diff --git a/client/config.toml b/client/config.toml
index cf791d2..a8462dd 100644
--- a/client/config.toml
+++ b/client/config.toml
@@ -74,7 +74,7 @@ move_left = [""]
 move_right = ["right"]
 suggestion_down = ["ctrl+n", "tab"]
 suggestion_up = ["ctrl+p", "shift+tab"]
-trigger_autocomplete = ["left"]
+trigger_autocomplete = ["tab"]
 
 [keybindings.command]
 exit_command_mode = ["ctrl+g", "esc"]
diff --git a/server/src/auth/handlers/register.rs b/server/src/auth/handlers/register.rs
index 63b6190..66a683f 100644
--- a/server/src/auth/handlers/register.rs
+++ b/server/src/auth/handlers/register.rs
@@ -11,6 +11,11 @@ pub async fn register(
     pool: &PgPool,
     payload: RegisterRequest,
 ) -> Result<Response<AuthResponse>, Status> {
+    // Validate required fields
+    if payload.email.trim().is_empty() {
+        return Err(Status::invalid_argument("Email is required"));
+    }
+    
     // Validate passwords match
     if payload.password != payload.password_confirmation {
         return Err(Status::invalid_argument(AuthError::PasswordMismatch.to_string()));
@@ -41,6 +46,15 @@ pub async fn register(
             if db_err.constraint() == Some("valid_roles") {
                 return Status::invalid_argument(format!("Invalid role specified: '{}'", role_to_insert));
             }
+            // Check for specific constraint violations
+            if let Some(constraint) = db_err.constraint() {
+                if constraint.contains("users_username_key") {
+                    return Status::already_exists("Username already exists".to_string());
+                }
+                if constraint.contains("users_email_key") {
+                    return Status::already_exists("Email already exists".to_string());
+                }
+            }
         }
         if e.to_string().contains("duplicate key") {
             Status::already_exists(AuthError::UserExists.to_string())