How to send custom headers in the first handshake that occurs in the WebSocket protocol?

I want to use custom header in my initial request "**X-Abc-Def : xxxxx"

WebSocket clients are Python & Android client.

You need to mention which WebSocket clients you are using. A quick google search showed me at least two different ones for android.

In the python websocket-client you can indeed pass custom headers easily - there's a keyword argument headers available for this; see the following example from the docs:

conn = create_connection("ws://echo.websocket.org/", headers={"User-Agent": "MyProgram"})

"headers" is wrong key word, should be "header". the following code works for me. ``` conn = create_connection("ws://echo.websocket.org/", header={"User-Agent": "MyProgram"}) ``` – wazhao Jul 7 '17 at 1:55