Setup the engine

Setup the engine

For all engines

Within the file config.yml:

• Enter the directory containing the engine executable in the engine: dir field.
• Enter the executable name in the engine: name field (In Windows you may need to type a name with ".exe", like "lczero.exe")
• If you want the engine to run in a different directory (e.g., if the engine needs to read or write files at a certain location), enter that directory in the engine: working_dir field.
  • If this field is blank or missing, the current directory will be used.
  • IMPORTANT NOTE: If this field is used, the running engine will look for files and directories (Syzygy tablebases, for example) relative to this path, not the directory where lichess-bot was launched. Files and folders specified with absolute paths are unaffected.

As an optional convenience, there is a folder named engines within the lichess-bot folder where you can copy your engine and all the files it needs. This is the default executable location in the config.yml.default file.

For Leela Chess Zero

LeelaChessZero: Mac/Linux

• Download the weights for the id you want to play from here.
• Extract the weights from the zip archive and rename it to latest.txt.
• For Mac/Linux, build the lczero binary yourself following LeelaChessZero/lc0/README.
• Copy both the files into the engine.dir directory.
• Change the engine.name and engine.engine_options.weights keys in config.yml file to lczero and weights.pb.gz.
• You can specify the number of engine.uci_options.threads in the config.yml file as well.
• To start: python3 lichess-bot.py.

LeelaChessZero: Windows CPU 2021

• For Windows modern CPUs, download the lczero binary from the latest Lc0 release (e.g. lc0-v0.27.0-windows-cpu-dnnl.zip).
• Unzip the file, it comes with lc0.exe , dnnl.dll, and a weights file example, 703810.pb.gz (amongst other files).
• All three main files need to be copied to the engines directory.
• The lc0.exe should be doubleclicked and the windows safesearch warning about it being unsigned should be cleared (be careful and be sure you have the genuine file).
• Change the engine.name key in the config.yml file to lc0.exe, no need to edit the config.yml file concerning the weights file as the lc0.exe will use whatever *.pb.gz is in the same folder (have only one *pb.gz file in the engines directory).
• To start: python3 lichess-bot.py.

Next step: Configure lichess-bot

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