feat: add ability to configure the agent (also theme switcher) (#3)

### Explanation

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### Issue

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### Attestations

- [ ] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [ ] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [ ] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

- [ ] I have run the linter and resolved any errors.
- [ ] My pull request uses an appropriate title, matching the conventional commit standards.
- [ ] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

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### Versioning

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Reviewed-on: #3
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src-tauri/Cargo.lock

@@ -1403,6 +1403,8 @@ dependencies = [
  "tauri-plugin-dialog",
  "tauri-plugin-opener",
  "tauri-plugin-shell",
+ "tauri-plugin-store",
+ "tempfile",
  "tokio",
  "uuid",
 ]
@@ -3761,6 +3763,22 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "tauri-plugin-store"
+version = "2.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca1a8ff83c269b115e98726ffc13f9e548a10161544a92ad121d6d0a96e16ea"
+dependencies = [
+ "dunce",
+ "serde",
+ "serde_json",
+ "tauri",
+ "tauri-plugin",
+ "thiserror 2.0.17",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "tauri-runtime"
 version = "2.9.2"

src-tauri/Cargo.toml

@@ -22,4 +22,6 @@ serde_json = "1"
 tokio = { version = "1", features = ["full"] }
 parking_lot = "0.12"
 uuid = { version = "1", features = ["v4"] }
+tauri-plugin-store = "2.4.2"
+tempfile = "3"
 

src-tauri/src/commands.rs

@@ -1,16 +1,19 @@
 use tauri::{AppHandle, State};
+use tauri_plugin_store::StoreExt;
 
+use crate::config::{ClaudeStartOptions, HikariConfig};
 use crate::wsl_bridge::SharedBridge;
 
+const CONFIG_STORE_KEY: &str = "config";
+
 #[tauri::command]
 pub async fn start_claude(
     app: AppHandle,
     bridge: State<'_, SharedBridge>,
-    working_dir: String,
-    allowed_tools: Option<Vec<String>>,
+    options: ClaudeStartOptions,
 ) -> Result<(), String> {
     let mut bridge = bridge.lock();
-    bridge.start(app, &working_dir, allowed_tools.unwrap_or_default())
+    bridge.start(app, options)
 }
 
 #[tauri::command]
@@ -42,3 +45,30 @@ pub async fn get_working_directory(bridge: State<'_, SharedBridge>) -> Result<St
 pub async fn select_wsl_directory() -> Result<String, String> {
     Ok("/home".to_string())
 }
+
+#[tauri::command]
+pub async fn get_config(app: AppHandle) -> Result<HikariConfig, String> {
+    let store = app
+        .store("hikari-config.json")
+        .map_err(|e| e.to_string())?;
+
+    match store.get(CONFIG_STORE_KEY) {
+        Some(value) => {
+            serde_json::from_value(value.clone()).map_err(|e| e.to_string())
+        }
+        None => Ok(HikariConfig::default()),
+    }
+}
+
+#[tauri::command]
+pub async fn save_config(app: AppHandle, config: HikariConfig) -> Result<(), String> {
+    let store = app
+        .store("hikari-config.json")
+        .map_err(|e| e.to_string())?;
+
+    let value = serde_json::to_value(&config).map_err(|e| e.to_string())?;
+    store.set(CONFIG_STORE_KEY, value);
+    store.save().map_err(|e| e.to_string())?;
+
+    Ok(())
+}

src-tauri/src/config.rs

@@ -0,0 +1,96 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ClaudeStartOptions {
+    #[serde(default)]
+    pub working_dir: String,
+
+    #[serde(default)]
+    pub model: Option<String>,
+
+    #[serde(default)]
+    pub api_key: Option<String>,
+
+    #[serde(default)]
+    pub custom_instructions: Option<String>,
+
+    #[serde(default)]
+    pub mcp_servers_json: Option<String>,
+
+    #[serde(default)]
+    pub allowed_tools: Vec<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct HikariConfig {
+    #[serde(default)]
+    pub model: Option<String>,
+
+    #[serde(default)]
+    pub api_key: Option<String>,
+
+    #[serde(default)]
+    pub custom_instructions: Option<String>,
+
+    #[serde(default)]
+    pub mcp_servers_json: Option<String>,
+
+    #[serde(default)]
+    pub auto_granted_tools: Vec<String>,
+
+    #[serde(default)]
+    pub theme: Theme,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum Theme {
+    #[default]
+    Dark,
+    Light,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_default_config() {
+        let config = HikariConfig::default();
+        assert!(config.model.is_none());
+        assert!(config.api_key.is_none());
+        assert!(config.custom_instructions.is_none());
+        assert!(config.mcp_servers_json.is_none());
+        assert!(config.auto_granted_tools.is_empty());
+        assert_eq!(config.theme, Theme::Dark);
+    }
+
+    #[test]
+    fn test_config_serialization() {
+        let config = HikariConfig {
+            model: Some("claude-sonnet-4-20250514".to_string()),
+            api_key: None,
+            custom_instructions: Some("Be helpful".to_string()),
+            mcp_servers_json: None,
+            auto_granted_tools: vec!["Read".to_string(), "Glob".to_string()],
+            theme: Theme::Light,
+        };
+
+        let json = serde_json::to_string(&config).unwrap();
+        let deserialized: HikariConfig = serde_json::from_str(&json).unwrap();
+
+        assert_eq!(deserialized.model, config.model);
+        assert_eq!(deserialized.custom_instructions, config.custom_instructions);
+        assert_eq!(deserialized.auto_granted_tools, config.auto_granted_tools);
+        assert_eq!(deserialized.theme, Theme::Light);
+    }
+
+    #[test]
+    fn test_theme_serialization() {
+        let dark = Theme::Dark;
+        let light = Theme::Light;
+
+        assert_eq!(serde_json::to_string(&dark).unwrap(), "\"dark\"");
+        assert_eq!(serde_json::to_string(&light).unwrap(), "\"light\"");
+    }
+}

src-tauri/src/lib.rs

@@ -1,4 +1,5 @@
 mod commands;
+mod config;
 mod types;
 mod wsl_bridge;
 
@@ -13,6 +14,7 @@ pub fn run() {
         .plugin(tauri_plugin_dialog::init())
         .plugin(tauri_plugin_opener::init())
         .plugin(tauri_plugin_shell::init())
+        .plugin(tauri_plugin_store::Builder::new().build())
         .manage(bridge)
         .invoke_handler(tauri::generate_handler![
             start_claude,
@@ -21,6 +23,8 @@ pub fn run() {
             is_claude_running,
             get_working_directory,
             select_wsl_directory,
+            get_config,
+            save_config,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");

src-tauri/src/wsl_bridge.rs

@@ -4,10 +4,12 @@ use std::process::{Child, ChildStdin, Command, Stdio};
 use std::sync::Arc;
 use std::thread;
 use tauri::{AppHandle, Emitter};
+use tempfile::NamedTempFile;
 
 #[cfg(target_os = "windows")]
 use std::os::windows::process::CommandExt;
 
+use crate::config::ClaudeStartOptions;
 use crate::types::{CharacterState, ClaudeMessage, ConnectionStatus, ContentBlock, StateChangeEvent, OutputEvent, PermissionPromptEvent};
 
 const SEARCH_TOOLS: [&str; 5] = ["Read", "Glob", "Grep", "WebSearch", "WebFetch"];
@@ -69,6 +71,7 @@ pub struct WslBridge {
     stdin: Option<ChildStdin>,
     working_directory: String,
     session_id: Option<String>,
+    mcp_config_file: Option<NamedTempFile>,
 }
 
 impl WslBridge {
@@ -78,22 +81,50 @@ impl WslBridge {
             stdin: None,
             working_directory: String::new(),
             session_id: None,
+            mcp_config_file: None,
         }
     }
 
-    pub fn start(&mut self, app: AppHandle, working_dir: &str, allowed_tools: Vec<String>) -> Result<(), String> {
+    pub fn start(&mut self, app: AppHandle, options: ClaudeStartOptions) -> Result<(), String> {
         if self.process.is_some() {
             return Err("Process already running".to_string());
         }
 
-        self.working_directory = working_dir.to_string();
+        let working_dir = &options.working_dir;
+        self.working_directory = working_dir.clone();
 
         emit_connection_status(&app, ConnectionStatus::Connecting);
 
+        // Create temp file for MCP config if provided
+        let mcp_config_path = if let Some(ref mcp_json) = options.mcp_servers_json {
+            if !mcp_json.trim().is_empty() {
+                // Validate JSON before writing
+                serde_json::from_str::<serde_json::Value>(mcp_json)
+                    .map_err(|e| format!("Invalid MCP servers JSON: {}", e))?;
+
+                let mut temp_file = NamedTempFile::new()
+                    .map_err(|e| format!("Failed to create temp file for MCP config: {}", e))?;
+                temp_file
+                    .write_all(mcp_json.as_bytes())
+                    .map_err(|e| format!("Failed to write MCP config: {}", e))?;
+                temp_file
+                    .flush()
+                    .map_err(|e| format!("Failed to flush MCP config: {}", e))?;
+
+                let path = temp_file.path().to_string_lossy().to_string();
+                self.mcp_config_file = Some(temp_file);
+                Some(path)
+            } else {
+                None
+            }
+        } else {
+            None
+        };
+
         // Detect if we're running inside WSL or on Windows
         let is_wsl = detect_wsl();
         eprintln!("[DEBUG] is_wsl: {}", is_wsl);
-        eprintln!("[DEBUG] allowed_tools: {:?}", allowed_tools);
+        eprintln!("[DEBUG] options: {:?}", options);
 
         let mut command = if is_wsl {
             // Running inside WSL - call claude directly
@@ -111,12 +142,39 @@ impl WslBridge {
                 "--verbose",
             ]);
 
+            // Add model if specified
+            if let Some(ref model) = options.model {
+                if !model.is_empty() {
+                    cmd.args(["--model", model]);
+                }
+            }
+
             // Add allowed tools if any
-            for tool in &allowed_tools {
+            for tool in &options.allowed_tools {
                 cmd.args(["--allowedTools", tool]);
             }
 
+            // Add custom instructions as system prompt if specified
+            if let Some(ref instructions) = options.custom_instructions {
+                if !instructions.is_empty() {
+                    cmd.args(["--system-prompt", instructions]);
+                }
+            }
+
+            // Add MCP config if provided
+            if let Some(ref mcp_path) = mcp_config_path {
+                cmd.args(["--mcp-config", mcp_path]);
+            }
+
             cmd.current_dir(working_dir);
+
+            // Set API key as environment variable if specified
+            if let Some(ref api_key) = options.api_key {
+                if !api_key.is_empty() {
+                    cmd.env("ANTHROPIC_API_KEY", api_key);
+                }
+            }
+
             cmd
         } else {
             // Running on Windows - use wsl with bash login shell to ensure PATH is loaded
@@ -125,15 +183,45 @@ impl WslBridge {
 
             // Build the claude command with all arguments
             let mut claude_cmd = format!(
-                "cd '{}' && claude --output-format stream-json --input-format stream-json --verbose",
+                "cd '{}' && ",
                 working_dir
             );
 
+            // Set API key as environment variable if specified
+            if let Some(ref api_key) = options.api_key {
+                if !api_key.is_empty() {
+                    claude_cmd.push_str(&format!("ANTHROPIC_API_KEY='{}' ", api_key));
+                }
+            }
+
+            claude_cmd.push_str("claude --output-format stream-json --input-format stream-json --verbose");
+
+            // Add model if specified
+            if let Some(ref model) = options.model {
+                if !model.is_empty() {
+                    claude_cmd.push_str(&format!(" --model '{}'", model));
+                }
+            }
+
             // Add allowed tools if any
-            for tool in &allowed_tools {
+            for tool in &options.allowed_tools {
                 claude_cmd.push_str(&format!(" --allowedTools '{}'", tool));
             }
 
+            // Add custom instructions as system prompt if specified
+            if let Some(ref instructions) = options.custom_instructions {
+                if !instructions.is_empty() {
+                    // Escape single quotes in instructions
+                    let escaped = instructions.replace('\'', "'\\''");
+                    claude_cmd.push_str(&format!(" --system-prompt '{}'", escaped));
+                }
+            }
+
+            // Add MCP config if provided
+            if let Some(ref mcp_path) = mcp_config_path {
+                claude_cmd.push_str(&format!(" --mcp-config '{}'", mcp_path));
+            }
+
             // Use bash -lc to load login profile (ensures PATH includes claude)
             cmd.args(["-e", "bash", "-lc", &claude_cmd]);
 
@@ -212,6 +300,7 @@ impl WslBridge {
         }
         self.stdin = None;
         self.session_id = None;
+        self.mcp_config_file = None; // Temp file is automatically deleted when dropped
         emit_connection_status(app, ConnectionStatus::Disconnected);
     }