[feat] show server window in the bottom-right corner of the screen

[feat] add server window
[feat] support drag-and-drop file sending, refs #63
2026-03-23 00:20:17 +08:00 · 2026-01-19 17:42:22 +08:00 · 2026-01-19 00:47:34 +08:00 · 2026-01-14 18:13:22 +08:00 · 2026-01-13 18:13:54 +08:00 · 2026-01-12 17:28:19 +08:00
24 changed files with 5190 additions and 2447 deletions
--- a/README.md
+++ b/README.md
@@ -181,7 +181,7 @@ sudo docker run -d \
  -e MAX_PORT=xxxxx \
  -v /var/lib/crossdesk:/var/lib/crossdesk \
  -v /var/log/crossdesk:/var/log/crossdesk \
-  crossdesk/crossdesk-server:v1.1.2
+  crossdesk/crossdesk-server:v1.1.3
 ```

 上述命令中，用户需注意的参数如下：
@@ -229,21 +229,19 @@ sudo mkdir -p /var/lib/crossdesk /var/log/crossdesk
 sudo chown -R $(id -u):$(id -g) /var/lib/crossdesk /var/log/crossdesk
 ```

-## 证书文件
-在宿主机的 `/var/lib/crossdesk/certs` 路径下可找到证书文件 `crossdesk.cn_root.crt`，下载到你的客户端主机，并在客户端的**自托管服务器设置**中选择相应的**证书文件路径**。

 ### 客户端
-1. 点击右上角设置进入设置页面。<br>
+1. 点击右上角设置进入设置页面。<br><br>
 <img width="600" height="210" alt="image" src="https://github.com/user-attachments/assets/6431131d-b32a-4726-8783-6788f47baa3b" /><br><br>

-3. 点击点击**自托管服务器配置**。<br><br>
-<img width="600" height="160" alt="image" src="https://github.com/user-attachments/assets/24c761a3-1985-4d7e-84be-787383c2afb8" /><br><br>
+2. 点击点击`自托管服务器配置`按钮。<br><br>
+<img width="600" height="140" alt="image" src="https://github.com/user-attachments/assets/24c761a3-1985-4d7e-84be-787383c2afb8" /><br><br>

-5. 在**证书文件路径**选择框中找到 **crossdesk.cn_root.crt** 的存放路径，选中 **crossdesk.cn_root.crt**，点击确认。<br><br>
-<img width="600" height="220" alt="image" src="https://github.com/user-attachments/assets/4af7cd3a-c72e-44fb-b032-30e050019c2a" /><br><br>
+3. 输入`服务器地址`(**EXTERNAL_IP**)、`信令服务端口`(**CROSSDESK_SERVER_PORT**)、`中继服务端口`(**COTURN_PORT**)。<br><br>
+<img width="600" height="200" alt="image" src="https://github.com/user-attachments/assets/9a32ddd5-37f8-4bee-9a51-eae295820f9a" /><br><br>

-7. 勾选使用**自托管服务器配置**，点击确认配置生效。<br><br>
-<img width="600" height="160" alt="image" src="https://github.com/user-attachments/assets/1e455dc3-4087-4f37-a544-1ff9f8789383" /><br><br>
+4. 后续如果自托管服务器被重置或因其他原因导致证书更换，可以点击`重置证书指纹`按钮重置客户端保存的证书指纹。<br><br>
+<img width="600" height="200" alt="image" src="https://github.com/user-attachments/assets/d9e423ab-0c2b-4fab-b132-4dc27462d704" /><br><br>

 ### Web 客户端
 详情见项目 [CrossDesk Web Client](https://github.com/kunkundi/crossdesk-web-client)。
--- a/README_EN.md
+++ b/README_EN.md
@@ -189,7 +189,7 @@ sudo docker run -d \
  -e MAX_PORT=xxxxx \
  -v /var/lib/crossdesk:/var/lib/crossdesk \
  -v /var/log/crossdesk:/var/log/crossdesk \
-  crossdesk/crossdesk-server:v1.1.2
+  crossdesk/crossdesk-server:v1.1.3
 ```

 The parameters you need to pay attention to are as follows:
@@ -238,25 +238,21 @@ sudo mkdir -p /var/lib/crossdesk /var/log/crossdesk
 sudo chown -R $(id -u):$(id -g) /var/lib/crossdesk /var/log/crossdesk
 ```

-### Certificate Files
-You can find the certificate file `crossdesk.cn_root.crt` at `/var/lib/crossdesk/certs` on the host machine.
-Download it to your client device and select it in the **Certificate File Path** field under the CrossDesk client’s **Self-Hosted Server Settings**.
-
 ### Server Side
 Place **crossdesk.cn.key** and **crossdesk.cn_bundle.crt** into the **/path/to/your/certs** directory.

 ### Client Side
-1. Click the settings icon in the top-right corner to enter the settings page.<br>
+1. Click the settings icon in the top-right corner to enter the settings page.<br><br>
 <img width="600" height="210" alt="image" src="https://github.com/user-attachments/assets/6431131d-b32a-4726-8783-6788f47baa3b" /><br><br>

-2. Click **Self-Hosted Server Configuration**.<br><br>
+2. Click `Self-Hosted Server Configuration` button.<br><br>
 <img width="600" height="160" alt="image" src="https://github.com/user-attachments/assets/24c761a3-1985-4d7e-84be-787383c2afb8" /><br><br>

-3. In the **Certificate File Path** selection, locate and select the **crossdesk.cn_root.crt** file.<br><br>
-<img width="600" height="220" alt="image" src="https://github.com/user-attachments/assets/4af7cd3a-c72e-44fb-b032-30e050019c2a" /><br><br>
+3. Enter the `Server Address` (**EXTERNAL_IP**), `Signaling Service Port` (**CROSSDESK_SERVER_PORT**), and `Relay Service Port` (**COTURN_PORT**).<br><br>
+<img width="600" height="200" alt="image" src="https://github.com/user-attachments/assets/9a32ddd5-37f8-4bee-9a51-eae295820f9a" /><br><br>

-4. Check the option to use **Self-Hosted Server Configuration**.<br><br>
-<img width="600" height="160" alt="image" src="https://github.com/user-attachments/assets/1e455dc3-4087-4f37-a544-1ff9f8789383" /><br><br>
+4. If the self-hosted server is later reset or the certificate is replaced for any reason, you can click the `Reset Certificate Fingerprint` button to clear the certificate fingerprint saved on the client.<br><br>
+<img width="600" height="200" alt="image" src="https://github.com/user-attachments/assets/d9e423ab-0c2b-4fab-b132-4dc27462d704" /><br><br>

 ### Web Client
 See [CrossDesk Web Client](https://github.com/kunkundi/crossdesk-web-client)。
--- a/src/config_center/config_center.cpp
+++ b/src/config_center/config_center.cpp
@@ -77,6 +77,64 @@ int ConfigCenter::Load() {
  } else {
    cert_file_path_ = "";
  }
+  const char* cert_fingerprint_value =
+      ini_.GetValue(section_, "cert_fingerprint", nullptr);
+  if (cert_fingerprint_value != nullptr && strlen(cert_fingerprint_value) > 0) {
+    cert_fingerprint_ = cert_fingerprint_value;
+  } else {
+    cert_fingerprint_ = "";
+  }
+  const char* cert_fingerprint_server_host_value =
+      ini_.GetValue(section_, "cert_fingerprint_server_host", nullptr);
+  if (cert_fingerprint_server_host_value != nullptr &&
+      strlen(cert_fingerprint_server_host_value) > 0) {
+    cert_fingerprint_server_host_ = cert_fingerprint_server_host_value;
+  } else {
+    cert_fingerprint_server_host_ = "";
+  }
+
+  const char* default_cert_fingerprint_value =
+      ini_.GetValue(section_, "default_cert_fingerprint", nullptr);
+  if (default_cert_fingerprint_value != nullptr &&
+      strlen(default_cert_fingerprint_value) > 0) {
+    default_cert_fingerprint_ = default_cert_fingerprint_value;
+  } else {
+    default_cert_fingerprint_ = "";
+  }
+  const char* default_cert_fingerprint_server_host_value =
+      ini_.GetValue(section_, "default_cert_fingerprint_server_host", nullptr);
+  if (default_cert_fingerprint_server_host_value != nullptr &&
+      strlen(default_cert_fingerprint_server_host_value) > 0) {
+    default_cert_fingerprint_server_host_ =
+        default_cert_fingerprint_server_host_value;
+  } else {
+    default_cert_fingerprint_server_host_ = "";
+  }
+
+  if (enable_self_hosted_ && !cert_fingerprint_.empty() &&
+      !cert_fingerprint_server_host_.empty() &&
+      signal_server_host_ != cert_fingerprint_server_host_) {
+    LOG_INFO("Server IP changed from {} to {}, clearing old fingerprint",
+             cert_fingerprint_server_host_, signal_server_host_);
+    cert_fingerprint_.clear();
+    cert_fingerprint_server_host_.clear();
+    ini_.Delete(section_, "cert_fingerprint", false);
+    ini_.Delete(section_, "cert_fingerprint_server_host", false);
+    ini_.SaveFile(config_path_.c_str());
+  }
+
+  if (!enable_self_hosted_ && !default_cert_fingerprint_.empty() &&
+      !default_cert_fingerprint_server_host_.empty() &&
+      signal_server_host_default_ != default_cert_fingerprint_server_host_) {
+    LOG_INFO(
+        "Default server IP changed from {} to {}, clearing old fingerprint",
+        default_cert_fingerprint_server_host_, signal_server_host_default_);
+    default_cert_fingerprint_.clear();
+    default_cert_fingerprint_server_host_.clear();
+    ini_.Delete(section_, "default_cert_fingerprint", false);
+    ini_.Delete(section_, "default_cert_fingerprint_server_host", false);
+    ini_.SaveFile(config_path_.c_str());
+  }

  enable_autostart_ =
      ini_.GetBoolValue(section_, "enable_autostart", enable_autostart_);
@@ -108,6 +166,18 @@ int ConfigCenter::Save() {
    ini_.SetLongValue(section_, "coturn_server_port",
                      static_cast<long>(coturn_server_port_));
    ini_.SetValue(section_, "cert_file_path", cert_file_path_.c_str());
+    if (!cert_fingerprint_.empty()) {
+      ini_.SetValue(section_, "cert_fingerprint", cert_fingerprint_.c_str());
+      ini_.SetValue(section_, "cert_fingerprint_server_host",
+                    cert_fingerprint_server_host_.c_str());
+    }
+  }
+
+  if (!default_cert_fingerprint_.empty()) {
+    ini_.SetValue(section_, "default_cert_fingerprint",
+                  default_cert_fingerprint_.c_str());
+    ini_.SetValue(section_, "default_cert_fingerprint_server_host",
+                  default_cert_fingerprint_server_host_.c_str());
  }

  ini_.SetBoolValue(section_, "enable_autostart", enable_autostart_);
@@ -200,6 +270,15 @@ int ConfigCenter::SetSrtp(bool enable_srtp) {
 }

 int ConfigCenter::SetServerHost(const std::string& signal_server_host) {
+  if (enable_self_hosted_ && !cert_fingerprint_.empty() &&
+      signal_server_host != signal_server_host_) {
+    LOG_INFO("Server IP changed from {} to {}, clearing old fingerprint",
+             signal_server_host_, signal_server_host);
+    cert_fingerprint_.clear();
+    cert_fingerprint_server_host_.clear();
+    ini_.Delete(section_, "cert_fingerprint", false);
+    ini_.Delete(section_, "cert_fingerprint_server_host", false);
+  }
  signal_server_host_ = signal_server_host;
  ini_.SetValue(section_, "signal_server_host", signal_server_host_.c_str());
  SI_Error rc = ini_.SaveFile(config_path_.c_str());
@@ -241,6 +320,57 @@ int ConfigCenter::SetCertFilePath(const std::string& cert_file_path) {
  return 0;
 }

+int ConfigCenter::SetCertFingerprint(const std::string& fingerprint) {
+  cert_fingerprint_ = fingerprint;
+  cert_fingerprint_server_host_ = signal_server_host_;
+  ini_.SetValue(section_, "cert_fingerprint", cert_fingerprint_.c_str());
+  ini_.SetValue(section_, "cert_fingerprint_server_host",
+                cert_fingerprint_server_host_.c_str());
+  SI_Error rc = ini_.SaveFile(config_path_.c_str());
+  if (rc < 0) {
+    return -1;
+  }
+  return 0;
+}
+
+int ConfigCenter::SetDefaultCertFingerprint(const std::string& fingerprint) {
+  default_cert_fingerprint_ = fingerprint;
+  default_cert_fingerprint_server_host_ = signal_server_host_default_;
+  ini_.SetValue(section_, "default_cert_fingerprint",
+                default_cert_fingerprint_.c_str());
+  ini_.SetValue(section_, "default_cert_fingerprint_server_host",
+                default_cert_fingerprint_server_host_.c_str());
+  SI_Error rc = ini_.SaveFile(config_path_.c_str());
+  if (rc < 0) {
+    return -1;
+  }
+  return 0;
+}
+
+int ConfigCenter::ClearCertFingerprint() {
+  cert_fingerprint_.clear();
+  cert_fingerprint_server_host_.clear();
+  ini_.Delete(section_, "cert_fingerprint", false);
+  ini_.Delete(section_, "cert_fingerprint_server_host", false);
+  SI_Error rc = ini_.SaveFile(config_path_.c_str());
+  if (rc < 0) {
+    return -1;
+  }
+  return 0;
+}
+
+int ConfigCenter::ClearDefaultCertFingerprint() {
+  default_cert_fingerprint_.clear();
+  default_cert_fingerprint_server_host_.clear();
+  ini_.Delete(section_, "default_cert_fingerprint", false);
+  ini_.Delete(section_, "default_cert_fingerprint_server_host", false);
+  SI_Error rc = ini_.SaveFile(config_path_.c_str());
+  if (rc < 0) {
+    return -1;
+  }
+  return 0;
+}
+
 int ConfigCenter::SetSelfHosted(bool enable_self_hosted) {
  enable_self_hosted_ = enable_self_hosted;
  ini_.SetBoolValue(section_, "enable_self_hosted", enable_self_hosted_);
@@ -272,6 +402,28 @@ int ConfigCenter::SetSelfHosted(bool enable_self_hosted) {
    if (cert_file_path_value != nullptr && strlen(cert_file_path_value) > 0) {
      cert_file_path_ = cert_file_path_value;
    }
+    const char* cert_fingerprint_value =
+        ini_.GetValue(section_, "cert_fingerprint", nullptr);
+    if (cert_fingerprint_value != nullptr &&
+        strlen(cert_fingerprint_value) > 0) {
+      cert_fingerprint_ = cert_fingerprint_value;
+    }
+    const char* cert_fingerprint_server_host_value =
+        ini_.GetValue(section_, "cert_fingerprint_server_host", nullptr);
+    if (cert_fingerprint_server_host_value != nullptr &&
+        strlen(cert_fingerprint_server_host_value) > 0) {
+      cert_fingerprint_server_host_ = cert_fingerprint_server_host_value;
+    }
+
+    if (!cert_fingerprint_.empty() && !cert_fingerprint_server_host_.empty() &&
+        signal_server_host_ != cert_fingerprint_server_host_) {
+      LOG_INFO("Server IP changed from {} to {}, clearing old fingerprint",
+               cert_fingerprint_server_host_, signal_server_host_);
+      cert_fingerprint_.clear();
+      cert_fingerprint_server_host_.clear();
+      ini_.Delete(section_, "cert_fingerprint", false);
+      ini_.Delete(section_, "cert_fingerprint_server_host", false);
+    }

    ini_.SetValue(section_, "signal_server_host", signal_server_host_.c_str());
    ini_.SetLongValue(section_, "signal_server_port",
@@ -279,6 +431,11 @@ int ConfigCenter::SetSelfHosted(bool enable_self_hosted) {
    ini_.SetLongValue(section_, "coturn_server_port",
                      static_cast<long>(coturn_server_port_));
    ini_.SetValue(section_, "cert_file_path", cert_file_path_.c_str());
+    if (!cert_fingerprint_.empty()) {
+      ini_.SetValue(section_, "cert_fingerprint", cert_fingerprint_.c_str());
+      ini_.SetValue(section_, "cert_fingerprint_server_host",
+                    cert_fingerprint_server_host_.c_str());
+    }
  }

  SI_Error rc = ini_.SaveFile(config_path_.c_str());
@@ -368,6 +525,14 @@ int ConfigCenter::GetCoturnServerPort() const { return coturn_server_port_; }

 std::string ConfigCenter::GetCertFilePath() const { return cert_file_path_; }

+std::string ConfigCenter::GetCertFingerprint() const {
+  return cert_fingerprint_;
+}
+
+std::string ConfigCenter::GetDefaultCertFingerprint() const {
+  return default_cert_fingerprint_;
+}
+
 std::string ConfigCenter::GetDefaultServerHost() const {
  return signal_server_host_default_;
 }
--- a/src/config_center/config_center.h
+++ b/src/config_center/config_center.h
@@ -38,6 +38,10 @@ class ConfigCenter {
  int SetServerPort(int signal_server_port);
  int SetCoturnServerPort(int coturn_server_port);
  int SetCertFilePath(const std::string& cert_file_path);
+  int SetCertFingerprint(const std::string& fingerprint);
+  int SetDefaultCertFingerprint(const std::string& fingerprint);
+  int ClearCertFingerprint();
+  int ClearDefaultCertFingerprint();
  int SetSelfHosted(bool enable_self_hosted);
  int SetMinimizeToTray(bool enable_minimize_to_tray);
  int SetAutostart(bool enable_autostart);
@@ -56,6 +60,8 @@ class ConfigCenter {
  int GetSignalServerPort() const;
  int GetCoturnServerPort() const;
  std::string GetCertFilePath() const;
+  std::string GetCertFingerprint() const;
+  std::string GetDefaultCertFingerprint() const;
  std::string GetDefaultServerHost() const;
  int GetDefaultSignalServerPort() const;
  int GetDefaultCoturnServerPort() const;
@@ -88,6 +94,10 @@ class ConfigCenter {
  int coturn_server_port_default_ = 3478;
  std::string cert_file_path_ = "";
  std::string cert_file_path_default_ = "";
+  std::string cert_fingerprint_ = "";
+  std::string cert_fingerprint_server_host_ = "";
+  std::string default_cert_fingerprint_ = "";
+  std::string default_cert_fingerprint_server_host_ = "";
  bool enable_self_hosted_ = false;
  bool enable_minimize_to_tray_ = false;
  bool enable_autostart_ = false;
--- a/src/gui/assets/fonts/OPPOSans_Regular.h
+++ b/src/gui/assets/fonts/OPPOSans_Regular.h
--- a/src/gui/assets/localization/localization.h
+++ b/src/gui/assets/localization/localization.h
@@ -116,6 +116,9 @@ static std::vector<std::string> self_hosted_server_certificate_path = {
    reinterpret_cast<const char*>(u8"证书文件路径:"), "Certificate File Path:"};
 static std::vector<std::string> select_a_file = {
    reinterpret_cast<const char*>(u8"请选择文件"), "Please select a file"};
+static std::vector<std::string> reset_cert_fingerprint = {
+    reinterpret_cast<const char*>(u8"重置证书指纹"),
+    "Reset Certificate Fingerprint"};
 static std::vector<std::string> ok = {reinterpret_cast<const char*>(u8"确认"),
                                      "OK"};
 static std::vector<std::string> cancel = {
@@ -182,6 +185,19 @@ static std::vector<std::string> enable_daemon = {
 static std::vector<std::string> takes_effect_after_restart = {
    reinterpret_cast<const char*>(u8"重启后生效"),
    "Takes effect after restart"};
+static std::vector<std::string> select_file = {
+    reinterpret_cast<const char*>(u8"选择文件"), "Select File"};
+static std::vector<std::string> file_transfer_progress = {
+    reinterpret_cast<const char*>(u8"文件传输进度"), "File Transfer Progress"};
+static std::vector<std::string> queued = {
+    reinterpret_cast<const char*>(u8"队列中"), "Queued"};
+static std::vector<std::string> sending = {
+    reinterpret_cast<const char*>(u8"正在传输"), "Sending"};
+static std::vector<std::string> completed = {
+    reinterpret_cast<const char*>(u8"已完成"), "Completed"};
+static std::vector<std::string> failed = {
+    reinterpret_cast<const char*>(u8"失败"), "Failed"};
+
 #if _WIN32
 static std::vector<std::string> minimize_to_tray = {
    reinterpret_cast<const char*>(u8"退出时最小化到系统托盘:"),
--- a/src/gui/panels/local_peer_panel.cpp
+++ b/src/gui/panels/local_peer_panel.cpp
@@ -30,6 +30,7 @@ int Render::LocalWindow() {
  ImGui::SetCursorPos(
      ImVec2(io.DisplaySize.x * 0.045f, io.DisplaySize.y * 0.02f));

+  ImGui::SetWindowFontScale(0.9f);
  ImGui::TextColored(
      ImVec4(0.0f, 0.0f, 0.0f, 0.5f), "%s",
      localization::local_desktop[localization_language_index_].c_str());
--- a/src/gui/panels/recent_connections_panel.cpp
+++ b/src/gui/panels/recent_connections_panel.cpp
@@ -26,6 +26,7 @@ int Render::RecentConnectionsWindow() {
  ImGui::SetCursorPos(
      ImVec2(io.DisplaySize.x * 0.045f, io.DisplaySize.y * 0.02f));

+  ImGui::SetWindowFontScale(0.9f);
  ImGui::TextColored(
      ImVec4(0.0f, 0.0f, 0.0f, 0.5f), "%s",
      localization::recent_connections[localization_language_index_].c_str());
--- a/src/gui/panels/remote_peer_panel.cpp
+++ b/src/gui/panels/remote_peer_panel.cpp
@@ -31,6 +31,7 @@ int Render::RemoteWindow() {
  ImGui::SetCursorPos(
      ImVec2(io.DisplaySize.x * 0.057f, io.DisplaySize.y * 0.02f));

+  ImGui::SetWindowFontScale(0.9f);
  ImGui::TextColored(
      ImVec4(0.0f, 0.0f, 0.0f, 0.5f), "%s",
      localization::remote_desktop[localization_language_index_].c_str());
@@ -189,11 +190,11 @@ int Render::ConnectTo(const std::string& remote_id, const char* password,
        props->params_.user_id = props->local_id_.c_str();
        props->peer_ = CreatePeer(&props->params_);

-        props->control_window_width_ = title_bar_height_ * 8.0f;
+        props->control_window_width_ = title_bar_height_ * 9.0f;
        props->control_window_height_ = title_bar_height_ * 1.3f;
        props->control_window_min_width_ = title_bar_height_ * 0.65f;
        props->control_window_min_height_ = title_bar_height_ * 1.3f;
-        props->control_window_max_width_ = title_bar_height_ * 8.0f;
+        props->control_window_max_width_ = title_bar_height_ * 9.0f;
        props->control_window_max_height_ = title_bar_height_ * 6.0f;

        if (!props->peer_) {
@@ -205,7 +206,11 @@ int Render::ConnectTo(const std::string& remote_id, const char* password,
          AddVideoStream(props->peer_, display_info.name.c_str());
        }
        AddAudioStream(props->peer_, props->audio_label_.c_str());
-        AddDataStream(props->peer_, props->data_label_.c_str());
+        AddDataStream(props->peer_, props->data_label_.c_str(), false);
+        AddDataStream(props->peer_, props->control_data_label_.c_str(), true);
+        AddDataStream(props->peer_, props->file_label_.c_str(), true);
+        AddDataStream(props->peer_, props->file_feedback_label_.c_str(), true);
+        AddDataStream(props->peer_, props->clipboard_label_.c_str(), true);

        props->connection_status_ = ConnectionStatus::Connecting;

--- a/src/gui/render.cpp
+++ b/src/gui/render.cpp
@@ -9,9 +9,11 @@
 #include <thread>

 #include "OPPOSans_Regular.h"
+#include "clipboard.h"
 #include "device_controller_factory.h"
 #include "fa_regular_400.h"
 #include "fa_solid_900.h"
+#include "file_transfer.h"
 #include "layout_relative.h"
 #include "localization.h"
 #include "platform.h"
@@ -537,13 +539,13 @@ int Render::CreateConnectionPeer() {
  std::string signal_server_ip;
  int signal_server_port;
  int coturn_server_port;
-  std::string tls_cert_path;
+  std::string tls_cert_fingerprint;

  if (config_center_->IsSelfHosted()) {
    signal_server_ip = config_center_->GetSignalServerHost();
    signal_server_port = config_center_->GetSignalServerPort();
    coturn_server_port = config_center_->GetCoturnServerPort();
-    tls_cert_path = config_center_->GetCertFilePath();
+    tls_cert_fingerprint = config_center_->GetCertFingerprint();

    std::string current_self_hosted_ip = config_center_->GetSignalServerHost();
    bool use_cached_id = false;
@@ -604,7 +606,7 @@ int Render::CreateConnectionPeer() {
    signal_server_ip = config_center_->GetDefaultServerHost();
    signal_server_port = config_center_->GetDefaultSignalServerPort();
    coturn_server_port = config_center_->GetDefaultCoturnServerPort();
-    tls_cert_path = config_center_->GetDefaultCertFilePath();
+    tls_cert_fingerprint = config_center_->GetDefaultCertFingerprint();
    params_.user_id = client_id_with_password_;
  }

@@ -649,9 +651,30 @@ int Render::CreateConnectionPeer() {
  strncpy((char*)params_.turn_server_password, "crossdeskpw",
          sizeof(params_.turn_server_password) - 1);
  params_.turn_server_password[sizeof(params_.turn_server_password) - 1] = '\0';
-  strncpy(params_.tls_cert_path, tls_cert_path.c_str(),
-          sizeof(params_.tls_cert_path) - 1);
-  params_.tls_cert_path[sizeof(params_.tls_cert_path) - 1] = '\0';
+  strncpy(params_.tls_cert_fingerprint, tls_cert_fingerprint.c_str(),
+          sizeof(params_.tls_cert_fingerprint) - 1);
+  params_.tls_cert_fingerprint[sizeof(params_.tls_cert_fingerprint) - 1] = '\0';
+
+  if (config_center_->IsSelfHosted()) {
+    params_.on_cert_fingerprint = [](const char* fingerprint, void* user_data) {
+      Render* render = static_cast<Render*>(user_data);
+      if (render && render->config_center_) {
+        render->config_center_->SetCertFingerprint(fingerprint);
+        LOG_INFO("Saved self-hosted certificate fingerprint: {}", fingerprint);
+      }
+    };
+    params_.fingerprint_user_data = this;
+  } else {
+    params_.on_cert_fingerprint = [](const char* fingerprint, void* user_data) {
+      Render* render = static_cast<Render*>(user_data);
+      if (render && render->config_center_) {
+        render->config_center_->SetDefaultCertFingerprint(fingerprint);
+        LOG_INFO("Saved default server certificate fingerprint: {}",
+                 fingerprint);
+      }
+    };
+    params_.fingerprint_user_data = this;
+  }

  strncpy(params_.log_path, dll_log_path_.c_str(),
          sizeof(params_.log_path) - 1);
@@ -692,7 +715,11 @@ int Render::CreateConnectionPeer() {
    }

    AddAudioStream(peer_, audio_label_.c_str());
-    AddDataStream(peer_, data_label_.c_str());
+    AddDataStream(peer_, data_label_.c_str(), false);
+    AddDataStream(peer_, control_data_label_.c_str(), true);
+    AddDataStream(peer_, file_label_.c_str(), true);
+    AddDataStream(peer_, file_feedback_label_.c_str(), true);
+    AddDataStream(peer_, clipboard_label_.c_str(), true);
    return 0;
  } else {
    return -1;
@@ -912,6 +939,74 @@ int Render::DestroyStreamWindow() {
  return 0;
 }

+int Render::CreateServerWindow() {
+  if (server_window_created_) {
+    return 0;
+  }
+  server_ctx_ = ImGui::CreateContext();
+  if (!server_ctx_) {
+    LOG_ERROR("Server context is null");
+    return -1;
+  }
+  ImGui::SetCurrentContext(server_ctx_);
+  if (!SDL_CreateWindowAndRenderer("Server window", (int)server_window_width_,
+                                   (int)server_window_height_,
+                                   SDL_WINDOW_HIGH_PIXEL_DENSITY |
+                                       SDL_WINDOW_BORDERLESS |
+                                       SDL_WINDOW_TRANSPARENT,
+                                   &server_window_, &server_renderer_)) {
+    LOG_ERROR("Error creating server_window_ and server_renderer_: {}",
+              SDL_GetError());
+    return -1;
+  }
+
+  // Set window position to bottom-right corner
+  SDL_Rect display_bounds;
+  if (SDL_GetDisplayUsableBounds(SDL_GetDisplayForWindow(server_window_),
+                                 &display_bounds)) {
+    int window_x =
+        display_bounds.x + display_bounds.w - (int)server_window_width_;
+    int window_y =
+        display_bounds.y + display_bounds.h - (int)server_window_height_;
+    SDL_SetWindowPosition(server_window_, window_x, window_y);
+  }
+
+  SDL_SetWindowResizable(server_window_, false);
+
+  SDL_SetRenderDrawBlendMode(server_renderer_, SDL_BLENDMODE_BLEND);
+
+  // for window region action
+  SDL_SetWindowHitTest(server_window_, HitTestCallback, this);
+  SetupFontAndStyle(false);
+  ImGui_ImplSDL3_InitForSDLRenderer(server_window_, server_renderer_);
+  ImGui_ImplSDLRenderer3_Init(server_renderer_);
+
+  server_window_created_ = true;
+  server_window_inited_ = true;
+
+  LOG_INFO("Server window inited");
+
+  return 0;
+}
+
+int Render::DestroyServerWindow() {
+  if (server_ctx_) {
+    ImGui::SetCurrentContext(server_ctx_);
+  }
+
+  if (server_renderer_) {
+    SDL_DestroyRenderer(server_renderer_);
+  }
+
+  if (server_window_) {
+    SDL_DestroyWindow(server_window_);
+  }
+
+  server_window_created_ = false;
+
+  return 0;
+}
+
 int Render::SetupFontAndStyle(bool main_window) {
  float font_size = 32.0f;

@@ -969,7 +1064,13 @@ int Render::SetupFontAndStyle(bool main_window) {
            io.Fonts->AddFontFromFileTTF(font_paths[i], font_size, &config,
                                         io.Fonts->GetGlyphRangesChineseFull());
        if (main_windows_system_chinese_font_ != nullptr) {
-          LOG_INFO("Loaded system Chinese font: {}", font_paths[i]);
+          // Merge FontAwesome icons into the Chinese font
+          config.MergeMode = true;
+          static const ImWchar icon_ranges[] = {ICON_MIN_FA, ICON_MAX_FA, 0};
+          io.Fonts->AddFontFromMemoryTTF(fa_solid_900_ttf, fa_solid_900_ttf_len,
+                                         font_size, &config, icon_ranges);
+          config.MergeMode = false;
+          LOG_INFO("Loaded system Chinese font with icons: {}", font_paths[i]);
          break;
        }
      } else {
@@ -977,7 +1078,13 @@ int Render::SetupFontAndStyle(bool main_window) {
            io.Fonts->AddFontFromFileTTF(font_paths[i], font_size, &config,
                                         io.Fonts->GetGlyphRangesChineseFull());
        if (stream_windows_system_chinese_font_ != nullptr) {
-          LOG_INFO("Loaded system Chinese font: {}", font_paths[i]);
+          // Merge FontAwesome icons into the Chinese font
+          config.MergeMode = true;
+          static const ImWchar icon_ranges[] = {ICON_MIN_FA, ICON_MAX_FA, 0};
+          io.Fonts->AddFontFromMemoryTTF(fa_solid_900_ttf, fa_solid_900_ttf_len,
+                                         font_size, &config, icon_ranges);
+          config.MergeMode = false;
+          LOG_INFO("Loaded system Chinese font with icons: {}", font_paths[i]);
          break;
        }
      }
@@ -988,12 +1095,24 @@ int Render::SetupFontAndStyle(bool main_window) {
  if (main_window) {
    if (main_windows_system_chinese_font_ == nullptr) {
      main_windows_system_chinese_font_ = io.Fonts->AddFontDefault(&config);
-      LOG_WARN("System Chinese font not found, using default font");
+      // Merge FontAwesome icons into the default font
+      config.MergeMode = true;
+      static const ImWchar icon_ranges[] = {ICON_MIN_FA, ICON_MAX_FA, 0};
+      io.Fonts->AddFontFromMemoryTTF(fa_solid_900_ttf, fa_solid_900_ttf_len,
+                                     font_size, &config, icon_ranges);
+      config.MergeMode = false;
+      LOG_WARN("System Chinese font not found, using default font with icons");
    }
  } else {
    if (stream_windows_system_chinese_font_ == nullptr) {
      stream_windows_system_chinese_font_ = io.Fonts->AddFontDefault(&config);
-      LOG_WARN("System Chinese font not found, using default font");
+      // Merge FontAwesome icons into the default font
+      config.MergeMode = true;
+      static const ImWchar icon_ranges[] = {ICON_MIN_FA, ICON_MAX_FA, 0};
+      io.Fonts->AddFontFromMemoryTTF(fa_solid_900_ttf, fa_solid_900_ttf_len,
+                                     font_size, &config, icon_ranges);
+      config.MergeMode = false;
+      LOG_WARN("System Chinese font not found, using default font with icons");
    }
  }

@@ -1132,6 +1251,39 @@ int Render::DrawStreamWindow() {
  return 0;
 }

+int Render::DrawServerWindow() {
+  if (!server_ctx_) {
+    LOG_ERROR("Server context is null");
+    return -1;
+  }
+
+  if (server_window_) {
+    int w = 0, h = 0;
+    SDL_GetWindowSize(server_window_, &w, &h);
+    if (w > 0 && h > 0) {
+      server_window_width_ = (float)w;
+      server_window_height_ = (float)h;
+    }
+  }
+
+  ImGui::SetCurrentContext(server_ctx_);
+  ImGui_ImplSDLRenderer3_NewFrame();
+  ImGui_ImplSDL3_NewFrame();
+  ImGui::NewFrame();
+  ServerWindow();
+  ImGui::Render();
+  // Transparent clear for compact (shaped) mode; opaque clear for normal mode.
+  if (server_window_compact_) {
+    SDL_SetRenderDrawColor(server_renderer_, 0, 0, 0, 0);
+  } else {
+    SDL_SetRenderDrawColor(server_renderer_, 255, 255, 255, 255);
+  }
+  SDL_RenderClear(server_renderer_);
+  ImGui_ImplSDLRenderer3_RenderDrawData(ImGui::GetDrawData(), server_renderer_);
+  SDL_RenderPresent(server_renderer_);
+  return 0;
+}
+
 int Render::Run() {
  latest_version_info_ = CheckUpdate();
  if (!latest_version_info_.empty() &&
@@ -1243,6 +1395,36 @@ void Render::InitializeModules() {
    keyboard_capturer_ = (KeyboardCapturer*)device_controller_factory_->Create(
        DeviceControllerFactory::Device::Keyboard);
    CreateConnectionPeer();
+
+    // start clipboard monitoring with callback to send data to peers
+    Clipboard::StartMonitoring(
+        100, [this](const char* data, size_t size) -> int {
+          // send clipboard data to all connected peers
+          std::shared_lock lock(client_properties_mutex_);
+          int ret = -1;
+          for (const auto& [remote_id, props] : client_properties_) {
+            if (props && props->peer_ && props->connection_established_) {
+              ret = SendReliableDataFrame(props->peer_, data, size,
+                                          props->clipboard_label_.c_str());
+              if (ret != 0) {
+                LOG_WARN("Failed to send clipboard data to peer [{}], ret={}",
+                         remote_id.c_str(), ret);
+                return ret;
+              }
+            }
+          }
+
+          ret = SendReliableDataFrame(peer_, data, size,
+                                      clipboard_label_.c_str());
+          if (ret != 0) {
+            LOG_WARN("Failed to send clipboard data to peer [{}], ret={}",
+                     remote_id_display_, ret);
+            return ret;
+          }
+
+          return 0;
+        });
+
    modules_inited_ = true;
  }
 }
@@ -1276,12 +1458,17 @@ void Render::MainLoop() {
    UpdateLabels();
    HandleRecentConnections();
    HandleStreamWindow();
+    HandleServerWindow();

    DrawMainWindow();
    if (stream_window_inited_) {
      DrawStreamWindow();
    }

+    if (is_server_mode_) {
+      DrawServerWindow();
+    }
+
    UpdateInteractions();

    if (need_to_send_host_info_) {
@@ -1319,8 +1506,8 @@ void Render::MainLoop() {
      remote_action.i.host_name_size = host_name.size();

      std::string msg = remote_action.to_json();
-      int ret =
-          SendDataFrame(peer_, msg.data(), msg.size(), data_label_.c_str());
+      int ret = SendReliableDataFrame(peer_, msg.data(), msg.size(),
+                                      control_data_label_.c_str());
      FreeRemoteAction(remote_action);
      if (0 == ret) {
        need_to_send_host_info_ = false;
@@ -1373,7 +1560,21 @@ void Render::HandleStreamWindow() {
  }
 }

+void Render::HandleServerWindow() {
+  if (need_to_create_server_window_) {
+    CreateServerWindow();
+    need_to_create_server_window_ = false;
+  }
+
+  if (need_to_destroy_server_window_) {
+    DestroyServerWindow();
+    need_to_destroy_server_window_ = false;
+  }
+}
+
 void Render::Cleanup() {
+  Clipboard::StopMonitoring();
+
  if (screen_capturer_) {
    screen_capturer_->Destroy();
    delete screen_capturer_;
@@ -1521,6 +1722,166 @@ void Render::CleanSubStreamWindowProperties(
  }
 }

+void Render::StartFileTransfer(std::shared_ptr<SubStreamWindowProperties> props,
+                               const std::filesystem::path& file_path,
+                               const std::string& file_label) {
+  if (!props || !props->peer_) {
+    LOG_ERROR("StartFileTransfer: invalid props or peer");
+    return;
+  }
+
+  bool expected = false;
+  if (!props->file_sending_.compare_exchange_strong(expected, true)) {
+    // Already sending, this should not happen if called correctly
+    LOG_WARN(
+        "StartFileTransfer called but file_sending_ is already true, "
+        "file should have been queued: {}",
+        file_path.filename().string().c_str());
+    return;
+  }
+
+  auto peer = props->peer_;
+  auto props_weak = std::weak_ptr<SubStreamWindowProperties>(props);
+  Render* render_ptr = this;
+
+  std::thread([peer, file_path, file_label, props_weak, render_ptr]() {
+    auto props_locked = props_weak.lock();
+    if (!props_locked) {
+      return;
+    }
+
+    std::error_code ec;
+    uint64_t total_size = std::filesystem::file_size(file_path, ec);
+    if (ec) {
+      LOG_ERROR("Failed to get file size: {}", ec.message().c_str());
+      props_locked->file_sending_ = false;
+      return;
+    }
+
+    props_locked->file_sent_bytes_ = 0;
+    props_locked->file_total_bytes_ = total_size;
+    props_locked->file_send_rate_bps_ = 0;
+    props_locked->file_transfer_window_visible_ = true;
+    {
+      std::lock_guard<std::mutex> lock(props_locked->file_transfer_mutex_);
+      props_locked->file_send_start_time_ = std::chrono::steady_clock::now();
+      props_locked->file_send_last_update_time_ =
+          props_locked->file_send_start_time_;
+      props_locked->file_send_last_bytes_ = 0;
+    }
+
+    LOG_INFO(
+        "File transfer started: {} ({} bytes), file_sending_={}, "
+        "total_bytes_={}",
+        file_path.filename().string(), total_size,
+        props_locked->file_sending_.load(),
+        props_locked->file_total_bytes_.load());
+
+    FileSender sender;
+    uint32_t file_id = FileSender::NextFileId();
+
+    {
+      std::lock_guard<std::shared_mutex> lock(
+          render_ptr->file_id_to_props_mutex_);
+      render_ptr->file_id_to_props_[file_id] = props_weak;
+    }
+
+    props_locked->current_file_id_ = file_id;
+
+    // Update file transfer list: mark as sending
+    // Find the queued file that matches the exact file path
+    {
+      std::lock_guard<std::mutex> lock(props_locked->file_transfer_list_mutex_);
+      for (auto& info : props_locked->file_transfer_list_) {
+        if (info.file_path == file_path &&
+            info.status ==
+                SubStreamWindowProperties::FileTransferStatus::Queued) {
+          info.status = SubStreamWindowProperties::FileTransferStatus::Sending;
+          info.file_id = file_id;
+          info.file_size = total_size;
+          info.sent_bytes = 0;
+          break;
+        }
+      }
+    }
+
+    props_locked->file_transfer_window_visible_ = true;
+
+    // Progress will be updated via ACK from receiver
+    int ret = sender.SendFile(
+        file_path, file_path.filename().string(),
+        [peer, file_label](const char* buf, size_t sz) -> int {
+          return SendReliableDataFrame(peer, buf, sz, file_label.c_str());
+        },
+        64 * 1024, file_id);
+
+    // file_sending_ should remain true until we receive the final ACK from
+    // receiver
+    auto props_locked_final = props_weak.lock();
+    if (props_locked_final) {
+      // On error, set file_sending_ to false immediately to allow next file
+      if (ret != 0) {
+        props_locked_final->file_sending_ = false;
+        props_locked_final->file_transfer_window_visible_ = false;
+        props_locked_final->file_sent_bytes_ = 0;
+        props_locked_final->file_total_bytes_ = 0;
+        props_locked_final->file_send_rate_bps_ = 0;
+        props_locked_final->current_file_id_ = 0;
+
+        // Unregister file_id mapping on error
+        {
+          std::lock_guard<std::shared_mutex> lock(
+              render_ptr->file_id_to_props_mutex_);
+          render_ptr->file_id_to_props_.erase(file_id);
+        }
+
+        // Update file transfer list: mark as failed
+        {
+          std::lock_guard<std::mutex> lock(
+              props_locked_final->file_transfer_list_mutex_);
+          for (auto& info : props_locked_final->file_transfer_list_) {
+            if (info.file_id == file_id) {
+              info.status =
+                  SubStreamWindowProperties::FileTransferStatus::Failed;
+              break;
+            }
+          }
+        }
+
+        LOG_ERROR("FileSender::SendFile failed for [{}], ret={}",
+                  file_path.string().c_str(), ret);
+
+        render_ptr->ProcessFileQueue(props_locked_final);
+      }
+    }
+  }).detach();
+}
+
+void Render::ProcessFileQueue(
+    std::shared_ptr<SubStreamWindowProperties> props) {
+  if (!props) {
+    return;
+  }
+
+  if (props->file_sending_.load()) {
+    return;
+  }
+
+  SubStreamWindowProperties::QueuedFile queued_file;
+  {
+    std::lock_guard<std::mutex> lock(props->file_queue_mutex_);
+    if (props->file_send_queue_.empty()) {
+      return;
+    }
+    queued_file = props->file_send_queue_.front();
+    props->file_send_queue_.pop();
+  }
+
+  LOG_INFO("Processing next file in queue: {}",
+           queued_file.file_path.string().c_str());
+  StartFileTransfer(props, queued_file.file_path, queued_file.file_label);
+}
+
 void Render::UpdateRenderRect() {
  // std::shared_lock lock(client_properties_mutex_);
  for (auto& [_, props] : client_properties_) {
@@ -1589,6 +1950,16 @@ void Render::ProcessSdlEvent(const SDL_Event& event) {
    }
  }

+  if (server_window_inited_) {
+    if (server_ctx_) {
+      ImGui::SetCurrentContext(server_ctx_);
+      ImGui_ImplSDL3_ProcessEvent(&event);
+    } else {
+      LOG_ERROR("Server context is null");
+      return;
+    }
+  }
+
  switch (event.type) {
    case SDL_EVENT_QUIT:
      if (stream_window_inited_) {
@@ -1678,6 +2049,12 @@ void Render::ProcessSdlEvent(const SDL_Event& event) {
        foucs_on_main_window_ = false;
      }
      break;
+    case SDL_EVENT_DROP_FILE:
+      if (stream_window_ &&
+          SDL_GetWindowID(stream_window_) == event.window.windowID) {
+        ProcessFileDropEvent(event);
+      }
+      break;

    case SDL_EVENT_MOUSE_MOTION:
    case SDL_EVENT_MOUSE_BUTTON_DOWN:
@@ -1758,4 +2135,63 @@ void Render::ProcessSdlEvent(const SDL_Event& event) {
      break;
  }
 }
+
+void Render::ProcessFileDropEvent(const SDL_Event& event) {
+  if (event.type != SDL_EVENT_DROP_FILE) {
+    return;
+  }
+
+  if (!stream_window_inited_) {
+    return;
+  }
+
+  std::shared_lock lock(client_properties_mutex_);
+  for (auto& [_, props] : client_properties_) {
+    if (props->tab_selected_) {
+      if (event.drop.data == nullptr) {
+        LOG_ERROR("ProcessFileDropEvent: drop event data is null");
+        break;
+      }
+
+      if (!props || !props->peer_) {
+        LOG_ERROR("ProcessFileDropEvent: invalid props or peer");
+        break;
+      }
+
+      std::string utf8_path = static_cast<const char*>(event.drop.data);
+      std::filesystem::path file_path = std::filesystem::u8path(utf8_path);
+
+      // Check if file exists
+      std::error_code ec;
+      if (!std::filesystem::exists(file_path, ec)) {
+        LOG_ERROR("ProcessFileDropEvent: file does not exist: {}",
+                  file_path.string().c_str());
+        break;
+      }
+
+      // Check if it's a regular file
+      if (!std::filesystem::is_regular_file(file_path, ec)) {
+        LOG_ERROR("ProcessFileDropEvent: path is not a regular file: {}",
+                  file_path.string().c_str());
+        break;
+      }
+
+      // Get file size
+      uint64_t file_size = std::filesystem::file_size(file_path, ec);
+      if (ec) {
+        LOG_ERROR("ProcessFileDropEvent: failed to get file size: {}",
+                  ec.message().c_str());
+        break;
+      }
+
+      LOG_INFO("Drop file [{}] to send (size: {} bytes)", event.drop.data,
+               file_size);
+
+      // Use ProcessSelectedFile to handle the file processing
+      ProcessSelectedFile(utf8_path, props, props->file_label_);
+
+      break;
+    }
+  }
+}
 }  // namespace crossdesk
--- a/src/gui/render.h
+++ b/src/gui/render.h
@@ -11,10 +11,12 @@

 #include <atomic>
 #include <chrono>
+#include <filesystem>
 #include <fstream>
 #include <mutex>
 #include <nlohmann/json.hpp>
 #include <optional>
+#include <queue>
 #include <shared_mutex>
 #include <string>
 #include <unordered_map>
@@ -44,7 +46,11 @@ class Render {
    Params params_;
    PeerPtr* peer_ = nullptr;
    std::string audio_label_ = "control_audio";
-    std::string data_label_ = "control_data";
+    std::string data_label_ = "data";
+    std::string file_label_ = "file";
+    std::string control_data_label_ = "control_data";
+    std::string file_feedback_label_ = "file_feedback";
+    std::string clipboard_label_ = "clipboard";
    std::string local_id_ = "";
    std::string remote_id_ = "";
    bool exit_ = false;
@@ -122,6 +128,39 @@ class Render {
    int frame_count_ = 0;
    std::chrono::steady_clock::time_point last_time_;
    XNetTrafficStats net_traffic_stats_;
+
+    // File transfer progress
+    std::atomic<bool> file_sending_ = false;
+    std::atomic<uint64_t> file_sent_bytes_ = 0;
+    std::atomic<uint64_t> file_total_bytes_ = 0;
+    std::atomic<uint32_t> file_send_rate_bps_ = 0;
+    std::mutex file_transfer_mutex_;
+    std::chrono::steady_clock::time_point file_send_start_time_;
+    std::chrono::steady_clock::time_point file_send_last_update_time_;
+    uint64_t file_send_last_bytes_ = 0;
+    bool file_transfer_window_visible_ = false;
+    std::atomic<uint32_t> current_file_id_{0};
+
+    struct QueuedFile {
+      std::filesystem::path file_path;
+      std::string file_label;
+    };
+    std::queue<QueuedFile> file_send_queue_;
+    std::mutex file_queue_mutex_;
+
+    enum class FileTransferStatus { Queued, Sending, Completed, Failed };
+
+    struct FileTransferInfo {
+      std::string file_name;
+      std::filesystem::path file_path;
+      uint64_t file_size = 0;
+      FileTransferStatus status = FileTransferStatus::Queued;
+      uint64_t sent_bytes = 0;
+      uint32_t file_id = 0;
+      uint32_t rate_bps = 0;
+    };
+    std::vector<FileTransferInfo> file_transfer_list_;
+    std::mutex file_transfer_list_mutex_;
  };

 public:
@@ -142,6 +181,7 @@ class Render {
  void UpdateInteractions();
  void HandleRecentConnections();
  void HandleStreamWindow();
+  void HandleServerWindow();
  void Cleanup();
  void CleanupFactories();
  void CleanupPeer(std::shared_ptr<SubStreamWindowProperties> props);
@@ -151,12 +191,19 @@ class Render {
  void UpdateRenderRect();
  void ProcessSdlEvent(const SDL_Event& event);

+  void ProcessFileDropEvent(const SDL_Event& event);
+
+  void ProcessSelectedFile(const std::string& path,
+                           std::shared_ptr<SubStreamWindowProperties>& props,
+                           const std::string& file_label);
+
 private:
  int CreateStreamRenderWindow();
  int TitleBar(bool main_window);
  int MainWindow();
  int UpdateNotificationWindow();
  int StreamWindow();
+  int ServerWindow();
  int LocalWindow();
  int RemoteWindow();
  int RecentConnectionsWindow();
@@ -172,6 +219,7 @@ class Render {
  int ShowRecentConnections();
  void Hyperlink(const std::string& label, const std::string& url,
                 const float window_width);
+  int FileTransferWindow(std::shared_ptr<SubStreamWindowProperties>& props);

 private:
  int ConnectTo(const std::string& remote_id, const char* password,
@@ -180,11 +228,15 @@ class Render {
  int DestroyMainWindow();
  int CreateStreamWindow();
  int DestroyStreamWindow();
+  int CreateServerWindow();
+  int DestroyServerWindow();
  int SetupFontAndStyle(bool main_window);
  int DestroyMainWindowContext();
  int DestroyStreamWindowContext();
+  int DestroyServerWindowContext();
  int DrawMainWindow();
  int DrawStreamWindow();
+  int DrawServerWindow();
  int ConfirmDeleteConnection();
  int NetTrafficStats(std::shared_ptr<SubStreamWindowProperties>& props);
  void DrawConnectionStatusText(
@@ -201,14 +253,17 @@ class Render {
 public:
  static void OnReceiveVideoBufferCb(const XVideoFrame* video_frame,
                                     const char* user_id, size_t user_id_size,
+                                     const char* src_id, size_t src_id_size,
                                     void* user_data);

  static void OnReceiveAudioBufferCb(const char* data, size_t size,
                                     const char* user_id, size_t user_id_size,
+                                     const char* src_id, size_t src_id_size,
                                     void* user_data);

  static void OnReceiveDataBufferCb(const char* data, size_t size,
                                    const char* user_id, size_t user_id_size,
+                                    const char* src_id, size_t src_id_size,
                                    void* user_data);

  static void OnSignalStatusCb(SignalStatus status, const char* user_id,
@@ -259,6 +314,12 @@ class Render {

  int CreateConnectionPeer();

+  // File transfer helper functions
+  void StartFileTransfer(std::shared_ptr<SubStreamWindowProperties> props,
+                         const std::filesystem::path& file_path,
+                         const std::string& file_label);
+  void ProcessFileQueue(std::shared_ptr<SubStreamWindowProperties> props);
+
  int AudioDeviceInit();
  int AudioDeviceDestroy();

@@ -432,6 +493,35 @@ class Render {
  float stream_window_dpi_scaling_w_ = 1.0f;
  float stream_window_dpi_scaling_h_ = 1.0f;

+  // server window render
+  SDL_Window* server_window_ = nullptr;
+  SDL_Renderer* server_renderer_ = nullptr;
+  ImGuiContext* server_ctx_ = nullptr;
+
+  // server window properties
+  bool need_to_create_server_window_ = false;
+  bool need_to_destroy_server_window_ = false;
+  bool server_window_created_ = false;
+  bool server_window_inited_ = false;
+  int server_window_width_default_ = 300;
+  int server_window_height_default_ = 450;
+  float server_window_width_ = 300;
+  float server_window_height_ = 450;
+  float server_window_title_bar_height_ = 30.0f;
+  SDL_PixelFormat server_pixformat_ = SDL_PIXELFORMAT_NV12;
+  int server_window_width_real_ = 400;
+  int server_window_height_real_ = 450;
+  float server_window_dpi_scaling_w_ = 1.0f;
+  float server_window_dpi_scaling_h_ = 1.0f;
+
+  // server window compact mode (50x50) toggle
+  bool server_window_compact_ = false;
+  int server_window_width_before_compact_ = 0;
+  int server_window_height_before_compact_ = 0;
+  int server_window_x_before_compact_ = 0;
+  int server_window_y_before_compact_ = 0;
+  bool server_window_bounds_saved_ = false;
+
  bool label_inited_ = false;
  bool connect_button_pressed_ = false;
  bool password_validating_ = false;
@@ -448,6 +538,7 @@ class Render {
  bool fullscreen_button_pressed_ = false;
  bool focus_on_input_widget_ = true;
  bool is_client_mode_ = false;
+  bool is_server_mode_ = false;
  bool reload_recent_connections_ = true;
  bool show_confirm_delete_connection_ = false;
  bool delete_connection_ = false;
@@ -464,7 +555,16 @@ class Render {
  std::string video_secondary_label_ = "secondary_display";
  std::string audio_label_ = "audio";
  std::string data_label_ = "data";
+  std::string info_label_ = "info";
+  std::string control_data_label_ = "control_data";
+  std::string file_label_ = "file";
+  std::string file_feedback_label_ = "file_feedback";
+  std::string clipboard_label_ = "clipboard";
  Params params_;
+  // Map file_id to props for tracking file transfer progress via ACK
+  std::unordered_map<uint32_t, std::weak_ptr<SubStreamWindowProperties>>
+      file_id_to_props_;
+  std::shared_mutex file_id_to_props_mutex_;
  SDL_AudioDeviceID input_dev_;
  SDL_AudioDeviceID output_dev_;
  ScreenCapturerFactory* screen_capturer_factory_ = nullptr;
--- a/src/gui/render_callback.cpp
+++ b/src/gui/render_callback.cpp
@@ -1,8 +1,16 @@
+#include <chrono>
 #include <cmath>
+#include <cstdlib>
+#include <cstring>
+#include <filesystem>
 #include <fstream>
+#include <unordered_map>

+#include "clipboard.h"
 #include "device_controller.h"
+#include "file_transfer.h"
 #include "localization.h"
+#include "minirtc.h"
 #include "platform.h"
 #include "rd_log.h"
 #include "render.h"
@@ -212,6 +220,7 @@ void Render::SdlCaptureAudioOut([[maybe_unused]] void* userdata,

 void Render::OnReceiveVideoBufferCb(const XVideoFrame* video_frame,
                                    const char* user_id, size_t user_id_size,
+                                    const char* src_id, size_t src_id_size,
                                    void* user_data) {
  Render* render = (Render*)user_data;
  if (!render) {
@@ -279,6 +288,7 @@ void Render::OnReceiveVideoBufferCb(const XVideoFrame* video_frame,

 void Render::OnReceiveAudioBufferCb(const char* data, size_t size,
                                    const char* user_id, size_t user_id_size,
+                                    const char* src_id, size_t src_id_size,
                                    void* user_data) {
  Render* render = (Render*)user_data;
  if (!render) {
@@ -298,12 +308,142 @@ void Render::OnReceiveAudioBufferCb(const char* data, size_t size,

 void Render::OnReceiveDataBufferCb(const char* data, size_t size,
                                   const char* user_id, size_t user_id_size,
+                                   const char* src_id, size_t src_id_size,
                                   void* user_data) {
  Render* render = (Render*)user_data;
  if (!render) {
    return;
  }

+  std::string source_id = std::string(src_id, src_id_size);
+  if (source_id == render->file_label_) {
+    std::string remote_user_id = std::string(user_id, user_id_size);
+
+    static FileReceiver receiver;
+    receiver.SetOnSendAck([render](const FileTransferAck& ack) -> int {
+      return SendReliableDataFrame(
+          render->peer_, reinterpret_cast<const char*>(&ack),
+          sizeof(FileTransferAck), render->file_feedback_label_.c_str());
+    });
+
+    receiver.OnData(data, size);
+    return;
+  } else if (source_id == render->clipboard_label_) {
+    if (size > 0) {
+      std::string clipboard_text(data, size);
+      if (!Clipboard::SetText(clipboard_text)) {
+        LOG_ERROR("Failed to set clipboard content from remote");
+      }
+    }
+    return;
+  } else if (source_id == render->file_feedback_label_) {
+    if (size < sizeof(FileTransferAck)) {
+      LOG_ERROR("FileTransferAck: buffer too small, size={}", size);
+      return;
+    }
+
+    FileTransferAck ack{};
+    memcpy(&ack, data, sizeof(FileTransferAck));
+
+    if (ack.magic != kFileAckMagic) {
+      LOG_ERROR(
+          "FileTransferAck: invalid magic, got 0x{:08X}, expected 0x{:08X}",
+          ack.magic, kFileAckMagic);
+      return;
+    }
+
+    std::shared_ptr<SubStreamWindowProperties> props = nullptr;
+    {
+      std::shared_lock lock(render->file_id_to_props_mutex_);
+      auto it = render->file_id_to_props_.find(ack.file_id);
+      if (it != render->file_id_to_props_.end()) {
+        props = it->second.lock();
+      }
+    }
+
+    if (!props) {
+      LOG_WARN("FileTransferAck: no props found for file_id={}", ack.file_id);
+      return;
+    }
+
+    // Update progress based on ACK
+    props->file_sent_bytes_ = ack.acked_offset;
+    props->file_total_bytes_ = ack.total_size;
+
+    uint32_t rate_bps = 0;
+    {
+      uint32_t data_channel_bitrate =
+          props->net_traffic_stats_.data_outbound_stats.bitrate;
+
+      if (data_channel_bitrate > 0 && props->file_sending_.load()) {
+        rate_bps = static_cast<uint32_t>(data_channel_bitrate * 0.99f);
+
+        uint32_t current_rate = props->file_send_rate_bps_.load();
+        if (current_rate > 0) {
+          // 70% old + 30% new for smoother display
+          rate_bps = static_cast<uint32_t>(current_rate * 0.7 + rate_bps * 0.3);
+        }
+      } else {
+        rate_bps = props->file_send_rate_bps_.load();
+      }
+
+      props->file_send_rate_bps_ = rate_bps;
+      props->file_send_last_bytes_ = ack.acked_offset;
+      auto now = std::chrono::steady_clock::now();
+      props->file_send_last_update_time_ = now;
+    }
+
+    // Update file transfer list: update progress and rate
+    {
+      std::lock_guard<std::mutex> lock(props->file_transfer_list_mutex_);
+      for (auto& info : props->file_transfer_list_) {
+        if (info.file_id == ack.file_id) {
+          info.sent_bytes = ack.acked_offset;
+          info.file_size = ack.total_size;
+          info.rate_bps = rate_bps;
+          break;
+        }
+      }
+    }
+
+    // Check if transfer is completed
+    if ((ack.flags & 0x01) != 0) {
+      // Transfer completed - receiver has finished receiving the file
+      // Reopen window if it was closed by user
+      props->file_transfer_window_visible_ = true;
+      props->file_sending_ = false;  // Mark sending as finished
+      LOG_INFO(
+          "File transfer completed via ACK, file_id={}, total_size={}, "
+          "acked_offset={}",
+          ack.file_id, ack.total_size, ack.acked_offset);
+
+      // Update file transfer list: mark as completed
+      {
+        std::lock_guard<std::mutex> lock(props->file_transfer_list_mutex_);
+        for (auto& info : props->file_transfer_list_) {
+          if (info.file_id == ack.file_id) {
+            info.status =
+                SubStreamWindowProperties::FileTransferStatus::Completed;
+            info.sent_bytes = ack.total_size;
+            break;
+          }
+        }
+      }
+
+      // Unregister file_id mapping after completion
+      {
+        std::lock_guard<std::shared_mutex> lock(
+            render->file_id_to_props_mutex_);
+        render->file_id_to_props_.erase(ack.file_id);
+      }
+
+      // Process next file in queue
+      render->ProcessFileQueue(props);
+    }
+
+    return;
+  }
+
  std::string json_str(data, size);
  RemoteAction remote_action;

@@ -482,7 +622,8 @@ void Render::OnConnectionStatusCb(ConnectionStatus status, const char* user_id,

    switch (status) {
      case ConnectionStatus::Connected: {
-        render->need_to_send_host_info_ = true;
+        render->need_to_create_server_window_ = true;
+        render->is_server_mode_ = true;
        render->start_screen_capturer_ = true;
        render->start_speaker_capturer_ = true;
 #ifdef CROSSDESK_DEBUG
@@ -507,6 +648,8 @@ void Render::OnConnectionStatusCb(ConnectionStatus status, const char* user_id,
                                 kv.second == ConnectionStatus::Failed ||
                                 kv.second == ConnectionStatus::Disconnected;
                        })) {
+          render->need_to_destroy_server_window_ = true;
+          render->is_server_mode_ = false;
          render->start_screen_capturer_ = false;
          render->start_speaker_capturer_ = false;
          render->start_mouse_controller_ = false;
--- a/src/gui/toolbars/control_bar.cpp
+++ b/src/gui/toolbars/control_bar.cpp
@@ -1,10 +1,32 @@
+#include <algorithm>
+#include <atomic>
+#include <chrono>
+#include <filesystem>
+#include <fstream>
+#include <thread>
+#include <vector>
+
+#include "file_transfer.h"
 #include "layout.h"
 #include "localization.h"
 #include "rd_log.h"
 #include "render.h"
+#include "tinyfiledialogs.h"

 namespace crossdesk {

+std::string OpenFileDialog(std::string title) {
+  const char* path = tinyfd_openFileDialog(title.c_str(),
+                                           "",       // default path
+                                           0,        // number of filters
+                                           nullptr,  // filters
+                                           nullptr,  // filter description
+                                           0         // no multiple selection
+  );
+
+  return path ? path : "";
+}
+
 int CountDigits(int number) {
  if (number == 0) return 1;
  return (int)std::floor(std::log10(std::abs(number))) + 1;
@@ -31,6 +53,77 @@ int LossRateDisplay(float loss_rate) {
  return 0;
 }

+void Render::ProcessSelectedFile(
+    const std::string& path, std::shared_ptr<SubStreamWindowProperties>& props,
+    const std::string& file_label) {
+  if (path.empty()) {
+    return;
+  }
+
+  LOG_INFO("Selected file: {}", path.c_str());
+
+  std::filesystem::path file_path = std::filesystem::u8path(path);
+
+  // Get file size
+  std::error_code ec;
+  uint64_t file_size = std::filesystem::file_size(file_path, ec);
+  if (ec) {
+    LOG_ERROR("Failed to get file size: {}", ec.message().c_str());
+    file_size = 0;
+  }
+
+  // Add file to transfer list
+  {
+    std::lock_guard<std::mutex> lock(props->file_transfer_list_mutex_);
+    SubStreamWindowProperties::FileTransferInfo info;
+    info.file_name = file_path.filename().u8string();
+    info.file_path = file_path;  // Store full path for precise matching
+    info.file_size = file_size;
+    info.status = SubStreamWindowProperties::FileTransferStatus::Queued;
+    info.sent_bytes = 0;
+    info.file_id = 0;
+    info.rate_bps = 0;
+    props->file_transfer_list_.push_back(info);
+  }
+  props->file_transfer_window_visible_ = true;
+
+  if (props->file_sending_.load()) {
+    // Add to queue
+    size_t queue_size = 0;
+    {
+      std::lock_guard<std::mutex> lock(props->file_queue_mutex_);
+      SubStreamWindowProperties::QueuedFile queued_file;
+      queued_file.file_path = file_path;
+      queued_file.file_label = file_label;
+      props->file_send_queue_.push(queued_file);
+      queue_size = props->file_send_queue_.size();
+    }
+    LOG_INFO("File added to queue: {} ({} files in queue)",
+             file_path.filename().string().c_str(), queue_size);
+  } else {
+    StartFileTransfer(props, file_path, file_label);
+
+    if (props->file_sending_.load()) {
+    } else {
+      // Failed to start (race condition: another file started between
+      // check and call) Add to queue
+      size_t queue_size = 0;
+      {
+        std::lock_guard<std::mutex> lock(props->file_queue_mutex_);
+        SubStreamWindowProperties::QueuedFile queued_file;
+        queued_file.file_path = file_path;
+        queued_file.file_label = file_label;
+        props->file_send_queue_.push(queued_file);
+        queue_size = props->file_send_queue_.size();
+      }
+      LOG_INFO(
+          "File added to queue after race condition: {} ({} files in "
+          "queue)",
+          file_path.filename().string().c_str(), queue_size);
+    }
+  }
+}
+
 int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
  float button_width = title_bar_height_ * 0.8f;
  float button_height = title_bar_height_ * 0.8f;
@@ -41,14 +134,14 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
  if (props->control_bar_expand_) {
    ImGui::SetCursorPosX(props->is_control_bar_in_left_
                             ? props->control_window_width_ * 1.03f
-                             : props->control_window_width_ * 0.2f);
+                             : props->control_window_width_ * 0.17f);

    ImDrawList* draw_list = ImGui::GetWindowDrawList();
    if (!props->is_control_bar_in_left_) {
      draw_list->AddLine(
-          ImVec2(ImGui::GetCursorScreenPos().x - button_height * 0.56f,
+          ImVec2(ImGui::GetCursorScreenPos().x - button_height * 0.5f,
                 ImGui::GetCursorScreenPos().y + button_height * 0.2f),
-          ImVec2(ImGui::GetCursorScreenPos().x - button_height * 0.56f,
+          ImVec2(ImGui::GetCursorScreenPos().x - button_height * 0.5f,
                 ImGui::GetCursorScreenPos().y + button_height * 0.8f),
          IM_COL32(178, 178, 178, 255), 2.0f);
    }
@@ -73,8 +166,8 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
          remote_action.d = i;
          if (props->connection_status_ == ConnectionStatus::Connected) {
            std::string msg = remote_action.to_json();
-            SendDataFrame(props->peer_, msg.c_str(), msg.size(),
-                          props->data_label_.c_str());
+            SendReliableDataFrame(props->peer_, msg.c_str(), msg.size(),
+                                  props->control_data_label_.c_str());
          }
        }
        props->display_selectable_hovered_ = ImGui::IsWindowHovered();
@@ -154,8 +247,8 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
        remote_action.type = ControlType::audio_capture;
        remote_action.a = props->audio_capture_button_pressed_;
        std::string msg = remote_action.to_json();
-        SendDataFrame(props->peer_, msg.c_str(), msg.size(),
-                      props->data_label_.c_str());
+        SendReliableDataFrame(props->peer_, msg.c_str(), msg.size(),
+                              props->control_data_label_.c_str());
      }
    }

@@ -175,6 +268,16 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
          line_thickness);
    }

+    ImGui::SameLine();
+    std::string open_folder = ICON_FA_FOLDER_OPEN;
+    if (ImGui::Button(open_folder.c_str(),
+                      ImVec2(button_width, button_height))) {
+      std::string title =
+          localization::select_file[localization_language_index_];
+      std::string path = OpenFileDialog(title);
+      this->ProcessSelectedFile(path, props, file_label_);
+    }
+
    ImGui::SameLine();
    // net traffic stats button
    bool button_color_style_pushed = false;
@@ -238,9 +341,9 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {

    if (props->is_control_bar_in_left_) {
      draw_list->AddLine(
-          ImVec2(ImGui::GetCursorScreenPos().x + button_height * 0.2f,
+          ImVec2(ImGui::GetCursorScreenPos().x + button_height * 0.13f,
                 ImGui::GetCursorScreenPos().y + button_height * 0.2f),
-          ImVec2(ImGui::GetCursorScreenPos().x + button_height * 0.2f,
+          ImVec2(ImGui::GetCursorScreenPos().x + button_height * 0.13f,
                 ImGui::GetCursorScreenPos().y + button_height * 0.8f),
          IM_COL32(178, 178, 178, 255), 2.0f);
    }
@@ -250,7 +353,7 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {

  float expand_button_pos_x =
      props->control_bar_expand_ ? (props->is_control_bar_in_left_
-                                        ? props->control_window_width_ * 1.91f
+                                        ? props->control_window_width_ * 1.917f
                                        : props->control_window_width_ * 0.03f)
                                 : (props->is_control_bar_in_left_
                                        ? props->control_window_width_ * 1.02f
--- a/src/gui/windows/file_transfer_window.cpp
+++ b/src/gui/windows/file_transfer_window.cpp
@@ -0,0 +1,242 @@
+#include <algorithm>
+#include <cmath>
+
+#include "IconsFontAwesome6.h"
+#include "layout.h"
+#include "localization.h"
+#include "rd_log.h"
+#include "render.h"
+
+namespace crossdesk {
+
+namespace {
+int CountDigits(int number) {
+  if (number == 0) return 1;
+  return (int)std::floor(std::log10(std::abs(number))) + 1;
+}
+
+int BitrateDisplay(int bitrate) {
+  int num_of_digits = CountDigits(bitrate);
+  if (num_of_digits <= 3) {
+    ImGui::Text("%d bps", bitrate);
+  } else if (num_of_digits > 3 && num_of_digits <= 6) {
+    ImGui::Text("%d kbps", bitrate / 1000);
+  } else {
+    ImGui::Text("%.1f mbps", bitrate / 1000000.0f);
+  }
+  return 0;
+}
+}  // namespace
+
+int Render::FileTransferWindow(
+    std::shared_ptr<SubStreamWindowProperties>& props) {
+  // Only show window if there are files in transfer list or currently
+  // transferring
+  std::vector<SubStreamWindowProperties::FileTransferInfo> file_list;
+  {
+    std::lock_guard<std::mutex> lock(props->file_transfer_list_mutex_);
+    file_list = props->file_transfer_list_;
+  }
+
+  // Sort file list: Sending first, then Completed, then Queued, then Failed
+  std::sort(
+      file_list.begin(), file_list.end(),
+      [](const SubStreamWindowProperties::FileTransferInfo& a,
+         const SubStreamWindowProperties::FileTransferInfo& b) {
+        // Priority: Sending > Completed > Queued > Failed
+        auto get_priority =
+            [](SubStreamWindowProperties::FileTransferStatus status) {
+              switch (status) {
+                case SubStreamWindowProperties::FileTransferStatus::Sending:
+                  return 0;
+                case SubStreamWindowProperties::FileTransferStatus::Completed:
+                  return 1;
+                case SubStreamWindowProperties::FileTransferStatus::Queued:
+                  return 2;
+                case SubStreamWindowProperties::FileTransferStatus::Failed:
+                  return 3;
+              }
+              return 3;
+            };
+        return get_priority(a.status) < get_priority(b.status);
+      });
+
+  // Only show window if file_transfer_window_visible_ is true
+  // Window can be closed by user even during transfer
+  // It will be reopened automatically when:
+  // 1. A file transfer completes (in render_callback.cpp)
+  // 2. A new file starts sending from queue (in render.cpp)
+  if (!props->file_transfer_window_visible_) {
+    return 0;
+  }
+
+  ImGuiIO& io = ImGui::GetIO();
+
+  // Position window at bottom-left of stream window
+  // Adjust window size based on number of files
+  float file_transfer_window_width = main_window_width_ * 0.6f;
+  float file_transfer_window_height =
+      main_window_height_ * 0.3f;  // Dynamic height
+  float pos_x = file_transfer_window_width * 0.05f;
+  float pos_y = stream_window_height_ - file_transfer_window_height -
+                file_transfer_window_width * 0.05;
+  float same_line_width = file_transfer_window_width * 0.1f;
+
+  ImGui::SetNextWindowPos(ImVec2(pos_x, pos_y), ImGuiCond_Always);
+  ImGui::SetNextWindowSize(
+      ImVec2(file_transfer_window_width, file_transfer_window_height),
+      ImGuiCond_Always);
+
+  // Set Chinese font for proper display
+  if (stream_windows_system_chinese_font_) {
+    ImGui::PushFont(stream_windows_system_chinese_font_);
+  }
+
+  ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 3.0f);
+  ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 1.0f);
+  ImGui::PushStyleColor(ImGuiCol_WindowBg, ImVec4(1.0f, 1.0f, 1.0f, 0.9f));
+  ImGui::PushStyleColor(ImGuiCol_Border, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+  ImGui::PushStyleColor(ImGuiCol_TitleBg, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+  ImGui::PushStyleColor(ImGuiCol_TitleBgActive, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+
+  ImGui::SetWindowFontScale(0.5f);
+  bool window_opened = true;
+  if (ImGui::Begin(
+          localization::file_transfer_progress[localization_language_index_]
+              .c_str(),
+          &window_opened,
+          ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize |
+              ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoSavedSettings |
+              ImGuiWindowFlags_NoScrollbar)) {
+    ImGui::SetWindowFontScale(1.0f);
+    ImGui::SetWindowFontScale(0.5f);
+    ImGui::PopStyleColor(4);
+    ImGui::PopStyleVar(2);
+
+    // Close button handling
+    if (!window_opened) {
+      props->file_transfer_window_visible_ = false;
+      ImGui::End();
+      return 0;
+    }
+
+    // Display file list
+    if (file_list.empty()) {
+      ImGui::Text("No files in transfer queue");
+    } else {
+      // Use a scrollable child window for the file list
+      ImGui::SetWindowFontScale(0.5f);
+      ImGui::BeginChild(
+          "FileList", ImVec2(0, file_transfer_window_height * 0.75f),
+          ImGuiChildFlags_Border, ImGuiWindowFlags_HorizontalScrollbar);
+      ImGui::SetWindowFontScale(1.0f);
+      ImGui::SetWindowFontScale(0.5f);
+
+      for (size_t i = 0; i < file_list.size(); ++i) {
+        const auto& info = file_list[i];
+        ImGui::PushID(static_cast<int>(i));
+
+        // Status icon and file name
+        const char* status_icon = "";
+        ImVec4 status_color(0.5f, 0.5f, 0.5f, 1.0f);
+        const char* status_text = "";
+
+        switch (info.status) {
+          case SubStreamWindowProperties::FileTransferStatus::Queued:
+            status_icon = ICON_FA_CLOCK;
+            status_color =
+                ImVec4(0.5f, 0.6f, 0.7f, 1.0f);  // Common blue-gray for queued
+            status_text =
+                localization::queued[localization_language_index_].c_str();
+            break;
+          case SubStreamWindowProperties::FileTransferStatus::Sending:
+            status_icon = ICON_FA_ARROW_UP;
+            status_color = ImVec4(0.2f, 0.6f, 1.0f, 1.0f);
+            status_text =
+                localization::sending[localization_language_index_].c_str();
+            break;
+          case SubStreamWindowProperties::FileTransferStatus::Completed:
+            status_icon = ICON_FA_CHECK;
+            status_color = ImVec4(0.0f, 0.8f, 0.0f, 1.0f);
+            status_text =
+                localization::completed[localization_language_index_].c_str();
+            break;
+          case SubStreamWindowProperties::FileTransferStatus::Failed:
+            status_icon = ICON_FA_XMARK;
+            status_color = ImVec4(1.0f, 0.2f, 0.2f, 1.0f);
+            status_text =
+                localization::failed[localization_language_index_].c_str();
+            break;
+        }
+
+        ImGui::TextColored(status_color, "%s", status_icon);
+        ImGui::SameLine();
+        ImGui::Text("%s", info.file_name.c_str());
+        ImGui::SameLine();
+        ImGui::TextColored(status_color, "%s", status_text);
+
+        // Progress bar for sending files
+        if (info.status ==
+                SubStreamWindowProperties::FileTransferStatus::Sending &&
+            info.file_size > 0) {
+          float progress = static_cast<float>(info.sent_bytes) /
+                           static_cast<float>(info.file_size);
+          progress = (std::max)(0.0f, (std::min)(1.0f, progress));
+
+          float text_height = ImGui::GetTextLineHeight();
+          ImGui::ProgressBar(
+              progress, ImVec2(file_transfer_window_width * 0.5f, text_height),
+              "");
+          ImGui::SameLine();
+
+          ImGui::Text("%.1f%%", progress * 100.0f);
+          ImGui::SameLine();
+
+          float speed_x_pos = file_transfer_window_width * 0.65f;
+          ImGui::SetCursorPosX(speed_x_pos);
+          BitrateDisplay(static_cast<int>(info.rate_bps));
+        } else if (info.status ==
+                   SubStreamWindowProperties::FileTransferStatus::Completed) {
+          // Show completed size
+          char size_str[64];
+          if (info.file_size < 1024) {
+            snprintf(size_str, sizeof(size_str), "%llu B",
+                     (unsigned long long)info.file_size);
+          } else if (info.file_size < 1024 * 1024) {
+            snprintf(size_str, sizeof(size_str), "%.2f KB",
+                     info.file_size / 1024.0f);
+          } else {
+            snprintf(size_str, sizeof(size_str), "%.2f MB",
+                     info.file_size / (1024.0f * 1024.0f));
+          }
+          ImGui::Text("Size: %s", size_str);
+        }
+
+        ImGui::PopID();
+        ImGui::Spacing();
+      }
+
+      ImGui::SetWindowFontScale(1.0f);
+      ImGui::SetWindowFontScale(0.5f);
+      ImGui::EndChild();
+      ImGui::SetWindowFontScale(1.0f);
+    }
+    ImGui::SetWindowFontScale(1.0f);
+    ImGui::SetWindowFontScale(0.5f);
+    ImGui::End();
+    ImGui::SetWindowFontScale(1.0f);
+
+    // Pop Chinese font if it was pushed
+    if (stream_windows_system_chinese_font_) {
+      ImGui::PopFont();
+    }
+  } else {
+    ImGui::PopStyleColor(4);
+    ImGui::PopStyleVar(2);
+  }
+  ImGui::SetWindowFontScale(1.0f);
+
+  return 0;
+}
+
+}  // namespace crossdesk
--- a/src/gui/windows/server_settings_window.cpp
+++ b/src/gui/windows/server_settings_window.cpp
@@ -214,20 +214,31 @@ int Render::SelfHostedServerWindow() {

      ImGui::Separator();

+      // {
+      //   ImGui::AlignTextToFramePadding();
+      //   ImGui::Text(
+      //       "%s",
+      //       localization::reset_cert_fingerprint[localization_language_index_]
+      //           .c_str());
+      //   ImGui::SameLine();
+      //   if (ConfigCenter::LANGUAGE::CHINESE == localization_language_) {
+      //     ImGui::SetCursorPosX(title_bar_button_width_ * 2.5f);
+      //   } else {
+      //     ImGui::SetCursorPosX(title_bar_button_width_ * 3.43f);
+      //   }
+      //   ImGui::SetNextItemWidth(title_bar_button_width_ * 3.8f);
+
+      //   ShowSimpleFileBrowser();
+      // }
+
      {
        ImGui::AlignTextToFramePadding();
-        ImGui::Text("%s", localization::self_hosted_server_certificate_path
+        if (ImGui::Button(localization::reset_cert_fingerprint
                              [localization_language_index_]
-                                  .c_str());
-        ImGui::SameLine();
-        if (ConfigCenter::LANGUAGE::CHINESE == localization_language_) {
-          ImGui::SetCursorPosX(title_bar_button_width_ * 2.5f);
-        } else {
-          ImGui::SetCursorPosX(title_bar_button_width_ * 3.43f);
+                                  .c_str())) {
+          config_center_->ClearCertFingerprint();
+          LOG_INFO("Certificate fingerprint cleared by user");
        }
-        ImGui::SetNextItemWidth(title_bar_button_width_ * 3.8f);
-
-        ShowSimpleFileBrowser();
      }

      if (stream_window_inited_) {
--- a/src/gui/windows/server_window.cpp
+++ b/src/gui/windows/server_window.cpp
@@ -0,0 +1,225 @@
+#include <cmath>
+#include <vector>
+
+#include "rd_log.h"
+#include "render.h"
+
+namespace crossdesk {
+
+static void SetServerWindowCircleShape(SDL_Window* window, int diameter) {
+  if (!window || diameter <= 0) {
+    return;
+  }
+
+  const int pitch = diameter * 4;
+  std::vector<unsigned char> pixels((size_t)diameter * (size_t)diameter * 4, 0);
+
+  // Sub-pixel centered circle helps symmetry on even diameters.
+  const float r = (float)diameter * 0.5f;
+  const float cx = r - 0.5f;
+  const float cy = r - 0.5f;
+
+  for (int y = 0; y < diameter; ++y) {
+    for (int x = 0; x < diameter; ++x) {
+      const float dx = (float)x - cx;
+      const float dy = (float)y - cy;
+      const float dist = std::sqrt(dx * dx + dy * dy);
+
+      // 1px soft edge to reduce jaggies on small circles.
+      float a = r + 0.5f - dist;
+      if (a < 0.0f) a = 0.0f;
+      if (a > 1.0f) a = 1.0f;
+      const unsigned char alpha = (unsigned char)(a * 255.0f);
+      const size_t idx = ((size_t)y * (size_t)diameter + (size_t)x) * 4;
+      pixels[idx + 0] = 255;    // R
+      pixels[idx + 1] = 255;    // G
+      pixels[idx + 2] = 255;    // B
+      pixels[idx + 3] = alpha;  // A
+    }
+  }
+
+  SDL_Surface* shape = SDL_CreateSurfaceFrom(
+      diameter, diameter, SDL_PIXELFORMAT_RGBA32, pixels.data(), pitch);
+  if (!shape) {
+    LOG_ERROR("SDL_CreateSurfaceFrom failed: {}", SDL_GetError());
+    return;
+  }
+
+  if (!SDL_SetWindowShape(window, shape)) {
+    LOG_ERROR("SDL_SetWindowShape failed: {}", SDL_GetError());
+  }
+
+  SDL_DestroySurface(shape);
+}
+
+int Render::ServerWindow() {
+  ImGui::SetNextWindowSize(ImVec2(server_window_width_, server_window_height_),
+                           ImGuiCond_Always);
+  ImGui::SetNextWindowPos(ImVec2(0, 0), ImGuiCond_Always);
+
+  if (server_window_compact_) {
+    ImGui::SetNextWindowBgAlpha(0.0f);
+  }
+
+  ImGui::Begin("##server_window", nullptr,
+               ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize |
+                   ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoCollapse |
+                   ImGuiWindowFlags_NoScrollbar |
+                   ImGuiWindowFlags_NoScrollWithMouse);
+
+  // Compact mode: show a 50x50 clickable square that restores the window.
+  if (server_window_compact_) {
+    ImDrawList* draw_list = ImGui::GetWindowDrawList();
+    ImGui::SetCursorPos(ImVec2(0.0f, 0.0f));
+    if (ImGui::InvisibleButton(
+            "##server_compact_restore",
+            ImVec2(server_window_width_, server_window_height_))) {
+      if (server_window_) {
+        SDL_SetWindowShape(server_window_, nullptr);
+      }
+      if (server_window_ && server_window_bounds_saved_ &&
+          server_window_width_before_compact_ > 0 &&
+          server_window_height_before_compact_ > 0) {
+        SDL_SetWindowSize(server_window_, server_window_width_before_compact_,
+                          server_window_height_before_compact_);
+        SDL_SetWindowPosition(server_window_, server_window_x_before_compact_,
+                              server_window_y_before_compact_);
+
+        server_window_width_ = (float)server_window_width_before_compact_;
+        server_window_height_ = (float)server_window_height_before_compact_;
+      }
+      server_window_compact_ = false;
+      server_window_bounds_saved_ = false;
+    }
+
+    // Draw a visible circular affordance.
+    const float w = server_window_width_;
+    const float h = server_window_height_;
+    const float radius = (w < h ? w : h) * 0.5f - 1.0f;
+    const ImVec2 center(w * 0.5f, h * 0.5f);
+    draw_list->AddCircleFilled(center, radius, IM_COL32(255, 255, 255, 220),
+                               32);
+    draw_list->AddCircle(center, radius, IM_COL32(0, 0, 0, 255), 32, 2.0f);
+    // A simple "restore" hint.
+    draw_list->AddRect(
+        ImVec2(center.x - radius * 0.35f, center.y - radius * 0.35f),
+        ImVec2(center.x + radius * 0.35f, center.y + radius * 0.35f),
+        IM_COL32(0, 0, 0, 255), 2.0f, 0, 2.0f);
+
+    ImGui::End();
+    return 0;
+  }
+
+  ImGui::PushStyleColor(ImGuiCol_ChildBg, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+  ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
+  ImGui::SetNextWindowPos(ImVec2(0, 0), ImGuiCond_Always);
+  ImGui::BeginChild(
+      "ServerTitleBar",
+      ImVec2(server_window_width_, server_window_title_bar_height_),
+      ImGuiChildFlags_Border,
+      ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_NoMove |
+          ImGuiWindowFlags_NoBringToFrontOnFocus);
+
+  ImDrawList* draw_list = ImGui::GetWindowDrawList();
+
+  ImGui::PushStyleColor(ImGuiCol_ChildBg, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+  ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
+
+  float server_title_bar_button_width = server_window_title_bar_height_;
+  float server_title_bar_button_height = server_window_title_bar_height_;
+
+  float minimize_button_pos_x =
+      server_window_width_ - server_title_bar_button_width * 2;
+  ImGui::SetCursorPos(ImVec2(minimize_button_pos_x, 0.0f));
+  ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0, 0, 0, 0));
+  ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0, 0, 0, 0.1f));
+  ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImVec4(1.0f, 1.0f, 1.0f, 1.0f));
+
+  float minimize_pos_x =
+      minimize_button_pos_x + server_title_bar_button_width * 0.33f;
+  float minimize_pos_y = server_title_bar_button_height * 0.5f;
+  std::string server_minimize_button = "##minimize";  // ICON_FA_MINUS;
+  if (ImGui::Button(server_minimize_button.c_str(),
+                    ImVec2(server_title_bar_button_width,
+                           server_title_bar_button_height))) {
+    if (server_window_) {
+      int w = 0, h = 0;
+      int x = 0, y = 0;
+      SDL_GetWindowSize(server_window_, &w, &h);
+      SDL_GetWindowPosition(server_window_, &x, &y);
+      server_window_width_before_compact_ = w;
+      server_window_height_before_compact_ = h;
+      server_window_x_before_compact_ = x;
+      server_window_y_before_compact_ = y;
+      server_window_bounds_saved_ = true;
+
+      constexpr int kCompactSize = 50;
+      SDL_SetWindowSize(server_window_, kCompactSize, kCompactSize);
+
+      // Move to bottom-right of the current display's usable bounds.
+      SDL_Rect display_bounds;
+      if (SDL_GetDisplayUsableBounds(SDL_GetDisplayForWindow(server_window_),
+                                     &display_bounds)) {
+        int compact_x = display_bounds.x + display_bounds.w - kCompactSize;
+        int compact_y = display_bounds.y + display_bounds.h - kCompactSize;
+        SDL_SetWindowPosition(server_window_, compact_x, compact_y);
+      }
+
+      // Use pixel size to match transparency buffer on HiDPI.
+      int w_px = kCompactSize;
+      int h_px = kCompactSize;
+      SDL_GetWindowSizeInPixels(server_window_, &w_px, &h_px);
+      const int diameter = (w_px < h_px ? w_px : h_px);
+      SetServerWindowCircleShape(server_window_, diameter);
+
+      server_window_compact_ = true;
+    }
+  }
+  draw_list->AddLine(
+      ImVec2(minimize_pos_x, minimize_pos_y),
+      ImVec2(minimize_pos_x + server_title_bar_button_width * 0.33f,
+             minimize_pos_y),
+      IM_COL32(0, 0, 0, 255));
+  ImGui::PopStyleColor(3);
+
+  float xmark_button_pos_x =
+      server_window_width_ - server_title_bar_button_width;
+  ImGui::SetCursorPos(ImVec2(xmark_button_pos_x, 0.0f));
+  ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0, 0, 0, 0));
+  ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(1.0f, 0, 0, 1.0f));
+  ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImVec4(1.0f, 0, 0, 0.5f));
+
+  float xmark_pos_x = xmark_button_pos_x + server_title_bar_button_width * 0.5f;
+  float xmark_pos_y = server_title_bar_button_height * 0.5f;
+  float xmark_size = server_title_bar_button_width * 0.33f;
+  std::string server_close_button = "##xmark";  // ICON_FA_XMARK;
+  if (ImGui::Button(server_close_button.c_str(),
+                    ImVec2(server_title_bar_button_width,
+                           server_title_bar_button_height))) {
+    LOG_ERROR("Close button clicked");
+    LeaveConnection(peer_, self_hosted_id_);
+  }
+
+  draw_list->AddLine(ImVec2(xmark_pos_x - xmark_size / 2 - 0.25f,
+                            xmark_pos_y - xmark_size / 2 + 0.75f),
+                     ImVec2(xmark_pos_x + xmark_size / 2 - 1.5f,
+                            xmark_pos_y + xmark_size / 2 - 0.5f),
+                     IM_COL32(0, 0, 0, 255));
+  draw_list->AddLine(
+      ImVec2(xmark_pos_x + xmark_size / 2 - 1.75f,
+             xmark_pos_y - xmark_size / 2 + 0.75f),
+      ImVec2(xmark_pos_x - xmark_size / 2, xmark_pos_y + xmark_size / 2 - 1.0f),
+      IM_COL32(0, 0, 0, 255));
+
+  ImGui::PopStyleColor(3);
+  ImGui::PopStyleVar();
+  ImGui::PopStyleColor();
+
+  ImGui::EndChild();
+  ImGui::PopStyleVar();
+  ImGui::PopStyleColor();
+
+  ImGui::End();
+  return 0;
+}
+}  // namespace crossdesk
--- a/src/gui/windows/stream_window.cpp
+++ b/src/gui/windows/stream_window.cpp
@@ -138,6 +138,9 @@ int Render::StreamWindow() {
          UpdateRenderRect();

          ControlWindow(props);
+          
+          // Show file transfer window if needed
+          FileTransferWindow(props);

          focused_remote_id_ = props->remote_id_;

@@ -233,6 +236,10 @@ int Render::StreamWindow() {
        UpdateRenderRect();

        ControlWindow(props);
+        
+        // Show file transfer window if needed
+        FileTransferWindow(props);
+        
        ImGui::End();

        if (!props->peer_) {
--- a/src/tools/clipboard.cpp
+++ b/src/tools/clipboard.cpp
@@ -0,0 +1,534 @@
+
+#include "clipboard.h"
+
+#include <atomic>
+#include <chrono>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include "rd_log.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#elif __linux__
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xfixes.h>
+
+#include <cstring>
+#include <memory>
+#endif
+
+namespace crossdesk {
+
+std::atomic<bool> g_monitoring{false};
+std::thread g_monitor_thread;
+std::mutex g_monitor_mutex;
+std::string g_last_clipboard_text;
+int g_check_interval_ms = 100;
+Clipboard::OnClipboardChanged g_on_clipboard_changed;
+
+#ifdef _WIN32
+HWND g_clipboard_wnd = nullptr;
+const char* g_clipboard_class_name = "CrossDeskClipboardMonitor";
+#endif
+
+#ifdef __linux__
+Display* g_x11_display = nullptr;
+Atom g_clipboard_atom = None;
+Atom g_xfixes_selection_notify = None;
+#endif
+}  // namespace crossdesk
+
+namespace crossdesk {
+
+#ifdef _WIN32
+std::string Clipboard::GetText() {
+  if (!OpenClipboard(nullptr)) {
+    LOG_ERROR("Clipboard::GetText: failed to open clipboard");
+    return "";
+  }
+
+  std::string result;
+  HANDLE hData = GetClipboardData(CF_UNICODETEXT);
+  if (hData != nullptr) {
+    wchar_t* pszText = static_cast<wchar_t*>(GlobalLock(hData));
+    if (pszText != nullptr) {
+      int size_needed = WideCharToMultiByte(CP_UTF8, 0, pszText, -1, nullptr, 0,
+                                            nullptr, nullptr);
+      if (size_needed > 0) {
+        // -1 because WideCharToMultiByte contains '\0'
+        result.resize(size_needed - 1);
+        WideCharToMultiByte(CP_UTF8, 0, pszText, -1, &result[0], size_needed,
+                            nullptr, nullptr);
+      }
+      GlobalUnlock(hData);
+    }
+  }
+
+  CloseClipboard();
+  return result;
+}
+
+bool Clipboard::SetText(const std::string& text) {
+  if (!OpenClipboard(nullptr)) {
+    LOG_ERROR("Clipboard::SetText: failed to open clipboard");
+    return false;
+  }
+
+  if (!EmptyClipboard()) {
+    LOG_ERROR("Clipboard::SetText: failed to empty clipboard");
+    CloseClipboard();
+    return false;
+  }
+
+  // Convert UTF-8 string to wide char
+  int size_needed =
+      MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, nullptr, 0);
+  if (size_needed <= 0) {
+    LOG_ERROR("Clipboard::SetText: failed to convert to wide char");
+    CloseClipboard();
+    return false;
+  }
+
+  HGLOBAL hMem = GlobalAlloc(GMEM_MOVEABLE, size_needed * sizeof(wchar_t));
+  if (hMem == nullptr) {
+    LOG_ERROR("Clipboard::SetText: failed to allocate memory");
+    CloseClipboard();
+    return false;
+  }
+
+  wchar_t* pszText = static_cast<wchar_t*>(GlobalLock(hMem));
+  if (pszText == nullptr) {
+    LOG_ERROR("Clipboard::SetText: failed to lock memory");
+    GlobalFree(hMem);
+    CloseClipboard();
+    return false;
+  }
+
+  MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, pszText, size_needed);
+  GlobalUnlock(hMem);
+
+  if (SetClipboardData(CF_UNICODETEXT, hMem) == nullptr) {
+    LOG_ERROR("Clipboard::SetText: failed to set clipboard data");
+    GlobalFree(hMem);
+    CloseClipboard();
+    return false;
+  }
+
+  CloseClipboard();
+  return true;
+}
+
+bool Clipboard::HasText() {
+  if (!OpenClipboard(nullptr)) {
+    return false;
+  }
+
+  bool has_text = IsClipboardFormatAvailable(CF_UNICODETEXT) ||
+                  IsClipboardFormatAvailable(CF_TEXT);
+  CloseClipboard();
+  return has_text;
+}
+
+#elif __APPLE__
+// macOS implementation is in clipboard_mac.mm
+#elif __linux__
+
+std::string Clipboard::GetText() {
+  Display* display = XOpenDisplay(nullptr);
+  if (display == nullptr) {
+    LOG_ERROR("Clipboard::GetText: failed to open X display");
+    return "";
+  }
+
+  std::string result;
+  Window owner = XGetSelectionOwner(display, XA_PRIMARY);
+  if (owner == None) {
+    // Try using CLIPBOARD
+    owner =
+        XGetSelectionOwner(display, XInternAtom(display, "CLIPBOARD", False));
+    if (owner == None) {
+      XCloseDisplay(display);
+      return "";
+    }
+  }
+
+  Atom selection = XA_PRIMARY;
+  Atom target = XInternAtom(display, "UTF8_STRING", False);
+  if (target == None) {
+    target = XA_STRING;
+  }
+
+  XEvent event;
+  Window window = XCreateSimpleWindow(display, DefaultRootWindow(display), 0, 0,
+                                      1, 1, 0, 0, 0);
+  XSelectInput(display, window, PropertyChangeMask);
+
+  XConvertSelection(display, selection, target, XA_PRIMARY, window,
+                    CurrentTime);
+
+  // Wait for selection conversion to complete
+  bool done = false;
+  while (!done) {
+    XNextEvent(display, &event);
+    if (event.type == SelectionNotify) {
+      if (event.xselection.property == None) {
+        // Try using CLIPBOARD
+        if (selection == XA_PRIMARY) {
+          selection = XInternAtom(display, "CLIPBOARD", False);
+          XConvertSelection(display, selection, target, XA_PRIMARY, window,
+                            CurrentTime);
+          continue;
+        }
+        break;
+      }
+
+      Atom actual_type;
+      int actual_format;
+      unsigned long nitems;
+      unsigned long bytes_after;
+      unsigned char* data = nullptr;
+
+      if (XGetWindowProperty(display, window, XA_PRIMARY, 0, LONG_MAX / 4,
+                             False, AnyPropertyType, &actual_type,
+                             &actual_format, &nitems, &bytes_after,
+                             &data) == Success) {
+        if (data != nullptr) {
+          result = std::string(reinterpret_cast<char*>(data), nitems);
+          XFree(data);
+        }
+        done = true;
+      }
+    }
+  }
+
+  XDestroyWindow(display, window);
+  XCloseDisplay(display);
+  return result;
+}
+
+bool Clipboard::SetText(const std::string& text) {
+  Display* display = XOpenDisplay(nullptr);
+  if (display == nullptr) {
+    LOG_ERROR("Clipboard::SetText: failed to open X display");
+    return false;
+  }
+
+  Window window = XCreateSimpleWindow(display, DefaultRootWindow(display), 0, 0,
+                                      1, 1, 0, 0, 0);
+  Atom clipboard = XInternAtom(display, "CLIPBOARD", False);
+  Atom utf8_string = XInternAtom(display, "UTF8_STRING", False);
+  Atom targets = XInternAtom(display, "TARGETS", False);
+  Atom xa_string = XA_STRING;
+
+  XSetSelectionOwner(display, clipboard, window, CurrentTime);
+  if (XGetSelectionOwner(display, clipboard) != window) {
+    LOG_ERROR("Clipboard::SetText: failed to set selection owner");
+    XDestroyWindow(display, window);
+    XCloseDisplay(display);
+    return false;
+  }
+
+  XChangeProperty(display, window, XA_PRIMARY, utf8_string, 8, PropModeReplace,
+                  reinterpret_cast<const unsigned char*>(text.c_str()),
+                  static_cast<int>(text.length()));
+
+  XEvent event;
+  while (true) {
+    XNextEvent(display, &event);
+    if (event.type == SelectionRequest) {
+      XSelectionRequestEvent* req = &event.xselectionrequest;
+      XSelectionEvent se;
+      se.type = SelectionNotify;
+      se.display = req->display;
+      se.requestor = req->requestor;
+      se.selection = req->selection;
+      se.time = req->time;
+      se.target = req->target;
+      se.property = req->property;
+
+      if (req->target == targets) {
+        // Return supported formats
+        Atom supported[] = {utf8_string, xa_string, targets};
+        XChangeProperty(display, req->requestor, req->property, XA_ATOM, 32,
+                        PropModeReplace,
+                        reinterpret_cast<unsigned char*>(supported), 3);
+        se.property = req->property;
+      } else if (req->target == utf8_string || req->target == xa_string) {
+        // Return text data
+        XChangeProperty(display, req->requestor, req->property, req->target, 8,
+                        PropModeReplace,
+                        reinterpret_cast<const unsigned char*>(text.c_str()),
+                        static_cast<int>(text.length()));
+        se.property = req->property;
+      } else {
+        se.property = None;
+      }
+
+      XSendEvent(display, req->requestor, False, 0,
+                 reinterpret_cast<XEvent*>(&se));
+      XSync(display, False);
+    } else if (event.type == SelectionClear) {
+      break;
+    }
+  }
+
+  XDestroyWindow(display, window);
+  XCloseDisplay(display);
+  return true;
+}
+
+bool Clipboard::HasText() {
+  Display* display = XOpenDisplay(nullptr);
+  if (display == nullptr) {
+    return false;
+  }
+
+  Atom clipboard = XInternAtom(display, "CLIPBOARD", False);
+  Window owner = XGetSelectionOwner(display, clipboard);
+  if (owner == None) {
+    owner = XGetSelectionOwner(display, XA_PRIMARY);
+  }
+
+  XCloseDisplay(display);
+  return owner != None;
+}
+
+#else
+
+std::string Clipboard::GetText() {
+  LOG_ERROR("Clipboard::GetText: unsupported platform");
+  return "";
+}
+
+bool Clipboard::SetText(const std::string& text) {
+  LOG_ERROR("Clipboard::SetText: unsupported platform");
+  return false;
+}
+
+bool Clipboard::HasText() {
+  LOG_ERROR("Clipboard::HasText: unsupported platform");
+  return false;
+}
+
+#endif
+
+void HandleClipboardChange() {
+  if (!Clipboard::HasText()) {
+    std::lock_guard<std::mutex> lock(g_monitor_mutex);
+    if (!g_last_clipboard_text.empty()) {
+      g_last_clipboard_text.clear();
+      LOG_INFO("Clipboard content cleared");
+    }
+    return;
+  }
+
+  std::string current_text = Clipboard::GetText();
+
+  // Check if the content has changed
+  {
+    std::lock_guard<std::mutex> lock(g_monitor_mutex);
+    if (current_text != g_last_clipboard_text) {
+      g_last_clipboard_text = current_text;
+      if (!current_text.empty()) {
+        if (g_on_clipboard_changed) {
+          int ret = g_on_clipboard_changed(current_text.c_str(),
+                                           current_text.length());
+          if (ret != 0) {
+            LOG_WARN("Clipboard callback returned error: {}", ret);
+          }
+        }
+      }
+    }
+  }
+}
+
+#ifdef _WIN32
+LRESULT CALLBACK ClipboardWndProc(HWND hwnd, UINT uMsg, WPARAM wParam,
+                                  LPARAM lParam) {
+  if (uMsg == WM_CLIPBOARDUPDATE) {
+    HandleClipboardChange();
+    return 0;
+  }
+  return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+static void MonitorThreadFunc() {
+  // Create a hidden window to receive clipboard messages
+  WNDCLASSA wc = {0};
+  wc.lpfnWndProc = ClipboardWndProc;
+  wc.hInstance = GetModuleHandle(nullptr);
+  wc.lpszClassName = g_clipboard_class_name;
+  RegisterClassA(&wc);
+
+  g_clipboard_wnd = CreateWindowA(g_clipboard_class_name, nullptr, 0, 0, 0, 0,
+                                  0, HWND_MESSAGE, nullptr, nullptr, nullptr);
+  if (!g_clipboard_wnd) {
+    LOG_ERROR("Failed to create clipboard monitor window");
+    g_monitoring.store(false);
+    return;
+  }
+
+  // Register clipboard format listener
+  if (!AddClipboardFormatListener(g_clipboard_wnd)) {
+    LOG_ERROR("Failed to add clipboard format listener");
+    DestroyWindow(g_clipboard_wnd);
+    g_clipboard_wnd = nullptr;
+    g_monitoring.store(false);
+    return;
+  }
+
+  LOG_INFO("Clipboard event monitoring started (Windows)");
+
+  MSG msg;
+  while (g_monitoring.load()) {
+    BOOL ret = GetMessage(&msg, nullptr, 0, 0);
+    if (ret == 0 || ret == -1) {
+      break;
+    }
+    TranslateMessage(&msg);
+    DispatchMessage(&msg);
+  }
+
+  RemoveClipboardFormatListener(g_clipboard_wnd);
+  if (g_clipboard_wnd) {
+    DestroyWindow(g_clipboard_wnd);
+    g_clipboard_wnd = nullptr;
+  }
+  UnregisterClassA(g_clipboard_class_name, GetModuleHandle(nullptr));
+}
+
+#elif __APPLE__
+// macOS use notification mechanism, need external functions
+extern void StartMacOSClipboardMonitoring();
+extern void StopMacOSClipboardMonitoring();
+
+static void MonitorThreadFunc() { StartMacOSClipboardMonitoring(); }
+
+#elif __linux__
+static void MonitorThreadFunc() {
+  g_x11_display = XOpenDisplay(nullptr);
+  if (!g_x11_display) {
+    LOG_ERROR("Failed to open X display for clipboard monitoring");
+    g_monitoring.store(false);
+    return;
+  }
+
+  // Check if XFixes extension is available
+  int event_base, error_base;
+  if (!XFixesQueryExtension(g_x11_display, &event_base, &error_base)) {
+    LOG_WARN("XFixes extension not available, falling back to polling");
+    XCloseDisplay(g_x11_display);
+    g_x11_display = nullptr;
+    // fallback to polling mode
+    while (g_monitoring.load()) {
+      std::this_thread::sleep_for(
+          std::chrono::milliseconds(g_check_interval_ms));
+      if (!g_monitoring.load()) {
+        break;
+      }
+      HandleClipboardChange();
+    }
+    return;
+  }
+
+  g_clipboard_atom = XInternAtom(g_x11_display, "CLIPBOARD", False);
+  g_xfixes_selection_notify =
+      XInternAtom(g_x11_display, "XFIXES_SELECTION_NOTIFY", False);
+
+  // Create event window
+  Window root = DefaultRootWindow(g_x11_display);
+  Window event_window =
+      XCreateSimpleWindow(g_x11_display, root, 0, 0, 1, 1, 0, 0, 0);
+
+  // Select events to monitor
+  XFixesSelectSelectionInput(g_x11_display, event_window, g_clipboard_atom,
+                             XFixesSetSelectionOwnerNotifyMask |
+                                 XFixesSelectionWindowDestroyNotifyMask |
+                                 XFixesSelectionClientCloseNotifyMask);
+
+  LOG_INFO("Clipboard event monitoring started (Linux XFixes)");
+
+  XEvent event;
+  while (g_monitoring.load()) {
+    XNextEvent(g_x11_display, &event);
+    if (event.type == event_base + XFixesSelectionNotify) {
+      HandleClipboardChange();
+    }
+  }
+
+  XFixesSelectSelectionInput(g_x11_display, event_window, g_clipboard_atom, 0);
+  XDestroyWindow(g_x11_display, event_window);
+  XCloseDisplay(g_x11_display);
+  g_x11_display = nullptr;
+}
+
+#else
+// Fallback to polling mode for other platforms
+static void MonitorThreadFunc() {
+  while (g_monitoring.load()) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(g_check_interval_ms));
+    if (!g_monitoring.load()) {
+      break;
+    }
+    HandleClipboardChange();
+  }
+}
+#endif
+
+void Clipboard::StartMonitoring(int check_interval_ms,
+                                OnClipboardChanged on_changed) {
+  if (g_monitoring.load()) {
+    LOG_WARN("Clipboard monitoring is already running");
+    return;
+  }
+
+  g_check_interval_ms = check_interval_ms > 0 ? check_interval_ms : 100;
+  {
+    std::lock_guard<std::mutex> lock(g_monitor_mutex);
+    g_on_clipboard_changed = on_changed;
+    if (HasText()) {
+      g_last_clipboard_text = GetText();
+    } else {
+      g_last_clipboard_text.clear();
+    }
+  }
+  g_monitoring.store(true);
+
+  g_monitor_thread = std::thread(MonitorThreadFunc);
+  LOG_INFO("Clipboard event monitoring started");
+}
+
+void Clipboard::StopMonitoring() {
+  if (!g_monitoring.load()) {
+    return;
+  }
+
+  g_monitoring.store(false);
+
+#ifdef _WIN32
+  if (g_clipboard_wnd) {
+    PostMessage(g_clipboard_wnd, WM_QUIT, 0, 0);
+  }
+#elif __APPLE__
+  StopMacOSClipboardMonitoring();
+#endif
+
+  if (g_monitor_thread.joinable()) {
+    g_monitor_thread.join();
+  }
+
+  {
+    std::lock_guard<std::mutex> lock(g_monitor_mutex);
+    g_last_clipboard_text.clear();
+    g_on_clipboard_changed = nullptr;
+  }
+
+  LOG_INFO("Clipboard monitoring stopped");
+}
+
+bool Clipboard::IsMonitoring() { return g_monitoring.load(); }
+
+}  // namespace crossdesk
--- a/src/tools/clipboard.h
+++ b/src/tools/clipboard.h
@@ -0,0 +1,38 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2025-12-28
+ * Copyright (c) 2025 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _CLIPBOARD_H_
+#define _CLIPBOARD_H_
+
+#include <functional>
+#include <string>
+
+namespace crossdesk {
+
+class Clipboard {
+ public:
+  using OnClipboardChanged = std::function<int(const char* data, size_t size)>;
+
+  Clipboard() = default;
+  ~Clipboard() = default;
+
+  static std::string GetText();
+
+  static bool SetText(const std::string& text);
+
+  static bool HasText();
+
+  static void StartMonitoring(int check_interval_ms = 100,
+                              OnClipboardChanged on_changed = nullptr);
+
+  static void StopMonitoring();
+
+  static bool IsMonitoring();
+};
+
+}  // namespace crossdesk
+
+#endif
--- a/src/tools/clipboard_mac.mm
+++ b/src/tools/clipboard_mac.mm
@@ -0,0 +1,120 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2025-12-18
+ * Copyright (c) 2025 by DI JUNKUN, All Rights Reserved.
+ */
+
+#include "clipboard.h"
+
+#include <AppKit/AppKit.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <atomic>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include "rd_log.h"
+
+namespace crossdesk {
+
+extern std::atomic<bool> g_monitoring;
+extern std::mutex g_monitor_mutex;
+extern std::string g_last_clipboard_text;
+extern Clipboard::OnClipboardChanged g_on_clipboard_changed;
+
+static CFRunLoopRef g_monitor_runloop = nullptr;
+
+std::string Clipboard::GetText() {
+  @autoreleasepool {
+    NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+    NSString* string = [pasteboard stringForType:NSPasteboardTypeString];
+    if (string == nil) {
+      return "";
+    }
+    return std::string([string UTF8String]);
+  }
+}
+
+bool Clipboard::SetText(const std::string& text) {
+  @autoreleasepool {
+    NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+    [pasteboard clearContents];
+    NSString* string = [NSString stringWithUTF8String:text.c_str()];
+    if (string == nil) {
+      LOG_ERROR("Clipboard::SetText: failed to create NSString");
+      return false;
+    }
+    BOOL success = [pasteboard setString:string forType:NSPasteboardTypeString];
+    return success == YES;
+  }
+}
+
+bool Clipboard::HasText() {
+  @autoreleasepool {
+    NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+    NSArray* types = [pasteboard types];
+    return [types containsObject:NSPasteboardTypeString];
+  }
+}
+
+extern void HandleClipboardChange();
+
+void StartMacOSClipboardMonitoring() {
+  @autoreleasepool {
+    NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+
+    // Store RunLoop reference for waking up
+    NSRunLoop* runLoop = [NSRunLoop currentRunLoop];
+    g_monitor_runloop = [runLoop getCFRunLoop];
+    if (g_monitor_runloop) {
+      CFRetain(g_monitor_runloop);
+    }
+
+    // Track changeCount to detect clipboard changes
+    // Use __block to allow modification inside the block
+    __block NSInteger lastChangeCount = [pasteboard changeCount];
+
+    LOG_INFO("Clipboard event monitoring started (macOS)");
+
+    // Use a timer to periodically check changeCount
+    // This is more reliable than NSPasteboardDidChangeNotification which may not be available
+    NSTimer* timer =
+        [NSTimer scheduledTimerWithTimeInterval:0.1
+                                        repeats:YES
+                                          block:^(NSTimer* timer) {
+                                            if (!g_monitoring.load()) {
+                                              [timer invalidate];
+                                              return;
+                                            }
+                                            NSInteger currentChangeCount = [pasteboard changeCount];
+                                            if (currentChangeCount != lastChangeCount) {
+                                              lastChangeCount = currentChangeCount;
+                                              HandleClipboardChange();
+                                            }
+                                          }];
+
+    while (g_monitoring.load()) {
+      @autoreleasepool {
+        NSDate* date = [NSDate dateWithTimeIntervalSinceNow:0.1];
+        [runLoop runMode:NSDefaultRunLoopMode beforeDate:date];
+      }
+    }
+
+    // Cleanup
+    [timer invalidate];
+    if (g_monitor_runloop) {
+      CFRelease(g_monitor_runloop);
+      g_monitor_runloop = nullptr;
+    }
+  }
+}
+
+void StopMacOSClipboardMonitoring() {
+  // Wake up the RunLoop immediately so it can check g_monitoring and exit
+  // This ensures the RunLoop exits promptly instead of waiting up to 0.1 seconds
+  if (g_monitor_runloop) {
+    CFRunLoopWakeUp(g_monitor_runloop);
+  }
+}
+
+}  // namespace crossdesk
--- a/src/tools/file_transfer.cpp
+++ b/src/tools/file_transfer.cpp
@@ -0,0 +1,307 @@
+#include "file_transfer.h"
+
+#include <atomic>
+#include <chrono>
+
+#include "rd_log.h"
+
+namespace crossdesk {
+
+namespace {
+std::atomic<uint32_t> g_next_file_id{1};
+}  // namespace
+
+uint32_t FileSender::NextFileId() { return g_next_file_id.fetch_add(1); }
+
+int FileSender::SendFile(const std::filesystem::path& path,
+                         const std::string& label, const SendFunc& send,
+                         std::size_t chunk_size, uint32_t file_id) {
+  if (!send) {
+    LOG_ERROR("FileSender::SendFile: send function is empty");
+    return -1;
+  }
+
+  std::error_code ec;
+  if (!std::filesystem::exists(path, ec) ||
+      !std::filesystem::is_regular_file(path, ec)) {
+    LOG_ERROR("FileSender::SendFile: file [{}] not found or not regular",
+              path.string().c_str());
+    return -1;
+  }
+
+  uint64_t total_size = std::filesystem::file_size(path, ec);
+  if (ec) {
+    LOG_ERROR("FileSender::SendFile: failed to get size of [{}]: {}",
+              path.string().c_str(), ec.message().c_str());
+    return -1;
+  }
+
+  std::ifstream ifs(path, std::ios::binary);
+  if (!ifs.is_open()) {
+    LOG_ERROR("FileSender::SendFile: failed to open [{}]",
+              path.string().c_str());
+    return -1;
+  }
+  LOG_INFO("FileSender send file {}, total size {}, file_id={}",
+           path.string().c_str(), total_size, file_id);
+
+  if (file_id == 0) {
+    file_id = NextFileId();
+  }
+  const uint32_t final_file_id = file_id;
+  uint64_t offset = 0;
+  bool is_first = true;
+  std::string file_name = label.empty() ? path.filename().string() : label;
+
+  std::vector<char> buffer;
+  buffer.resize(chunk_size);
+
+  while (ifs && offset < total_size) {
+    uint64_t remaining = total_size - offset;
+    uint32_t to_read =
+        static_cast<uint32_t>(std::min<uint64_t>(remaining, chunk_size));
+
+    ifs.read(buffer.data(), static_cast<std::streamsize>(to_read));
+    std::streamsize bytes_read = ifs.gcount();
+    if (bytes_read <= 0) {
+      break;
+    }
+
+    bool is_last = (offset + static_cast<uint64_t>(bytes_read) >= total_size);
+    const std::string* name_ptr = is_first ? &file_name : nullptr;
+
+    std::vector<char> chunk = BuildChunk(
+        final_file_id, offset, total_size, buffer.data(),
+        static_cast<uint32_t>(bytes_read), name_ptr, is_first, is_last);
+
+    int ret = send(chunk.data(), chunk.size());
+    if (ret != 0) {
+      LOG_ERROR("FileSender::SendFile: send failed for [{}], ret={}",
+                path.string().c_str(), ret);
+      return ret;
+    }
+
+    offset += static_cast<uint64_t>(bytes_read);
+    is_first = false;
+  }
+
+  return 0;
+}
+
+std::vector<char> FileSender::BuildChunk(uint32_t file_id, uint64_t offset,
+                                         uint64_t total_size, const char* data,
+                                         uint32_t data_size,
+                                         const std::string* file_name,
+                                         bool is_first, bool is_last) {
+  FileChunkHeader header{};
+  header.magic = kFileChunkMagic;
+  header.file_id = file_id;
+  header.offset = offset;
+  header.total_size = total_size;
+  header.chunk_size = data_size;
+  header.name_len =
+      (file_name && is_first) ? static_cast<uint16_t>(file_name->size()) : 0;
+  header.flags = 0;
+  if (is_first) header.flags |= 0x01;
+  if (is_last) header.flags |= 0x02;
+
+  std::size_t total_size_bytes =
+      sizeof(FileChunkHeader) + header.name_len + header.chunk_size;
+
+  std::vector<char> buffer;
+  buffer.resize(total_size_bytes);
+
+  std::size_t offset_bytes = 0;
+  memcpy(buffer.data() + offset_bytes, &header, sizeof(FileChunkHeader));
+  offset_bytes += sizeof(FileChunkHeader);
+
+  if (header.name_len > 0 && file_name) {
+    memcpy(buffer.data() + offset_bytes, file_name->data(), header.name_len);
+    offset_bytes += header.name_len;
+  }
+
+  if (header.chunk_size > 0 && data) {
+    memcpy(buffer.data() + offset_bytes, data, header.chunk_size);
+  }
+
+  return buffer;
+}
+
+// ---------- FileReceiver ----------
+
+FileReceiver::FileReceiver() : output_dir_(GetDefaultDesktopPath()) {}
+
+FileReceiver::FileReceiver(const std::filesystem::path& output_dir)
+    : output_dir_(output_dir) {
+  std::error_code ec;
+  if (!output_dir_.empty()) {
+    std::filesystem::create_directories(output_dir_, ec);
+    if (ec) {
+      LOG_ERROR("FileReceiver: failed to create output dir [{}]: {}",
+                output_dir_.string().c_str(), ec.message().c_str());
+    }
+  }
+}
+
+std::filesystem::path FileReceiver::GetDefaultDesktopPath() {
+#ifdef _WIN32
+  const char* home_env = std::getenv("USERPROFILE");
+#else
+  const char* home_env = std::getenv("HOME");
+#endif
+  if (!home_env) {
+    return std::filesystem::path{};
+  }
+
+  std::filesystem::path desktop_path =
+      std::filesystem::path(home_env) / "Desktop";
+
+  std::error_code ec;
+  std::filesystem::create_directories(desktop_path, ec);
+  if (ec) {
+    LOG_ERROR("FileReceiver: failed to create desktop directory [{}]: {}",
+              desktop_path.string().c_str(), ec.message().c_str());
+  }
+
+  return desktop_path;
+}
+
+bool FileReceiver::OnData(const char* data, size_t size) {
+  if (!data || size < sizeof(FileChunkHeader)) {
+    LOG_ERROR("FileReceiver::OnData: invalid buffer");
+    return false;
+  }
+
+  FileChunkHeader header{};
+  memcpy(&header, data, sizeof(FileChunkHeader));
+
+  if (header.magic != kFileChunkMagic) {
+    return false;
+  }
+
+  std::size_t header_and_name =
+      sizeof(FileChunkHeader) + static_cast<std::size_t>(header.name_len);
+  if (size < header_and_name ||
+      size < header_and_name + static_cast<std::size_t>(header.chunk_size)) {
+    LOG_ERROR("FileReceiver::OnData: buffer too small for header + payload");
+    return false;
+  }
+
+  const char* name_ptr = data + sizeof(FileChunkHeader);
+  std::string file_name;
+  const std::string* file_name_ptr = nullptr;
+  if (header.name_len > 0) {
+    file_name.assign(name_ptr,
+                     name_ptr + static_cast<std::size_t>(header.name_len));
+    file_name_ptr = &file_name;
+  }
+
+  const char* payload = data + header_and_name;
+  std::size_t payload_size =
+      static_cast<std::size_t>(header.chunk_size);  // may be 0
+
+  return HandleChunk(header, payload, payload_size, file_name_ptr);
+}
+
+bool FileReceiver::HandleChunk(const FileChunkHeader& header,
+                               const char* payload, size_t payload_size,
+                               const std::string* file_name) {
+  auto it = contexts_.find(header.file_id);
+  if (it == contexts_.end()) {
+    // new file context must start with first chunk.
+    if ((header.flags & 0x01) == 0) {
+      LOG_ERROR("FileReceiver: received non-first chunk for unknown file_id={}",
+                header.file_id);
+      return false;
+    }
+
+    FileContext ctx;
+    ctx.total_size = header.total_size;
+
+    std::string filename;
+    if (file_name && !file_name->empty()) {
+      filename = *file_name;
+    } else {
+      filename = "received_" + std::to_string(header.file_id);
+    }
+
+    ctx.file_name = filename;
+
+    std::filesystem::path save_path = output_dir_.empty()
+                                          ? std::filesystem::path(filename)
+                                          : output_dir_ / filename;
+
+    // if file exists, append timestamp.
+    std::error_code ec;
+    if (std::filesystem::exists(save_path, ec)) {
+      auto now = std::chrono::system_clock::now();
+      auto ts = std::chrono::duration_cast<std::chrono::milliseconds>(
+                    now.time_since_epoch())
+                    .count();
+      save_path = save_path.parent_path() /
+                  (save_path.stem().string() + "_" + std::to_string(ts) +
+                   save_path.extension().string());
+    }
+
+    ctx.ofs.open(save_path, std::ios::binary | std::ios::trunc);
+    if (!ctx.ofs.is_open()) {
+      LOG_ERROR("FileReceiver: failed to open [{}] for writing",
+                save_path.string().c_str());
+      return false;
+    }
+
+    contexts_.emplace(header.file_id, std::move(ctx));
+    it = contexts_.find(header.file_id);
+  }
+
+  FileContext& ctx = it->second;
+
+  if (payload_size > 0 && payload) {
+    ctx.ofs.seekp(static_cast<std::streamoff>(header.offset), std::ios::beg);
+    ctx.ofs.write(payload, static_cast<std::streamsize>(payload_size));
+    if (!ctx.ofs.good()) {
+      LOG_ERROR("FileReceiver: write failed for file_id={}", header.file_id);
+      return false;
+    }
+    ctx.received += static_cast<uint64_t>(payload_size);
+  }
+
+  // Send ACK after processing chunk
+  if (on_send_ack_) {
+    FileTransferAck ack{};
+    ack.magic = kFileAckMagic;
+    ack.file_id = header.file_id;
+    ack.acked_offset = header.offset + static_cast<uint64_t>(payload_size);
+    ack.total_size = header.total_size;
+    ack.flags = 0;
+
+    bool is_last = (header.flags & 0x02) != 0;
+    if (is_last || ctx.received >= ctx.total_size) {
+      ack.flags |= 0x01;  // completed
+    }
+
+    int ret = on_send_ack_(ack);
+    if (ret != 0) {
+      LOG_ERROR("FileReceiver: failed to send ACK for file_id={}, ret={}",
+                header.file_id, ret);
+    }
+  }
+
+  bool is_last = (header.flags & 0x02) != 0;
+  if (is_last || ctx.received >= ctx.total_size) {
+    ctx.ofs.close();
+
+    std::filesystem::path saved_path =
+        output_dir_.empty() ? std::filesystem::path(ctx.file_name)
+                            : output_dir_ / ctx.file_name;
+
+    LOG_INFO("FileReceiver: file received complete, file_id={}, size={}",
+             header.file_id, ctx.received);
+
+    contexts_.erase(header.file_id);
+  }
+
+  return true;
+}
+
+}  // namespace crossdesk
--- a/src/tools/file_transfer.h
+++ b/src/tools/file_transfer.h
@@ -0,0 +1,114 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2025-12-18
+ * Copyright (c) 2025 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _FILE_TRANSFER_H_
+#define _FILE_TRANSFER_H_
+
+#include <cstdint>
+#include <filesystem>
+#include <fstream>
+#include <functional>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace crossdesk {
+
+// Magic constants for file transfer protocol
+constexpr uint32_t kFileChunkMagic = 0x4A4E544D;  // 'JNTM'
+constexpr uint32_t kFileAckMagic = 0x4A4E5443;    // 'JNTC'
+
+#pragma pack(push, 1)
+struct FileChunkHeader {
+  uint32_t magic;       // magic to identify file-transfer chunks
+  uint32_t file_id;     // unique id per file transfer
+  uint64_t offset;      // offset in file
+  uint64_t total_size;  // total file size
+  uint32_t chunk_size;  // payload size in this chunk
+  uint16_t name_len;    // filename length (bytes), only set on first chunk
+  uint8_t flags;        // bit0: is_first, bit1: is_last, others reserved
+};
+
+struct FileTransferAck {
+  uint32_t magic;         // magic to identify file-transfer ack
+  uint32_t file_id;       // must match FileChunkHeader.file_id
+  uint64_t acked_offset;  // received offset
+  uint64_t total_size;    // total file size
+  uint32_t flags;         // bit0: completed, bit1: error
+};
+#pragma pack(pop)
+
+class FileSender {
+ public:
+  using SendFunc = std::function<int(const char* data, size_t size)>;
+
+ public:
+  FileSender() = default;
+
+  // generate a new file id
+  static uint32_t NextFileId();
+
+  // synchronously send a file using the provided send function.
+  // `path`  : full path to the local file.
+  // `label` : logical filename to send (usually path.filename()).
+  // `send`  : callback that pushes one encoded chunk into the data channel.
+  // `file_id` : file id to use (0 means auto-generate).
+  // Return 0 on success, <0 on error.
+  int SendFile(const std::filesystem::path& path, const std::string& label,
+               const SendFunc& send, std::size_t chunk_size = 64 * 1024,
+               uint32_t file_id = 0);
+
+  // build a single encoded chunk buffer according to FileChunkHeader protocol.
+  static std::vector<char> BuildChunk(uint32_t file_id, uint64_t offset,
+                                      uint64_t total_size, const char* data,
+                                      uint32_t data_size,
+                                      const std::string* file_name,
+                                      bool is_first, bool is_last);
+};
+
+class FileReceiver {
+ public:
+  struct FileContext {
+    std::string file_name;
+    uint64_t total_size = 0;
+    uint64_t received = 0;
+    std::ofstream ofs;
+  };
+
+  using OnFileComplete =
+      std::function<void(const std::filesystem::path& saved_path)>;
+  using OnSendAck = std::function<int(const FileTransferAck& ack)>;
+
+ public:
+  // save to default desktop directory.
+  FileReceiver();
+
+  // save to a specified directory.
+  explicit FileReceiver(const std::filesystem::path& output_dir);
+
+  // process one received data buffer (one chunk).
+  // return true if parsed and processed successfully, false otherwise.
+  bool OnData(const char* data, size_t size);
+
+  void SetOnSendAck(OnSendAck cb) { on_send_ack_ = cb; }
+
+  const std::filesystem::path& OutputDir() const { return output_dir_; }
+
+ private:
+  static std::filesystem::path GetDefaultDesktopPath();
+
+  bool HandleChunk(const FileChunkHeader& header, const char* payload,
+                   size_t payload_size, const std::string* file_name);
+
+ private:
+  std::filesystem::path output_dir_;
+  std::unordered_map<uint32_t, FileContext> contexts_;
+  OnSendAck on_send_ack_ = nullptr;
+};
+
+}  // namespace crossdesk
+
+#endif
--- a/submodules/minirtc
+++ b/submodules/minirtc
--- a/xmake.lua
+++ b/xmake.lua
@@ -33,6 +33,7 @@ add_requires("imgui v1.92.1-docking", {configs = {sdl3 = true, sdl3_renderer = t
 add_requires("openssl3 3.3.2", {system = false})
 add_requires("nlohmann_json 3.11.3")
 add_requires("cpp-httplib v0.26.0", {configs = {ssl = true}})
+add_requires("tinyfiledialogs 3.15.1")

 if is_os("windows") then
    add_requires("libyuv", "miniaudio 0.11.21")
@@ -168,13 +169,22 @@ target("version_checker")
    add_files("src/version_checker/*.cpp")
    add_includedirs("src/version_checker", {public = true})

+target("tools")
+    set_kind("object")
+    add_deps("rd_log")
+    add_files("src/tools/*.cpp")
+    if is_os("macosx") then
+        add_files("src/tools/*.mm")
+    end
+    add_includedirs("src/tools", {public = true})
+
 target("gui")
    set_kind("object")
-    add_packages("libyuv")
+    add_packages("libyuv", "tinyfiledialogs")
    add_defines("CROSSDESK_VERSION=\"" .. (get_config("CROSSDESK_VERSION") or "Unknown") .. "\"")
    add_deps("rd_log", "common", "assets", "config_center", "minirtc", 
        "path_manager", "screen_capturer", "speaker_capturer", 
-        "device_controller", "thumbnail", "version_checker")
+        "device_controller", "thumbnail", "version_checker", "tools")
    add_files("src/gui/*.cpp", "src/gui/panels/*.cpp", "src/gui/toolbars/*.cpp",
        "src/gui/windows/*.cpp")
    add_includedirs("src/gui", "src/gui/panels", "src/gui/toolbars",
Author	SHA1	Message	Date
dijunkun	fd242d50c1	[feat] show server window in the bottom-right corner of the screen	2026-01-19 17:42:22 +08:00
dijunkun	d6d8ecd6c5	[feat] add server window	2026-01-19 00:47:34 +08:00
dijunkun	669fac7f50	[feat] support drag-and-drop file sending, refs #63	2026-01-14 18:13:22 +08:00
dijunkun	92d670916e	[fix] fix incorrect data send function used for control data	2026-01-13 18:13:54 +08:00
dijunkun	0155413c12	[feat] use reliable transmission to send control info	2026-01-12 17:28:19 +08:00
dijunkun	8468be6532	[fix] update MiniRTC	2026-01-12 17:27:49 +08:00
dijunkun	78c82f778a	[chore] remove SetOnFileComplete() in class FileReceiver	2025-12-29 12:48:14 +08:00
dijunkun	ab89a3d41a	[fix] fix clipboard copy from remote device to controller	2025-12-29 12:46:19 +08:00
dijunkun	5f320af6e6	[fix] fix macOS clipboard monitoring compilation error using changeCount polling	2025-12-29 01:01:08 +08:00
dijunkun	17b7ba6b72	[feat] support clipboard sharing, refs #35	2025-12-29 00:53:14 +08:00
dijunkun	c70ebdfe15	[fix] correct file send rate calculation by using data channel feedback	2025-12-29 00:53:14 +08:00
dijunkun	a3e564f160	[feat] support multi-file transfer, refs #45	2025-12-29 00:52:58 +08:00
dijunkun	eea37424c9	[feat] use receiver ack to calculate file transfer progress	2025-12-25 18:13:18 +08:00
dijunkun	b322181853	[feat] add file transfer window to show file sending info	2025-12-24 18:12:50 +08:00
dijunkun	3ad66f5e0b	[fix] fix file transfer	2025-12-24 01:45:59 +08:00
dijunkun	4035e0dd13	[feat] upgrade MiniRTC and expose source ID in data callbacks	2025-12-23 00:53:47 +08:00
dijunkun	832b820096	[fix] update MiniRTC to latest version and add logging for sent file size	2025-12-22 18:33:53 +08:00
dijunkun	d337971de0	[feat] update MiniRTC api calling	2025-12-19 18:22:34 +08:00
dijunkun	a967dc72d7	[feat] use SendReliableDataFrame() instead of SendDataFrame()	2025-12-19 01:46:16 +08:00
dijunkun	5066fcda48	[feat] implement file transfer module	2025-12-18 18:30:51 +08:00
dijunkun	e7bdf42694	[feat] add file transfer button to control bar	2025-12-18 01:54:03 +08:00
dijunkun	875fea88ee	[chore] adjust main window title font size	2025-12-18 01:32:38 +08:00
dijunkun	b2654ea9db	[feat] use fingerprint-based verification for both default and self-hosted servers	2025-12-10 03:46:03 +08:00
dijunkun	8f8e415262	[chore] update README	2025-12-10 03:38:05 +08:00
dijunkun	5ff624f7b2	[feat] use fingerprint-based verification for TLS connection	2025-12-10 03:28:28 +08:00
dijunkun	e09243f1ec	[chore] update README	2025-12-10 00:23:04 +08:00