Add local default agent configuration support

crates/chat-cli/src/cli/agent/mod.rs

@@ -649,6 +649,7 @@ impl Agents {
         // 2. If the above is missing or invalid, assume one that is specified by chat.defaultAgent
         // 3. If the above is missing or invalid, assume the in-memory default
         let active_idx = 'active_idx: {
+            // 1. Command line argument --agent
             if let Some(name) = agent_name {
                 if all_agents.iter().any(|a| a.name.as_str() == name) {
                     break 'active_idx name.to_string();
@@ -659,14 +660,38 @@ impl Agents {
                     style::Print("Error"),
                     style::SetForegroundColor(Color::Yellow),
                     style::Print(format!(
-                        ": no agent with name {} found. Falling back to user specified default",
+                        ": no agent with name {} found. Falling back to local default",
                         name
                     )),
                     style::Print("\n"),
                     style::SetForegroundColor(Color::Reset)
                 );
             }
 
+            // 2. Local settings .amazonq/settings.json
+            if let Ok(current_dir) = std::env::current_dir() {
+                if let Ok(local_settings) = crate::database::local_settings::LocalSettings::new(&current_dir).await {
+                    if let Some(local_default) = local_settings.get_string(Setting::ChatDefaultAgent) {
+                        if all_agents.iter().any(|a| a.name == local_default) {
+                            break 'active_idx local_default;
+                        }
+                        let _ = queue!(
+                            output,
+                            style::SetForegroundColor(Color::Red),
+                            style::Print("Error"),
+                            style::SetForegroundColor(Color::Yellow),
+                            style::Print(format!(
+                                ": local default agent {} not found. Falling back to global default",
+                                local_default
+                            )),
+                            style::Print("\n"),
+                            style::SetForegroundColor(Color::Reset)
+                        );
+                    }
+                }
+            }
+
+            // 3. Global settings
             if let Some(user_set_default) = os.database.settings.get_string(Setting::ChatDefaultAgent) {
                 if all_agents.iter().any(|a| a.name == user_set_default) {
                     break 'active_idx user_set_default;
@@ -677,14 +702,15 @@ impl Agents {
                     style::Print("Error"),
                     style::SetForegroundColor(Color::Yellow),
                     style::Print(format!(
-                        ": user defined default {} not found. Falling back to in-memory default",
+                        ": global default agent {} not found. Falling back to in-memory default",
                         user_set_default
                     )),
                     style::Print("\n"),
                     style::SetForegroundColor(Color::Reset)
                 );
             }
 
+            // 4. In-memory default
             all_agents.push({
                 let mut agent = Agent::default();
                 if mcp_enabled {

crates/chat-cli/src/database/local_settings.rs

@@ -0,0 +1,68 @@
+use std::path::Path;
+
+use serde_json::{Map, Value};
+use tokio::fs::File;
+use tokio::io::AsyncReadExt;
+
+use super::{DatabaseError, settings::Setting};
+
+/// Local settings for a specific workspace/project directory
+#[derive(Debug, Clone, Default)]
+pub struct LocalSettings(Map<String, Value>);
+
+impl LocalSettings {
+    /// Create a new LocalSettings instance by reading from the workspace directory
+    pub async fn new(workspace_dir: &Path) -> Result<Self, DatabaseError> {
+        let settings_path = workspace_dir.join(".amazonq").join("settings.json");
+
+        Ok(Self(match settings_path.exists() {
+            true => {
+                let mut file = File::open(&settings_path).await?;
+                let mut buf = Vec::new();
+                file.read_to_end(&mut buf).await?;
+                serde_json::from_slice(&buf)?
+            },
+            false => Map::new(),
+        }))
+    }
+
+    /// Get a setting value
+    pub fn get(&self, key: Setting) -> Option<&Value> {
+        self.0.get(key.as_ref())
+    }
+
+    /// Get a string setting value
+    pub fn get_string(&self, key: Setting) -> Option<String> {
+        self.get(key).and_then(|value| value.as_str().map(|s| s.into()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::TempDir;
+
+    #[tokio::test]
+    async fn test_local_settings_new_empty() {
+        let temp_dir = TempDir::new().unwrap();
+        let settings = LocalSettings::new(temp_dir.path()).await.unwrap();
+        assert!(settings.0.is_empty());
+    }
+
+    #[tokio::test]
+    async fn test_local_settings_get_string() {
+        let temp_dir = TempDir::new().unwrap();
+
+        // Create a settings file manually
+        let amazonq_dir = temp_dir.path().join(".amazonq");
+        tokio::fs::create_dir_all(&amazonq_dir).await.unwrap();
+        let settings_path = amazonq_dir.join("settings.json");
+        tokio::fs::write(&settings_path, r#"{"chat.defaultAgent": "test_agent"}"#).await.unwrap();
+
+        let settings = LocalSettings::new(temp_dir.path()).await.unwrap();
+        assert_eq!(
+            settings.get_string(Setting::ChatDefaultAgent),
+            Some("test_agent".to_string())
+        );
+    }
+}

crates/chat-cli/src/database/mod.rs

@@ -1,4 +1,5 @@
 pub mod settings;
+pub mod local_settings;
 
 use std::ops::Deref;
 use std::path::Path;