♟️🤖 ChessKitEngine

A Swift package for the following chess engines:

ChessKitEngine implements the Universal Chess Interface protocol for communication between chess engines and user interfaces built with Swift.

For a related Swift package that manages chess logic, see chesskit-swift.

Usage

• Add a package dependency to your Xcode project or Swift Package:

  .package(url: "https://github.com/chesskit-app/chesskit-engine", from: "0.2.0")

• Next you can import ChessKitEngine to use it in your Swift code: ``` swift import ChessKitEngine

// …

## Features

* Initialize an engine and set response handler
``` swift
// create Stockfish engine
let engine = Engine(type: .stockfish)

// set response handler
engine.receiveResponse = { response in
    print(response)
}

// start listening for engine responses
engine.start()

• Send UCI protocol commands ``` swift // check that engine is running before sending commands guard engine.isRunning else { return }

// stop any current engine processing engine.send(command: .stop)

// set engine position to standard starting chess position engine.send(command: .position(.startpos))

// start engine analysis with maximum depth of 15 engine.send(command: .go(depth: 15))

* Update engine position after a move is made
``` swift
// FEN after 1. e4
let newPosition = "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1"

engine.send(command: .stop)
engine.send(command: .position(.fen(newPosition)))
engine.send(command: .go(depth: 15))

• Receive engine’s analysis of current position

  // receiveResponse is called whenever the engine publishes a response
  engine.receiveResponse = { response in
    switch response {
    case let .info(info):
        print(info.score)   // engine evaluation score in centipawns
        print(info.pv)      // array of move strings representing best line
    default:
        break
    }
  }

• Terminate engine communication

  // stop listening for engine responses
  engine.stop()

• Enable engine response logging ``` swift // log engine commands and responses to the console engine.loggingEnabled = true

// Logging is off by default since engines can be very // verbose while analyzing positions and returning evaluations.

## Supported Engines

The following engines are currently supported:
| | Engine  | Version | License | Options Reference |
| :---: | --- | :---: | :---: | :---: |
| <img src="https://stockfishchess.org/images/logo/icon_512x512.png" width="25" /> | [Stockfish](https://stockfishchess.org) | [15.1](https://github.com/official-stockfish/Stockfish/tree/sf_15.1) | [GPL v3](https://github.com/official-stockfish/Stockfish/blob/sf_15.1/Copying.txt) | [🔗](https://github.com/official-stockfish/Stockfish/tree/sf_15.1#the-uci-protocol-and-available-options)
| <img src="https://lczero.org/images/logo.svg" width="25" /> | [lc0](https://lczero.org) | [0.29](https://github.com/LeelaChessZero/lc0/tree/v0.29.0) | [GPL v3](https://github.com/LeelaChessZero/lc0/blob/v0.29.0/COPYING) | [🔗](https://github.com/LeelaChessZero/lc0/wiki/Lc0-options)

## Author

[@pdil](https://github.com/pdil)

## License

`ChessKitEngine` is distributed under the [MIT License](https://github.com/chesskit-app/chesskit-engine/blob/master/LICENSE).