Free online chess server. Play chess in a clean interface. No registration, no ads, no plugin required. Play chess with the computer, friends or random opponents.
Long ago, I made an app that controlled a headless Firefox instance and would manipulate a Chess.com webpage via an API. Then I found a guy to help build a custom wooden chess board I could monitor with an ESP32 and make calls to that API for moves, bridging a real board in a DIY setup. Never did finish the board, but realizing now I should have released the API layer.
An LED in the corner of each square would light up an existing piece and the place to move it to. The Pi would ping the API, which would compare the current location to the board on the webpage to determine the change.