This library is deprecated. You can directly use the WebSockets library (https://github.com/Links2004/arduinoWebSockets). It supports a SocketIOclient class. See the example there.

A socket.io-client implementation for ESP8266 and Arduino.

• Install
• Functions
• Miscellaneous
• Example
• Contribution

To compile you have to add a reference to the linker. To do so edit platform.txt in $ARDUINO_IDE/hardware/esp8266com/esp8266 and add '-lstdc++' to the line

compiler.c.elf.libs= ...

💡 Note: See ESP8266 for Arduino IDE (xtensa-lx106-elf-gcc) and std::map linking error.

Best thing is to use the Arduino Library Manager.

1. Go to Sketch > Include Library > Manage Libraries.
2. Install WebSockets by Markus Sattler
3. Install SocketIoClient
4. Select Sketch > Include Library > SocketIoClient

1. SocketIoClient::begin()
2. SocketIoClient::beginSSL()
3. SocketIoClient::disconnect()
4. SocketIoClient::emit()
5. SocketIoClient::loop()
6. SocketIoClient::on()
7. SocketIoClient::remove()
8. SocketIoClient::setAuthorization()

Open connection to socket.io server.

host url to socket.io server port port to connect on. Defaults to 80 or 443 (SSL) path path to connect to on server. Defaults to "/socket.io/?transport=websocket"

socket.begin("my.socket-io.server", 443, "/socket.io/?transport=websocket");

Open SSL connection to socket.io server.

host url to socket.io server port port to connect on. Defaults to 80 or 443 (SSL) path path to connect to on server. Defaults to "/socket.io/?transport=websocket" fingerprint the SSL fingerprint. Defaults to ""

socket.beginSSL("my.socket-io.server", 443, "/socket.io/?transport=websocket", "26 96 1C 2A 51 07 FD 15 80 96 93 AE F7 32 CE B9 0D 01 55 C4");

Disconnect from the server.

socket.disconnect();

Emits an event to the server.

event name of the event to be emitted payload string of the payload to be sent with the event. Plain strings and object property names should be encapsulated in quotes.

socket.emit("plainString", "\"this is a plain string\"");
socket.emit("jsonObject", "{\"foo\":\"bar\"}");

Processes the websocket. Should be called in Arduino main loop.

Binds a function to an event.

event name of the event to bind to callback callback function to call when the event is triggered Function signature must be

void (const char * payload, size_t length)

void event(const char * payload, size_t length) {
	// do stuff
}
socket.on("event", event);

• connect - when user is connected to server
• disconnect - when user is disconnected from the server

Removes the previously added event.

event name of the event binded

socket.remove("event");

Set HTTP Basic auth username and password.

socket.setAuthorization("username", "password");

To go along with the socket.io-client implementation of socket.io the connect event is triggered upon successfully opened connection to server. To utilize simply add

socket.on("connect", handler)

Likewise, disconnect event is triggered upon terminated connection.

See Example

Based on the great work of Links2004 / arduinoWebSockets.