TMS FNC WebSocket Server

TTMSFNCWebSocketServer is a headless component for hosting a WebSocket endpoint that accepts multiple simultaneous client connections and exchanges text or binary messages with them. It implements the RFC 6455 WebSocket protocol on top of an Indy HTTP server, serves each client on its own thread, and supports TLS-secured wss:// endpoints. Use it to push live data to browsers, apps, and devices from a VCL or FMX application.

Documentation

Start here	Use when
Get started	Install, configure, start a server, and handle your first client connection.
Guides	Task guides: running a server, broadcasting, connection data, connection health, and TLS.
API reference	Full property, method, and event reference.

Supported frameworks

Framework	Support
VCL	Win32 and Win64.
FMX	Windows, macOS, iOS, Android, and Linux.
TMS WEB Core	Not available; a browser cannot host a server.

Minimal example

Set a port and path, wire the connection events, and start listening:

Start a WebSocket serverPascal

procedure TForm1.StartServer;
begin
  FServer := TTMSFNCWebSocketServer.Create(Self);
  FServer.Port := 5050;              // default is 8888
  FServer.PathName := 'chat';        // clients connect to ws://<host>:5050/chat
  FServer.AutoSyncEvents := True;    // raise events on the main thread

  FServer.OnConnect := ServerConnect;
  FServer.OnDisconnect := ServerDisconnect;
  FServer.OnMessageReceived := ServerMessageReceived;

  FServer.Active := True;            // begin listening for clients
end;

procedure TForm1.StopServer;
begin
  FServer.Active := False;           // stop listening and drop all clients
end;

procedure TForm1.ServerConnect(Sender: TObject; AConnection: TTMSFNCWebSocketConnection);
begin
  // A TCP connection arrived; the WebSocket handshake has not happened yet.
  Log('Connection from ' + AConnection.PeerIP);
end;

procedure TForm1.ServerDisconnect(Sender: TObject; AConnection: TTMSFNCWebSocketConnection);
begin
  Log('A client disconnected');
end;

API map

Role	Classes
Main component	`TTMSFNCWebSocketServer`
Client connections	`TTMSFNCWebSocketServerConnection` (one connected client, with `UserData`), derived from `TTMSFNCWebSocketConnection` (send, ping, pong, and close frames); `TTMSFNCWebSocketConnections`
Handshake	`TTMSFNCWebSocketRequest` (the client's handshake request)
Transport	`TTMSFNCWebSocketHTTPServer`
Selectors and event types	`TTMSFNCWebSocketSendToCallBack`, `TTMSFNCWebSocketAllowConnectionEvent`, `TTMSFNCWebSocketHandshakeSentEvent`, `TTMSFNCWebSocketServerGetSSLPasswordEvent`, `TTMSFNCWebSocketServerCreateIOHandlerEvent`
Specialized descendant	`TTMSFNCWhatsAppServer` — WhatsApp webhook host

Guides

Area	Guide
Server lifecycle	Running a server — start and stop, port and path, accepting connections, lifecycle events, and event threads.
Messaging	Broadcasting messages — broadcasts, selector-based sends, relaying, frames, and removing clients.
Per-client state	Custom connection data — `UserData`, ownership, and routing on stored data.
Reliability	Connection health — ping, pong, close frames, and dropping dead clients.
Security	Secure connections — certificates, PFX conversion, and OpenSSL 3.x IO handlers.