
+    let content = std::fs::read_to_string(&path).map_err(|e| ConfigError::ReadFailed {
+        path: path.clone(),
+        source: e,
+    })?;
+    toml::from_str(&content).map_err(|e| ConfigError::ParseFailed { path, source: e })
+}

crates/k-launcher-config/src/types.rs

@@ -0,0 +1,200 @@
+use serde::Deserialize;
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Rgba {
+    red: f32,
+    green: f32,
+    blue: f32,
+    alpha: f32,
+}
+
+impl<'de> serde::Deserialize<'de> for Rgba {
+    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        let [red, green, blue, alpha] = <[f32; 4]>::deserialize(deserializer)?;
+        Ok(Self::new(red, green, blue, alpha))
+    }
+}
+
+impl Rgba {
+    pub fn new(red: f32, green: f32, blue: f32, alpha: f32) -> Self {
+        Self {
+            red: red.clamp(0.0, 255.0),
+            green: green.clamp(0.0, 255.0),
+            blue: blue.clamp(0.0, 255.0),
+            alpha: alpha.clamp(0.0, 1.0),
+        }
+    }
+
+    pub fn red(&self) -> f32 {
+        self.red
+    }
+
+    pub fn green(&self) -> f32 {
+        self.green
+    }
+
+    pub fn blue(&self) -> f32 {
+        self.blue
+    }
+
+    pub fn alpha(&self) -> f32 {
+        self.alpha
+    }
+
+    pub fn red_u8(&self) -> u8 {
+        self.red as u8
+    }
+
+    pub fn green_u8(&self) -> u8 {
+        self.green as u8
+    }
+
+    pub fn blue_u8(&self) -> u8 {
+        self.blue as u8
+    }
+
+    pub fn alpha_byte(&self) -> u8 {
+        (self.alpha * 255.0) as u8
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct WindowCfg {
+    pub width: f32,
+    pub height: f32,
+    pub decorations: bool,
+    pub transparent: bool,
+    pub resizable: bool,
+}
+
+impl Default for WindowCfg {
+    fn default() -> Self {
+        Self {
+            width: 600.0,
+            height: 400.0,
+            decorations: false,
+            transparent: true,
+            resizable: false,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct AppearanceCfg {
+    pub background_rgba: Rgba,
+    pub border_rgba: Rgba,
+    pub border_width: f32,
+    pub border_radius: f32,
+    pub search_font_size: f32,
+    pub title_size: f32,
+    pub desc_size: f32,
+    pub row_radius: f32,
+    pub placeholder: String,
+    pub selected_row_rgba: Rgba,
+    pub unselected_row_rgba: Rgba,
+    pub description_rgba: Rgba,
+    pub no_results_rgba: Rgba,
+    pub error_rgba: Rgba,
+    pub icon_size: f32,
+}
+
+impl Default for AppearanceCfg {
+    fn default() -> Self {
+        Self {
+            background_rgba: Rgba::new(20.0, 20.0, 30.0, 0.9),
+            border_rgba: Rgba::new(229.0, 125.0, 33.0, 1.0),
+            border_width: 1.0,
+            border_radius: 8.0,
+            search_font_size: 18.0,
+            title_size: 15.0,
+            desc_size: 12.0,
+            row_radius: 4.0,
+            placeholder: "Search apps, type > for commands, = for math".to_string(),
+            selected_row_rgba: Rgba::new(229.0, 125.0, 33.0, 1.0),
+            unselected_row_rgba: Rgba::new(255.0, 255.0, 255.0, 0.07),
+            description_rgba: Rgba::new(210.0, 215.0, 230.0, 1.0),
+            no_results_rgba: Rgba::new(180.0, 180.0, 200.0, 0.5),
+            error_rgba: Rgba::new(255.0, 80.0, 80.0, 1.0),
+            icon_size: 24.0,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct SearchCfg {
+    pub max_results: usize,
+    pub debounce_ms: u64,
+    pub frecency_compact_threshold: usize,
+}
+
+impl Default for SearchCfg {
+    fn default() -> Self {
+        Self {
+            max_results: 8,
+            debounce_ms: 50,
+            frecency_compact_threshold: 50,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct LoggingCfg {
+    pub max_log_files: usize,
+}
+
+impl Default for LoggingCfg {
+    fn default() -> Self {
+        Self { max_log_files: 7 }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize, Default)]
+pub struct TerminalCfg {
+    pub cmd: Option<String>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct ExternalPluginCfg {
+    pub name: String,
+    pub path: String,
+    pub args: Vec<String>,
+    pub timeout_secs: u64,
+}
+
+impl Default for ExternalPluginCfg {
+    fn default() -> Self {
+        Self {
+            name: String::new(),
+            path: String::new(),
+            args: vec![],
+            timeout_secs: 5,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct PluginsCfg {
+    pub calc: bool,
+    pub cmd: bool,
+    pub files: bool,
+    pub apps: bool,
+    pub external: Vec<ExternalPluginCfg>,
+}
+
+impl Default for PluginsCfg {
+    fn default() -> Self {
+        Self {
+            calc: true,
+            cmd: true,
+            files: true,
+            apps: true,
+            external: vec![],
+        }
+    }
+}

crates/k-launcher-config/tests/config.rs

@@ -0,0 +1,75 @@
+use k_launcher_config::Config;
+
+#[test]
+fn default_config_has_sane_values() {
+    let cfg = Config::default();
+    assert_eq!(cfg.search.max_results, 8);
+    assert_eq!(cfg.window.width, 600.0);
+    assert_eq!(cfg.window.height, 400.0);
+    assert!(!cfg.window.decorations);
+    assert!(cfg.window.transparent);
+    assert!(!cfg.window.resizable);
+    assert!(cfg.plugins.calc);
+    assert!(cfg.plugins.apps);
+    assert_eq!(cfg.appearance.search_font_size, 18.0);
+    assert_eq!(
+        cfg.appearance.placeholder,
+        "Search apps, type > for commands, = for math"
+    );
+}
+
+#[test]
+fn parse_partial_toml_uses_defaults() {
+    let toml_str = "[search]\nmax_results = 5\n";
+    let cfg: Config = toml::from_str(toml_str).unwrap();
+    assert_eq!(cfg.search.max_results, 5);
+    assert_eq!(cfg.window.width, 600.0);
+    assert_eq!(cfg.appearance.search_font_size, 18.0);
+    assert!(cfg.plugins.apps);
+}
+
+#[test]
+fn parse_full_toml_roundtrip() {
+    let toml_str = r#"
+[window]
+width = 800.0
+height = 500.0
+decorations = true
+transparent = false
+resizable = true
+
+[appearance]
+background_rgba = [10.0, 10.0, 20.0, 0.8]
+border_rgba = [100.0, 200.0, 255.0, 1.0]
+border_width = 2.0
+border_radius = 12.0
+search_font_size = 20.0
+title_size = 16.0
+desc_size = 13.0
+row_radius = 6.0
+placeholder = "Type here..."
+
+[search]
+max_results = 12
+
+[plugins]
+calc = false
+cmd = true
+files = false
+apps = true
+"#;
+    let cfg: Config = toml::from_str(toml_str).unwrap();
+    assert_eq!(cfg.window.width, 800.0);
+    assert_eq!(cfg.window.height, 500.0);
+    assert!(cfg.window.decorations);
+    assert!(!cfg.window.transparent);
+    assert_eq!(
+        cfg.appearance.background_rgba,
+        k_launcher_config::Rgba::new(10.0, 10.0, 20.0, 0.8)
+    );
+    assert_eq!(cfg.appearance.search_font_size, 20.0);
+    assert_eq!(cfg.appearance.placeholder, "Type here...");
+    assert_eq!(cfg.search.max_results, 12);
+    assert!(!cfg.plugins.calc);
+    assert!(!cfg.plugins.files);
+}

crates/k-launcher-domain/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "k-launcher-domain"
+version = "0.2.0"
+edition = "2024"
+
+[dependencies]
+async-trait = { workspace = true }
+serde = { workspace = true }

crates/k-launcher-domain/src/action.rs

@@ -0,0 +1,7 @@
+#[derive(Clone)]
+pub enum LaunchAction {
+    SpawnProcess(String),
+    SpawnInTerminal(String),
+    OpenPath(String),
+    CopyToClipboard(String),
+}

crates/k-launcher-domain/src/constants.rs

@@ -0,0 +1,6 @@
+pub const APP_NAME: &str = "k-launcher";
+pub const APP_TITLE: &str = "K-Launcher";
+pub const CONFIG_FILENAME: &str = "config.toml";
+pub const FRECENCY_SNAPSHOT_FILENAME: &str = "frecency.json";
+pub const LOG_DIR_NAME: &str = "logs";
+pub const LOG_FILE_PREFIX: &str = "k-launcher.log";

crates/k-launcher-domain/src/lib.rs

@@ -0,0 +1,10 @@
+mod action;
+pub mod constants;
+mod newtypes;
+pub mod ports;
+mod search_result;
+
+pub use action::*;
+pub use newtypes::*;
+pub use ports::*;
+pub use search_result::*;

crates/k-launcher-domain/src/newtypes.rs

@@ -0,0 +1,46 @@
+#[derive(Debug, Clone, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
+pub struct ResultId(String);
+
+impl ResultId {
+    pub fn new(id: impl Into<String>) -> Self {
+        let id = id.into();
+        debug_assert!(!id.is_empty(), "ResultId must not be empty");
+        Self(id)
+    }
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+pub struct ResultTitle(String);
+
+impl ResultTitle {
+    pub fn new(title: impl Into<String>) -> Self {
+        let title = title.into();
+        debug_assert!(!title.is_empty(), "ResultTitle must not be empty");
+        Self(title)
+    }
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, serde::Serialize, serde::Deserialize,
+)]
+pub struct Score(u32);
+
+impl Score {
+    pub const MAX: Self = Self(u32::MAX);
+
+    pub fn new(value: u32) -> Self {
+        Self(value)
+    }
+    pub fn value(self) -> u32 {
+        self.0
+    }
+    pub fn saturating_add(self, other: u32) -> Self {
+        Self(self.0.saturating_add(other))
+    }
+}

crates/k-launcher-domain/src/ports.rs

@@ -0,0 +1,15 @@
+use async_trait::async_trait;
+
+use crate::{LaunchAction, ResultId, SearchResult};
+
+pub trait AppLauncher: Send + Sync {
+    fn execute(&self, action: &LaunchAction);
+}
+
+#[async_trait]
+pub trait Plugin: Send + Sync {
+    fn name(&self) -> &str;
+    async fn search(&self, query: &str) -> Vec<SearchResult>;
+    fn on_selected(&self, _id: &ResultId) {}
+    fn shutdown(&self) {}
+}

crates/k-launcher-domain/src/search_result.rs

@@ -0,0 +1,25 @@
+use std::sync::Arc;
+
+use crate::action::LaunchAction;
+use crate::newtypes::{ResultId, ResultTitle, Score};
+
+#[derive(Clone)]
+pub struct SearchResult {
+    pub id: ResultId,
+    pub title: ResultTitle,
+    pub description: Option<Arc<str>>,
+    pub icon: Option<Arc<str>>,
+    pub score: Score,
+    pub action: LaunchAction,
+}
+
+impl std::fmt::Debug for SearchResult {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("SearchResult")
+            .field("id", &self.id)
+            .field("title", &self.title)
+            .field("icon", &self.icon)
+            .field("score", &self.score)
+            .finish_non_exhaustive()
+    }
+}

crates/k-launcher-domain/tests/newtypes.rs

@@ -0,0 +1,16 @@
+use k_launcher_domain::{ResultId, ResultTitle, Score};
+
+#[test]
+fn newtype_result_id() {
+    assert_eq!(ResultId::new("x").as_str(), "x");
+}
+
+#[test]
+fn newtype_score() {
+    assert_eq!(Score::new(42).value(), 42);
+}
+
+#[test]
+fn newtype_title() {
+    assert_eq!(ResultTitle::new("hello").as_str(), "hello");
+}

crates/k-launcher-kernel/Cargo.toml

@@ -1,11 +1,18 @@
 [package]
 name = "k-launcher-kernel"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [dependencies]
-async-trait = { workspace = true }
-futures = { workspace = true }
+futures = "0.3"
+k-launcher-domain = { workspace = true }
 serde = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
+
+[dev-dependencies]
+async-trait = { workspace = true }
+k-launcher-domain = { workspace = true }
+plugin-calc = { workspace = true }
+plugin-cmd = { workspace = true }
+tokio = { workspace = true }

crates/k-launcher-kernel/src/kernel.rs

@@ -0,0 +1,56 @@
+use std::sync::Arc;
+
+use futures::future::join_all;
+
+use k_launcher_domain::{Plugin, ResultId, SearchResult};
+
+pub struct Kernel {
+    plugins: Vec<Arc<dyn Plugin>>,
+    max_results: usize,
+}
+
+impl Kernel {
+    pub fn new(plugins: Vec<Arc<dyn Plugin>>, max_results: usize) -> Self {
+        Self {
+            plugins,
+            max_results,
+        }
+    }
+
+    pub fn on_selected(&self, id: &ResultId) {
+        for plugin in &self.plugins {
+            plugin.on_selected(id);
+        }
+    }
+
+    pub fn shutdown(&self) {
+        for plugin in &self.plugins {
+            plugin.shutdown();
+        }
+    }
+
+    pub async fn search(&self, query: &str) -> Vec<SearchResult> {
+        use futures::FutureExt;
+        use std::panic::AssertUnwindSafe;
+
+        let futures = self
+            .plugins
+            .iter()
+            .map(|p| AssertUnwindSafe(p.search(query)).catch_unwind());
+        let outcomes = join_all(futures).await;
+        let mut flat: Vec<SearchResult> = outcomes
+            .into_iter()
+            .zip(self.plugins.iter())
+            .flat_map(|(outcome, plugin)| match outcome {
+                Ok(results) => results,
+                Err(_) => {
+                    tracing::error!(plugin = plugin.name(), "plugin panicked during search");
+                    vec![]
+                }
+            })
+            .collect();
+        flat.sort_by_key(|r| std::cmp::Reverse(r.score));
+        flat.truncate(self.max_results);
+        flat
+    }
+}

crates/k-launcher-kernel/src/lib.rs

@@ -1,280 +1,3 @@
-use std::sync::Arc;
+mod kernel;
 
-use async_trait::async_trait;
-use futures::future::join_all;
-
-// --- Newtypes ---
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
-pub struct ResultId(String);
-
-impl ResultId {
-    pub fn new(id: impl Into<String>) -> Self {
-        Self(id.into())
-    }
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
-pub struct ResultTitle(String);
-
-impl ResultTitle {
-    pub fn new(title: impl Into<String>) -> Self {
-        Self(title.into())
-    }
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-#[derive(
-    Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, serde::Serialize, serde::Deserialize,
-)]
-pub struct Score(u32);
-
-impl Score {
-    pub fn new(value: u32) -> Self {
-        Self(value)
-    }
-    pub fn value(self) -> u32 {
-        self.0
-    }
-}
-
-// --- LaunchAction (port) ---
-
-pub enum LaunchAction {
-    SpawnProcess(String),
-    SpawnInTerminal(String),
-    OpenPath(String),
-    CopyToClipboard(String),
-}
-
-// --- AppLauncher port trait ---
-
-pub trait AppLauncher: Send + Sync {
-    fn execute(&self, action: &LaunchAction);
-}
-
-// --- SearchResult ---
-
-pub struct SearchResult {
-    pub id: ResultId,
-    pub title: ResultTitle,
-    pub description: Option<String>,
-    pub icon: Option<String>,
-    pub score: Score,
-    pub action: LaunchAction,
-}
-
-impl std::fmt::Debug for SearchResult {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("SearchResult")
-            .field("id", &self.id)
-            .field("title", &self.title)
-            .field("icon", &self.icon)
-            .field("score", &self.score)
-            .finish_non_exhaustive()
-    }
-}
-
-// --- Plugin trait ---
-
-#[async_trait]
-pub trait Plugin: Send + Sync {
-    fn name(&self) -> &str;
-    async fn search(&self, query: &str) -> Vec<SearchResult>;
-    fn on_selected(&self, _id: &ResultId) {}
-}
-
-// --- SearchEngine port trait ---
-
-#[async_trait]
-pub trait SearchEngine: Send + Sync {
-    async fn search(&self, query: &str) -> Vec<SearchResult>;
-    fn on_selected(&self, id: &ResultId);
-}
-
-// --- NullSearchEngine ---
-
-pub struct NullSearchEngine;
-
-#[async_trait]
-impl SearchEngine for NullSearchEngine {
-    async fn search(&self, _query: &str) -> Vec<SearchResult> {
-        vec![]
-    }
-    fn on_selected(&self, _id: &ResultId) {}
-}
-
-// --- Kernel (Application use case) ---
-
-pub struct Kernel {
-    plugins: Vec<Arc<dyn Plugin>>,
-    max_results: usize,
-}
-
-impl Kernel {
-    pub fn new(plugins: Vec<Arc<dyn Plugin>>, max_results: usize) -> Self {
-        Self {
-            plugins,
-            max_results,
-        }
-    }
-
-    pub fn on_selected(&self, id: &ResultId) {
-        for plugin in &self.plugins {
-            plugin.on_selected(id);
-        }
-    }
-
-    pub async fn search(&self, query: &str) -> Vec<SearchResult> {
-        use futures::FutureExt;
-        use std::panic::AssertUnwindSafe;
-
-        let futures = self
-            .plugins
-            .iter()
-            .map(|p| AssertUnwindSafe(p.search(query)).catch_unwind());
-        let outcomes = join_all(futures).await;
-        let mut flat: Vec<SearchResult> = outcomes
-            .into_iter()
-            .zip(self.plugins.iter())
-            .flat_map(|(outcome, plugin)| match outcome {
-                Ok(results) => results,
-                Err(_) => {
-                    tracing::error!(plugin = plugin.name(), "plugin panicked during search");
-                    vec![]
-                }
-            })
-            .collect();
-        flat.sort_by(|a, b| b.score.cmp(&a.score));
-        flat.truncate(self.max_results);
-        flat
-    }
-}
-
-#[async_trait]
-impl SearchEngine for Kernel {
-    async fn search(&self, query: &str) -> Vec<SearchResult> {
-        self.search(query).await
-    }
-    fn on_selected(&self, id: &ResultId) {
-        self.on_selected(id);
-    }
-}
-
-// --- Tests ---
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    struct MockPlugin {
-        results: Vec<(&'static str, u32)>,
-    }
-
-    impl MockPlugin {
-        fn returns(results: Vec<(&'static str, u32)>) -> Self {
-            Self { results }
-        }
-    }
-
-    #[async_trait]
-    impl Plugin for MockPlugin {
-        fn name(&self) -> &str {
-            "mock"
-        }
-
-        async fn search(&self, _query: &str) -> Vec<SearchResult> {
-            self.results
-                .iter()
-                .enumerate()
-                .map(|(i, (title, score))| SearchResult {
-                    id: ResultId::new(format!("id-{i}")),
-                    title: ResultTitle::new(*title),
-                    description: None,
-                    icon: None,
-                    score: Score::new(*score),
-                    action: LaunchAction::SpawnProcess("mock".to_string()),
-                })
-                .collect()
-        }
-    }
-
-    #[test]
-    fn newtype_result_id() {
-        assert_eq!(ResultId::new("x").as_str(), "x");
-    }
-
-    #[test]
-    fn newtype_score() {
-        assert_eq!(Score::new(42).value(), 42);
-    }
-
-    #[test]
-    fn newtype_title() {
-        assert_eq!(ResultTitle::new("hello").as_str(), "hello");
-    }
-
-    #[tokio::test]
-    async fn empty_kernel_returns_empty() {
-        let k = Kernel::new(vec![], 8);
-        assert!(k.search("x").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn kernel_sorts_by_score_desc() {
-        let plugin = Arc::new(MockPlugin::returns(vec![
-            ("lower", 5),
-            ("higher", 10),
-            ("middle", 7),
-        ]));
-        let k = Kernel::new(vec![plugin], 8);
-        let results = k.search("q").await;
-        assert_eq!(results[0].score.value(), 10);
-        assert_eq!(results[1].score.value(), 7);
-        assert_eq!(results[2].score.value(), 5);
-    }
-
-    struct PanicPlugin;
-
-    #[async_trait]
-    impl Plugin for PanicPlugin {
-        fn name(&self) -> &str {
-            "panic-plugin"
-        }
-
-        async fn search(&self, _query: &str) -> Vec<SearchResult> {
-            panic!("test panic");
-        }
-    }
-
-    #[tokio::test]
-    async fn kernel_continues_after_plugin_panic() {
-        let panic_plugin = Arc::new(PanicPlugin);
-        let normal_plugin = Arc::new(MockPlugin::returns(vec![("survivor", 5)]));
-        let k = Kernel::new(vec![panic_plugin, normal_plugin], 8);
-        let results = k.search("q").await;
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].title.as_str(), "survivor");
-    }
-
-    #[tokio::test]
-    async fn kernel_truncates_at_max_results() {
-        let plugin = Arc::new(MockPlugin::returns(vec![
-            ("a", 10),
-            ("b", 9),
-            ("c", 8),
-            ("d", 7),
-            ("e", 6),
-        ]));
-        let k = Kernel::new(vec![plugin], 3);
-        let results = k.search("q").await;
-        assert_eq!(results.len(), 3);
-        assert_eq!(results[0].score.value(), 10);
-        assert_eq!(results[2].score.value(), 8);
-    }
-}
+pub use kernel::*;

crates/k-launcher-kernel/tests/integration.rs

@@ -0,0 +1,42 @@
+use std::sync::Arc;
+
+use k_launcher_kernel::Kernel;
+use plugin_calc::CalcPlugin;
+use plugin_cmd::CmdPlugin;
+
+fn make_kernel() -> Kernel {
+    Kernel::new(
+        vec![Arc::new(CalcPlugin::new()), Arc::new(CmdPlugin::new())],
+        8,
+    )
+}
+
+#[tokio::test]
+async fn full_pipeline_calc() {
+    let kernel = make_kernel();
+    let results = kernel.search("2+2").await;
+    assert!(!results.is_empty());
+    assert_eq!(results[0].title.as_str(), "= 4");
+}
+
+#[tokio::test]
+async fn full_pipeline_cmd() {
+    let kernel = make_kernel();
+    let results = kernel.search("> echo hello").await;
+    assert!(!results.is_empty());
+    assert_eq!(results[0].title.as_str(), "Run: echo hello");
+}
+
+#[tokio::test]
+async fn full_pipeline_no_match() {
+    let kernel = make_kernel();
+    let results = kernel.search("xyzzy").await;
+    assert!(results.is_empty());
+}
+
+#[tokio::test]
+async fn full_pipeline_empty_query() {
+    let kernel = make_kernel();
+    let results = kernel.search("").await;
+    assert!(results.is_empty());
+}

crates/k-launcher-kernel/tests/kernel.rs

@@ -0,0 +1,107 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use k_launcher_domain::Plugin;
+use k_launcher_domain::{LaunchAction, ResultId, ResultTitle, Score, SearchResult};
+use k_launcher_kernel::Kernel;
+
+struct MockResult {
+    title: &'static str,
+    score: u32,
+}
+
+struct MockPlugin {
+    results: Vec<MockResult>,
+}
+
+impl MockPlugin {
+    fn returns(results: Vec<(&'static str, u32)>) -> Self {
+        Self {
+            results: results
+                .into_iter()
+                .map(|(title, score)| MockResult { title, score })
+                .collect(),
+        }
+    }
+}
+
+#[async_trait]
+impl Plugin for MockPlugin {
+    fn name(&self) -> &str {
+        "mock"
+    }
+
+    async fn search(&self, _query: &str) -> Vec<SearchResult> {
+        self.results
+            .iter()
+            .enumerate()
+            .map(|(i, r)| SearchResult {
+                id: ResultId::new(format!("id-{i}")),
+                title: ResultTitle::new(r.title),
+                description: None,
+                icon: None,
+                score: Score::new(r.score),
+                action: LaunchAction::SpawnProcess("mock".to_string()),
+            })
+            .collect()
+    }
+}
+
+#[tokio::test]
+async fn empty_kernel_returns_empty() {
+    let k = Kernel::new(vec![], 8);
+    assert!(k.search("x").await.is_empty());
+}
+
+#[tokio::test]
+async fn kernel_sorts_by_score_desc() {
+    let plugin = Arc::new(MockPlugin::returns(vec![
+        ("lower", 5),
+        ("higher", 10),
+        ("middle", 7),
+    ]));
+    let k = Kernel::new(vec![plugin], 8);
+    let results = k.search("q").await;
+    assert_eq!(results[0].score.value(), 10);
+    assert_eq!(results[1].score.value(), 7);
+    assert_eq!(results[2].score.value(), 5);
+}
+
+struct PanicPlugin;
+
+#[async_trait]
+impl Plugin for PanicPlugin {
+    fn name(&self) -> &str {
+        "panic-plugin"
+    }
+
+    async fn search(&self, _query: &str) -> Vec<SearchResult> {
+        panic!("test panic");
+    }
+}
+
+#[tokio::test]
+async fn kernel_continues_after_plugin_panic() {
+    let panic_plugin = Arc::new(PanicPlugin);
+    let normal_plugin = Arc::new(MockPlugin::returns(vec![("survivor", 5)]));
+    let k = Kernel::new(vec![panic_plugin, normal_plugin], 8);
+    let results = k.search("q").await;
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].title.as_str(), "survivor");
+}
+
+#[tokio::test]
+async fn kernel_truncates_at_max_results() {
+    let plugin = Arc::new(MockPlugin::returns(vec![
+        ("a", 10),
+        ("b", 9),
+        ("c", 8),
+        ("d", 7),
+        ("e", 6),
+    ]));
+    let k = Kernel::new(vec![plugin], 3);
+    let results = k.search("q").await;
+    assert_eq!(results.len(), 3);
+    assert_eq!(results[0].score.value(), 10);
+    assert_eq!(results[2].score.value(), 8);
+}

crates/k-launcher-os-bridge/Cargo.toml

@@ -1,8 +1,9 @@
 [package]
 name = "k-launcher-os-bridge"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [dependencies]
-k-launcher-kernel = { path = "../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
 libc = "0.2"
+tracing = { workspace = true }

crates/k-launcher-os-bridge/src/launcher.rs

@@ -0,0 +1,50 @@
+use k_launcher_domain::{AppLauncher, LaunchAction};
+
+use crate::shell::shell_split;
+use crate::spawn::{copy_to_clipboard, open_path, spawn_detached};
+use crate::terminal::resolve_terminal;
+
+pub struct UnixAppLauncher {
+    terminal_cmd: Option<String>,
+}
+
+impl UnixAppLauncher {
+    pub fn new(terminal_cmd: Option<String>) -> Self {
+        Self { terminal_cmd }
+    }
+}
+
+impl AppLauncher for UnixAppLauncher {
+    fn execute(&self, action: &LaunchAction) {
+        match action {
+            LaunchAction::SpawnProcess(cmd) => spawn_command(cmd),
+            LaunchAction::SpawnInTerminal(cmd) => {
+                spawn_in_terminal(cmd, self.terminal_cmd.as_deref())
+            }
+            LaunchAction::OpenPath(path) => open_path(path),
+            LaunchAction::CopyToClipboard(val) => copy_to_clipboard(val),
+        }
+    }
+}
+
+fn spawn_command(cmd: &str) {
+    let parts = shell_split(cmd);
+    if let Some((bin, args)) = parts.split_first() {
+        spawn_detached(bin, args);
+    }
+}
+
+fn spawn_in_terminal(cmd: &str, configured: Option<&str>) {
+    let Some(terminal) = resolve_terminal(configured) else {
+        return;
+    };
+    let mut args = terminal.exec_flag;
+    const SHELL: &str = "sh";
+    const SHELL_CMD_FLAG: &str = "-c";
+    args.extend([
+        SHELL.to_string(),
+        SHELL_CMD_FLAG.to_string(),
+        cmd.to_string(),
+    ]);
+    spawn_detached(&terminal.bin, &args);
+}

crates/k-launcher-os-bridge/src/lib.rs

@@ -1,2 +1,7 @@
-mod unix_launcher;
-pub use unix_launcher::UnixAppLauncher;
+mod launcher;
+mod shell;
+mod spawn;
+mod terminal;
+
+pub use launcher::UnixAppLauncher;
+pub use shell::shell_split;

crates/k-launcher-os-bridge/src/shell.rs

@@ -0,0 +1,22 @@
+pub fn shell_split(cmd: &str) -> Vec<String> {
+    let mut tokens = Vec::new();
+    let mut current = String::new();
+    let mut in_quotes = false;
+
+    for ch in cmd.chars() {
+        match ch {
+            '"' => in_quotes = !in_quotes,
+            ' ' | '\t' if !in_quotes => {
+                if !current.is_empty() {
+                    tokens.push(current.clone());
+                    current.clear();
+                }
+            }
+            _ => current.push(ch),
+        }
+    }
+    if !current.is_empty() {
+        tokens.push(current);
+    }
+    tokens
+}

crates/k-launcher-os-bridge/src/spawn.rs

@@ -0,0 +1,49 @@
+use std::io::Write;
+use std::os::unix::process::CommandExt;
+use std::process::{Command, Stdio};
+
+const XDG_OPEN: &str = "xdg-open";
+const WL_COPY: &str = "wl-copy";
+const XCLIP: &str = "xclip";
+
+pub(crate) fn spawn_detached(bin: &str, args: &[String]) {
+    // SAFETY: setsid() is async-signal-safe; called in forked child before exec
+    if let Err(e) = unsafe {
+        Command::new(bin)
+            .args(args)
+            .stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .stderr(Stdio::null())
+            .pre_exec(|| {
+                libc::setsid();
+                Ok(())
+            })
+            .spawn()
+    } {
+        tracing::warn!("failed to spawn detached process '{bin}': {e}");
+    }
+}
+
+pub(crate) fn open_path(path: &str) {
+    if let Err(e) = Command::new(XDG_OPEN).arg(path).spawn() {
+        tracing::warn!("failed to open path '{path}': {e}");
+    }
+}
+
+pub(crate) fn copy_to_clipboard(val: &str) {
+    if Command::new(WL_COPY).arg(val).spawn().is_err() {
+        copy_to_clipboard_xclip(val);
+    }
+}
+
+fn copy_to_clipboard_xclip(val: &str) {
+    if let Ok(mut child) = Command::new(XCLIP)
+        .args(["-selection", "clipboard"])
+        .stdin(Stdio::piped())
+        .spawn()
+        && let Some(stdin) = child.stdin.as_mut()
+        && let Err(e) = stdin.write_all(val.as_bytes())
+    {
+        tracing::warn!("failed to write to xclip stdin: {e}");
+    }
+}

crates/k-launcher-os-bridge/src/terminal.rs

@@ -0,0 +1,86 @@
+pub(crate) struct TerminalCommand {
+    pub bin: String,
+    pub exec_flag: Vec<String>,
+}
+
+struct KnownTerminal {
+    bin: &'static str,
+    exec_flag: &'static str,
+}
+
+const KNOWN_TERMINALS: &[KnownTerminal] = &[
+    KnownTerminal {
+        bin: "foot",
+        exec_flag: "-e",
+    },
+    KnownTerminal {
+        bin: "kitty",
+        exec_flag: "-e",
+    },
+    KnownTerminal {
+        bin: "alacritty",
+        exec_flag: "-e",
+    },
+    KnownTerminal {
+        bin: "wezterm",
+        exec_flag: "start",
+    },
+    KnownTerminal {
+        bin: "konsole",
+        exec_flag: "-e",
+    },
+    KnownTerminal {
+        bin: "xterm",
+        exec_flag: "-e",
+    },
+];
+
+fn find_in_path(bin: &str) -> bool {
+    std::env::var_os("PATH")
+        .iter()
+        .flat_map(|p| std::env::split_paths(p))
+        .any(|dir| dir.join(bin).is_file())
+}
+
+fn parse_term_cmd(s: &str) -> TerminalCommand {
+    let mut parts = s.split_whitespace();
+    let bin = parts.next().unwrap_or("").to_string();
+    let exec_flag = parts.map(str::to_string).collect();
+    TerminalCommand { bin, exec_flag }
+}
+
+pub(crate) fn resolve_terminal(configured: Option<&str>) -> Option<TerminalCommand> {
+    if let Some(cmd) = configured.filter(|s| !s.is_empty()) {
+        let term = parse_term_cmd(cmd);
+        if !term.bin.is_empty() {
+            return Some(term);
+        }
+    }
+    if let Ok(val) = std::env::var("TERM_CMD") {
+        let val = val.trim().to_string();
+        if !val.is_empty() {
+            let term = parse_term_cmd(&val);
+            if !term.bin.is_empty() {
+                return Some(term);
+            }
+        }
+    }
+    if let Ok(val) = std::env::var("TERMINAL") {
+        let bin = val.trim().to_string();
+        if !bin.is_empty() {
+            return Some(TerminalCommand {
+                bin,
+                exec_flag: vec!["-e".to_string()],
+            });
+        }
+    }
+    for terminal in KNOWN_TERMINALS {
+        if find_in_path(terminal.bin) {
+            return Some(TerminalCommand {
+                bin: terminal.bin.to_string(),
+                exec_flag: vec![terminal.exec_flag.to_string()],
+            });
+        }
+    }
+    None
+}

crates/k-launcher-os-bridge/src/unix_launcher.rs

@@ -1,190 +0,0 @@
-use std::os::unix::process::CommandExt;
-use std::process::{Command, Stdio};
-
-use k_launcher_kernel::{AppLauncher, LaunchAction};
-
-fn shell_split(cmd: &str) -> Vec<String> {
-    let mut tokens = Vec::new();
-    let mut current = String::new();
-    let mut in_quotes = false;
-
-    for ch in cmd.chars() {
-        match ch {
-            '"' => in_quotes = !in_quotes,
-            ' ' | '\t' if !in_quotes => {
-                if !current.is_empty() {
-                    tokens.push(current.clone());
-                    current.clear();
-                }
-            }
-            _ => current.push(ch),
-        }
-    }
-    if !current.is_empty() {
-        tokens.push(current);
-    }
-    tokens
-}
-
-fn parse_term_cmd(s: &str) -> (String, Vec<String>) {
-    let mut parts = s.split_whitespace();
-    let bin = parts.next().unwrap_or("").to_string();
-    let args = parts.map(str::to_string).collect();
-    (bin, args)
-}
-
-fn which(bin: &str) -> bool {
-    Command::new("which")
-        .arg(bin)
-        .stdout(Stdio::null())
-        .stderr(Stdio::null())
-        .status()
-        .map(|s| s.success())
-        .unwrap_or(false)
-}
-
-fn resolve_terminal() -> Option<(String, Vec<String>)> {
-    if let Ok(val) = std::env::var("TERM_CMD") {
-        let val = val.trim().to_string();
-        if !val.is_empty() {
-            let (bin, args) = parse_term_cmd(&val);
-            if !bin.is_empty() {
-                return Some((bin, args));
-            }
-        }
-    }
-    if let Ok(val) = std::env::var("TERMINAL") {
-        let bin = val.trim().to_string();
-        if !bin.is_empty() {
-            return Some((bin, vec!["-e".to_string()]));
-        }
-    }
-    for (bin, flag) in &[
-        ("foot", "-e"),
-        ("kitty", "-e"),
-        ("alacritty", "-e"),
-        ("wezterm", "start"),
-        ("konsole", "-e"),
-        ("xterm", "-e"),
-    ] {
-        if which(bin) {
-            return Some((bin.to_string(), vec![flag.to_string()]));
-        }
-    }
-    None
-}
-
-pub struct UnixAppLauncher;
-
-impl UnixAppLauncher {
-    pub fn new() -> Self {
-        Self
-    }
-}
-
-impl Default for UnixAppLauncher {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl AppLauncher for UnixAppLauncher {
-    fn execute(&self, action: &LaunchAction) {
-        match action {
-            LaunchAction::SpawnProcess(cmd) => {
-                let parts = shell_split(cmd);
-                if let Some((bin, args)) = parts.split_first() {
-                    let _ = unsafe {
-                        Command::new(bin)
-                            .args(args)
-                            .stdin(Stdio::null())
-                            .stdout(Stdio::null())
-                            .stderr(Stdio::null())
-                            .pre_exec(|| {
-                                libc::setsid();
-                                Ok(())
-                            })
-                            .spawn()
-                    };
-                }
-            }
-            LaunchAction::SpawnInTerminal(cmd) => {
-                let Some((term_bin, term_args)) = resolve_terminal() else {
-                    return;
-                };
-                let _ = unsafe {
-                    Command::new(&term_bin)
-                        .args(&term_args)
-                        .arg("sh")
-                        .arg("-c")
-                        .arg(cmd)
-                        .stdin(Stdio::null())
-                        .stdout(Stdio::null())
-                        .stderr(Stdio::null())
-                        .pre_exec(|| {
-                            libc::setsid();
-                            Ok(())
-                        })
-                        .spawn()
-                };
-            }
-            LaunchAction::OpenPath(path) => {
-                let _ = Command::new("xdg-open").arg(path).spawn();
-            }
-            LaunchAction::CopyToClipboard(val) => {
-                if Command::new("wl-copy").arg(val).spawn().is_err() {
-                    use std::io::Write;
-                    if let Ok(mut child) = Command::new("xclip")
-                        .args(["-selection", "clipboard"])
-                        .stdin(Stdio::piped())
-                        .spawn()
-                        && let Some(stdin) = child.stdin.as_mut()
-                    {
-                        let _ = stdin.write_all(val.as_bytes());
-                    }
-                }
-            }
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::shell_split;
-
-    #[test]
-    fn split_simple() {
-        assert_eq!(shell_split("firefox"), vec!["firefox"]);
-    }
-
-    #[test]
-    fn split_with_args() {
-        assert_eq!(
-            shell_split("firefox --new-window"),
-            vec!["firefox", "--new-window"]
-        );
-    }
-
-    #[test]
-    fn split_quoted_path() {
-        assert_eq!(shell_split(r#""My App" --flag"#), vec!["My App", "--flag"]);
-    }
-
-    #[test]
-    fn split_quoted_with_spaces() {
-        assert_eq!(
-            shell_split(r#"env "FOO BAR" baz"#),
-            vec!["env", "FOO BAR", "baz"]
-        );
-    }
-
-    #[test]
-    fn split_empty() {
-        assert!(shell_split("").is_empty());
-    }
-
-    #[test]
-    fn split_extra_whitespace() {
-        assert_eq!(shell_split("  a   b  "), vec!["a", "b"]);
-    }
-}

crates/k-launcher-os-bridge/tests/shell_split.rs

@@ -0,0 +1,37 @@
+use k_launcher_os_bridge::shell_split;
+
+#[test]
+fn split_simple() {
+    assert_eq!(shell_split("firefox"), vec!["firefox"]);
+}
+
+#[test]
+fn split_with_args() {
+    assert_eq!(
+        shell_split("firefox --new-window"),
+        vec!["firefox", "--new-window"]
+    );
+}
+
+#[test]
+fn split_quoted_path() {
+    assert_eq!(shell_split(r#""My App" --flag"#), vec!["My App", "--flag"]);
+}
+
+#[test]
+fn split_quoted_with_spaces() {
+    assert_eq!(
+        shell_split(r#"env "FOO BAR" baz"#),
+        vec!["env", "FOO BAR", "baz"]
+    );
+}
+
+#[test]
+fn split_empty() {
+    assert!(shell_split("").is_empty());
+}
+
+#[test]
+fn split_extra_whitespace() {
+    assert_eq!(shell_split("  a   b  "), vec!["a", "b"]);
+}

crates/k-launcher-plugin-host/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k-launcher-plugin-host"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -9,8 +9,11 @@ path = "src/lib.rs"
 
 [dependencies]
 async-trait = { workspace = true }
-k-launcher-kernel = { path = "../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+thiserror = { workspace = true }
 tokio = { workspace = true, features = ["process", "io-util", "sync", "time"] }
 tracing = { workspace = true }
+
+[dev-dependencies]

crates/k-launcher-plugin-host/src/error.rs

@@ -0,0 +1,13 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum PluginError {
+    #[error("plugin spawn failed: {0}")]
+    SpawnFailed(#[from] std::io::Error),
+    #[error("search timed out after {timeout_secs}s")]
+    Timeout { timeout_secs: u64 },
+    #[error("protocol error: {0}")]
+    Protocol(String),
+    #[error("plugin process error: {0}")]
+    ProcessError(String),
+}

crates/k-launcher-plugin-host/src/lib.rs

@@ -1,218 +1,6 @@
-use async_trait::async_trait;
-use k_launcher_kernel::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
-use serde::{Deserialize, Serialize};
-use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter};
-use tokio::process::{ChildStdin, ChildStdout, Command};
-use tokio::sync::Mutex;
+pub mod error;
+mod plugin;
+mod protocol;
 
-// --- Protocol types ---
-
-#[derive(Serialize)]
-struct Query {
-    query: String,
-}
-
-#[derive(Deserialize)]
-struct ExternalResult {
-    id: String,
-    title: String,
-    score: u32,
-    #[serde(default)]
-    description: Option<String>,
-    #[serde(default)]
-    icon: Option<String>,
-    action: ExternalAction,
-}
-
-#[derive(Deserialize)]
-#[serde(tag = "type")]
-enum ExternalAction {
-    SpawnProcess { cmd: String },
-    CopyToClipboard { text: String },
-    OpenPath { path: String },
-}
-
-// --- Process I/O handle ---
-
-struct ProcessIo {
-    stdin: BufWriter<ChildStdin>,
-    stdout: BufReader<ChildStdout>,
-}
-
-async fn do_search(
-    io: &mut ProcessIo,
-    query: &str,
-) -> Result<Vec<ExternalResult>, Box<dyn std::error::Error + Send + Sync>> {
-    let line = serde_json::to_string(&Query {
-        query: query.to_string(),
-    })?;
-    io.stdin.write_all(line.as_bytes()).await?;
-    io.stdin.write_all(b"\n").await?;
-    io.stdin.flush().await?;
-    let mut response = String::new();
-    io.stdout.read_line(&mut response).await?;
-    Ok(serde_json::from_str(&response)?)
-}
-
-// --- ExternalPlugin ---
-
-pub struct ExternalPlugin {
-    name: String,
-    path: String,
-    args: Vec<String>,
-    inner: Mutex<Option<ProcessIo>>,
-}
-
-impl ExternalPlugin {
-    pub fn new(name: impl Into<String>, path: impl Into<String>, args: Vec<String>) -> Self {
-        Self {
-            name: name.into(),
-            path: path.into(),
-            args,
-            inner: Mutex::new(None),
-        }
-    }
-
-    async fn spawn(&self) -> std::io::Result<ProcessIo> {
-        let mut child = Command::new(&self.path)
-            .args(&self.args)
-            .stdin(std::process::Stdio::piped())
-            .stdout(std::process::Stdio::piped())
-            .spawn()?;
-        let stdin = BufWriter::new(child.stdin.take().unwrap());
-        let stdout = BufReader::new(child.stdout.take().unwrap());
-        Ok(ProcessIo { stdin, stdout })
-    }
-}
-
-#[async_trait]
-impl Plugin for ExternalPlugin {
-    fn name(&self) -> &str {
-        &self.name
-    }
-
-    async fn search(&self, query: &str) -> Vec<SearchResult> {
-        let mut guard = self.inner.lock().await;
-
-        if guard.is_none() {
-            match self.spawn().await {
-                Ok(io) => *guard = Some(io),
-                Err(e) => {
-                    tracing::warn!("failed to spawn plugin {}: {e}", self.name);
-                    return vec![];
-                }
-            }
-        }
-
-        let result = match guard.as_mut() {
-            Some(io) => {
-                tokio::time::timeout(std::time::Duration::from_secs(5), do_search(io, query))
-                    .await
-                    .unwrap_or_else(|_| {
-                        tracing::warn!("plugin {} search timed out", self.name);
-                        Err("timeout".into())
-                    })
-            }
-            None => unreachable!(),
-        };
-
-        match result {
-            Ok(results) => results
-                .into_iter()
-                .map(|r| SearchResult {
-                    id: ResultId::new(r.id),
-                    title: ResultTitle::new(r.title),
-                    description: r.description,
-                    icon: r.icon,
-                    score: Score::new(r.score),
-                    action: match r.action {
-                        ExternalAction::SpawnProcess { cmd } => LaunchAction::SpawnProcess(cmd),
-                        ExternalAction::CopyToClipboard { text } => {
-                            LaunchAction::CopyToClipboard(text)
-                        }
-                        ExternalAction::OpenPath { path } => LaunchAction::OpenPath(path),
-                    },
-                })
-                .collect(),
-            Err(e) => {
-                tracing::warn!("plugin {} error: {e}", self.name);
-                *guard = None;
-                vec![]
-            }
-        }
-    }
-}
-
-// --- Tests ---
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn query_serializes_correctly() {
-        let q = Query {
-            query: "firefox".to_string(),
-        };
-        assert_eq!(serde_json::to_string(&q).unwrap(), r#"{"query":"firefox"}"#);
-    }
-
-    #[test]
-    fn result_parses_spawn_action() {
-        let json = r#"[{"id":"1","title":"Firefox","score":80,"action":{"type":"SpawnProcess","cmd":"firefox"}}]"#;
-        let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].id, "1");
-        assert_eq!(results[0].title, "Firefox");
-        assert_eq!(results[0].score, 80);
-        assert!(
-            matches!(&results[0].action, ExternalAction::SpawnProcess { cmd } if cmd == "firefox")
-        );
-    }
-
-    #[test]
-    fn result_parses_copy_action() {
-        let json = r#"[{"id":"c","title":"= 4","score":90,"action":{"type":"CopyToClipboard","text":"4"}}]"#;
-        let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
-        assert!(
-            matches!(&results[0].action, ExternalAction::CopyToClipboard { text } if text == "4")
-        );
-    }
-
-    #[test]
-    fn result_parses_open_path_action() {
-        let json = r#"[{"id":"f","title":"/home/user","score":50,"action":{"type":"OpenPath","path":"/home/user"}}]"#;
-        let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
-        assert!(
-            matches!(&results[0].action, ExternalAction::OpenPath { path } if path == "/home/user")
-        );
-    }
-
-    #[test]
-    fn result_parses_optional_fields() {
-        let json = r#"[{"id":"x","title":"X","score":10,"description":"desc","icon":"/icon.png","action":{"type":"SpawnProcess","cmd":"x"}}]"#;
-        let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
-        assert_eq!(results[0].description.as_deref(), Some("desc"));
-        assert_eq!(results[0].icon.as_deref(), Some("/icon.png"));
-    }
-
-    #[test]
-    fn result_parses_missing_optional_fields() {
-        let json =
-            r#"[{"id":"x","title":"X","score":10,"action":{"type":"SpawnProcess","cmd":"x"}}]"#;
-        let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
-        assert!(results[0].description.is_none());
-        assert!(results[0].icon.is_none());
-    }
-
-    #[test]
-    fn invalid_json_is_err() {
-        assert!(serde_json::from_str::<Vec<ExternalResult>>("not json").is_err());
-    }
-
-    // Unused import suppression for Arc (used only in production code path)
-    fn _assert_send_sync() {
-        fn check<T: Send + Sync>() {}
-        check::<ExternalPlugin>();
-    }
-}
+pub use plugin::*;
+pub use protocol::*;

crates/k-launcher-plugin-host/src/plugin.rs

@@ -0,0 +1,137 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use k_launcher_domain::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter};
+use tokio::process::{ChildStdin, ChildStdout, Command};
+use tokio::sync::Mutex;
+
+use crate::error::PluginError;
+use crate::protocol::{ExternalAction, ExternalResult, Query};
+
+struct ProcessIo {
+    stdin: BufWriter<ChildStdin>,
+    stdout: BufReader<ChildStdout>,
+}
+
+async fn do_search(io: &mut ProcessIo, query: &str) -> Result<Vec<ExternalResult>, PluginError> {
+    let line = serde_json::to_string(&Query {
+        query: query.to_string(),
+    })
+    .map_err(|e| PluginError::Protocol(e.to_string()))?;
+    io.stdin
+        .write_all(line.as_bytes())
+        .await
+        .map_err(|e| PluginError::ProcessError(e.to_string()))?;
+    io.stdin
+        .write_all(b"\n")
+        .await
+        .map_err(|e| PluginError::ProcessError(e.to_string()))?;
+    io.stdin
+        .flush()
+        .await
+        .map_err(|e| PluginError::ProcessError(e.to_string()))?;
+    let mut response = String::new();
+    io.stdout
+        .read_line(&mut response)
+        .await
+        .map_err(|e| PluginError::ProcessError(e.to_string()))?;
+    serde_json::from_str(&response).map_err(|e| PluginError::Protocol(e.to_string()))
+}
+
+pub struct ExternalPlugin {
+    name: String,
+    path: String,
+    args: Vec<String>,
+    timeout_secs: u64,
+    inner: Mutex<Option<ProcessIo>>,
+}
+
+impl ExternalPlugin {
+    pub fn new(
+        name: impl Into<String>,
+        path: impl Into<String>,
+        args: Vec<String>,
+        timeout_secs: u64,
+    ) -> Self {
+        Self {
+            name: name.into(),
+            path: path.into(),
+            args,
+            timeout_secs,
+            inner: Mutex::new(None),
+        }
+    }
+
+    async fn spawn(&self) -> std::io::Result<ProcessIo> {
+        let mut child = Command::new(&self.path)
+            .args(&self.args)
+            .stdin(std::process::Stdio::piped())
+            .stdout(std::process::Stdio::piped())
+            .spawn()?;
+        let stdin = BufWriter::new(child.stdin.take().unwrap());
+        let stdout = BufReader::new(child.stdout.take().unwrap());
+        Ok(ProcessIo { stdin, stdout })
+    }
+}
+
+#[async_trait]
+impl Plugin for ExternalPlugin {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    async fn search(&self, query: &str) -> Vec<SearchResult> {
+        let mut guard = self.inner.lock().await;
+
+        if guard.is_none() {
+            match self.spawn().await {
+                Ok(io) => *guard = Some(io),
+                Err(e) => {
+                    tracing::warn!("failed to spawn plugin {}: {e}", self.name);
+                    return vec![];
+                }
+            }
+        }
+
+        let result = match guard.as_mut() {
+            Some(io) => tokio::time::timeout(
+                std::time::Duration::from_secs(self.timeout_secs),
+                do_search(io, query),
+            )
+            .await
+            .unwrap_or(Err(PluginError::Timeout {
+                timeout_secs: self.timeout_secs,
+            })),
+            None => unreachable!(),
+        };
+
+        match result {
+            Ok(results) => results
+                .into_iter()
+                .map(|r| SearchResult {
+                    id: ResultId::new(r.id),
+                    title: ResultTitle::new(r.title),
+                    description: r.description.map(Arc::from),
+                    icon: r.icon.map(Arc::from),
+                    score: Score::new(r.score),
+                    action: match r.action {
+                        ExternalAction::SpawnProcess { cmd } => LaunchAction::SpawnProcess(cmd),
+                        ExternalAction::SpawnInTerminal { cmd } => {
+                            LaunchAction::SpawnInTerminal(cmd)
+                        }
+                        ExternalAction::CopyToClipboard { text } => {
+                            LaunchAction::CopyToClipboard(text)
+                        }
+                        ExternalAction::OpenPath { path } => LaunchAction::OpenPath(path),
+                    },
+                })
+                .collect(),
+            Err(e) => {
+                tracing::warn!("plugin {} error: {e}", self.name);
+                *guard = None;
+                vec![]
+            }
+        }
+    }
+}

crates/k-launcher-plugin-host/src/protocol.rs

@@ -0,0 +1,27 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize)]
+pub struct Query {
+    pub query: String,
+}
+
+#[derive(Deserialize)]
+pub struct ExternalResult {
+    pub id: String,
+    pub title: String,
+    pub score: u32,
+    #[serde(default)]
+    pub description: Option<String>,
+    #[serde(default)]
+    pub icon: Option<String>,
+    pub action: ExternalAction,
+}
+
+#[derive(Deserialize)]
+#[serde(tag = "type")]
+pub enum ExternalAction {
+    SpawnProcess { cmd: String },
+    SpawnInTerminal { cmd: String },
+    CopyToClipboard { text: String },
+    OpenPath { path: String },
+}

crates/k-launcher-plugin-host/tests/protocol.rs

@@ -0,0 +1,70 @@
+use k_launcher_plugin_host::{ExternalAction, ExternalPlugin, ExternalResult, Query};
+
+#[test]
+fn query_serializes_correctly() {
+    let q = Query {
+        query: "firefox".to_string(),
+    };
+    assert_eq!(serde_json::to_string(&q).unwrap(), r#"{"query":"firefox"}"#);
+}
+
+#[test]
+fn result_parses_spawn_action() {
+    let json = r#"[{"id":"1","title":"Firefox","score":80,"action":{"type":"SpawnProcess","cmd":"firefox"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].id, "1");
+    assert_eq!(results[0].title, "Firefox");
+    assert_eq!(results[0].score, 80);
+    assert!(matches!(&results[0].action, ExternalAction::SpawnProcess { cmd } if cmd == "firefox"));
+}
+
+#[test]
+fn result_parses_copy_action() {
+    let json =
+        r#"[{"id":"c","title":"= 4","score":90,"action":{"type":"CopyToClipboard","text":"4"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert!(matches!(&results[0].action, ExternalAction::CopyToClipboard { text } if text == "4"));
+}
+
+#[test]
+fn result_parses_open_path_action() {
+    let json = r#"[{"id":"f","title":"/home/user","score":50,"action":{"type":"OpenPath","path":"/home/user"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert!(
+        matches!(&results[0].action, ExternalAction::OpenPath { path } if path == "/home/user")
+    );
+}
+
+#[test]
+fn result_parses_spawn_in_terminal_action() {
+    let json = r#"[{"id":"t","title":"htop","score":70,"action":{"type":"SpawnInTerminal","cmd":"htop"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert!(matches!(&results[0].action, ExternalAction::SpawnInTerminal { cmd } if cmd == "htop"));
+}
+
+#[test]
+fn result_parses_optional_fields() {
+    let json = r#"[{"id":"x","title":"X","score":10,"description":"desc","icon":"/icon.png","action":{"type":"SpawnProcess","cmd":"x"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert_eq!(results[0].description.as_deref(), Some("desc"));
+    assert_eq!(results[0].icon.as_deref(), Some("/icon.png"));
+}
+
+#[test]
+fn result_parses_missing_optional_fields() {
+    let json = r#"[{"id":"x","title":"X","score":10,"action":{"type":"SpawnProcess","cmd":"x"}}]"#;
+    let results: Vec<ExternalResult> = serde_json::from_str(json).unwrap();
+    assert!(results[0].description.is_none());
+    assert!(results[0].icon.is_none());
+}
+
+#[test]
+fn invalid_json_is_err() {
+    assert!(serde_json::from_str::<Vec<ExternalResult>>("not json").is_err());
+}
+
+fn _assert_send_sync() {
+    fn check<T: Send + Sync>() {}
+    check::<ExternalPlugin>();
+}

crates/k-launcher-ui-core/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "k-launcher-ui-core"
+version = "0.2.0"
+edition = "2024"
+
+[dependencies]
+k-launcher-config = { workspace = true }
+k-launcher-domain = { workspace = true }
+k-launcher-kernel = { workspace = true }

crates/k-launcher-ui-core/src/lib.rs

@@ -0,0 +1,171 @@
+use std::sync::Arc;
+
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::AppLauncher;
+use k_launcher_domain::{LaunchAction, SearchResult};
+use k_launcher_kernel::Kernel;
+
+pub struct LauncherState {
+    query: String,
+    results: Vec<SearchResult>,
+    selected: usize,
+    engine: Option<Arc<Kernel>>,
+    launcher: Arc<dyn AppLauncher>,
+    cfg: AppearanceCfg,
+    debounce_ms: u64,
+    search_epoch: u64,
+    error: Option<String>,
+}
+
+pub enum Action {
+    QueryChanged(String),
+    MoveDown,
+    MoveUp,
+    LaunchSelected,
+    Exit,
+    EngineReady(Arc<Kernel>),
+    EngineInitFailed(String),
+    ResultsReady {
+        epoch: u64,
+        results: Vec<SearchResult>,
+    },
+}
+
+pub enum Effect {
+    SearchAfterDebounce {
+        query: String,
+        debounce_ms: u64,
+        epoch: u64,
+    },
+    LaunchAndExit(LaunchAction),
+    Exit,
+    TriggerSearch(String),
+    None,
+}
+
+impl LauncherState {
+    pub fn new(launcher: Arc<dyn AppLauncher>, cfg: AppearanceCfg, debounce_ms: u64) -> Self {
+        Self {
+            query: String::new(),
+            results: vec![],
+            selected: 0,
+            engine: None,
+            launcher,
+            cfg,
+            debounce_ms,
+            search_epoch: 0,
+            error: None,
+        }
+    }
+
+    pub fn handle(&mut self, action: Action) -> Effect {
+        match action {
+            Action::QueryChanged(q) => {
+                self.query = q;
+                self.selected = 0;
+                self.error = None;
+
+                let Some(_engine) = &self.engine else {
+                    return Effect::None;
+                };
+
+                self.search_epoch += 1;
+                Effect::SearchAfterDebounce {
+                    query: self.query.clone(),
+                    debounce_ms: self.debounce_ms,
+                    epoch: self.search_epoch,
+                }
+            }
+
+            Action::MoveDown => {
+                let len = self.results.len();
+                if len > 0 {
+                    self.selected = (self.selected + 1).min(len - 1);
+                }
+                Effect::None
+            }
+
+            Action::MoveUp => {
+                self.selected = self.selected.saturating_sub(1);
+                Effect::None
+            }
+
+            Action::LaunchSelected => {
+                if let Some(result) = self.results.get(self.selected) {
+                    if let Some(engine) = &self.engine {
+                        engine.on_selected(&result.id);
+                    }
+                    let action = result.action.clone();
+                    self.shutdown_engine();
+                    return Effect::LaunchAndExit(action);
+                }
+                self.shutdown_engine();
+                Effect::Exit
+            }
+
+            Action::Exit => {
+                self.shutdown_engine();
+                Effect::Exit
+            }
+
+            Action::EngineReady(kernel) => {
+                self.engine = Some(kernel);
+                Effect::TriggerSearch(self.query.clone())
+            }
+
+            Action::EngineInitFailed(msg) => {
+                self.error = Some(msg);
+                Effect::None
+            }
+
+            Action::ResultsReady { epoch, results } => {
+                if epoch == self.search_epoch {
+                    self.results = results;
+                }
+                Effect::None
+            }
+        }
+    }
+
+    pub fn query(&self) -> &str {
+        &self.query
+    }
+
+    pub fn results(&self) -> &[SearchResult] {
+        &self.results
+    }
+
+    pub fn selected(&self) -> usize {
+        self.selected
+    }
+
+    pub fn cfg(&self) -> &AppearanceCfg {
+        &self.cfg
+    }
+
+    pub fn error(&self) -> Option<&str> {
+        self.error.as_deref()
+    }
+
+    pub fn is_loading(&self) -> bool {
+        self.engine.is_none() && self.error.is_none()
+    }
+
+    pub fn engine(&self) -> Option<&Arc<Kernel>> {
+        self.engine.as_ref()
+    }
+
+    pub fn launcher(&self) -> &Arc<dyn AppLauncher> {
+        &self.launcher
+    }
+
+    pub fn search_epoch(&self) -> u64 {
+        self.search_epoch
+    }
+
+    fn shutdown_engine(&self) {
+        if let Some(engine) = &self.engine {
+            engine.shutdown();
+        }
+    }
+}

crates/k-launcher-ui-core/tests/state.rs

@@ -0,0 +1,158 @@
+use std::sync::Arc;
+
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::AppLauncher;
+use k_launcher_domain::*;
+use k_launcher_kernel::Kernel;
+use k_launcher_ui_core::{Action, Effect, LauncherState};
+
+struct NoopLauncher;
+
+impl AppLauncher for NoopLauncher {
+    fn execute(&self, _action: &LaunchAction) {}
+}
+
+fn make_state() -> LauncherState {
+    LauncherState::new(Arc::new(NoopLauncher), AppearanceCfg::default(), 50)
+}
+
+fn make_result(id: &str) -> SearchResult {
+    SearchResult {
+        id: ResultId::new(id),
+        title: ResultTitle::new(id),
+        description: None,
+        icon: None,
+        score: Score::new(100),
+        action: LaunchAction::CopyToClipboard(id.to_string()),
+    }
+}
+
+fn make_state_with_engine() -> LauncherState {
+    let kernel = Arc::new(Kernel::new(vec![], 10));
+    let mut state = make_state();
+    let _ = state.handle(Action::EngineReady(kernel));
+    state
+}
+
+#[test]
+fn move_down_clamps_to_last_result() {
+    let mut state = make_state();
+    state.handle(Action::ResultsReady {
+        epoch: 0,
+        results: vec![make_result("a"), make_result("b"), make_result("c")],
+    });
+
+    state.handle(Action::MoveDown);
+    state.handle(Action::MoveDown);
+    state.handle(Action::MoveDown);
+    state.handle(Action::MoveDown);
+
+    assert_eq!(state.selected(), 2);
+}
+
+#[test]
+fn move_up_does_not_go_below_zero() {
+    let mut state = make_state();
+    state.handle(Action::ResultsReady {
+        epoch: 0,
+        results: vec![make_result("a"), make_result("b")],
+    });
+
+    state.handle(Action::MoveUp);
+    state.handle(Action::MoveUp);
+
+    assert_eq!(state.selected(), 0);
+}
+
+#[test]
+fn query_changed_resets_selected() {
+    let mut state = make_state_with_engine();
+    state.handle(Action::ResultsReady {
+        epoch: state.search_epoch(),
+        results: vec![make_result("a"), make_result("b"), make_result("c")],
+    });
+    state.handle(Action::MoveDown);
+    state.handle(Action::MoveDown);
+    assert_eq!(state.selected(), 2);
+
+    state.handle(Action::QueryChanged("new".to_string()));
+    assert_eq!(state.selected(), 0);
+}
+
+#[test]
+fn engine_ready_returns_trigger_search() {
+    let mut state = make_state();
+    let kernel = Arc::new(Kernel::new(vec![], 10));
+    let effect = state.handle(Action::EngineReady(kernel));
+
+    assert!(matches!(effect, Effect::TriggerSearch(_)));
+}
+
+#[test]
+fn launch_selected_with_no_results_returns_exit() {
+    let mut state = make_state_with_engine();
+    let effect = state.handle(Action::LaunchSelected);
+
+    assert!(matches!(effect, Effect::Exit));
+}
+
+#[test]
+fn results_ready_with_wrong_epoch_is_ignored() {
+    let mut state = make_state_with_engine();
+    let current_epoch = state.search_epoch();
+
+    state.handle(Action::ResultsReady {
+        epoch: current_epoch + 999,
+        results: vec![make_result("stale")],
+    });
+
+    assert!(state.results().is_empty());
+}
+
+#[test]
+fn query_changed_without_engine_returns_none() {
+    let mut state = make_state();
+    let effect = state.handle(Action::QueryChanged("hello".to_string()));
+
+    assert!(matches!(effect, Effect::None));
+    assert_eq!(state.query(), "hello");
+}
+
+#[test]
+fn query_changed_with_engine_returns_search_after_debounce() {
+    let mut state = make_state_with_engine();
+    let effect = state.handle(Action::QueryChanged("test".to_string()));
+
+    match effect {
+        Effect::SearchAfterDebounce {
+            query,
+            debounce_ms,
+            epoch,
+        } => {
+            assert_eq!(query, "test");
+            assert_eq!(debounce_ms, 50);
+            assert_eq!(epoch, state.search_epoch());
+        }
+        _ => panic!("expected SearchAfterDebounce"),
+    }
+}
+
+#[test]
+fn launch_selected_with_results_returns_launch_and_exit() {
+    let mut state = make_state_with_engine();
+    state.handle(Action::ResultsReady {
+        epoch: state.search_epoch(),
+        results: vec![make_result("app1")],
+    });
+
+    let effect = state.handle(Action::LaunchSelected);
+    assert!(matches!(effect, Effect::LaunchAndExit(_)));
+}
+
+#[test]
+fn engine_init_failed_sets_error() {
+    let mut state = make_state();
+    state.handle(Action::EngineInitFailed("boom".to_string()));
+
+    assert_eq!(state.error(), Some("boom"));
+}

crates/k-launcher-ui-egui/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k-launcher-ui-egui"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -10,6 +10,9 @@ path = "src/lib.rs"
 [dependencies]
 eframe = { version = "0.31", default-features = false, features = ["default_fonts", "wayland", "x11", "glow"] }
 egui = "0.31"
-k-launcher-config = { path = "../k-launcher-config" }
-k-launcher-kernel = { path = "../k-launcher-kernel" }
+k-launcher-config = { workspace = true }
+k-launcher-domain = { workspace = true }
+k-launcher-kernel = { workspace = true }
+k-launcher-ui-core = { workspace = true }
 tokio = { workspace = true }
+tracing = { workspace = true }

crates/k-launcher-ui-egui/src/app.rs

@@ -1,169 +1,153 @@
 use std::sync::{Arc, mpsc};
 
-use egui::{Color32, Key, ViewportCommand};
-use k_launcher_kernel::{AppLauncher, SearchEngine, SearchResult};
+use egui::ViewportCommand;
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::AppLauncher;
+use k_launcher_domain::SearchResult;
+use k_launcher_kernel::Kernel;
+use k_launcher_ui_core::{Action, Effect, LauncherState};
 
-const BG: Color32 = Color32::from_rgba_premultiplied(20, 20, 30, 230);
-const BORDER_COLOR: Color32 = Color32::from_rgb(229, 125, 33);
-const SELECTED_BG: Color32 = Color32::from_rgba_premultiplied(0, 100, 140, 180);
-const DIM_TEXT: Color32 = Color32::from_rgb(180, 185, 200);
+use crate::input::{InputAction, process_input};
+use crate::render;
+use crate::style;
 
 pub struct KLauncherApp {
-    engine: Arc<dyn SearchEngine>,
-    launcher: Arc<dyn AppLauncher>,
-    query: String,
-    results: Vec<SearchResult>,
-    selected: usize,
+    pub(crate) inner: LauncherState,
     rt: tokio::runtime::Handle,
     result_tx: mpsc::SyncSender<Vec<SearchResult>>,
-    result_rx: mpsc::Receiver<Vec<SearchResult>>,
+    pub(crate) result_rx: mpsc::Receiver<Vec<SearchResult>>,
 }
 
 impl KLauncherApp {
     fn new(
-        engine: Arc<dyn SearchEngine>,
+        engine: Arc<Kernel>,
         launcher: Arc<dyn AppLauncher>,
         rt: tokio::runtime::Handle,
+        cfg: AppearanceCfg,
     ) -> Self {
-        let (result_tx, result_rx) = mpsc::sync_channel(4);
-        Self {
-            engine,
-            launcher,
-            query: String::new(),
-            results: vec![],
-            selected: 0,
+        const RESULT_CHANNEL_CAPACITY: usize = 4;
+        let (result_tx, result_rx) = mpsc::sync_channel(RESULT_CHANNEL_CAPACITY);
+        let mut inner = LauncherState::new(launcher, cfg, 0);
+
+        let effect = inner.handle(Action::EngineReady(engine));
+
+        let app = Self {
+            inner,
             rt,
             result_tx,
             result_rx,
-        }
+        };
+
+        app.execute_effect(effect);
+        app
     }
 
     fn trigger_search(&self, query: String) {
-        let engine = self.engine.clone();
+        let Some(engine) = self.inner.engine().cloned() else {
+            return;
+        };
         let tx = self.result_tx.clone();
         self.rt.spawn(async move {
             let results = engine.search(&query).await;
-            let _ = tx.send(results);
+            if let Err(e) = tx.send(results) {
+                tracing::warn!("search result channel closed: {e}");
+            }
         });
     }
+
+    fn poll_search_results(&mut self) {
+        if let Ok(results) = self.result_rx.try_recv() {
+            self.inner.handle(Action::ResultsReady {
+                epoch: self.inner.search_epoch(),
+                results,
+            });
+        }
+    }
+
+    fn execute_effect(&self, effect: Effect) {
+        match effect {
+            Effect::TriggerSearch(q) => self.trigger_search(q),
+            Effect::SearchAfterDebounce { query, .. } => self.trigger_search(query),
+            _ => {}
+        }
+    }
+
+    fn handle_action(&mut self, action: Action, ctx: &egui::Context) {
+        let effect = self.inner.handle(action);
+        match effect {
+            Effect::LaunchAndExit(action) => {
+                self.inner.launcher().execute(&action);
+                ctx.send_viewport_cmd(ViewportCommand::Close);
+            }
+            Effect::Exit => {
+                ctx.send_viewport_cmd(ViewportCommand::Close);
+            }
+            other => self.execute_effect(other),
+        }
+    }
+
+    fn render_panel(&mut self, ctx: &egui::Context) {
+        let cfg = self.inner.cfg().clone();
+        egui::CentralPanel::default()
+            .frame(style::outer_frame(&cfg))
+            .show(ctx, |ui| {
+                let query = self.inner.query().to_string();
+                let mut query_buf = query;
+                let response = render::render_search_bar(ui, &mut query_buf, &cfg);
+
+                if response.changed() {
+                    self.handle_action(Action::QueryChanged(query_buf), ctx);
+                }
+
+                response.request_focus();
+                ui.add_space(8.0);
+
+                if self.inner.is_loading() {
+                    render::render_loading_state(ui, &cfg);
+                    return;
+                }
+
+                if self.inner.results().is_empty() && !self.inner.query().is_empty() {
+                    render::render_empty_state(ui, &cfg);
+                    return;
+                }
+
+                render::render_result_list(ui, self.inner.results(), self.inner.selected(), &cfg);
+            });
+    }
 }
 
 impl eframe::App for KLauncherApp {
     fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        if let Ok(results) = self.result_rx.try_recv() {
-            self.results = results;
-        }
+        self.poll_search_results();
 
-        let mut close = false;
-        let mut launch_selected = false;
-
-        ctx.input(|i| {
-            if i.key_pressed(Key::Escape) {
-                close = true;
-            }
-            if i.key_pressed(Key::Enter) {
-                launch_selected = true;
-            }
-            if i.key_pressed(Key::ArrowDown) {
-                let len = self.results.len();
-                if len > 0 {
-                    self.selected = (self.selected + 1).min(len - 1);
-                }
-            }
-            if i.key_pressed(Key::ArrowUp) && self.selected > 0 {
-                self.selected -= 1;
-            }
-        });
-
-        if close {
-            ctx.send_viewport_cmd(ViewportCommand::Close);
-            return;
-        }
-
-        if launch_selected {
-            if let Some(result) = self.results.get(self.selected) {
-                self.engine.on_selected(&result.id);
-                self.launcher.execute(&result.action);
-            }
-            ctx.send_viewport_cmd(ViewportCommand::Close);
-            return;
-        }
-
-        let frame = egui::Frame::new()
-            .fill(BG)
-            .stroke(egui::Stroke::new(1.0, BORDER_COLOR))
-            .inner_margin(egui::Margin::same(12))
-            .corner_radius(egui::CornerRadius::same(8));
-
-        egui::CentralPanel::default().frame(frame).show(ctx, |ui| {
-            let response = ui.add_sized(
-                [ui.available_width(), 36.0],
-                egui::TextEdit::singleline(&mut self.query)
-                    .hint_text("Search...")
-                    .font(egui::TextStyle::Heading),
-            );
-
-            if response.changed() {
-                self.selected = 0;
-                self.trigger_search(self.query.clone());
-            }
-
-            response.request_focus();
-
-            ui.add_space(8.0);
-
-            if self.results.is_empty() && !self.query.is_empty() {
-                ui.add_space(20.0);
-                ui.with_layout(egui::Layout::top_down(egui::Align::Center), |ui| {
-                    ui.colored_label(DIM_TEXT, "No results");
-                });
+        match process_input(ctx) {
+            InputAction::Close => {
+                self.handle_action(Action::Exit, ctx);
                 return;
             }
+            InputAction::LaunchSelected => {
+                self.handle_action(Action::LaunchSelected, ctx);
+                return;
+            }
+            InputAction::MoveDown => {
+                self.inner.handle(Action::MoveDown);
+            }
+            InputAction::MoveUp => {
+                self.inner.handle(Action::MoveUp);
+            }
+            InputAction::None => {}
+        }
 
-            egui::ScrollArea::vertical().show(ui, |ui| {
-                ui.set_width(ui.available_width());
-                for (i, result) in self.results.iter().enumerate() {
-                    let is_selected = i == self.selected;
-                    let bg = if is_selected {
-                        SELECTED_BG
-                    } else {
-                        Color32::TRANSPARENT
-                    };
-
-                    let row_frame = egui::Frame::new()
-                        .fill(bg)
-                        .inner_margin(egui::Margin {
-                            left: 8,
-                            right: 8,
-                            top: 6,
-                            bottom: 6,
-                        })
-                        .corner_radius(egui::CornerRadius::same(4));
-
-                    row_frame.show(ui, |ui| {
-                        ui.set_width(ui.available_width());
-                        ui.horizontal(|ui| {
-                            ui.add_space(8.0);
-                            ui.vertical(|ui| {
-                                ui.label(result.title.as_str());
-                                if let Some(desc) = &result.description {
-                                    ui.colored_label(DIM_TEXT, desc);
-                                }
-                            });
-                        });
-                    });
-
-                    ui.add_space(2.0);
-                }
-            });
-        });
+        self.render_panel(ctx);
     }
 }
 
 pub fn run(
-    engine: Arc<dyn SearchEngine>,
+    engine: Arc<Kernel>,
     launcher: Arc<dyn AppLauncher>,
     window_cfg: &k_launcher_config::WindowCfg,
+    appearance_cfg: AppearanceCfg,
 ) -> Result<(), eframe::Error> {
     let rt = tokio::runtime::Runtime::new().expect("tokio runtime");
     let handle = rt.handle().clone();
@@ -179,8 +163,15 @@ pub fn run(
     };
 
     eframe::run_native(
-        "K-Launcher",
+        k_launcher_domain::constants::APP_TITLE,
         options,
-        Box::new(move |_cc| Ok(Box::new(KLauncherApp::new(engine, launcher, handle)))),
+        Box::new(move |_cc| {
+            Ok(Box::new(KLauncherApp::new(
+                engine,
+                launcher,
+                handle,
+                appearance_cfg,
+            )))
+        }),
     )
 }

crates/k-launcher-ui-egui/src/input.rs

@@ -0,0 +1,25 @@
+use egui::Key;
+
+pub enum InputAction {
+    Close,
+    LaunchSelected,
+    MoveDown,
+    MoveUp,
+    None,
+}
+
+pub fn process_input(ctx: &egui::Context) -> InputAction {
+    ctx.input(|i| {
+        if i.key_pressed(Key::Escape) {
+            InputAction::Close
+        } else if i.key_pressed(Key::Enter) {
+            InputAction::LaunchSelected
+        } else if i.key_pressed(Key::ArrowDown) {
+            InputAction::MoveDown
+        } else if i.key_pressed(Key::ArrowUp) {
+            InputAction::MoveUp
+        } else {
+            InputAction::None
+        }
+    })
+}

crates/k-launcher-ui-egui/src/lib.rs

@@ -1,13 +1,19 @@
 mod app;
+mod input;
+mod render;
+mod style;
 
 use std::sync::Arc;
 
-use k_launcher_kernel::{AppLauncher, SearchEngine};
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::AppLauncher;
+use k_launcher_kernel::Kernel;
 
 pub fn run(
-    engine: Arc<dyn SearchEngine>,
+    engine: Arc<Kernel>,
     launcher: Arc<dyn AppLauncher>,
     window_cfg: &k_launcher_config::WindowCfg,
-) -> Result<(), eframe::Error> {
-    app::run(engine, launcher, window_cfg)
+    appearance_cfg: AppearanceCfg,
+) -> Result<(), String> {
+    app::run(engine, launcher, window_cfg, appearance_cfg).map_err(|e| e.to_string())
 }

crates/k-launcher-ui-egui/src/render.rs

@@ -0,0 +1,58 @@
+use egui::Ui;
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::SearchResult;
+
+use crate::style::{self, ROW_SPACING, SEARCH_BAR_HEIGHT, to_color32};
+
+pub fn render_search_bar(ui: &mut Ui, query: &mut String, cfg: &AppearanceCfg) -> egui::Response {
+    ui.add_sized(
+        [ui.available_width(), SEARCH_BAR_HEIGHT],
+        egui::TextEdit::singleline(query)
+            .hint_text(&cfg.placeholder)
+            .font(egui::TextStyle::Heading),
+    )
+}
+
+pub fn render_loading_state(ui: &mut Ui, cfg: &AppearanceCfg) {
+    ui.add_space(20.0);
+    ui.with_layout(egui::Layout::top_down(egui::Align::Center), |ui| {
+        ui.colored_label(to_color32(&cfg.no_results_rgba), "Loading...");
+    });
+}
+
+pub fn render_empty_state(ui: &mut Ui, cfg: &AppearanceCfg) {
+    ui.add_space(20.0);
+    ui.with_layout(egui::Layout::top_down(egui::Align::Center), |ui| {
+        ui.colored_label(to_color32(&cfg.no_results_rgba), "No results");
+    });
+}
+
+pub fn render_result_list(
+    ui: &mut Ui,
+    results: &[SearchResult],
+    selected: usize,
+    cfg: &AppearanceCfg,
+) {
+    egui::ScrollArea::vertical().show(ui, |ui| {
+        ui.set_width(ui.available_width());
+        for (i, result) in results.iter().enumerate() {
+            render_result_row(ui, result, i == selected, cfg);
+            ui.add_space(ROW_SPACING);
+        }
+    });
+}
+
+fn render_result_row(ui: &mut Ui, result: &SearchResult, is_selected: bool, cfg: &AppearanceCfg) {
+    style::result_row_frame(is_selected, cfg).show(ui, |ui| {
+        ui.set_width(ui.available_width());
+        ui.horizontal(|ui| {
+            ui.add_space(8.0);
+            ui.vertical(|ui| {
+                ui.label(result.title.as_str());
+                if let Some(desc) = &result.description {
+                    ui.colored_label(to_color32(&cfg.description_rgba), desc.as_ref());
+                }
+            });
+        });
+    });
+}

crates/k-launcher-ui-egui/src/style.rs

@@ -0,0 +1,39 @@
+use egui::{Color32, CornerRadius, Frame, Margin, Stroke};
+use k_launcher_config::AppearanceCfg;
+
+pub const SEARCH_BAR_HEIGHT: f32 = 36.0;
+pub const CONTENT_MARGIN: i8 = 12;
+pub const ROW_SPACING: f32 = 2.0;
+
+const ROW_PADDING_VERTICAL: i8 = 6;
+const ROW_PADDING_HORIZONTAL: i8 = 8;
+
+pub(crate) fn to_color32(c: &k_launcher_config::Rgba) -> Color32 {
+    Color32::from_rgba_unmultiplied(c.red_u8(), c.green_u8(), c.blue_u8(), c.alpha_byte())
+}
+
+pub fn outer_frame(cfg: &AppearanceCfg) -> Frame {
+    Frame::new()
+        .fill(to_color32(&cfg.background_rgba))
+        .stroke(Stroke::new(cfg.border_width, to_color32(&cfg.border_rgba)))
+        .inner_margin(Margin::same(CONTENT_MARGIN))
+        .corner_radius(CornerRadius::same(cfg.border_radius as u8))
+}
+
+pub fn result_row_frame(is_selected: bool, cfg: &AppearanceCfg) -> Frame {
+    let bg = if is_selected {
+        to_color32(&cfg.selected_row_rgba)
+    } else {
+        to_color32(&cfg.unselected_row_rgba)
+    };
+
+    Frame::new()
+        .fill(bg)
+        .inner_margin(Margin {
+            left: ROW_PADDING_HORIZONTAL,
+            right: ROW_PADDING_HORIZONTAL,
+            top: ROW_PADDING_VERTICAL,
+            bottom: ROW_PADDING_VERTICAL,
+        })
+        .corner_radius(CornerRadius::same(cfg.row_radius as u8))
+}

crates/k-launcher-ui/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k-launcher-ui"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -8,8 +8,10 @@ name = "k_launcher_ui"
 path = "src/lib.rs"
 
 [dependencies]
-iced = { workspace = true }
-k-launcher-config = { path = "../k-launcher-config" }
-k-launcher-kernel = { path = "../k-launcher-kernel" }
-k-launcher-os-bridge = { path = "../k-launcher-os-bridge" }
+iced = { version = "0.14", default-features = false, features = ["image", "svg", "tokio", "tiny-skia", "wayland", "x11", "crisp", "web-colors", "thread-pool"] }
+k-launcher-config = { workspace = true }
+k-launcher-domain = { workspace = true }
+k-launcher-kernel = { workspace = true }
+k-launcher-os-bridge = { workspace = true }
+k-launcher-ui-core = { workspace = true }
 tokio = { workspace = true }

crates/k-launcher-ui/src/app.rs

@@ -1,20 +1,18 @@
 use std::sync::Arc;
 
-use iced::{
-    Border, Color, Element, Length, Size, Subscription, Task, event,
-    keyboard::{Event as KeyEvent, Key, key::Named},
-    widget::{Space, column, container, image, row, scrollable, svg, text, text_input},
-    window,
-};
+use iced::{Size, Subscription, Task, event, keyboard::Event as KeyEvent, window};
 
 use k_launcher_config::AppearanceCfg;
-use k_launcher_kernel::{AppLauncher, NullSearchEngine, SearchEngine, SearchResult};
+use k_launcher_domain::AppLauncher;
+use k_launcher_domain::SearchResult;
+use k_launcher_kernel::Kernel;
+use k_launcher_ui_core::LauncherState;
 
-static INPUT_ID: std::sync::LazyLock<iced::widget::Id> =
+pub(crate) static INPUT_ID: std::sync::LazyLock<iced::widget::Id> =
     std::sync::LazyLock::new(|| iced::widget::Id::new("search"));
 
 #[derive(Clone)]
-pub(crate) struct EngineHandle(Arc<dyn SearchEngine>);
+pub(crate) struct EngineHandle(pub(crate) Arc<Kernel>);
 
 impl std::fmt::Debug for EngineHandle {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -22,250 +20,22 @@ impl std::fmt::Debug for EngineHandle {
     }
 }
 
-fn rgba(c: &[f32; 4]) -> Color {
-    Color::from_rgba8(c[0] as u8, c[1] as u8, c[2] as u8, c[3])
-}
-
-pub struct KLauncherApp {
-    engine: Arc<dyn SearchEngine>,
-    launcher: Arc<dyn AppLauncher>,
-    query: String,
-    results: Arc<Vec<SearchResult>>,
-    selected: usize,
-    cfg: AppearanceCfg,
-    error: Option<String>,
-    search_epoch: u64,
-}
-
-impl KLauncherApp {
-    fn new(
-        engine: Arc<dyn SearchEngine>,
-        launcher: Arc<dyn AppLauncher>,
-        cfg: AppearanceCfg,
-    ) -> Self {
-        Self {
-            engine,
-            launcher,
-            query: String::new(),
-            results: Arc::new(vec![]),
-            selected: 0,
-            cfg,
-            error: None,
-            search_epoch: 0,
-        }
-    }
+pub(crate) struct KLauncherApp {
+    pub(crate) inner: LauncherState,
 }
 
 #[derive(Debug, Clone)]
-pub enum Message {
+pub(crate) enum Message {
     QueryChanged(String),
-    ResultsReady(u64, Arc<Vec<SearchResult>>),
+    ResultsReady {
+        epoch: u64,
+        results: Arc<Vec<SearchResult>>,
+    },
     KeyPressed(KeyEvent),
     EngineReady(EngineHandle),
     EngineInitFailed(String),
 }
 
-fn update(state: &mut KLauncherApp, message: Message) -> Task<Message> {
-    match message {
-        Message::QueryChanged(q) => {
-            state.error = None;
-            state.query = q.clone();
-            state.selected = 0;
-            state.search_epoch += 1;
-            let epoch = state.search_epoch;
-            let engine = state.engine.clone();
-            Task::perform(
-                async move {
-                    tokio::time::sleep(std::time::Duration::from_millis(50)).await;
-                    (epoch, engine.search(&q).await)
-                },
-                |(epoch, results)| Message::ResultsReady(epoch, Arc::new(results)),
-            )
-        }
-        Message::ResultsReady(epoch, results) => {
-            if epoch == state.search_epoch {
-                state.results = results;
-            }
-            Task::none()
-        }
-        Message::EngineInitFailed(msg) => {
-            state.error = Some(msg);
-            Task::none()
-        }
-        Message::EngineReady(handle) => {
-            state.engine = handle.0;
-            if !state.query.is_empty() {
-                let q = state.query.clone();
-                return Task::done(Message::QueryChanged(q));
-            }
-            Task::none()
-        }
-        Message::KeyPressed(event) => {
-            let key = match event {
-                KeyEvent::KeyPressed { key, .. } => key,
-                _ => return Task::none(),
-            };
-            let Key::Named(named) = key else {
-                return Task::none();
-            };
-            let len = state.results.len();
-            match named {
-                Named::Escape => {
-                    std::process::exit(0);
-                }
-                Named::ArrowDown => {
-                    if len > 0 {
-                        state.selected = (state.selected + 1).min(len - 1);
-                    }
-                }
-                Named::ArrowUp => {
-                    if state.selected > 0 {
-                        state.selected -= 1;
-                    }
-                }
-                Named::Enter => {
-                    if let Some(result) = state.results.get(state.selected) {
-                        state.engine.on_selected(&result.id);
-                        state.launcher.execute(&result.action);
-                    }
-                    std::process::exit(0);
-                }
-                _ => {}
-            }
-            Task::none()
-        }
-    }
-}
-
-fn view(state: &KLauncherApp) -> Element<'_, Message> {
-    let cfg = &state.cfg;
-    let border_color = rgba(&cfg.border_rgba);
-
-    let search_bar = text_input(&cfg.placeholder, &state.query)
-        .id(INPUT_ID.clone())
-        .on_input(Message::QueryChanged)
-        .padding(12)
-        .size(cfg.search_font_size)
-        .style(|theme, _status| {
-            let mut s =
-                iced::widget::text_input::default(theme, iced::widget::text_input::Status::Active);
-            s.border = Border {
-                color: Color::TRANSPARENT,
-                width: 0.0,
-                radius: 0.0.into(),
-            };
-            s
-        });
-
-    let row_radius: f32 = cfg.row_radius;
-    let title_size: f32 = cfg.title_size;
-    let desc_size: f32 = cfg.desc_size;
-
-    let result_rows: Vec<Element<'_, Message>> = state
-        .results
-        .iter()
-        .enumerate()
-        .map(|(i, result)| {
-            let is_selected = i == state.selected;
-            let bg_color = if is_selected {
-                border_color
-            } else {
-                Color::from_rgba8(255, 255, 255, 0.07)
-            };
-            let icon_el: Element<'_, Message> = match &result.icon {
-                Some(p) if p.ends_with(".svg") => {
-                    svg(svg::Handle::from_path(p)).width(24).height(24).into()
-                }
-                Some(p) => image(image::Handle::from_path(p))
-                    .width(24)
-                    .height(24)
-                    .into(),
-                None => Space::new().width(24).height(24).into(),
-            };
-            let title_col: Element<'_, Message> = if let Some(desc) = &result.description {
-                column![
-                    text(result.title.as_str()).size(title_size),
-                    text(desc)
-                        .size(desc_size)
-                        .color(Color::from_rgba8(210, 215, 230, 1.0)),
-                ]
-                .into()
-            } else {
-                text(result.title.as_str()).size(title_size).into()
-            };
-            container(row![icon_el, title_col].spacing(8).align_y(iced::Center))
-                .width(Length::Fill)
-                .padding([6, 12])
-                .style(move |_theme| container::Style {
-                    background: Some(iced::Background::Color(bg_color)),
-                    border: Border {
-                        color: Color::TRANSPARENT,
-                        width: 0.0,
-                        radius: row_radius.into(),
-                    },
-                    ..Default::default()
-                })
-                .into()
-        })
-        .collect();
-
-    let results_list = if state.results.is_empty() && !state.query.is_empty() {
-        scrollable(
-            container(
-                text("No results")
-                    .size(title_size)
-                    .color(Color::from_rgba8(180, 180, 200, 0.5)),
-            )
-            .width(Length::Fill)
-            .align_x(iced::Center)
-            .padding([20, 0]),
-        )
-        .height(Length::Fill)
-    } else {
-        scrollable(column(result_rows).spacing(2).width(Length::Fill)).height(Length::Fill)
-    };
-
-    let maybe_error: Option<Element<'_, Message>> = state.error.as_ref().map(|msg| {
-        container(
-            text(msg.as_str())
-                .size(12.0)
-                .color(Color::from_rgba8(255, 80, 80, 1.0)),
-        )
-        .width(Length::Fill)
-        .padding([4, 12])
-        .into()
-    });
-
-    let mut content_children: Vec<Element<'_, Message>> =
-        vec![search_bar.into(), results_list.into()];
-    if let Some(err) = maybe_error {
-        content_children.push(err);
-    }
-    let content = column(content_children)
-        .spacing(8)
-        .padding(12)
-        .width(Length::Fill)
-        .height(Length::Fill);
-
-    let bg_color = rgba(&cfg.background_rgba);
-    let border_width = cfg.border_width;
-    let border_radius = cfg.border_radius;
-
-    container(content)
-        .width(Length::Fill)
-        .height(Length::Fill)
-        .style(move |_theme| container::Style {
-            background: Some(iced::Background::Color(bg_color)),
-            border: Border {
-                color: border_color,
-                width: border_width,
-                radius: border_radius.into(),
-            },
-            ..Default::default()
-        })
-        .into()
-}
-
 fn subscription(_state: &KLauncherApp) -> Subscription<Message> {
     event::listen_with(|ev, _status, _id| match ev {
         iced::Event::Keyboard(ke) => Some(Message::KeyPressed(ke)),
@@ -274,18 +44,16 @@ fn subscription(_state: &KLauncherApp) -> Subscription<Message> {
 }
 
 pub fn run(
-    engine_factory: Arc<dyn Fn() -> Arc<dyn SearchEngine> + Send + Sync>,
+    engine_factory: Arc<dyn Fn() -> Arc<Kernel> + Send + Sync>,
     launcher: Arc<dyn AppLauncher>,
     window_cfg: &k_launcher_config::WindowCfg,
     appearance_cfg: AppearanceCfg,
+    debounce_ms: u64,
 ) -> iced::Result {
     iced::application(
         move || {
-            let app = KLauncherApp::new(
-                Arc::new(NullSearchEngine),
-                launcher.clone(),
-                appearance_cfg.clone(),
-            );
+            let inner = LauncherState::new(launcher.clone(), appearance_cfg.clone(), debounce_ms);
+            let app = KLauncherApp { inner };
             let focus = iced::widget::operation::focus(INPUT_ID.clone());
             let ef = engine_factory.clone();
             let init = Task::perform(
@@ -301,10 +69,10 @@ pub fn run(
             );
             (app, Task::batch([focus, init]))
         },
-        update,
-        view,
+        crate::update::update,
+        crate::view::view,
     )
-    .title("K-Launcher")
+    .title(k_launcher_domain::constants::APP_TITLE)
     .subscription(subscription)
     .window(window::Settings {
         size: Size::new(window_cfg.width, window_cfg.height),

crates/k-launcher-ui/src/lib.rs

@@ -1,15 +1,27 @@
 mod app;
+mod style;
+mod update;
+mod view;
 
 use std::sync::Arc;
 
-use k_launcher_config::{AppearanceCfg, WindowCfg};
-use k_launcher_kernel::{AppLauncher, SearchEngine};
+use k_launcher_config::{AppearanceCfg, SearchCfg, WindowCfg};
+use k_launcher_domain::AppLauncher;
+use k_launcher_kernel::Kernel;
 
 pub fn run(
-    engine_factory: Arc<dyn Fn() -> Arc<dyn SearchEngine> + Send + Sync>,
+    engine_factory: Arc<dyn Fn() -> Arc<Kernel> + Send + Sync>,
     launcher: Arc<dyn AppLauncher>,
     window_cfg: &WindowCfg,
     appearance_cfg: AppearanceCfg,
-) -> iced::Result {
-    app::run(engine_factory, launcher, window_cfg, appearance_cfg)
+    search_cfg: &SearchCfg,
+) -> Result<(), String> {
+    app::run(
+        engine_factory,
+        launcher,
+        window_cfg,
+        appearance_cfg,
+        search_cfg.debounce_ms,
+    )
+    .map_err(|e| e.to_string())
 }

crates/k-launcher-ui/src/style.rs

@@ -0,0 +1,60 @@
+use iced::{Border, Color, widget::container, widget::text_input};
+
+// ---- layout constants ----
+pub(crate) const ROW_PADDING: [u16; 2] = [6, 12];
+pub(crate) const ROW_SPACING: f32 = 2.0;
+pub(crate) const CONTENT_PADDING: u16 = 12;
+pub(crate) const CONTENT_SPACING: f32 = 8.0;
+pub(crate) const EMPTY_STATE_PADDING: [u16; 2] = [20, 0];
+pub(crate) const ERROR_FONT_SIZE: f32 = 12.0;
+pub(crate) const ERROR_PADDING: [u16; 2] = [4, 12];
+
+// ---- helpers ----
+pub(crate) fn rgba(c: &k_launcher_config::Rgba) -> Color {
+    Color::from_rgba8(c.red_u8(), c.green_u8(), c.blue_u8(), c.alpha())
+}
+
+pub(crate) fn search_input_style(
+    theme: &iced::Theme,
+    _status: text_input::Status,
+) -> text_input::Style {
+    let mut s = text_input::default(theme, text_input::Status::Active);
+    s.border = Border {
+        color: Color::TRANSPARENT,
+        width: 0.0,
+        radius: 0.0.into(),
+    };
+    s
+}
+
+pub(crate) fn result_row_style(
+    bg_color: Color,
+    row_radius: f32,
+) -> impl Fn(&iced::Theme) -> container::Style {
+    move |_theme| container::Style {
+        background: Some(iced::Background::Color(bg_color)),
+        border: Border {
+            color: Color::TRANSPARENT,
+            width: 0.0,
+            radius: row_radius.into(),
+        },
+        ..Default::default()
+    }
+}
+
+pub(crate) fn outer_container_style(
+    bg: Color,
+    border_color: Color,
+    width: f32,
+    radius: f32,
+) -> impl Fn(&iced::Theme) -> container::Style {
+    move |_theme| container::Style {
+        background: Some(iced::Background::Color(bg)),
+        border: Border {
+            color: border_color,
+            width,
+            radius: radius.into(),
+        },
+        ..Default::default()
+    }
+}

crates/k-launcher-ui/src/update.rs

@@ -0,0 +1,77 @@
+use std::sync::Arc;
+
+use iced::{
+    Task,
+    keyboard::{Event as KeyEvent, Key, key::Named},
+};
+
+use k_launcher_ui_core::{Action, Effect};
+
+use crate::app::{KLauncherApp, Message};
+
+pub(crate) fn update(state: &mut KLauncherApp, message: Message) -> Task<Message> {
+    let action = match message {
+        Message::QueryChanged(q) => Action::QueryChanged(q),
+        Message::ResultsReady { epoch, results } => {
+            let results = Arc::try_unwrap(results).unwrap_or_else(|arc| (*arc).clone());
+            Action::ResultsReady { epoch, results }
+        }
+        Message::EngineInitFailed(msg) => Action::EngineInitFailed(msg),
+        Message::EngineReady(handle) => Action::EngineReady(handle.0),
+        Message::KeyPressed(event) => match map_key_event(event) {
+            Some(a) => a,
+            None => return Task::none(),
+        },
+    };
+
+    let effect = state.inner.handle(action);
+    execute_effect(state, effect)
+}
+
+fn map_key_event(event: KeyEvent) -> Option<Action> {
+    let key = match event {
+        KeyEvent::KeyPressed { key, .. } => key,
+        _ => return None,
+    };
+    let Key::Named(named) = key else {
+        return None;
+    };
+    match named {
+        Named::Escape => Some(Action::Exit),
+        Named::ArrowDown => Some(Action::MoveDown),
+        Named::ArrowUp => Some(Action::MoveUp),
+        Named::Enter => Some(Action::LaunchSelected),
+        _ => None,
+    }
+}
+
+fn execute_effect(state: &KLauncherApp, effect: Effect) -> Task<Message> {
+    match effect {
+        Effect::SearchAfterDebounce {
+            query,
+            debounce_ms,
+            epoch,
+        } => {
+            let Some(engine) = state.inner.engine().cloned() else {
+                return Task::none();
+            };
+            Task::perform(
+                async move {
+                    tokio::time::sleep(std::time::Duration::from_millis(debounce_ms)).await;
+                    (epoch, engine.search(&query).await)
+                },
+                |(epoch, results)| Message::ResultsReady {
+                    epoch,
+                    results: Arc::new(results),
+                },
+            )
+        }
+        Effect::LaunchAndExit(action) => {
+            state.inner.launcher().execute(&action);
+            iced::exit()
+        }
+        Effect::Exit => iced::exit(),
+        Effect::TriggerSearch(q) => Task::done(Message::QueryChanged(q)),
+        Effect::None => Task::none(),
+    }
+}

crates/k-launcher-ui/src/view.rs

@@ -0,0 +1,164 @@
+use std::sync::Arc;
+
+use iced::{
+    Element, Length,
+    widget::{Space, column, container, image, row, scrollable, svg, text, text_input},
+};
+
+use k_launcher_config::AppearanceCfg;
+use k_launcher_domain::SearchResult;
+
+use crate::app::{INPUT_ID, KLauncherApp, Message};
+use crate::style;
+
+pub(crate) fn view(state: &KLauncherApp) -> Element<'_, Message> {
+    let cfg = state.inner.cfg();
+
+    let mut content_children: Vec<Element<'_, Message>> =
+        vec![search_bar(cfg, state.inner.query()), results_section(state)];
+    if let Some(err) = state.inner.error() {
+        content_children.push(error_bar(err, cfg));
+    }
+
+    let content = column(content_children)
+        .spacing(style::CONTENT_SPACING)
+        .padding(style::CONTENT_PADDING)
+        .width(Length::Fill)
+        .height(Length::Fill);
+
+    container(content)
+        .width(Length::Fill)
+        .height(Length::Fill)
+        .style(style::outer_container_style(
+            style::rgba(&cfg.background_rgba),
+            style::rgba(&cfg.border_rgba),
+            cfg.border_width,
+            cfg.border_radius,
+        ))
+        .into()
+}
+
+fn search_bar<'a>(cfg: &'a AppearanceCfg, query: &'a str) -> Element<'a, Message> {
+    text_input(&cfg.placeholder, query)
+        .id(INPUT_ID.clone())
+        .on_input(Message::QueryChanged)
+        .padding(style::CONTENT_PADDING)
+        .size(cfg.search_font_size)
+        .style(style::search_input_style)
+        .into()
+}
+
+fn results_section<'a>(state: &'a KLauncherApp) -> Element<'a, Message> {
+    if state.inner.is_loading() {
+        loading_state(state.inner.cfg())
+    } else if state.inner.results().is_empty() && !state.inner.query().is_empty() {
+        empty_state(state.inner.cfg())
+    } else {
+        result_list(state)
+    }
+}
+
+fn loading_state(cfg: &AppearanceCfg) -> Element<'static, Message> {
+    container(
+        text("Loading...")
+            .size(cfg.title_size)
+            .color(style::rgba(&cfg.no_results_rgba)),
+    )
+    .width(Length::Fill)
+    .align_x(iced::Center)
+    .padding(style::EMPTY_STATE_PADDING)
+    .into()
+}
+
+fn empty_state(cfg: &AppearanceCfg) -> Element<'static, Message> {
+    scrollable(
+        container(
+            text("No results")
+                .size(cfg.title_size)
+                .color(style::rgba(&cfg.no_results_rgba)),
+        )
+        .width(Length::Fill)
+        .align_x(iced::Center)
+        .padding(style::EMPTY_STATE_PADDING),
+    )
+    .height(Length::Fill)
+    .into()
+}
+
+fn result_list<'a>(state: &'a KLauncherApp) -> Element<'a, Message> {
+    let cfg = state.inner.cfg();
+    let selected = state.inner.selected();
+    let rows: Vec<Element<'_, Message>> = state
+        .inner
+        .results()
+        .iter()
+        .enumerate()
+        .map(|(i, result)| result_row(result, i == selected, cfg))
+        .collect();
+
+    scrollable(column(rows).spacing(style::ROW_SPACING).width(Length::Fill))
+        .height(Length::Fill)
+        .into()
+}
+
+fn result_row<'a>(
+    result: &'a SearchResult,
+    is_selected: bool,
+    cfg: &AppearanceCfg,
+) -> Element<'a, Message> {
+    let bg_color = if is_selected {
+        style::rgba(&cfg.selected_row_rgba)
+    } else {
+        style::rgba(&cfg.unselected_row_rgba)
+    };
+
+    container(
+        row![result_icon(&result.icon, cfg), title_column(result, cfg)]
+            .spacing(style::CONTENT_SPACING)
+            .align_y(iced::Center),
+    )
+    .width(Length::Fill)
+    .padding(style::ROW_PADDING)
+    .style(style::result_row_style(bg_color, cfg.row_radius))
+    .into()
+}
+
+fn result_icon<'a>(icon_path: &'a Option<Arc<str>>, cfg: &AppearanceCfg) -> Element<'a, Message> {
+    let size = cfg.icon_size;
+    match icon_path {
+        Some(p) if p.ends_with(".svg") => svg(svg::Handle::from_path(p.as_ref()))
+            .width(size)
+            .height(size)
+            .into(),
+        Some(p) => image(image::Handle::from_path(p.as_ref()))
+            .width(size)
+            .height(size)
+            .into(),
+        None => Space::new().width(size).height(size).into(),
+    }
+}
+
+fn title_column<'a>(result: &'a SearchResult, cfg: &AppearanceCfg) -> Element<'a, Message> {
+    if let Some(desc) = &result.description {
+        column![
+            text(result.title.as_str()).size(cfg.title_size),
+            text(desc.as_ref())
+                .size(cfg.desc_size)
+                .color(style::rgba(&cfg.description_rgba)),
+        ]
+        .into()
+    } else {
+        text(result.title.as_str()).size(cfg.title_size).into()
+    }
+}
+
+fn error_bar<'a>(msg: &'a str, cfg: &AppearanceCfg) -> Element<'a, Message> {
+    container(
+        text(msg)
+            .size(style::ERROR_FONT_SIZE)
+            .color(style::rgba(&cfg.error_rgba)),
+    )
+    .width(Length::Fill)
+    .padding(style::ERROR_PADDING)
+    .into()
+}

crates/k-launcher/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k-launcher"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 default-run = "k-launcher"
 
@@ -23,19 +23,21 @@ required-features = ["egui"]
 egui = ["dep:k-launcher-ui-egui"]
 
 [dependencies]
-iced = { workspace = true }
-k-launcher-config = { path = "../k-launcher-config" }
-k-launcher-kernel = { path = "../k-launcher-kernel" }
-k-launcher-plugin-host = { path = "../k-launcher-plugin-host" }
-k-launcher-os-bridge = { path = "../k-launcher-os-bridge" }
-k-launcher-ui = { path = "../k-launcher-ui" }
-k-launcher-ui-egui = { path = "../k-launcher-ui-egui", optional = true }
-plugin-apps = { path = "../plugins/plugin-apps" }
-plugin-calc = { path = "../plugins/plugin-calc" }
-plugin-cmd = { path = "../plugins/plugin-cmd" }
-plugin-files = { path = "../plugins/plugin-files" }
+k-launcher-config = { workspace = true }
+k-launcher-kernel = { workspace = true }
+k-launcher-domain = { workspace = true }
+k-launcher-plugin-host = { workspace = true }
+k-launcher-os-bridge = { workspace = true }
+k-launcher-ui = { workspace = true }
+k-launcher-ui-egui = { workspace = true, optional = true }
+plugin-apps = { workspace = true }
+plugin-calc = { workspace = true }
+plugin-cmd = { workspace = true }
+plugin-files = { workspace = true }
 dirs = { workspace = true }
+thiserror = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
+ctrlc = { workspace = true }
 tracing-appender = "0.2"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

crates/k-launcher/src/engine.rs

@@ -0,0 +1,39 @@
+use std::sync::Arc;
+
+use k_launcher_kernel::Kernel;
+use k_launcher_plugin_host::ExternalPlugin;
+#[cfg(target_os = "linux")]
+use plugin_apps::linux::FsDesktopEntrySource;
+use plugin_apps::{AppsPlugin, frecency::FrecencyStore};
+use plugin_calc::CalcPlugin;
+use plugin_cmd::CmdPlugin;
+use plugin_files::FilesPlugin;
+
+pub(crate) fn build_engine(cfg: Arc<k_launcher_config::Config>) -> Arc<Kernel> {
+    let frecency = FrecencyStore::load(cfg.search.frecency_compact_threshold);
+    let mut plugins: Vec<Arc<dyn k_launcher_domain::Plugin>> = vec![];
+    if cfg.plugins.cmd {
+        plugins.push(Arc::new(CmdPlugin::new()));
+    }
+    if cfg.plugins.calc {
+        plugins.push(Arc::new(CalcPlugin::new()));
+    }
+    if cfg.plugins.files {
+        plugins.push(Arc::new(FilesPlugin::new()));
+    }
+    if cfg.plugins.apps {
+        plugins.push(Arc::new(AppsPlugin::new(
+            FsDesktopEntrySource::new(),
+            frecency,
+        )));
+    }
+    for ext in &cfg.plugins.external {
+        plugins.push(Arc::new(ExternalPlugin::new(
+            &ext.name,
+            &ext.path,
+            ext.args.clone(),
+            ext.timeout_secs,
+        )));
+    }
+    Arc::new(Kernel::new(plugins, cfg.search.max_results))
+}

crates/k-launcher/src/error.rs

@@ -0,0 +1,7 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum AppError {
+    #[error("UI error: {0}")]
+    Ui(String),
+}

crates/k-launcher/src/logging.rs

@@ -0,0 +1,53 @@
+use k_launcher_domain::constants::{APP_NAME, LOG_DIR_NAME, LOG_FILE_PREFIX};
+
+const FALLBACK_LOG_DIR: &str = "/tmp/k-launcher/logs";
+const DEFAULT_LOG_LEVEL: &str = "info";
+
+pub(crate) fn init_logging(
+    cfg: &k_launcher_config::Config,
+) -> tracing_appender::non_blocking::WorkerGuard {
+    use tracing_subscriber::{EnvFilter, layer::SubscriberExt, util::SubscriberInitExt};
+
+    let log_dir = dirs::data_local_dir()
+        .map(|d| d.join(APP_NAME).join(LOG_DIR_NAME))
+        .unwrap_or_else(|| std::path::PathBuf::from(FALLBACK_LOG_DIR));
+    std::fs::create_dir_all(&log_dir).ok();
+
+    let file_appender = tracing_appender::rolling::RollingFileAppender::builder()
+        .rotation(tracing_appender::rolling::Rotation::DAILY)
+        .filename_prefix(LOG_FILE_PREFIX)
+        .max_log_files(cfg.logging.max_log_files)
+        .build(&log_dir)
+        .expect("log appender");
+    let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);
+
+    let env_filter =
+        EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(DEFAULT_LOG_LEVEL));
+
+    tracing_subscriber::registry()
+        .with(env_filter)
+        .with(tracing_subscriber::fmt::layer().with_writer(std::io::stderr))
+        .with(tracing_subscriber::fmt::layer().with_writer(non_blocking))
+        .init();
+
+    guard
+}
+
+pub(crate) fn install_panic_hook() {
+    let default_hook = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |info| {
+        let location = info
+            .location()
+            .map(|l| format!("{}:{}:{}", l.file(), l.line(), l.column()))
+            .unwrap_or_else(|| "unknown".to_string());
+        let payload = if let Some(s) = info.payload().downcast_ref::<&str>() {
+            (*s).to_string()
+        } else if let Some(s) = info.payload().downcast_ref::<String>() {
+            s.clone()
+        } else {
+            "unknown panic".to_string()
+        };
+        tracing::error!("PANIC at {location}: {payload}");
+        default_hook(info);
+    }));
+}

crates/k-launcher/src/main.rs

@@ -1,79 +1,46 @@
 use std::sync::Arc;
 
-use k_launcher_kernel::Kernel;
 use k_launcher_os_bridge::UnixAppLauncher;
-use k_launcher_plugin_host::ExternalPlugin;
-#[cfg(target_os = "linux")]
-use plugin_apps::linux::FsDesktopEntrySource;
-use plugin_apps::{AppsPlugin, frecency::FrecencyStore};
-use plugin_calc::CalcPlugin;
-use plugin_cmd::CmdPlugin;
-use plugin_files::FilesPlugin;
 
-fn init_logging() -> tracing_appender::non_blocking::WorkerGuard {
-    use tracing_subscriber::{EnvFilter, layer::SubscriberExt, util::SubscriberInitExt};
+mod engine;
+mod error;
+mod logging;
 
-    let log_dir = dirs::data_local_dir()
-        .map(|d| d.join("k-launcher/logs"))
-        .unwrap_or_else(|| std::path::PathBuf::from("/tmp/k-launcher/logs"));
-    std::fs::create_dir_all(&log_dir).ok();
-
-    let file_appender = tracing_appender::rolling::daily(&log_dir, "k-launcher.log");
-    let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);
-
-    let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info"));
-
-    tracing_subscriber::registry()
-        .with(env_filter)
-        .with(tracing_subscriber::fmt::layer().with_writer(std::io::stderr))
-        .with(tracing_subscriber::fmt::layer().with_writer(non_blocking))
-        .init();
-
-    guard
-}
+use error::AppError;
 
 fn main() {
-    let _guard = init_logging();
+    if std::env::args().any(|a| a == "--version" || a == "-V") {
+        println!("{} {}", env!("CARGO_PKG_NAME"), env!("CARGO_PKG_VERSION"));
+        return;
+    }
 
-    if let Err(e) = run_ui() {
-        eprintln!("error: UI: {e}");
+    let cfg = Arc::new(k_launcher_config::load());
+    let _guard = logging::init_logging(&cfg);
+    logging::install_panic_hook();
+
+    ctrlc::set_handler(|| {
+        tracing::info!("received shutdown signal");
+        std::process::exit(0);
+    })
+    .ok();
+
+    if let Err(e) = run_ui(cfg) {
+        eprintln!("error: {e}");
         std::process::exit(1);
     }
 }
 
-fn build_engine(cfg: Arc<k_launcher_config::Config>) -> Arc<dyn k_launcher_kernel::SearchEngine> {
-    let frecency = FrecencyStore::load();
-    let mut plugins: Vec<Arc<dyn k_launcher_kernel::Plugin>> = vec![];
-    if cfg.plugins.cmd {
-        plugins.push(Arc::new(CmdPlugin::new()));
-    }
-    if cfg.plugins.calc {
-        plugins.push(Arc::new(CalcPlugin::new()));
-    }
-    if cfg.plugins.files {
-        plugins.push(Arc::new(FilesPlugin::new()));
-    }
-    if cfg.plugins.apps {
-        plugins.push(Arc::new(AppsPlugin::new(
-            FsDesktopEntrySource::new(),
-            frecency,
-        )));
-    }
-    for ext in &cfg.plugins.external {
-        plugins.push(Arc::new(ExternalPlugin::new(
-            &ext.name,
-            &ext.path,
-            ext.args.clone(),
-        )));
-    }
-    Arc::new(Kernel::new(plugins, cfg.search.max_results))
-}
-
-fn run_ui() -> iced::Result {
-    let cfg = Arc::new(k_launcher_config::load());
-    let launcher = Arc::new(UnixAppLauncher::new());
+fn run_ui(cfg: Arc<k_launcher_config::Config>) -> Result<(), AppError> {
+    let launcher = Arc::new(UnixAppLauncher::new(cfg.terminal.cmd.clone()));
     let factory_cfg = cfg.clone();
-    let factory: Arc<dyn Fn() -> Arc<dyn k_launcher_kernel::SearchEngine> + Send + Sync> =
-        Arc::new(move || build_engine(factory_cfg.clone()));
-    k_launcher_ui::run(factory, launcher, &cfg.window, cfg.appearance.clone())
+    let factory: Arc<dyn Fn() -> Arc<k_launcher_kernel::Kernel> + Send + Sync> =
+        Arc::new(move || engine::build_engine(factory_cfg.clone()));
+    k_launcher_ui::run(
+        factory,
+        launcher,
+        &cfg.window,
+        cfg.appearance.clone(),
+        &cfg.search,
+    )
+    .map_err(AppError::Ui)
 }

crates/k-launcher/src/main_egui.rs

@@ -1,27 +1,38 @@
 use std::sync::Arc;
 
-use k_launcher_kernel::Kernel;
 use k_launcher_os_bridge::UnixAppLauncher;
-#[cfg(target_os = "linux")]
-use plugin_apps::linux::FsDesktopEntrySource;
-use plugin_apps::{AppsPlugin, frecency::FrecencyStore};
-use plugin_calc::CalcPlugin;
-use plugin_cmd::CmdPlugin;
-use plugin_files::FilesPlugin;
 
-fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let cfg = k_launcher_config::load();
-    let launcher = Arc::new(UnixAppLauncher::new());
-    let frecency = FrecencyStore::load();
-    let kernel: Arc<dyn k_launcher_kernel::SearchEngine> = Arc::new(Kernel::new(
-        vec![
-            Arc::new(CmdPlugin::new()),
-            Arc::new(CalcPlugin::new()),
-            Arc::new(FilesPlugin::new()),
-            Arc::new(AppsPlugin::new(FsDesktopEntrySource::new(), frecency)),
-        ],
-        8,
-    ));
-    k_launcher_ui_egui::run(kernel, launcher, &cfg.window)?;
-    Ok(())
+mod engine;
+mod error;
+mod logging;
+
+use error::AppError;
+
+fn main() {
+    if std::env::args().any(|a| a == "--version" || a == "-V") {
+        println!("{} {}", env!("CARGO_PKG_NAME"), env!("CARGO_PKG_VERSION"));
+        return;
+    }
+
+    let cfg = Arc::new(k_launcher_config::load());
+    let _guard = logging::init_logging(&cfg);
+    logging::install_panic_hook();
+
+    ctrlc::set_handler(|| {
+        tracing::info!("received shutdown signal");
+        std::process::exit(0);
+    })
+    .ok();
+
+    if let Err(e) = run_ui(cfg) {
+        eprintln!("error: {e}");
+        std::process::exit(1);
+    }
+}
+
+fn run_ui(cfg: Arc<k_launcher_config::Config>) -> Result<(), AppError> {
+    let launcher = Arc::new(UnixAppLauncher::new(cfg.terminal.cmd.clone()));
+    let kernel = engine::build_engine(cfg.clone());
+    k_launcher_ui_egui::run(kernel, launcher, &cfg.window, cfg.appearance.clone())
+        .map_err(AppError::Ui)
 }

crates/plugins/plugin-apps/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "plugin-apps"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -9,10 +9,11 @@ path = "src/lib.rs"
 
 [dependencies]
 async-trait = { workspace = true }
-bincode = { workspace = true }
+bincode = { version = "2", features = ["serde"] }
 dirs = { workspace = true }
-k-launcher-kernel = { path = "../../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
 nucleo-matcher = "0.3"
+parking_lot = { workspace = true }
 serde = { workspace = true }
 serde_json = "1.0"
 tokio = { workspace = true }
@@ -21,3 +22,7 @@ tracing = { workspace = true }
 [target.'cfg(target_os = "linux")'.dependencies]
 linicon = "2.3.0"
 xdg = "3"
+
+[dev-dependencies]
+k-launcher-domain = { workspace = true }
+tokio = { workspace = true }

crates/plugins/plugin-apps/src/cache.rs

@@ -0,0 +1,110 @@
+use std::{
+    collections::HashMap,
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+
+use crate::frecency::FrecencyStore;
+use crate::types::{AppName, DesktopEntrySource};
+
+pub struct CachedEntry {
+    pub(crate) id: String,
+    pub(crate) name: AppName,
+    pub(crate) name_lowercase: String,
+    pub(crate) keywords_lowercase: Vec<String>,
+    pub(crate) category: Option<Arc<str>>,
+    pub(crate) icon: Option<Arc<str>>,
+    pub(crate) exec: String,
+}
+
+#[derive(serde::Serialize, serde::Deserialize)]
+struct CachedEntryData {
+    id: String,
+    name: String,
+    name_lowercase: String,
+    keywords_lowercase: Vec<String>,
+    category: Option<String>,
+    icon: Option<String>,
+    exec: String,
+}
+
+pub fn cache_path() -> Option<PathBuf> {
+    dirs::cache_dir().map(|d| d.join("k-launcher/apps.bin"))
+}
+
+pub fn load_from_path(path: &Path) -> Option<HashMap<String, CachedEntry>> {
+    let data = std::fs::read(path).ok()?;
+    let (entries_data, _): (Vec<CachedEntryData>, _) =
+        bincode::serde::decode_from_slice(&data, bincode::config::standard()).ok()?;
+    let map = entries_data
+        .into_iter()
+        .map(|e| {
+            let cached = CachedEntry {
+                id: e.id.clone(),
+                name: AppName::new(e.name),
+                name_lowercase: e.name_lowercase,
+                keywords_lowercase: e.keywords_lowercase,
+                category: e.category.map(Arc::from),
+                icon: e.icon.map(Arc::from),
+                exec: e.exec,
+            };
+            (e.id, cached)
+        })
+        .collect();
+    Some(map)
+}
+
+pub fn save_to_path(path: &Path, entries: &HashMap<String, CachedEntry>) {
+    if let Some(dir) = path.parent() {
+        std::fs::create_dir_all(dir).ok();
+    }
+    let data: Vec<CachedEntryData> = entries
+        .values()
+        .map(|e| CachedEntryData {
+            id: e.id.clone(),
+            name: e.name.as_str().to_string(),
+            name_lowercase: e.name_lowercase.clone(),
+            keywords_lowercase: e.keywords_lowercase.clone(),
+            category: e.category.as_deref().map(str::to_string),
+            icon: e.icon.as_deref().map(str::to_string),
+            exec: e.exec.clone(),
+        })
+        .collect();
+    if let Ok(encoded) = bincode::serde::encode_to_vec(&data, bincode::config::standard()) {
+        std::fs::write(path, encoded).ok();
+    }
+}
+
+pub fn build_entries(
+    source: &impl DesktopEntrySource,
+    _frecency: &Arc<FrecencyStore>,
+) -> HashMap<String, CachedEntry> {
+    source
+        .entries()
+        .into_iter()
+        .map(|e| {
+            let id = format!("app-{}:{}", e.name.as_str(), e.exec.as_str());
+            let name_lowercase = e.name.as_str().to_lowercase();
+            let keywords_lowercase = e.keywords.iter().map(|k| k.to_lowercase()).collect();
+            #[cfg(target_os = "linux")]
+            let icon: Option<Arc<str>> = e
+                .icon
+                .as_ref()
+                .and_then(|p| crate::linux::resolve_icon_path(p.as_str()))
+                .map(Arc::from);
+            #[cfg(not(target_os = "linux"))]
+            let icon: Option<Arc<str>> = None;
+            let exec = e.exec.as_str().to_string();
+            let cached = CachedEntry {
+                id: id.clone(),
+                name_lowercase,
+                keywords_lowercase,
+                category: e.category.map(Arc::from),
+                icon,
+                exec,
+                name: e.name,
+            };
+            (id, cached)
+        })
+        .collect()
+}

crates/plugins/plugin-apps/src/frecency.rs

@@ -1,10 +1,13 @@
 use std::{
     collections::HashMap,
+    fs::{File, OpenOptions},
+    io::{BufRead, BufReader, Write},
     path::PathBuf,
-    sync::{Arc, Mutex},
+    sync::Arc,
     time::{SystemTime, UNIX_EPOCH},
 };
 
+use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -13,41 +16,64 @@ struct Entry {
     last_used: u64,
 }
 
+#[derive(Serialize, Deserialize)]
+struct LogRecord {
+    id: String,
+    ts: u64,
+}
+
 pub struct FrecencyStore {
-    path: PathBuf,
+    snapshot_path: PathBuf,
+    log_path: PathBuf,
     data: Mutex<HashMap<String, Entry>>,
+    log_count: Mutex<usize>,
+    compact_threshold: usize,
 }
 
 impl FrecencyStore {
-    pub fn new(path: PathBuf) -> Arc<Self> {
-        let data = std::fs::read_to_string(&path)
+    pub fn new(snapshot_path: PathBuf, compact_threshold: usize) -> Arc<Self> {
+        let mut data: HashMap<String, Entry> = std::fs::read_to_string(&snapshot_path)
             .ok()
             .and_then(|s| serde_json::from_str(&s).ok())
             .unwrap_or_default();
-        Arc::new(Self {
-            path,
+
+        let log_path = snapshot_path.with_extension("log");
+        let log_count = replay_log_into(&log_path, &mut data);
+
+        let store = Arc::new(Self {
+            snapshot_path,
+            log_path,
             data: Mutex::new(data),
-        })
+            log_count: Mutex::new(log_count),
+            compact_threshold,
+        });
+
+        if log_count >= compact_threshold {
+            store.compact();
+        }
+
+        store
     }
 
-    #[cfg(test)]
     pub fn new_for_test() -> Arc<Self> {
         Arc::new(Self {
-            path: PathBuf::from("/dev/null"),
+            snapshot_path: PathBuf::from("/dev/null"),
+            log_path: PathBuf::from("/dev/null"),
             data: Mutex::new(HashMap::new()),
+            log_count: Mutex::new(0),
+            compact_threshold: usize::MAX,
         })
     }
 
-    pub fn load() -> Arc<Self> {
+    pub fn load(compact_threshold: usize) -> Arc<Self> {
         let Some(data_home) = xdg::BaseDirectories::new().get_data_home() else {
             tracing::warn!("XDG_DATA_HOME unavailable; frecency disabled (in-memory only)");
-            return Arc::new(Self {
-                path: PathBuf::from("/dev/null"),
-                data: Mutex::new(HashMap::new()),
-            });
+            return Self::new_for_test();
         };
-        let path = data_home.join("k-launcher").join("frecency.json");
-        Self::new(path)
+        let path = data_home
+            .join(k_launcher_domain::constants::APP_NAME)
+            .join(k_launcher_domain::constants::FRECENCY_SNAPSHOT_FILENAME);
+        Self::new(path, compact_threshold)
     }
 
     pub fn record(&self, id: &str) {
@@ -55,26 +81,72 @@ impl FrecencyStore {
             .duration_since(UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
-        let json = {
-            let mut data = self.data.lock().unwrap();
+        {
+            let mut data = self.data.lock();
             let entry = data.entry(id.to_string()).or_insert(Entry {
                 count: 0,
                 last_used: 0,
             });
             entry.count += 1;
             entry.last_used = now;
-            serde_json::to_string(&*data).ok()
-        }; // lock released here
-        if let Some(json) = json {
-            if let Some(parent) = self.path.parent() {
-                let _ = std::fs::create_dir_all(parent);
+        }
+        self.append_log(id, now);
+    }
+
+    fn append_log(&self, id: &str, ts: u64) {
+        let record = LogRecord {
+            id: id.to_string(),
+            ts,
+        };
+        if let Ok(json) = serde_json::to_string(&record) {
+            if let Some(parent) = self.log_path.parent()
+                && let Err(e) = std::fs::create_dir_all(parent)
+            {
+                tracing::warn!("failed to create frecency dir: {e}");
             }
-            let _ = std::fs::write(&self.path, json);
+            if let Ok(mut file) = OpenOptions::new()
+                .create(true)
+                .append(true)
+                .open(&self.log_path)
+                && let Err(e) = writeln!(file, "{json}")
+            {
+                tracing::warn!("failed to write frecency log: {e}");
+            }
+        }
+        let mut count = self.log_count.lock();
+        *count += 1;
+        if *count >= self.compact_threshold {
+            drop(count);
+            self.compact();
         }
     }
 
+    pub fn compact(&self) {
+        let json = {
+            let data = self.data.lock();
+            serde_json::to_string(&*data).ok()
+        };
+        if let Some(json) = json {
+            if let Some(parent) = self.snapshot_path.parent()
+                && let Err(e) = std::fs::create_dir_all(parent)
+            {
+                tracing::warn!("failed to create frecency dir: {e}");
+            }
+            if std::fs::write(&self.snapshot_path, json).is_ok() {
+                if let Err(e) = File::create(&self.log_path) {
+                    tracing::warn!("failed to truncate frecency log: {e}");
+                }
+                *self.log_count.lock() = 0;
+            }
+        }
+    }
+
+    pub fn shutdown(&self) {
+        self.compact();
+    }
+
     pub fn frecency_score(&self, id: &str) -> u32 {
-        let data = self.data.lock().unwrap();
+        let data = self.data.lock();
         let Some(entry) = data.get(id) else { return 0 };
         let now = SystemTime::now()
             .duration_since(UNIX_EPOCH)
@@ -85,70 +157,73 @@ impl FrecencyStore {
     }
 
     pub fn top_ids(&self, n: usize) -> Vec<String> {
-        let data = self.data.lock().unwrap();
+        struct ScoredId {
+            id: String,
+            score: u32,
+        }
+
+        let data = self.data.lock();
         let now = SystemTime::now()
             .duration_since(UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
-        let mut scored: Vec<(String, u32)> = data
+        let mut scored: Vec<ScoredId> = data
             .iter()
             .map(|(id, entry)| {
                 let age_secs = now.saturating_sub(entry.last_used);
-                (id.clone(), entry.count * decay_factor(age_secs))
+                ScoredId {
+                    id: id.clone(),
+                    score: entry.count * decay_factor(age_secs),
+                }
             })
             .collect();
-        scored.sort_by(|a, b| b.1.cmp(&a.1));
-        scored.into_iter().take(n).map(|(id, _)| id).collect()
+
+        if scored.len() <= n {
+            scored.sort_by_key(|s| std::cmp::Reverse(s.score));
+            return scored.into_iter().map(|s| s.id).collect();
+        }
+
+        scored.select_nth_unstable_by_key(n, |s| std::cmp::Reverse(s.score));
+        scored.truncate(n);
+        scored.sort_by_key(|s| std::cmp::Reverse(s.score));
+        scored.into_iter().map(|s| s.id).collect()
     }
 }
 
+fn replay_log_into(log_path: &PathBuf, data: &mut HashMap<String, Entry>) -> usize {
+    let file = match File::open(log_path) {
+        Ok(f) => f,
+        Err(_) => return 0,
+    };
+    let mut count = 0;
+    for line in BufReader::new(file).lines() {
+        let Ok(line) = line else { continue };
+        let Ok(record) = serde_json::from_str::<LogRecord>(&line) else {
+            continue;
+        };
+        let entry = data.entry(record.id).or_insert(Entry {
+            count: 0,
+            last_used: 0,
+        });
+        entry.count += 1;
+        entry.last_used = record.ts;
+        count += 1;
+    }
+    count
+}
+
+const ONE_HOUR: u64 = 3600;
+const ONE_DAY: u64 = 86400;
+const DECAY_RECENT: u32 = 4;
+const DECAY_TODAY: u32 = 2;
+const DECAY_OLD: u32 = 1;
+
 fn decay_factor(age_secs: u64) -> u32 {
-    if age_secs < 3600 {
-        4
-    } else if age_secs < 86400 {
-        2
+    if age_secs < ONE_HOUR {
+        DECAY_RECENT
+    } else if age_secs < ONE_DAY {
+        DECAY_TODAY
     } else {
-        1
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn make_store() -> Arc<FrecencyStore> {
-        Arc::new(FrecencyStore {
-            path: PathBuf::from("/dev/null"),
-            data: Mutex::new(HashMap::new()),
-        })
-    }
-
-    #[test]
-    fn record_increments_count() {
-        let store = make_store();
-        store.record("app-firefox");
-        store.record("app-firefox");
-        let data = store.data.lock().unwrap();
-        assert_eq!(data["app-firefox"].count, 2);
-    }
-
-    #[test]
-    fn record_updates_last_used() {
-        let store = make_store();
-        store.record("app-firefox");
-        let data = store.data.lock().unwrap();
-        assert!(data["app-firefox"].last_used > 0);
-    }
-
-    #[test]
-    fn top_ids_returns_sorted_order() {
-        let store = make_store();
-        store.record("app-firefox");
-        store.record("app-code");
-        store.record("app-code");
-        store.record("app-code");
-        let top = store.top_ids(2);
-        assert_eq!(top[0], "app-code");
-        assert_eq!(top[1], "app-firefox");
+        DECAY_OLD
     }
 }

crates/plugins/plugin-apps/src/lib.rs

@@ -1,521 +1,12 @@
+mod cache;
 pub mod frecency;
 #[cfg(target_os = "linux")]
 pub mod linux;
+mod plugin;
+mod scoring;
+mod types;
 
-use std::{
-    collections::HashMap,
-    path::{Path, PathBuf},
-    sync::{Arc, RwLock},
-};
-
-use async_trait::async_trait;
-use k_launcher_kernel::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
-
-use crate::frecency::FrecencyStore;
-
-// --- Domain newtypes ---
-
-#[derive(Debug, Clone)]
-pub struct AppName(String);
-
-impl AppName {
-    pub fn new(s: impl Into<String>) -> Self {
-        Self(s.into())
-    }
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct ExecCommand(String);
-
-impl ExecCommand {
-    pub fn new(s: impl Into<String>) -> Self {
-        Self(s.into())
-    }
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct IconPath(String);
-
-impl IconPath {
-    pub fn new(s: impl Into<String>) -> Self {
-        Self(s.into())
-    }
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-// --- Desktop entry ---
-
-pub struct DesktopEntry {
-    pub name: AppName,
-    pub exec: ExecCommand,
-    pub icon: Option<IconPath>,
-    pub category: Option<String>,
-    pub keywords: Vec<String>,
-}
-
-// --- Swappable source trait (Application layer principle) ---
-
-pub trait DesktopEntrySource: Send + Sync {
-    fn entries(&self) -> Vec<DesktopEntry>;
-}
-
-// --- Cached entry (pre-computed at construction) ---
-
-struct CachedEntry {
-    id: String,
-    name: AppName,
-    keywords_lc: Vec<String>,
-    category: Option<String>,
-    icon: Option<String>,
-    exec: String,
-}
-
-// --- Serializable cache data (no closures) ---
-
-#[derive(serde::Serialize, serde::Deserialize)]
-struct CachedEntryData {
-    id: String,
-    name: String,
-    keywords_lc: Vec<String>,
-    category: Option<String>,
-    icon: Option<String>,
-    exec: String,
-}
-
-fn cache_path() -> Option<PathBuf> {
-    dirs::cache_dir().map(|d| d.join("k-launcher/apps.bin"))
-}
-
-fn load_from_path(path: &Path) -> Option<HashMap<String, CachedEntry>> {
-    let data = std::fs::read(path).ok()?;
-    let (entries_data, _): (Vec<CachedEntryData>, _) =
-        bincode::serde::decode_from_slice(&data, bincode::config::standard()).ok()?;
-    let map = entries_data
-        .into_iter()
-        .map(|e| {
-            let cached = CachedEntry {
-                id: e.id.clone(),
-                name: AppName::new(e.name),
-                keywords_lc: e.keywords_lc,
-                category: e.category,
-                icon: e.icon,
-                exec: e.exec,
-            };
-            (e.id, cached)
-        })
-        .collect();
-    Some(map)
-}
-
-fn save_to_path(path: &Path, entries: &HashMap<String, CachedEntry>) {
-    if let Some(dir) = path.parent() {
-        std::fs::create_dir_all(dir).ok();
-    }
-    let data: Vec<CachedEntryData> = entries
-        .values()
-        .map(|e| CachedEntryData {
-            id: e.id.clone(),
-            name: e.name.as_str().to_string(),
-            keywords_lc: e.keywords_lc.clone(),
-            category: e.category.clone(),
-            icon: e.icon.clone(),
-            exec: e.exec.clone(),
-        })
-        .collect();
-    if let Ok(encoded) = bincode::serde::encode_to_vec(&data, bincode::config::standard()) {
-        std::fs::write(path, encoded).ok();
-    }
-}
-
-fn build_entries(
-    source: &impl DesktopEntrySource,
-    _frecency: &Arc<FrecencyStore>,
-) -> HashMap<String, CachedEntry> {
-    source
-        .entries()
-        .into_iter()
-        .map(|e| {
-            let id = format!("app-{}:{}", e.name.as_str(), e.exec.as_str());
-            let keywords_lc = e.keywords.iter().map(|k| k.to_lowercase()).collect();
-            #[cfg(target_os = "linux")]
-            let icon = e
-                .icon
-                .as_ref()
-                .and_then(|p| linux::resolve_icon_path(p.as_str()));
-            #[cfg(not(target_os = "linux"))]
-            let icon: Option<String> = None;
-            let exec = e.exec.as_str().to_string();
-            let cached = CachedEntry {
-                id: id.clone(),
-                keywords_lc,
-                category: e.category,
-                icon,
-                exec,
-                name: e.name,
-            };
-            (id, cached)
-        })
-        .collect()
-}
-
-// --- Plugin ---
-
-pub struct AppsPlugin {
-    entries: Arc<RwLock<HashMap<String, CachedEntry>>>,
-    frecency: Arc<FrecencyStore>,
-}
-
-impl AppsPlugin {
-    pub fn new(source: impl DesktopEntrySource + 'static, frecency: Arc<FrecencyStore>) -> Self {
-        Self::new_impl(source, frecency, cache_path())
-    }
-
-    fn new_impl(
-        source: impl DesktopEntrySource + 'static,
-        frecency: Arc<FrecencyStore>,
-        cp: Option<PathBuf>,
-    ) -> Self {
-        let cached = cp.as_deref().and_then(load_from_path);
-
-        let entries = if let Some(from_cache) = cached {
-            // Serve cache immediately; refresh in background.
-            let map = Arc::new(RwLock::new(from_cache));
-            let entries_bg = Arc::clone(&map);
-            let frecency_bg = Arc::clone(&frecency);
-            let cp_bg = cp.clone();
-            std::thread::spawn(move || {
-                let fresh = build_entries(&source, &frecency_bg);
-                if let Some(path) = cp_bg {
-                    save_to_path(&path, &fresh);
-                }
-                *entries_bg.write().unwrap() = fresh;
-            });
-            map
-        } else {
-            // No cache: build synchronously, then persist.
-            let initial = build_entries(&source, &frecency);
-            if let Some(path) = &cp {
-                save_to_path(path, &initial);
-            }
-            Arc::new(RwLock::new(initial))
-        };
-
-        Self { entries, frecency }
-    }
-
-    #[cfg(test)]
-    fn new_for_test(
-        source: impl DesktopEntrySource + 'static,
-        frecency: Arc<FrecencyStore>,
-    ) -> Self {
-        Self::new_impl(source, frecency, None)
-    }
-}
-
-fn initials(name_lc: &str) -> String {
-    name_lc
-        .split_whitespace()
-        .filter_map(|w| w.chars().next())
-        .collect()
-}
-
-fn score_match(name: &str, query: &str) -> Option<u32> {
-    use nucleo_matcher::{
-        Config, Matcher, Utf32Str,
-        pattern::{CaseMatching, Normalization, Pattern},
-    };
-
-    let mut matcher = Matcher::new(Config::DEFAULT);
-    let pattern = Pattern::parse(query, CaseMatching::Ignore, Normalization::Smart);
-
-    let mut name_chars: Vec<char> = name.chars().collect();
-    let haystack = Utf32Str::new(name, &mut name_chars);
-    let score = pattern.score(haystack, &mut matcher);
-
-    if let Some(s) = score {
-        let name_lc = name.to_lowercase();
-        let query_lc = query.to_lowercase();
-        let bonus: u32 = if initials(&name_lc).starts_with(&query_lc) {
-            20
-        } else {
-            0
-        };
-        Some(s.saturating_add(bonus))
-    } else {
-        None
-    }
-}
-
-pub(crate) fn humanize_category(s: &str) -> String {
-    let mut result = String::new();
-    for ch in s.chars() {
-        if ch.is_uppercase() && !result.is_empty() {
-            result.push(' ');
-        }
-        result.push(ch);
-    }
-    result
-}
-
-#[async_trait]
-impl Plugin for AppsPlugin {
-    fn name(&self) -> &str {
-        "apps"
-    }
-
-    fn on_selected(&self, id: &ResultId) {
-        self.frecency.record(id.as_str());
-    }
-
-    async fn search(&self, query: &str) -> Vec<SearchResult> {
-        let entries = self.entries.read().unwrap();
-        if query.is_empty() {
-            return self
-                .frecency
-                .top_ids(5)
-                .iter()
-                .filter_map(|id| {
-                    let e = entries.get(id)?;
-                    let score = self.frecency.frecency_score(id).max(1);
-                    Some(SearchResult {
-                        id: ResultId::new(id),
-                        title: ResultTitle::new(e.name.as_str()),
-                        description: e.category.clone(),
-                        icon: e.icon.clone(),
-                        score: Score::new(score),
-                        action: LaunchAction::SpawnProcess(e.exec.clone()),
-                    })
-                })
-                .collect();
-        }
-
-        let query_lc = query.to_lowercase();
-        entries
-            .values()
-            .filter_map(|e| {
-                let score = score_match(e.name.as_str(), query).or_else(|| {
-                    e.keywords_lc
-                        .iter()
-                        .any(|k| k.contains(&query_lc))
-                        .then_some(50)
-                })?;
-                Some(SearchResult {
-                    id: ResultId::new(&e.id),
-                    title: ResultTitle::new(e.name.as_str()),
-                    description: e.category.clone(),
-                    icon: e.icon.clone(),
-                    score: Score::new(score),
-                    action: LaunchAction::SpawnProcess(e.exec.clone()),
-                })
-            })
-            .collect()
-    }
-}
-
-// --- Tests ---
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn ephemeral_frecency() -> Arc<FrecencyStore> {
-        FrecencyStore::new_for_test()
-    }
-
-    struct MockSource {
-        entries: Vec<(String, String, Option<String>, Vec<String>)>, // (name, exec, category, keywords)
-    }
-
-    impl MockSource {
-        fn with(entries: Vec<(&str, &str)>) -> Self {
-            Self {
-                entries: entries
-                    .into_iter()
-                    .map(|(n, e)| (n.to_string(), e.to_string(), None, vec![]))
-                    .collect(),
-            }
-        }
-
-        fn with_categories(entries: Vec<(&str, &str, &str)>) -> Self {
-            Self {
-                entries: entries
-                    .into_iter()
-                    .map(|(n, e, c)| (n.to_string(), e.to_string(), Some(c.to_string()), vec![]))
-                    .collect(),
-            }
-        }
-
-        fn with_keywords(entries: Vec<(&str, &str, Vec<&str>)>) -> Self {
-            Self {
-                entries: entries
-                    .into_iter()
-                    .map(|(n, e, kw)| {
-                        (
-                            n.to_string(),
-                            e.to_string(),
-                            None,
-                            kw.into_iter().map(|s| s.to_string()).collect(),
-                        )
-                    })
-                    .collect(),
-            }
-        }
-    }
-
-    impl DesktopEntrySource for MockSource {
-        fn entries(&self) -> Vec<DesktopEntry> {
-            self.entries
-                .iter()
-                .map(|(name, exec, category, keywords)| DesktopEntry {
-                    name: AppName::new(name.clone()),
-                    exec: ExecCommand::new(exec.clone()),
-                    icon: None,
-                    category: category.clone(),
-                    keywords: keywords.clone(),
-                })
-                .collect()
-        }
-    }
-
-    #[tokio::test]
-    async fn apps_prefix_match() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Firefox", "firefox")]),
-            ephemeral_frecency(),
-        );
-        let results = p.search("fire").await;
-        assert_eq!(results[0].title.as_str(), "Firefox");
-    }
-
-    #[tokio::test]
-    async fn apps_no_match_returns_empty() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Firefox", "firefox")]),
-            ephemeral_frecency(),
-        );
-        assert!(p.search("zz").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn apps_empty_query_no_frecency_returns_empty() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Firefox", "firefox")]),
-            ephemeral_frecency(),
-        );
-        assert!(p.search("").await.is_empty());
-    }
-
-    #[test]
-    fn score_match_abbreviation() {
-        assert_eq!(initials("visual studio code"), "vsc");
-        assert!(score_match("visual studio code", "vsc").is_some());
-    }
-
-    #[test]
-    fn score_match_exact_beats_prefix() {
-        let exact = score_match("firefox", "firefox");
-        let prefix = score_match("firefox", "fire");
-        let abbrev = score_match("gnu firefox", "gf");
-        let substr = score_match("ice firefox", "fire");
-        assert!(exact.is_some());
-        assert!(prefix.is_some());
-        assert!(abbrev.is_some());
-        assert!(substr.is_some());
-        assert!(exact.unwrap() > prefix.unwrap());
-    }
-
-    #[tokio::test]
-    async fn apps_abbreviation_match() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Visual Studio Code", "code")]),
-            ephemeral_frecency(),
-        );
-        let results = p.search("vsc").await;
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].title.as_str(), "Visual Studio Code");
-        assert!(results[0].score.value() > 0);
-    }
-
-    #[tokio::test]
-    async fn apps_keyword_match() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with_keywords(vec![("Code", "code", vec!["editor", "ide"])]),
-            ephemeral_frecency(),
-        );
-        let results = p.search("editor").await;
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].score.value(), 50);
-    }
-
-    #[tokio::test]
-    async fn apps_fuzzy_typo_match() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Firefox", "firefox")]),
-            ephemeral_frecency(),
-        );
-        let results = p.search("frefox").await;
-        assert!(
-            !results.is_empty(),
-            "nucleo should fuzzy-match 'frefox' to 'Firefox'"
-        );
-        assert!(results[0].score.value() > 0);
-    }
-
-    #[test]
-    fn humanize_category_splits_camel_case() {
-        assert_eq!(humanize_category("TextEditor"), "Text Editor");
-        assert_eq!(humanize_category("WebBrowser"), "Web Browser");
-        assert_eq!(humanize_category("Development"), "Development");
-    }
-
-    #[tokio::test]
-    async fn apps_category_appears_in_description() {
-        let p = AppsPlugin::new_for_test(
-            MockSource::with_categories(vec![("Code", "code", "Text Editor")]),
-            ephemeral_frecency(),
-        );
-        let results = p.search("code").await;
-        assert_eq!(results[0].description.as_deref(), Some("Text Editor"));
-    }
-
-    #[tokio::test]
-    async fn apps_empty_query_returns_top_frecent() {
-        let frecency = ephemeral_frecency();
-        frecency.record("app-Code:code");
-        frecency.record("app-Code:code");
-        frecency.record("app-Firefox:firefox");
-        let p = AppsPlugin::new_for_test(
-            MockSource::with(vec![("Firefox", "firefox"), ("Code", "code")]),
-            frecency,
-        );
-        let results = p.search("").await;
-        assert_eq!(results.len(), 2);
-        assert_eq!(results[0].title.as_str(), "Code");
-    }
-
-    #[test]
-    fn apps_loads_from_cache_when_source_is_empty() {
-        let frecency = ephemeral_frecency();
-        let cache_file =
-            std::env::temp_dir().join(format!("k-launcher-test-{}.bin", std::process::id()));
-
-        // Build entries from a real source and save to temp path
-        let source = MockSource::with(vec![("Firefox", "firefox")]);
-        let entries = build_entries(&source, &frecency);
-        save_to_path(&cache_file, &entries);
-
-        // Load from temp path — should contain Firefox
-        let loaded = load_from_path(&cache_file).unwrap();
-        assert!(loaded.contains_key("app-Firefox:firefox"));
-
-        std::fs::remove_file(&cache_file).ok();
-    }
-}
+pub use cache::{CachedEntry, build_entries, load_from_path, save_to_path};
+pub use plugin::*;
+pub use scoring::{humanize_category, new_matcher, parse_pattern, score_match};
+pub use types::*;

crates/plugins/plugin-apps/src/linux.rs

@@ -1,6 +1,6 @@
 use std::path::Path;
 
-use crate::humanize_category;
+use crate::scoring::humanize_category;
 use crate::{AppName, DesktopEntry, DesktopEntrySource, ExecCommand, IconPath};
 
 pub struct FsDesktopEntrySource;
@@ -45,7 +45,7 @@ impl DesktopEntrySource for FsDesktopEntrySource {
     }
 }
 
-pub(crate) fn clean_exec(exec: &str) -> String {
+pub fn clean_exec(exec: &str) -> String {
     // Tokenize respecting double-quoted strings, then filter field codes.
     let mut tokens: Vec<String> = Vec::new();
     let mut chars = exec.chars().peekable();
@@ -99,16 +99,18 @@ fn is_field_code(s: &str) -> bool {
     b.len() == 2 && b[0] == b'%' && b[1].is_ascii_alphabetic()
 }
 
+const ICON_LOOKUP_SIZE: u16 = 48;
+const ICON_THEMES: &[&str] = &["hicolor", "Adwaita", "breeze", "Papirus"];
+const PIXMAPS_DIR: &str = "/usr/share/pixmaps";
+
 pub fn resolve_icon_path(name: &str) -> Option<String> {
     if name.starts_with('/') && Path::new(name).exists() {
         return Some(name.to_string());
     }
-    // Try linicon freedesktop theme traversal
-    let themes = ["hicolor", "Adwaita", "breeze", "Papirus"];
-    for theme in &themes {
+    for theme in ICON_THEMES {
         if let Some(icon_path) = linicon::lookup_icon(name)
             .from_theme(theme)
-            .with_size(48)
+            .with_size(ICON_LOOKUP_SIZE)
             .find_map(|r| r.ok())
         {
             return Some(icon_path.path.to_string_lossy().into_owned());
@@ -116,8 +118,8 @@ pub fn resolve_icon_path(name: &str) -> Option<String> {
     }
     // Fallback to pixmaps
     let candidates = [
-        format!("/usr/share/pixmaps/{name}.png"),
-        format!("/usr/share/pixmaps/{name}.svg"),
+        format!("{PIXMAPS_DIR}/{name}.png"),
+        format!("{PIXMAPS_DIR}/{name}.svg"),
     ];
     candidates.into_iter().find(|p| Path::new(p).exists())
 }
@@ -187,31 +189,3 @@ fn parse_desktop_file(path: &Path) -> Option<DesktopEntry> {
         keywords,
     })
 }
-
-#[cfg(test)]
-mod exec_tests {
-    use super::clean_exec;
-
-    #[test]
-    fn strips_bare_field_code() {
-        assert_eq!(clean_exec("app --file %f"), "app --file");
-    }
-
-    #[test]
-    fn strips_multiple_field_codes() {
-        assert_eq!(clean_exec("app %U --flag"), "app --flag");
-    }
-
-    #[test]
-    fn preserves_quoted_value() {
-        assert_eq!(
-            clean_exec(r#"app --arg="value" %U"#),
-            r#"app --arg="value""#
-        );
-    }
-
-    #[test]
-    fn handles_plain_exec() {
-        assert_eq!(clean_exec("firefox"), "firefox");
-    }
-}

crates/plugins/plugin-apps/src/plugin.rs

@@ -0,0 +1,142 @@
+use std::{collections::HashMap, path::PathBuf, sync::Arc};
+
+use parking_lot::RwLock;
+
+use async_trait::async_trait;
+use k_launcher_domain::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+
+use crate::cache::{CachedEntry, build_entries, cache_path, load_from_path, save_to_path};
+use crate::frecency::FrecencyStore;
+use crate::scoring::{new_matcher, parse_pattern, score_match};
+use crate::types::DesktopEntrySource;
+
+const FRECENT_RESULTS_COUNT: usize = 5;
+const KEYWORD_MATCH_SCORE: u32 = 50;
+
+pub struct AppsPlugin {
+    entries: Arc<RwLock<HashMap<String, CachedEntry>>>,
+    frecency: Arc<FrecencyStore>,
+}
+
+impl AppsPlugin {
+    pub fn new(source: impl DesktopEntrySource + 'static, frecency: Arc<FrecencyStore>) -> Self {
+        Self::new_impl(source, frecency, cache_path())
+    }
+
+    fn new_impl(
+        source: impl DesktopEntrySource + 'static,
+        frecency: Arc<FrecencyStore>,
+        cp: Option<PathBuf>,
+    ) -> Self {
+        let cached = cp.as_deref().and_then(load_from_path);
+
+        let entries = if let Some(from_cache) = cached {
+            // Serve cache immediately; refresh in background.
+            let map = Arc::new(RwLock::new(from_cache));
+            let entries_bg = Arc::clone(&map);
+            let frecency_bg = Arc::clone(&frecency);
+            let cp_bg = cp.clone();
+            std::thread::spawn(move || {
+                let fresh = build_entries(&source, &frecency_bg);
+                if let Some(path) = cp_bg {
+                    save_to_path(&path, &fresh);
+                }
+                *entries_bg.write() = fresh;
+            });
+            map
+        } else {
+            // No cache: build synchronously, then persist.
+            let initial = build_entries(&source, &frecency);
+            if let Some(path) = &cp {
+                save_to_path(path, &initial);
+            }
+            Arc::new(RwLock::new(initial))
+        };
+
+        Self { entries, frecency }
+    }
+
+    pub fn new_for_test(
+        source: impl DesktopEntrySource + 'static,
+        frecency: Arc<FrecencyStore>,
+    ) -> Self {
+        Self::new_impl(source, frecency, None)
+    }
+}
+
+#[async_trait]
+impl Plugin for AppsPlugin {
+    fn name(&self) -> &str {
+        "apps"
+    }
+
+    fn on_selected(&self, id: &ResultId) {
+        self.frecency.record(id.as_str());
+    }
+
+    fn shutdown(&self) {
+        self.frecency.shutdown();
+    }
+
+    async fn search(&self, query: &str) -> Vec<SearchResult> {
+        let entries = self.entries.read();
+        if query.is_empty() {
+            return self
+                .frecency
+                .top_ids(FRECENT_RESULTS_COUNT)
+                .iter()
+                .filter_map(|id| {
+                    let e = entries.get(id)?;
+                    let score = self.frecency.frecency_score(id).max(1);
+                    Some(SearchResult {
+                        id: ResultId::new(id),
+                        title: ResultTitle::new(e.name.as_str()),
+                        description: e.category.clone(),
+                        icon: e.icon.clone(),
+                        score: Score::new(score),
+                        action: LaunchAction::SpawnProcess(e.exec.clone()),
+                    })
+                })
+                .collect();
+        }
+
+        let query_lowercase = query.to_lowercase();
+        let first_char = query_lowercase.chars().next().unwrap_or_default();
+        let mut matcher = new_matcher();
+        let pattern = parse_pattern(query);
+        let mut char_buf: Vec<char> = Vec::with_capacity(64);
+
+        entries
+            .values()
+            .filter(|e| {
+                e.name_lowercase.contains(first_char)
+                    || e.keywords_lowercase.iter().any(|k| k.contains(first_char))
+            })
+            .filter_map(|e| {
+                let match_score = score_match(
+                    &mut matcher,
+                    &pattern,
+                    e.name.as_str(),
+                    &mut char_buf,
+                    &e.name_lowercase,
+                    &query_lowercase,
+                )
+                .or_else(|| {
+                    e.keywords_lowercase
+                        .iter()
+                        .any(|k| k.contains(query_lowercase.as_str()))
+                        .then_some(KEYWORD_MATCH_SCORE)
+                })?;
+                let frecency_boost = self.frecency.frecency_score(&e.id);
+                Some(SearchResult {
+                    id: ResultId::new(&e.id),
+                    title: ResultTitle::new(e.name.as_str()),
+                    description: e.category.clone(),
+                    icon: e.icon.clone(),
+                    score: Score::new(match_score.saturating_add(frecency_boost)),
+                    action: LaunchAction::SpawnProcess(e.exec.clone()),
+                })
+            })
+            .collect()
+    }
+}

crates/plugins/plugin-apps/src/scoring.rs

@@ -0,0 +1,60 @@
+pub use nucleo_matcher::Matcher;
+use nucleo_matcher::{
+    Config, Utf32Str,
+    pattern::{CaseMatching, Normalization, Pattern},
+};
+
+pub fn new_matcher() -> Matcher {
+    Matcher::new(Config::DEFAULT)
+}
+
+pub fn parse_pattern(query: &str) -> Pattern {
+    Pattern::parse(query, CaseMatching::Ignore, Normalization::Smart)
+}
+
+fn matches_initials(name_lowercase: &str, query_lowercase: &str) -> bool {
+    let mut initials = name_lowercase
+        .split_whitespace()
+        .filter_map(|w| w.chars().next());
+    let mut query_chars = query_lowercase.chars();
+
+    for expected in &mut query_chars {
+        match initials.next() {
+            Some(initial) if initial == expected => continue,
+            _ => return false,
+        }
+    }
+    true
+}
+
+const INITIALS_BONUS: u32 = 20;
+
+pub fn score_match(
+    matcher: &mut Matcher,
+    pattern: &Pattern,
+    name: &str,
+    char_buf: &mut Vec<char>,
+    name_lowercase: &str,
+    query_lowercase: &str,
+) -> Option<u32> {
+    let haystack = Utf32Str::new(name, char_buf);
+    let score = pattern.score(haystack, matcher)?;
+
+    let bonus = if matches_initials(name_lowercase, query_lowercase) {
+        INITIALS_BONUS
+    } else {
+        0
+    };
+    Some(score.saturating_add(bonus))
+}
+
+pub fn humanize_category(s: &str) -> String {
+    let mut result = String::new();
+    for ch in s.chars() {
+        if ch.is_uppercase() && !result.is_empty() {
+            result.push(' ');
+        }
+        result.push(ch);
+    }
+    result
+}

crates/plugins/plugin-apps/src/types.rs

@@ -0,0 +1,53 @@
+// --- Domain newtypes ---
+
+#[derive(Debug, Clone)]
+pub struct AppName(String);
+
+impl AppName {
+    pub fn new(s: impl Into<String>) -> Self {
+        Self(s.into())
+    }
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ExecCommand(String);
+
+impl ExecCommand {
+    pub fn new(s: impl Into<String>) -> Self {
+        Self(s.into())
+    }
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct IconPath(String);
+
+impl IconPath {
+    pub fn new(s: impl Into<String>) -> Self {
+        Self(s.into())
+    }
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+// --- Desktop entry ---
+
+pub struct DesktopEntry {
+    pub name: AppName,
+    pub exec: ExecCommand,
+    pub icon: Option<IconPath>,
+    pub category: Option<String>,
+    pub keywords: Vec<String>,
+}
+
+// --- Swappable source trait (Application layer principle) ---
+
+pub trait DesktopEntrySource: Send + Sync {
+    fn entries(&self) -> Vec<DesktopEntry>;
+}

crates/plugins/plugin-apps/tests/frecency.rs

@@ -0,0 +1,21 @@
+use plugin_apps::frecency::FrecencyStore;
+
+#[test]
+fn record_increments_count() {
+    let store = FrecencyStore::new_for_test();
+    store.record("app-firefox");
+    store.record("app-firefox");
+    assert!(store.frecency_score("app-firefox") > 0);
+}
+
+#[test]
+fn top_ids_returns_sorted_order() {
+    let store = FrecencyStore::new_for_test();
+    store.record("app-firefox");
+    store.record("app-code");
+    store.record("app-code");
+    store.record("app-code");
+    let top = store.top_ids(2);
+    assert_eq!(top[0], "app-code");
+    assert_eq!(top[1], "app-firefox");
+}

crates/plugins/plugin-apps/tests/linux.rs

@@ -0,0 +1,27 @@
+#[cfg(target_os = "linux")]
+mod linux_tests {
+    use plugin_apps::linux::clean_exec;
+
+    #[test]
+    fn strips_bare_field_code() {
+        assert_eq!(clean_exec("app --file %f"), "app --file");
+    }
+
+    #[test]
+    fn strips_multiple_field_codes() {
+        assert_eq!(clean_exec("app %U --flag"), "app --flag");
+    }
+
+    #[test]
+    fn preserves_quoted_value() {
+        assert_eq!(
+            clean_exec(r#"app --arg="value" %U"#),
+            r#"app --arg="value""#
+        );
+    }
+
+    #[test]
+    fn handles_plain_exec() {
+        assert_eq!(clean_exec("firefox"), "firefox");
+    }
+}

crates/plugins/plugin-apps/tests/plugin.rs

@@ -0,0 +1,260 @@
+use std::sync::Arc;
+
+use k_launcher_domain::Plugin;
+use plugin_apps::frecency::FrecencyStore;
+use plugin_apps::{
+    AppName, AppsPlugin, DesktopEntry, DesktopEntrySource, ExecCommand, build_entries,
+    humanize_category, load_from_path, new_matcher, parse_pattern, save_to_path, score_match,
+};
+
+fn ephemeral_frecency() -> Arc<FrecencyStore> {
+    FrecencyStore::new_for_test()
+}
+
+struct MockEntry {
+    name: String,
+    exec: String,
+    category: Option<String>,
+    keywords: Vec<String>,
+}
+
+struct MockSource {
+    entries: Vec<MockEntry>,
+}
+
+impl MockSource {
+    fn with(entries: Vec<(&str, &str)>) -> Self {
+        Self {
+            entries: entries
+                .into_iter()
+                .map(|(n, e)| MockEntry {
+                    name: n.to_string(),
+                    exec: e.to_string(),
+                    category: None,
+                    keywords: vec![],
+                })
+                .collect(),
+        }
+    }
+
+    fn with_categories(entries: Vec<(&str, &str, &str)>) -> Self {
+        Self {
+            entries: entries
+                .into_iter()
+                .map(|(n, e, c)| MockEntry {
+                    name: n.to_string(),
+                    exec: e.to_string(),
+                    category: Some(c.to_string()),
+                    keywords: vec![],
+                })
+                .collect(),
+        }
+    }
+
+    fn with_keywords(entries: Vec<(&str, &str, Vec<&str>)>) -> Self {
+        Self {
+            entries: entries
+                .into_iter()
+                .map(|(n, e, kw)| MockEntry {
+                    name: n.to_string(),
+                    exec: e.to_string(),
+                    category: None,
+                    keywords: kw.into_iter().map(|s| s.to_string()).collect(),
+                })
+                .collect(),
+        }
+    }
+}
+
+impl DesktopEntrySource for MockSource {
+    fn entries(&self) -> Vec<DesktopEntry> {
+        self.entries
+            .iter()
+            .map(|e| DesktopEntry {
+                name: AppName::new(e.name.clone()),
+                exec: ExecCommand::new(e.exec.clone()),
+                icon: None,
+                category: e.category.clone(),
+                keywords: e.keywords.clone(),
+            })
+            .collect()
+    }
+}
+
+#[tokio::test]
+async fn apps_prefix_match() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Firefox", "firefox")]),
+        ephemeral_frecency(),
+    );
+    let results = p.search("fire").await;
+    assert_eq!(results[0].title.as_str(), "Firefox");
+}
+
+#[tokio::test]
+async fn apps_no_match_returns_empty() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Firefox", "firefox")]),
+        ephemeral_frecency(),
+    );
+    assert!(p.search("zz").await.is_empty());
+}
+
+#[tokio::test]
+async fn apps_empty_query_no_frecency_returns_empty() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Firefox", "firefox")]),
+        ephemeral_frecency(),
+    );
+    assert!(p.search("").await.is_empty());
+}
+
+#[test]
+fn score_match_abbreviation() {
+    let mut matcher = new_matcher();
+    let pattern = parse_pattern("vsc");
+    let mut buf = Vec::new();
+    assert!(
+        score_match(
+            &mut matcher,
+            &pattern,
+            "visual studio code",
+            &mut buf,
+            "visual studio code",
+            "vsc"
+        )
+        .is_some()
+    );
+}
+
+#[test]
+fn score_match_exact_beats_prefix() {
+    let mut matcher = new_matcher();
+    let mut buf = Vec::new();
+    let exact_pattern = parse_pattern("firefox");
+    let fire_pattern = parse_pattern("fire");
+    let gf_pattern = parse_pattern("gf");
+
+    let exact = score_match(
+        &mut matcher,
+        &exact_pattern,
+        "firefox",
+        &mut buf,
+        "firefox",
+        "firefox",
+    );
+    let prefix = score_match(
+        &mut matcher,
+        &fire_pattern,
+        "firefox",
+        &mut buf,
+        "firefox",
+        "fire",
+    );
+    let abbrev = score_match(
+        &mut matcher,
+        &gf_pattern,
+        "gnu firefox",
+        &mut buf,
+        "gnu firefox",
+        "gf",
+    );
+    let substr = score_match(
+        &mut matcher,
+        &fire_pattern,
+        "ice firefox",
+        &mut buf,
+        "ice firefox",
+        "fire",
+    );
+    assert!(exact.is_some());
+    assert!(prefix.is_some());
+    assert!(abbrev.is_some());
+    assert!(substr.is_some());
+    assert!(exact.unwrap() > prefix.unwrap());
+}
+
+#[tokio::test]
+async fn apps_abbreviation_match() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Visual Studio Code", "code")]),
+        ephemeral_frecency(),
+    );
+    let results = p.search("vsc").await;
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].title.as_str(), "Visual Studio Code");
+    assert!(results[0].score.value() > 0);
+}
+
+#[tokio::test]
+async fn apps_keyword_match() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with_keywords(vec![("Code", "code", vec!["editor", "ide"])]),
+        ephemeral_frecency(),
+    );
+    let results = p.search("editor").await;
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].score.value(), 50);
+}
+
+#[tokio::test]
+async fn apps_fuzzy_typo_match() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Firefox", "firefox")]),
+        ephemeral_frecency(),
+    );
+    let results = p.search("frefox").await;
+    assert!(
+        !results.is_empty(),
+        "nucleo should fuzzy-match 'frefox' to 'Firefox'"
+    );
+    assert!(results[0].score.value() > 0);
+}
+
+#[test]
+fn humanize_category_splits_camel_case() {
+    assert_eq!(humanize_category("TextEditor"), "Text Editor");
+    assert_eq!(humanize_category("WebBrowser"), "Web Browser");
+    assert_eq!(humanize_category("Development"), "Development");
+}
+
+#[tokio::test]
+async fn apps_category_appears_in_description() {
+    let p = AppsPlugin::new_for_test(
+        MockSource::with_categories(vec![("Code", "code", "Text Editor")]),
+        ephemeral_frecency(),
+    );
+    let results = p.search("code").await;
+    assert_eq!(results[0].description.as_deref(), Some("Text Editor"));
+}
+
+#[tokio::test]
+async fn apps_empty_query_returns_top_frecent() {
+    let frecency = ephemeral_frecency();
+    frecency.record("app-Code:code");
+    frecency.record("app-Code:code");
+    frecency.record("app-Firefox:firefox");
+    let p = AppsPlugin::new_for_test(
+        MockSource::with(vec![("Firefox", "firefox"), ("Code", "code")]),
+        frecency,
+    );
+    let results = p.search("").await;
+    assert_eq!(results.len(), 2);
+    assert_eq!(results[0].title.as_str(), "Code");
+}
+
+#[test]
+fn apps_loads_from_cache_when_source_is_empty() {
+    let frecency = ephemeral_frecency();
+    let cache_file =
+        std::env::temp_dir().join(format!("k-launcher-test-{}.bin", std::process::id()));
+
+    let source = MockSource::with(vec![("Firefox", "firefox")]);
+    let entries = build_entries(&source, &frecency);
+    save_to_path(&cache_file, &entries);
+
+    let loaded = load_from_path(&cache_file).unwrap();
+    assert!(loaded.contains_key("app-Firefox:firefox"));
+
+    std::fs::remove_file(&cache_file).ok();
+}

crates/plugins/plugin-calc/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "plugin-calc"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -10,5 +10,9 @@ path = "src/lib.rs"
 [dependencies]
 async-trait = { workspace = true }
 evalexpr = "13"
-k-launcher-kernel = { path = "../../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
+tokio = { workspace = true }
+
+[dev-dependencies]
+k-launcher-domain = { workspace = true }
 tokio = { workspace = true }

crates/plugins/plugin-calc/src/eval.rs

@@ -0,0 +1,45 @@
+use std::sync::LazyLock;
+
+pub(crate) const MATH_FNS: &[&str] = &[
+    "sqrt", "sin", "cos", "tan", "asin", "acos", "atan", "ln", "log2", "log10", "exp", "abs",
+    "ceil", "floor", "round",
+];
+
+pub(crate) fn strip_numeric_separators(expr: &str) -> String {
+    expr.replace('_', "")
+}
+
+pub(crate) fn should_eval(query: &str) -> bool {
+    let q = query.strip_prefix('=').unwrap_or(query);
+    q.chars()
+        .next()
+        .map(|c| c.is_ascii_digit() || c == '(' || c == '-')
+        .unwrap_or(false)
+        || query.starts_with('=')
+        || MATH_FNS.iter().any(|f| q.starts_with(f))
+}
+
+pub(crate) static MATH_CTX: LazyLock<evalexpr::HashMapContext<evalexpr::DefaultNumericTypes>> =
+    LazyLock::new(|| {
+        use evalexpr::*;
+        context_map! {
+            "pi" => float std::f64::consts::PI,
+            "e"  => float std::f64::consts::E,
+            "sqrt"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.sqrt()))),
+            "sin"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.sin()))),
+            "cos"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.cos()))),
+            "tan"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.tan()))),
+            "asin"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.asin()))),
+            "acos"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.acos()))),
+            "atan"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.atan()))),
+            "ln"    => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.ln()))),
+            "log2"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.log2()))),
+            "log10" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.log10()))),
+            "exp"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.exp()))),
+            "abs"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.abs()))),
+            "ceil"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.ceil()))),
+            "floor" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.floor()))),
+            "round" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.round())))
+        }
+        .expect("static math context must be valid")
+    });

crates/plugins/plugin-calc/src/lib.rs

@@ -1,154 +1,4 @@
-use async_trait::async_trait;
-use evalexpr::eval_number_with_context;
-use k_launcher_kernel::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
-use std::sync::LazyLock;
+mod eval;
+mod plugin;
 
-pub struct CalcPlugin;
-
-impl CalcPlugin {
-    pub fn new() -> Self {
-        Self
-    }
-}
-
-impl Default for CalcPlugin {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-fn strip_numeric_separators(expr: &str) -> String {
-    expr.replace('_', "")
-}
-
-const MATH_FNS: &[&str] = &[
-    "sqrt", "sin", "cos", "tan", "asin", "acos", "atan", "ln", "log2", "log10", "exp", "abs",
-    "ceil", "floor", "round",
-];
-
-fn should_eval(query: &str) -> bool {
-    let q = query.strip_prefix('=').unwrap_or(query);
-    q.chars()
-        .next()
-        .map(|c| c.is_ascii_digit() || c == '(' || c == '-')
-        .unwrap_or(false)
-        || query.starts_with('=')
-        || MATH_FNS.iter().any(|f| q.starts_with(f))
-}
-
-static MATH_CTX: LazyLock<evalexpr::HashMapContext<evalexpr::DefaultNumericTypes>> = LazyLock::new(
-    || {
-        use evalexpr::*;
-        context_map! {
-            "pi" => float std::f64::consts::PI,
-            "e"  => float std::f64::consts::E,
-            "sqrt"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.sqrt()))),
-            "sin"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.sin()))),
-            "cos"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.cos()))),
-            "tan"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.tan()))),
-            "asin"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.asin()))),
-            "acos"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.acos()))),
-            "atan"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.atan()))),
-            "ln"    => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.ln()))),
-            "log2"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.log2()))),
-            "log10" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.log10()))),
-            "exp"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.exp()))),
-            "abs"   => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.abs()))),
-            "ceil"  => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.ceil()))),
-            "floor" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.floor()))),
-            "round" => Function::new(|a: &Value<DefaultNumericTypes>| Ok(Value::from_float(a.as_number()?.round())))
-        }
-        .expect("static math context must be valid")
-    },
-);
-
-#[async_trait]
-impl Plugin for CalcPlugin {
-    fn name(&self) -> &str {
-        "calc"
-    }
-
-    async fn search(&self, query: &str) -> Vec<SearchResult> {
-        if !should_eval(query) {
-            return vec![];
-        }
-        let raw = query.strip_prefix('=').unwrap_or(query);
-        let expr_owned = strip_numeric_separators(raw);
-        let expr = expr_owned.as_str();
-        match eval_number_with_context(expr, &*MATH_CTX) {
-            Ok(n) if n.is_finite() => {
-                let value_str = if n.fract() == 0.0 {
-                    format!("{}", n as i64)
-                } else {
-                    format!("{n}")
-                };
-                let display = format!("= {value_str}");
-                vec![SearchResult {
-                    id: ResultId::new("calc-result"),
-                    title: ResultTitle::new(display),
-                    description: Some(format!("{expr_owned} · Enter to copy")),
-                    icon: None,
-                    score: Score::new(90),
-                    action: LaunchAction::CopyToClipboard(value_str),
-                }]
-            }
-            _ => vec![],
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[tokio::test]
-    async fn calc_valid_expr() {
-        let p = CalcPlugin::new();
-        let results = p.search("2+2").await;
-        assert_eq!(results[0].title.as_str(), "= 4");
-    }
-
-    #[tokio::test]
-    async fn calc_non_numeric_returns_empty() {
-        let p = CalcPlugin::new();
-        assert!(p.search("firefox").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn calc_bad_expr_returns_empty() {
-        let p = CalcPlugin::new();
-        assert!(p.search("1/0").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn calc_sqrt() {
-        let p = CalcPlugin::new();
-        let results = p.search("sqrt(9)").await;
-        assert_eq!(results[0].title.as_str(), "= 3");
-    }
-
-    #[tokio::test]
-    async fn calc_sin_pi() {
-        let p = CalcPlugin::new();
-        let results = p.search("sin(pi)").await;
-        assert!(!results.is_empty());
-        let title = results[0].title.as_str();
-        let val: f64 = title.trim_start_matches("= ").parse().unwrap();
-        assert!(val.abs() < 1e-10, "sin(pi) should be near zero, got {val}");
-    }
-
-    #[tokio::test]
-    async fn calc_underscore_separator() {
-        let p = CalcPlugin::new();
-        let results = p.search("1_000 * 2").await;
-        assert_eq!(results[0].title.as_str(), "= 2000");
-        assert_eq!(
-            results[0].description.as_deref(),
-            Some("1000 * 2 · Enter to copy")
-        );
-        assert!(matches!(
-            &results[0].action,
-            LaunchAction::CopyToClipboard(v) if v == "2000"
-        ));
-    }
-}
+pub use plugin::*;

crates/plugins/plugin-calc/src/plugin.rs

@@ -0,0 +1,59 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use evalexpr::eval_number_with_context;
+use k_launcher_domain::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+
+use crate::eval::{MATH_CTX, should_eval, strip_numeric_separators};
+
+const RESULT_ID: &str = "calc-result";
+const RESULT_SCORE: u32 = 90;
+
+pub struct CalcPlugin;
+
+impl CalcPlugin {
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl Default for CalcPlugin {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[async_trait]
+impl Plugin for CalcPlugin {
+    fn name(&self) -> &str {
+        "calc"
+    }
+
+    async fn search(&self, query: &str) -> Vec<SearchResult> {
+        if !should_eval(query) {
+            return vec![];
+        }
+        let raw = query.strip_prefix('=').unwrap_or(query);
+        let expr_owned = strip_numeric_separators(raw);
+        let expr = expr_owned.as_str();
+        match eval_number_with_context(expr, &*MATH_CTX) {
+            Ok(n) if n.is_finite() => {
+                let value_str = if n.fract() == 0.0 {
+                    format!("{}", n as i64)
+                } else {
+                    format!("{n}")
+                };
+                let display = format!("= {value_str}");
+                vec![SearchResult {
+                    id: ResultId::new(RESULT_ID),
+                    title: ResultTitle::new(display),
+                    description: Some(Arc::from(format!("{expr_owned} · Enter to copy"))),
+                    icon: None,
+                    score: Score::new(RESULT_SCORE),
+                    action: LaunchAction::CopyToClipboard(value_str),
+                }]
+            }
+            _ => vec![],
+        }
+    }
+}

crates/plugins/plugin-calc/tests/calc.rs

@@ -0,0 +1,53 @@
+use k_launcher_domain::{LaunchAction, Plugin};
+use plugin_calc::CalcPlugin;
+
+#[tokio::test]
+async fn calc_valid_expr() {
+    let p = CalcPlugin::new();
+    let results = p.search("2+2").await;
+    assert_eq!(results[0].title.as_str(), "= 4");
+}
+
+#[tokio::test]
+async fn calc_non_numeric_returns_empty() {
+    let p = CalcPlugin::new();
+    assert!(p.search("firefox").await.is_empty());
+}
+
+#[tokio::test]
+async fn calc_bad_expr_returns_empty() {
+    let p = CalcPlugin::new();
+    assert!(p.search("1/0").await.is_empty());
+}
+
+#[tokio::test]
+async fn calc_sqrt() {
+    let p = CalcPlugin::new();
+    let results = p.search("sqrt(9)").await;
+    assert_eq!(results[0].title.as_str(), "= 3");
+}
+
+#[tokio::test]
+async fn calc_sin_pi() {
+    let p = CalcPlugin::new();
+    let results = p.search("sin(pi)").await;
+    assert!(!results.is_empty());
+    let title = results[0].title.as_str();
+    let val: f64 = title.trim_start_matches("= ").parse().unwrap();
+    assert!(val.abs() < 1e-10, "sin(pi) should be near zero, got {val}");
+}
+
+#[tokio::test]
+async fn calc_underscore_separator() {
+    let p = CalcPlugin::new();
+    let results = p.search("1_000 * 2").await;
+    assert_eq!(results[0].title.as_str(), "= 2000");
+    assert_eq!(
+        results[0].description.as_deref(),
+        Some("1000 * 2 · Enter to copy")
+    );
+    assert!(matches!(
+        &results[0].action,
+        LaunchAction::CopyToClipboard(v) if v == "2000"
+    ));
+}

crates/plugins/plugin-cmd/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "plugin-cmd"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -9,7 +9,8 @@ path = "src/lib.rs"
 
 [dependencies]
 async-trait = { workspace = true }
-k-launcher-kernel = { path = "../../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
 
 [dev-dependencies]
+k-launcher-domain = { workspace = true }
 tokio = { workspace = true }

crates/plugins/plugin-cmd/src/lib.rs

@@ -1,5 +1,8 @@
 use async_trait::async_trait;
-use k_launcher_kernel::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+use k_launcher_domain::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+
+const CMD_PREFIX: char = '>';
+const RESULT_SCORE: u32 = 95;
 
 pub struct CmdPlugin;
 
@@ -22,7 +25,7 @@ impl Plugin for CmdPlugin {
     }
 
     async fn search(&self, query: &str) -> Vec<SearchResult> {
-        let Some(rest) = query.strip_prefix('>') else {
+        let Some(rest) = query.strip_prefix(CMD_PREFIX) else {
             return vec![];
         };
         let cmd = rest.trim();
@@ -34,36 +37,8 @@ impl Plugin for CmdPlugin {
             title: ResultTitle::new(format!("Run: {cmd}")),
             description: None,
             icon: None,
-            score: Score::new(95),
+            score: Score::new(RESULT_SCORE),
             action: LaunchAction::SpawnInTerminal(cmd.to_string()),
         }]
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[tokio::test]
-    async fn cmd_prefix_triggers() {
-        let p = CmdPlugin::new();
-        let results = p.search("> echo hello").await;
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].title.as_str(), "Run: echo hello");
-        assert_eq!(results[0].score.value(), 95);
-    }
-
-    #[tokio::test]
-    async fn cmd_empty_remainder_returns_empty() {
-        let p = CmdPlugin::new();
-        assert!(p.search(">").await.is_empty());
-        assert!(p.search(">   ").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn cmd_no_prefix_returns_empty() {
-        let p = CmdPlugin::new();
-        assert!(p.search("echo hello").await.is_empty());
-        assert!(p.search("firefox").await.is_empty());
-    }
-}

crates/plugins/plugin-cmd/tests/cmd.rs

@@ -0,0 +1,25 @@
+use k_launcher_domain::Plugin;
+use plugin_cmd::CmdPlugin;
+
+#[tokio::test]
+async fn cmd_prefix_triggers() {
+    let p = CmdPlugin::new();
+    let results = p.search("> echo hello").await;
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].title.as_str(), "Run: echo hello");
+    assert_eq!(results[0].score.value(), 95);
+}
+
+#[tokio::test]
+async fn cmd_empty_remainder_returns_empty() {
+    let p = CmdPlugin::new();
+    assert!(p.search(">").await.is_empty());
+    assert!(p.search(">   ").await.is_empty());
+}
+
+#[tokio::test]
+async fn cmd_no_prefix_returns_empty() {
+    let p = CmdPlugin::new();
+    assert!(p.search("echo hello").await.is_empty());
+    assert!(p.search("firefox").await.is_empty());
+}

crates/plugins/plugin-files/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "plugin-files"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
 [lib]
@@ -9,5 +9,9 @@ path = "src/lib.rs"
 
 [dependencies]
 async-trait = { workspace = true }
-k-launcher-kernel = { path = "../../k-launcher-kernel" }
+k-launcher-domain = { workspace = true }
+tokio = { workspace = true }
+
+[dev-dependencies]
+k-launcher-domain = { workspace = true }
 tokio = { workspace = true }

crates/plugins/plugin-files/src/lib.rs

@@ -2,8 +2,13 @@ mod platform;
 
 use std::path::Path;
 
+use std::sync::Arc;
+
 use async_trait::async_trait;
-use k_launcher_kernel::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+use k_launcher_domain::{LaunchAction, Plugin, ResultId, ResultTitle, Score, SearchResult};
+
+const MAX_FILE_RESULTS: usize = 20;
+const RESULT_SCORE: u32 = 50;
 
 pub struct FilesPlugin;
 
@@ -70,7 +75,7 @@ impl Plugin for FilesPlugin {
                     .map(|n| n.to_lowercase().starts_with(&prefix))
                     .unwrap_or(false)
             })
-            .take(20)
+            .take(MAX_FILE_RESULTS)
             .map(|entry| {
                 let full_path = entry.path();
                 let name = entry.file_name().to_string_lossy().to_string();
@@ -80,30 +85,12 @@ impl Plugin for FilesPlugin {
                 SearchResult {
                     id: ResultId::new(&path_str),
                     title: ResultTitle::new(title),
-                    description: Some(path_str.clone()),
+                    description: Some(Arc::from(path_str.as_str())),
                     icon: None,
-                    score: Score::new(50),
+                    score: Score::new(RESULT_SCORE),
                     action: LaunchAction::OpenPath(path_str),
                 }
             })
             .collect()
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[tokio::test]
-    async fn files_ignores_non_path_query() {
-        let p = FilesPlugin::new();
-        assert!(p.search("firefox").await.is_empty());
-    }
-
-    #[tokio::test]
-    async fn files_handles_root() {
-        let p = FilesPlugin::new();
-        let results = p.search("/").await;
-        assert!(!results.is_empty());
-    }
-}

crates/plugins/plugin-files/tests/files.rs

@@ -0,0 +1,15 @@
+use k_launcher_domain::Plugin;
+use plugin_files::FilesPlugin;
+
+#[tokio::test]
+async fn files_ignores_non_path_query() {
+    let p = FilesPlugin::new();
+    assert!(p.search("firefox").await.is_empty());
+}
+
+#[tokio::test]
+async fn files_handles_root() {
+    let p = FilesPlugin::new();
+    let results = p.search("/").await;
+    assert!(!results.is_empty());
+}

crates/plugins/plugin-url/Cargo.toml

@@ -1,8 +1,12 @@
 [package]
 name = "plugin-url"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
 
+[lib]
+name = "plugin_url"
+path = "src/lib.rs"
+
 [[bin]]
 name = "k-launcher-plugin-url"
 path = "src/main.rs"
@@ -10,3 +14,6 @@ path = "src/main.rs"
 [dependencies]
 serde = { workspace = true }
 serde_json = { workspace = true }
+
+[dev-dependencies]
+serde_json = { workspace = true }

crates/plugins/plugin-url/src/lib.rs

@@ -0,0 +1,60 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Deserialize)]
+pub struct Query {
+    pub query: String,
+}
+
+#[derive(Serialize)]
+pub struct Action {
+    pub r#type: &'static str,
+    pub path: String,
+}
+
+#[derive(Serialize)]
+pub struct UrlResult {
+    pub id: &'static str,
+    pub title: &'static str,
+    pub description: String,
+    pub score: u32,
+    pub action: Action,
+}
+
+const HTTP_PREFIX: &str = "http://";
+const HTTPS_PREFIX: &str = "https://";
+const WWW_PREFIX: &str = "www.";
+const RESULT_ID: &str = "url-open";
+const RESULT_TITLE: &str = "Open in Browser";
+const RESULT_SCORE: u32 = 95;
+const ACTION_TYPE: &str = "OpenPath";
+
+pub fn is_url(query: &str) -> bool {
+    query.starts_with(HTTP_PREFIX)
+        || query.starts_with(HTTPS_PREFIX)
+        || query.starts_with(WWW_PREFIX)
+}
+
+pub fn normalize(query: &str) -> String {
+    if query.starts_with(WWW_PREFIX) {
+        format!("{HTTPS_PREFIX}{query}")
+    } else {
+        query.to_string()
+    }
+}
+
+pub fn search(query: &str) -> Vec<UrlResult> {
+    if !is_url(query) {
+        return vec![];
+    }
+    let url = normalize(query);
+    vec![UrlResult {
+        id: RESULT_ID,
+        title: RESULT_TITLE,
+        description: url.clone(),
+        score: RESULT_SCORE,
+        action: Action {
+            r#type: ACTION_TYPE,
+            path: url,
+        },
+    }]
+}

crates/plugins/plugin-url/src/main.rs

@@ -1,55 +1,6 @@
 use std::io::{self, BufRead, Write};
 
-use serde::{Deserialize, Serialize};
-
-#[derive(Deserialize)]
-struct Query {
-    query: String,
-}
-
-#[derive(Serialize)]
-struct Action {
-    r#type: &'static str,
-    path: String,
-}
-
-#[derive(Serialize)]
-struct Result {
-    id: &'static str,
-    title: &'static str,
-    description: String,
-    score: u32,
-    action: Action,
-}
-
-fn is_url(query: &str) -> bool {
-    query.starts_with("http://") || query.starts_with("https://") || query.starts_with("www.")
-}
-
-fn normalize(query: &str) -> String {
-    if query.starts_with("www.") {
-        format!("https://{query}")
-    } else {
-        query.to_string()
-    }
-}
-
-fn search(query: &str) -> Vec<Result> {
-    if !is_url(query) {
-        return vec![];
-    }
-    let url = normalize(query);
-    vec![Result {
-        id: "url-open",
-        title: "Open in Browser",
-        description: url.clone(),
-        score: 95,
-        action: Action {
-            r#type: "OpenPath",
-            path: url.clone(),
-        },
-    }]
-}
+use plugin_url::{Query, search};
 
 fn main() -> io::Result<()> {
     let stdin = io::stdin();
@@ -68,63 +19,3 @@ fn main() -> io::Result<()> {
     }
     Ok(())
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn is_url_https() {
-        assert!(is_url("https://example.com"));
-    }
-
-    #[test]
-    fn is_url_http() {
-        assert!(is_url("http://example.com"));
-    }
-
-    #[test]
-    fn is_url_www() {
-        assert!(is_url("www.foo.com"));
-    }
-
-    #[test]
-    fn is_url_plain() {
-        assert!(!is_url("firefox"));
-    }
-
-    #[test]
-    fn is_url_empty() {
-        assert!(!is_url(""));
-    }
-
-    #[test]
-    fn normalize_www() {
-        assert_eq!(normalize("www.foo.com"), "https://www.foo.com");
-    }
-
-    #[test]
-    fn normalize_https() {
-        assert_eq!(normalize("https://example.com"), "https://example.com");
-    }
-
-    #[test]
-    fn search_returns_result() {
-        let results = search("https://example.com");
-        assert_eq!(results.len(), 1);
-        assert_eq!(results[0].action.path, "https://example.com");
-    }
-
-    #[test]
-    fn search_returns_empty() {
-        assert!(search("firefox").is_empty());
-    }
-
-    #[test]
-    fn result_serializes() {
-        let results = search("https://example.com");
-        let json = serde_json::to_string(&results).unwrap();
-        assert!(json.contains("OpenPath"));
-        assert!(json.contains("https://example.com"));
-    }
-}

crates/plugins/plugin-url/tests/url.rs

@@ -0,0 +1,56 @@
+use plugin_url::{is_url, normalize, search};
+
+#[test]
+fn is_url_https() {
+    assert!(is_url("https://example.com"));
+}
+
+#[test]
+fn is_url_http() {
+    assert!(is_url("http://example.com"));
+}
+
+#[test]
+fn is_url_www() {
+    assert!(is_url("www.foo.com"));
+}
+
+#[test]
+fn is_url_plain() {
+    assert!(!is_url("firefox"));
+}
+
+#[test]
+fn is_url_empty() {
+    assert!(!is_url(""));
+}
+
+#[test]
+fn normalize_www() {
+    assert_eq!(normalize("www.foo.com"), "https://www.foo.com");
+}
+
+#[test]
+fn normalize_https() {
+    assert_eq!(normalize("https://example.com"), "https://example.com");
+}
+
+#[test]
+fn search_returns_result() {
+    let results = search("https://example.com");
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].action.path, "https://example.com");
+}
+
+#[test]
+fn search_returns_empty() {
+    assert!(search("firefox").is_empty());
+}
+
+#[test]
+fn result_serializes() {
+    let results = search("https://example.com");
+    let json = serde_json::to_string(&results).unwrap();
+    assert!(json.contains("OpenPath"));
+    assert!(json.contains("https://example.com"));
+}