diff --git a/easytier-gui/src-tauri/src/main.rs b/easytier-gui/src-tauri/src/main.rs
index 6ce7ce36..867bfe19 100644
--- a/easytier-gui/src-tauri/src/main.rs
+++ b/easytier-gui/src-tauri/src/main.rs
@@ -235,15 +235,13 @@ static INSTANCE_MAP: once_cell::sync::Lazy<DashMap<String, NetworkInstance>> =
 
 // Learn more about Tauri commands at https://tauri.app/v1/guides/features/command
 #[tauri::command]
-fn parse_network_config(cfg: &str) -> Result<String, String> {
-    let cfg: NetworkConfig = serde_json::from_str(cfg).map_err(|e| e.to_string())?;
+fn parse_network_config(cfg: NetworkConfig) -> Result<String, String> {
     let toml = cfg.gen_config().map_err(|e| e.to_string())?;
     Ok(toml.dump())
 }
 
 #[tauri::command]
-fn run_network_instance(cfg: &str) -> Result<String, String> {
-    let cfg: NetworkConfig = serde_json::from_str(cfg).map_err(|e| e.to_string())?;
+fn run_network_instance(cfg: NetworkConfig) -> Result<(), String> {
     if INSTANCE_MAP.contains_key(&cfg.instance_id) {
         return Err("instance already exists".to_string());
     }
@@ -254,13 +252,11 @@ fn run_network_instance(cfg: &str) -> Result<String, String> {
 
     println!("instance {} started", instance_id);
     INSTANCE_MAP.insert(instance_id, instance);
-    Ok("".to_string())
+    Ok(())
 }
 
 #[tauri::command]
-fn retain_network_instance(instance_ids: &str) -> Result<(), String> {
-    let instance_ids: Vec<String> =
-        serde_json::from_str(instance_ids).map_err(|e| e.to_string())?;
+fn retain_network_instance(instance_ids: Vec<String>) -> Result<(), String> {
     let _ = INSTANCE_MAP.retain(|k, _| instance_ids.contains(k));
     println!(
         "instance {:?} retained",
@@ -273,14 +269,14 @@ fn retain_network_instance(instance_ids: &str) -> Result<(), String> {
 }
 
 #[tauri::command]
-fn collect_network_infos() -> Result<String, String> {
+fn collect_network_infos() -> Result<BTreeMap<String, NetworkInstanceRunningInfo>, String> {
     let mut ret = BTreeMap::new();
     for instance in INSTANCE_MAP.iter() {
         if let Some(info) = instance.get_running_info() {
             ret.insert(instance.key().clone(), info);
         }
     }
-    Ok(serde_json::to_string(&ret).map_err(|e| e.to_string())?)
+    Ok(ret)
 }
 
 #[tauri::command]
diff --git a/easytier-gui/src/composables/network.ts b/easytier-gui/src/composables/network.ts
index bbb0a016..7dbbd2d9 100644
--- a/easytier-gui/src/composables/network.ts
+++ b/easytier-gui/src/composables/network.ts
@@ -1,22 +1,22 @@
 import { invoke } from '@tauri-apps/api/tauri'
 import type { NetworkConfig, NetworkInstanceRunningInfo } from '~/types/network'
 
-export async function parseNetworkConfig(cfg: NetworkConfig): Promise<string> {
-  return invoke<string>('parse_network_config', { cfg: JSON.stringify(cfg) })
+export async function parseNetworkConfig(cfg: NetworkConfig) {
+  return invoke<string>('parse_network_config', { cfg })
 }
 
-export async function runNetworkInstance(cfg: NetworkConfig): Promise<string> {
-  return invoke<string>('run_network_instance', { cfg: JSON.stringify(cfg) })
+export async function runNetworkInstance(cfg: NetworkConfig) {
+  return invoke('run_network_instance', { cfg })
 }
 
-export async function retainNetworkInstance(instanceIds: string[]): Promise<string> {
-  return invoke<string>('retain_network_instance', { instanceIds: JSON.stringify(instanceIds) })
+export async function retainNetworkInstance(instanceIds: string[]) {
+  return invoke('retain_network_instance', { instanceIds })
 }
 
-export async function collectNetworkInfos(): Promise<Record<string, NetworkInstanceRunningInfo>> {
-  return JSON.parse(await invoke<string>('collect_network_infos'))
+export async function collectNetworkInfos() {
+  return await invoke<Record<string, NetworkInstanceRunningInfo>>('collect_network_infos')
 }
 
-export async function getOsHostname(): Promise<string> {
-  return await invoke('get_os_hostname')
-}
\ No newline at end of file
+export async function getOsHostname() {
+  return await invoke<string>('get_os_hostname')
+}