diff --git a/src/cli.rs b/src/cli.rs
index 117486ee4..40ab21188 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -36,7 +36,7 @@ impl Session {
             .lc
             .write()
             .unwrap()
-            .initialize(id.to_owned(), ConnType::PORT_FORWARD);
+            .initialize(id.to_owned(), ConnType::PORT_FORWARD, None);
         session
     }
 }
diff --git a/src/client/file_trait.rs b/src/client/file_trait.rs
index 2ecfca837..49e3f2358 100644
--- a/src/client/file_trait.rs
+++ b/src/client/file_trait.rs
@@ -7,7 +7,7 @@ pub trait FileManager: Interface {
         fs::get_home_as_string()
     }
 
-    #[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
+    #[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli", feature = "flutter")))]
     fn read_dir(&self, path: String, include_hidden: bool) -> sciter::Value {
         match fs::read_dir(&fs::get_path(&path), include_hidden) {
             Err(_) => sciter::Value::null(),
@@ -20,7 +20,7 @@ pub trait FileManager: Interface {
         }
     }
 
-    #[cfg(any(target_os = "android", target_os = "ios", feature = "cli"))]
+    #[cfg(any(target_os = "android", target_os = "ios", feature = "cli", feature = "flutter"))]
     fn read_dir(&self, path: &str, include_hidden: bool) -> String {
         use crate::common::make_fd_to_json;
         match fs::read_dir(&fs::get_path(path), include_hidden) {
diff --git a/src/common.rs b/src/common.rs
index 79a4664db..b66261ebe 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -762,3 +762,14 @@ pub fn make_fd_to_json(id: i32, path: String, entries: &Vec<FileEntry>) -> Strin
     fd_json.insert("entries".into(), json!(entries_out));
     serde_json::to_string(&fd_json).unwrap_or("".into())
 }
+
+/// The function to handle the url scheme sent by the system.
+///
+/// 1. Try to send the url scheme from ipc.
+/// 2. If failed to send the url scheme, we open a new main window to handle this url scheme.
+pub fn handle_url_scheme(url: String) {
+    if let Err(err) = crate::ipc::send_url_scheme(url.clone()) {
+        log::debug!("Send the url to the existing flutter process failed, {}. Let's open a new program to handle this.", err);
+        let _ = crate::run_me(vec![url]);
+    }
+}
\ No newline at end of file
diff --git a/src/flutter_ffi.rs b/src/flutter_ffi.rs
index a7e32d0b2..a79ef2de8 100644
--- a/src/flutter_ffi.rs
+++ b/src/flutter_ffi.rs
@@ -1119,13 +1119,6 @@ pub fn cm_switch_back(conn_id: i32) {
     crate::ui_cm_interface::switch_back(conn_id);
 }
 
-pub fn main_get_icon() -> String {
-    #[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
-    return ui_interface::get_icon();
-    #[cfg(any(target_os = "android", target_os = "ios", feature = "cli"))]
-    return String::new();
-}
-
 pub fn main_get_build_date() -> String {
     crate::BUILD_DATE.to_string()
 }
@@ -1305,7 +1298,7 @@ pub fn main_start_ipc_url_server() {
 #[allow(unused_variables)]
 pub fn send_url_scheme(_url: String) {
     #[cfg(target_os = "macos")]
-    std::thread::spawn(move || crate::ui::macos::handle_url_scheme(_url));
+    std::thread::spawn(move || crate::handle_url_scheme(_url));
 }
 
 #[cfg(target_os = "android")]
diff --git a/src/lib.rs b/src/lib.rs
index 7b94c8a2c..748d375b4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -20,7 +20,7 @@ pub use self::rendezvous_mediator::*;
 pub mod common;
 #[cfg(not(any(target_os = "ios")))]
 pub mod ipc;
-#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
+#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli", feature = "flutter")))]
 pub mod ui;
 mod version;
 pub use version::*;
diff --git a/src/main.rs b/src/main.rs
index 6500a8e4a..8bc375841 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@
 // Requires Rust 1.18.
 //#![windows_subsystem = "windows"]
 
+#[cfg(not(feature = "flutter"))]
 use librustdesk::*;
 
 #[cfg(any(target_os = "android", target_os = "ios"))]
@@ -16,7 +17,12 @@ fn main() {
     common::global_clean();
 }
 
-#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
+#[cfg(not(any(
+    target_os = "android",
+    target_os = "ios",
+    feature = "cli",
+    feature = "flutter"
+)))]
 fn main() {
     if !common::global_init() {
         return;
@@ -27,6 +33,11 @@ fn main() {
     common::global_clean();
 }
 
+#[cfg(feature = "flutter")]
+fn main() {
+    hbb_common::log::info!("Hello world!");
+}
+
 #[cfg(feature = "cli")]
 fn main() {
     if !common::global_init() {
diff --git a/src/ui.rs b/src/ui.rs
index 7973a0ba4..aede5fe7a 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -9,7 +9,7 @@ use sciter::Value;
 
 use hbb_common::{
     allow_err,
-    config::{self, PeerConfig},
+    config::{self, LocalConfig, PeerConfig},
     log,
 };
 
@@ -38,6 +38,7 @@ lazy_static::lazy_static! {
 #[cfg(not(any(feature = "flutter", feature = "cli")))]
 lazy_static::lazy_static! {
     pub static ref CUR_SESSION: Arc<Mutex<Option<Session<remote::SciterHandler>>>> = Default::default();
+    static ref CHILDREN : Children = Default::default();
 }
 
 struct UIHostHandler;
@@ -190,11 +191,11 @@ impl UI {
     }
 
     fn get_remote_id(&mut self) -> String {
-        get_remote_id()
+        LocalConfig::get_remote_id()
     }
 
     fn set_remote_id(&mut self, id: String) {
-        set_remote_id(id);
+        LocalConfig::set_remote_id(&id);
     }
 
     fn goto_install(&mut self) {
@@ -309,7 +310,10 @@ impl UI {
     }
 
     fn is_release(&self) -> bool {
-        is_release()
+        #[cfg(not(debug_assertions))]
+        return true;
+        #[cfg(debug_assertions)]
+        return false;
     }
 
     fn is_rdp_service_open(&self) -> bool {
@@ -329,11 +333,18 @@ impl UI {
     }
 
     fn closing(&mut self, x: i32, y: i32, w: i32, h: i32) {
-        closing(x, y, w, h)
+        crate::server::input_service::fix_key_down_timeout_at_exit();
+        LocalConfig::set_size(x, y, w, h);
     }
 
     fn get_size(&mut self) -> Value {
-        Value::from_iter(get_size())
+        let s = LocalConfig::get_size();
+        let mut v = Vec::new();
+        v.push(s.0);
+        v.push(s.1);
+        v.push(s.2);
+        v.push(s.3);
+        Value::from_iter(v)
     }
 
     fn get_mouse_time(&self) -> f64 {
@@ -388,7 +399,7 @@ impl UI {
 
     fn get_recent_sessions(&mut self) -> Value {
         // to-do: limit number of recent sessions, and remove old peer file
-        let peers: Vec<Value> = get_recent_sessions()
+        let peers: Vec<Value> = PeerConfig::peers()
             .drain(..)
             .map(|p| Self::get_peer_value(p.0, p.2))
             .collect();
@@ -396,11 +407,11 @@ impl UI {
     }
 
     fn get_icon(&mut self) -> String {
-        get_icon()
+        crate::get_icon()
     }
 
     fn remove_peer(&mut self, id: String) {
-        remove_peer(id)
+        PeerConfig::remove(&id);
     }
 
     fn remove_discovered(&mut self, id: String) {
@@ -442,7 +453,7 @@ impl UI {
     }
 
     fn get_software_update_url(&self) -> String {
-        get_software_update_url()
+        crate::SOFTWARE_UPDATE_URL.lock().unwrap().clone()
     }
 
     fn get_new_version(&self) -> String {
@@ -458,14 +469,30 @@ impl UI {
     }
 
     fn get_software_ext(&self) -> String {
-        get_software_ext()
+        #[cfg(windows)]
+        let p = "exe";
+        #[cfg(target_os = "macos")]
+        let p = "dmg";
+        #[cfg(target_os = "linux")]
+        let p = "deb";
+        p.to_owned()
     }
 
     fn get_software_store_path(&self) -> String {
-        get_software_store_path()
+        let mut p = std::env::temp_dir();
+        let name = crate::SOFTWARE_UPDATE_URL
+            .lock()
+            .unwrap()
+            .split("/")
+            .last()
+            .map(|x| x.to_owned())
+            .unwrap_or(crate::get_app_name());
+        p.push(name);
+        format!("{}.{}", p.to_string_lossy(), self.get_software_ext())
     }
 
     fn create_shortcut(&self, _id: String) {
+        #[cfg(windows)]
         create_shortcut(_id)
     }
 
@@ -495,7 +522,17 @@ impl UI {
     }
 
     fn open_url(&self, url: String) {
-        open_url(url)
+        #[cfg(windows)]
+        let p = "explorer";
+        #[cfg(target_os = "macos")]
+        let p = "open";
+        #[cfg(target_os = "linux")]
+        let p = if std::path::Path::new("/usr/bin/firefox").exists() {
+            "firefox"
+        } else {
+            "xdg-open"
+        };
+        allow_err!(std::process::Command::new(p).arg(url).spawn());
     }
 
     fn change_id(&self, id: String) {
@@ -508,7 +545,7 @@ impl UI {
     }
 
     fn is_ok_change_id(&self) -> bool {
-        is_ok_change_id()
+        machine_uid::get().is_ok()
     }
 
     fn get_async_job_status(&self) -> String {
@@ -516,11 +553,11 @@ impl UI {
     }
 
     fn t(&self, name: String) -> String {
-        t(name)
+        crate::client::translate(name)
     }
 
     fn is_xfce(&self) -> bool {
-        is_xfce()
+        crate::platform::is_xfce()
     }
 
     fn get_api_server(&self) -> String {
@@ -683,3 +720,43 @@ pub fn value_crash_workaround(values: &[Value]) -> Arc<Vec<Value>> {
     STUPID_VALUES.lock().unwrap().push(persist.clone());
     persist
 }
+
+#[inline]
+pub fn new_remote(id: String, remote_type: String) {
+    let mut lock = CHILDREN.lock().unwrap();
+    let args = vec![format!("--{}", remote_type), id.clone()];
+    let key = (id.clone(), remote_type.clone());
+    if let Some(c) = lock.1.get_mut(&key) {
+        if let Ok(Some(_)) = c.try_wait() {
+            lock.1.remove(&key);
+        } else {
+            if remote_type == "rdp" {
+                allow_err!(c.kill());
+                std::thread::sleep(std::time::Duration::from_millis(30));
+                c.try_wait().ok();
+                lock.1.remove(&key);
+            } else {
+                return;
+            }
+        }
+    }
+    match crate::run_me(args) {
+        Ok(child) => {
+            lock.1.insert(key, child);
+        }
+        Err(err) => {
+            log::error!("Failed to spawn remote: {}", err);
+        }
+    }
+}
+
+#[inline]
+pub fn recent_sessions_updated() -> bool {
+    let mut children = CHILDREN.lock().unwrap();
+    if children.0 {
+        children.0 = false;
+        true
+    } else {
+        false
+    }
+}
diff --git a/src/ui/macos.rs b/src/ui/macos.rs
index 8a1fc990c..cd0e5871b 100644
--- a/src/ui/macos.rs
+++ b/src/ui/macos.rs
@@ -180,22 +180,11 @@ extern "C" fn handle_menu_item(this: &mut Object, _: Sel, item: id) {
     }
 }
 
-/// The function to handle the url scheme sent by the system.
-///
-/// 1. Try to send the url scheme from ipc.
-/// 2. If failed to send the url scheme, we open a new main window to handle this url scheme.
-pub fn handle_url_scheme(url: String) {
-    if let Err(err) = crate::ipc::send_url_scheme(url.clone()) {
-        log::debug!("Send the url to the existing flutter process failed, {}. Let's open a new program to handle this.", err);
-        let _ = crate::run_me(vec![url]);
-    }
-}
-
 extern "C" fn handle_apple_event(_this: &Object, _cmd: Sel, event: u64, _reply: u64) {
     let event = event as *mut Object;
     let url = fruitbasket::parse_url_event(event);
     log::debug!("an event was received: {}", url);
-    std::thread::spawn(move || handle_url_scheme(url));
+    std::thread::spawn(move || crate::handle_url_scheme(url));
 }
 
 unsafe fn make_menu_item(title: &str, key: &str, tag: u32) -> *mut Object {
diff --git a/src/ui_interface.rs b/src/ui_interface.rs
index d357c9cef..6576c340c 100644
--- a/src/ui_interface.rs
+++ b/src/ui_interface.rs
@@ -2,7 +2,6 @@ use std::{
     collections::HashMap,
     process::Child,
     sync::{Arc, Mutex},
-    time::SystemTime,
 };
 
 #[cfg(any(target_os = "android", target_os = "ios"))]
@@ -31,7 +30,6 @@ pub type Children = Arc<Mutex<(bool, HashMap<(String, String), Child>)>>;
 type Status = (i32, bool, i64, String); // (status_num, key_confirmed, mouse_time, id)
 
 lazy_static::lazy_static! {
-    static ref CHILDREN : Children = Default::default();
     static ref UI_STATUS : Arc<Mutex<Status>> = Arc::new(Mutex::new((0, false, 0, "".to_owned())));
     static ref OPTIONS : Arc<Mutex<HashMap<String, String>>> = Arc::new(Mutex::new(Config::get_options()));
     static ref ASYNC_JOB_STATUS : Arc<Mutex<String>> = Default::default();
@@ -44,17 +42,6 @@ lazy_static::lazy_static! {
     pub static ref SENDER : Mutex<mpsc::UnboundedSender<ipc::Data>> = Mutex::new(check_connect_status(true));
 }
 
-#[inline]
-pub fn recent_sessions_updated() -> bool {
-    let mut children = CHILDREN.lock().unwrap();
-    if children.0 {
-        children.0 = false;
-        true
-    } else {
-        false
-    }
-}
-
 #[cfg(any(target_os = "android", target_os = "ios", feature = "flutter"))]
 #[inline]
 pub fn get_id() -> String {
@@ -64,16 +51,6 @@ pub fn get_id() -> String {
     return ipc::get_id();
 }
 
-#[inline]
-pub fn get_remote_id() -> String {
-    LocalConfig::get_remote_id()
-}
-
-#[inline]
-pub fn set_remote_id(id: String) {
-    LocalConfig::set_remote_id(&id);
-}
-
 #[inline]
 pub fn goto_install() {
     allow_err!(crate::run_me(vec!["--install"]));
@@ -419,24 +396,6 @@ pub fn is_installed_lower_version() -> bool {
     }
 }
 
-#[inline]
-pub fn closing(x: i32, y: i32, w: i32, h: i32) {
-    #[cfg(not(any(target_os = "android", target_os = "ios")))]
-    crate::server::input_service::fix_key_down_timeout_at_exit();
-    LocalConfig::set_size(x, y, w, h);
-}
-
-#[inline]
-pub fn get_size() -> Vec<i32> {
-    let s = LocalConfig::get_size();
-    let mut v = Vec::new();
-    v.push(s.0);
-    v.push(s.1);
-    v.push(s.2);
-    v.push(s.3);
-    v
-}
-
 #[inline]
 pub fn get_mouse_time() -> f64 {
     let ui_status = UI_STATUS.lock().unwrap();
@@ -507,51 +466,6 @@ pub fn store_fav(fav: Vec<String>) {
     LocalConfig::set_fav(fav);
 }
 
-#[inline]
-pub fn get_recent_sessions() -> Vec<(String, SystemTime, PeerConfig)> {
-    PeerConfig::peers()
-}
-
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
-pub fn get_icon() -> String {
-    crate::get_icon()
-}
-
-#[inline]
-pub fn remove_peer(id: String) {
-    PeerConfig::remove(&id);
-}
-
-#[inline]
-pub fn new_remote(id: String, remote_type: String) {
-    let mut lock = CHILDREN.lock().unwrap();
-    let args = vec![format!("--{}", remote_type), id.clone()];
-    let key = (id.clone(), remote_type.clone());
-    if let Some(c) = lock.1.get_mut(&key) {
-        if let Ok(Some(_)) = c.try_wait() {
-            lock.1.remove(&key);
-        } else {
-            if remote_type == "rdp" {
-                allow_err!(c.kill());
-                std::thread::sleep(std::time::Duration::from_millis(30));
-                c.try_wait().ok();
-                lock.1.remove(&key);
-            } else {
-                return;
-            }
-        }
-    }
-    match crate::run_me(args) {
-        Ok(child) => {
-            lock.1.insert(key, child);
-        }
-        Err(err) => {
-            log::error!("Failed to spawn remote: {}", err);
-        }
-    }
-}
-
 #[inline]
 pub fn is_process_trusted(_prompt: bool) -> bool {
     #[cfg(target_os = "macos")]
@@ -622,11 +536,6 @@ pub fn current_is_wayland() -> bool {
     return false;
 }
 
-#[inline]
-pub fn get_software_update_url() -> String {
-    SOFTWARE_UPDATE_URL.lock().unwrap().clone()
-}
-
 #[inline]
 pub fn get_new_version() -> String {
     hbb_common::get_version_from_url(&*SOFTWARE_UPDATE_URL.lock().unwrap())
@@ -643,36 +552,9 @@ pub fn get_app_name() -> String {
     crate::get_app_name()
 }
 
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios")))]
-pub fn get_software_ext() -> String {
-    #[cfg(windows)]
-    let p = "exe";
-    #[cfg(target_os = "macos")]
-    let p = "dmg";
-    #[cfg(target_os = "linux")]
-    let p = "deb";
-    p.to_owned()
-}
-
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios")))]
-pub fn get_software_store_path() -> String {
-    let mut p = std::env::temp_dir();
-    let name = SOFTWARE_UPDATE_URL
-        .lock()
-        .unwrap()
-        .split("/")
-        .last()
-        .map(|x| x.to_owned())
-        .unwrap_or(crate::get_app_name());
-    p.push(name);
-    format!("{}.{}", p.to_string_lossy(), get_software_ext())
-}
-
+#[cfg(windows)]
 #[inline]
 pub fn create_shortcut(_id: String) {
-    #[cfg(windows)]
     crate::platform::windows::create_shortcut(&_id).ok();
 }
 
@@ -719,22 +601,6 @@ pub fn get_uuid() -> String {
     base64::encode(hbb_common::get_uuid())
 }
 
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
-pub fn open_url(url: String) {
-    #[cfg(windows)]
-    let p = "explorer";
-    #[cfg(target_os = "macos")]
-    let p = "open";
-    #[cfg(target_os = "linux")]
-    let p = if std::path::Path::new("/usr/bin/firefox").exists() {
-        "firefox"
-    } else {
-        "xdg-open"
-    };
-    allow_err!(std::process::Command::new(p).arg(url).spawn());
-}
-
 #[cfg(any(target_os = "android", target_os = "ios", feature = "flutter"))]
 #[inline]
 pub fn change_id(id: String) {
@@ -756,23 +622,11 @@ pub fn post_request(url: String, body: String, header: String) {
     });
 }
 
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios")))]
-pub fn is_ok_change_id() -> bool {
-    machine_uid::get().is_ok()
-}
-
 #[inline]
 pub fn get_async_job_status() -> String {
     ASYNC_JOB_STATUS.lock().unwrap().clone()
 }
 
-#[inline]
-#[cfg(not(any(target_os = "android", target_os = "ios", feature = "cli")))]
-pub fn t(name: String) -> String {
-    crate::client::translate(name)
-}
-
 #[inline]
 pub fn get_langs() -> String {
     crate::lang::LANGS.to_string()
@@ -813,11 +667,6 @@ pub fn default_video_save_directory() -> String {
     "".to_owned()
 }
 
-#[inline]
-pub fn is_xfce() -> bool {
-    crate::platform::is_xfce()
-}
-
 #[inline]
 pub fn get_api_server() -> String {
     crate::get_api_server(
@@ -834,14 +683,6 @@ pub fn has_hwcodec() -> bool {
     return true;
 }
 
-#[inline]
-pub fn is_release() -> bool {
-    #[cfg(not(debug_assertions))]
-    return true;
-    #[cfg(debug_assertions)]
-    return false;
-}
-
 #[cfg(not(any(target_os = "android", target_os = "ios")))]
 #[inline]
 pub fn is_root() -> bool {