How to Use External Engine

Connect a powerful chess engine running on your computer to Kingside for deeper analysis. Follow these steps:

Download Engine Bridge

Download kingside-engine-bridge for your operating system from GitHub Releases.

Download from GitHub →

Install a Chess Engine

Install Stockfish or another UCI-compatible chess engine on your computer.

Download Stockfish →

Run the Bridge

Extract the archive and run the bridge binary. It will start a WebSocket server on port 9090.

./kingside-engine-bridge

Copy the Secret Key

Open config.yaml (created on first run) and copy the secret_key value.

config.yaml → secret_key: "your-key"

Open Analysis in Kingside

Go to any analysis page, click the ⚙ gear icon in the engine panel, and select "External Engine".

Enter Connection Details

Enter the WebSocket URL and your secret key from config.yaml.

ws://localhost:9090

Click Connect

Press Connect. The status indicator will turn green when connected. Your engine is now analyzing positions!

FAQ / Troubleshooting

Example config.yaml for each OS

The bridge creates config.yaml on first run. Below are correct examples for each operating system. Important: secret_key must always be in quotes (otherwise YAML parse error for hex values).

Windows

engine_path: ".\stockfish-windows-x86-64-avx2.exe"
port: 9090
secret_key: "5caa600aebd56a95a625637d6a55bc5e"

On Windows use .\ prefix for relative paths to the engine executable.

Linux

engine_path: "/usr/games/stockfish"
port: 9090
secret_key: "5caa600aebd56a95a625637d6a55bc5e"

macOS

engine_path: "/opt/homebrew/bin/stockfish"
port: 9090
secret_key: "5caa600aebd56a95a625637d6a55bc5e"

Always wrap secret_key in quotes — hex strings like 5caa... may be misinterpreted by YAML without them.