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The forever free, adless and open source chess server.
Scala JavaScript HTML CSS Ruby Emacs Lisp Other

README.md

lichess.org

lichess.org

It's a free online chess game focused on realtime and ease of use

It has a search engine, computer analysis, tournaments, simuls, forums, teams, tactic trainer, opening trainer, a mobile app, a monitoring console, and a network world map. The UI is available in 80 languages thanks to the community.

Lichess is written in Scala 2.11, and relies on Play 2.3 for the routing, templating, and JSON. Pure chess logic is contained in scalachess submodule. The codebase is fully asynchronous, making heavy use of Scala Futures and Akka 2 actors. Lichess talks to Stockfish deployed in an AI cluster of donated servers. It uses MongoDB 2.6 to store more than 68 million games, which are indexed by elasticsearch. HTTP requests and websocket connections are proxied by nginx 1.6. Client-side is written in mithril.js. The blog uses a free open content plan from prismic.io.

Join us on #lichess IRC channel on freenode for more info. Use github issues for bug reports and feature requests.

Installation

If you want to add a live chess section to your website, you are welcome to embed lichess. It's very easy.

This project source code is open for other developers to have an example of non-trivial scala/play2/mongodb application. You're welcome to reuse as much code as you want for your projects, and to get inspired by the solutions I propose to many common web development problems. But please don't just create a public lichess clone. Instead, just embed lichess using an <iframe>.

Also note that if I provide the source code, I do not offer support for your lichess instance. I will probably ignore any question about lichess installation and runtime issues.

HTTP API

Feel free to use lichess API in your applications and websites.

If the resource you need is not available yet, drop me an email at thibault.duplessis@gmail.com, and we'll discuss it.

GET /api/user/<username> fetch one user

> curl http://en.lichess.org/api/user/thibault
{
  "username": "thibault",
  "title": null,                            // chess title like FM or LM (lichess master)
  "url": "http://lichess.org/@/thibault",   // profile url
  "online": true,                           // is the player currently using lichess?
  "playing": "http://lichess.org/abcdefgh", // game being played, if any
  "engine": false,                          // true if the user is known to use a chess engine
  "language": "en",                         // prefered language
  "profile": {
    "bio": "Developer of lichess",
    "country": "FR",
    "firstName": "Thibault",
    "lastName": "Duplessis",
    "location": "Paris"
  },
  "perfs": {                                // user performances in different games
    "bullet": {
      "games": 35,                          // number of rated games played
      "rating": 1624,                       // Glicko2 rating
      "rd": 80,                             // Glicko2 rating deviation
      "prog": -13                           // progress over the last twelve games
    },
    "chess960": {
      "games": 1,
      "rating": 1739,
      "rd": 277,
      "prog": 33
    },
    "classical": {
      "games": 331,
      "rating": 1603,
      "rd": 65,
      "prog": 9
    },
    "kingOfTheHill": {
      "games": 3,
      "rating": 1622,
      "rd": 223,
      "prog": -62
    },
    "puzzle": {
      "games": 9,
      "rating": 902,
      "rd": 117,
      "prog": -328
    },
    "threeCheck": {
      "games": 1,
      "rating": 1662,
      "rd": 290
    }
  }
}

Example usage with JSONP:

$.ajax({
  url:'http://en.lichess.org/api/user/thibault',
  dataType:'jsonp',
  jsonp:'callback',
  success: function(data) {
    // data is a javascript object, do something with it!
    console.debug(JSON.stringify(data));
  }
});

GET /api/user fetch many users

> curl http://en.lichess.org/api/user?team=coders&nb=100

All parameters are optional.

name type default description
team string - filter users by team
nb int 10 maximum number of users to return
{
  "list": [
    {
      ... // see user document above
    },
    ... // other users
  ]
}

Example usage with JSONP:

$.ajax({
  url:'http://en.lichess.org/api/user',
  data: {
    team: 'coders',
    nb: 100
  },
  dataType:'jsonp',
  jsonp:'callback',
  success: function(data) {
    // data is a javascript object, do something with it!
    console.debug(JSON.stringify(data.list));
  }
});

GET /api/game fetch many games

> curl http://en.lichess.org/api/game?username=thibault&rated=1&nb=10

Games are returned by descendant chronological order. All parameters are optional.

name type default description
username string - filter games by user
rated 1 or 0 - filter rated or casual games
analysed 1 or 0 - filter only analysed (or not analysed) games
nb int 10 maximum number of games to return
with_analysis 1 or 0 0 include deep analysis data in the result
with_moves 1 or 0 0 include a list of PGN moves
with_opening 1 or 0 0 include opening informations
token string - security token (unlocks secret game data)
{
  "list": [
    {
      "id": "39b12Ikl",
      "variant": "chess960", // standard/chess960/fromPosition/kingOfTheHill/threeCheck
      "speed": "blitz", // bullet|blitz|classical|unlimited
      "perf": "chess960", // bullet|blitz|classical|chess960|kingOfTheHill|threeCheck
      "rated": true,
      "status": "mate", // (1)
      "clock":{          // all clock values are expressed in seconds
        "initial": 300,
        "increment": 8,
        "totalTime": 540  // evaluation of the game duration = initial + 30 * increment
      },
      "timestamp": 1389100907239,
      "turns": 44,
      "url": "http://lichess.org/x2kpaixn",
      "winner": "black",
      "players": {
        "white": {
          "userId": "thibault",
          "name": "Thibault D", // only in the case of imported game
          "rating": 1642,
          "analysis": {
            "blunder": 1,
            "inaccuracy": 0,
            "mistake": 2
          }
        },
        "black": ... // other player
      }
      "analysis": [ // only if the with_analysis flag is set
        {
          "eval": -26, // board evaluation in centipawns
          "move": "e4"
        },
        {
          "eval": -8,
          "move": "b5"
        },
        {
          "eval": -66,
          "move": "Nfe3",
          "variation": "c4 bxc4 Nfe3 c5 Qf1 f6 Rxc4 Bb7 b4 Ba6"
        },
        // ... more moves
      ],
      "moves": "Nf3 d5 g3 e6 Bg2 Be7 d3 Nf6 Nbd2 O-O O-O c6 Rfe1 b6 e4 Bb7", // with_moves flag
      "opening": { // with_opening flag
        "code": "A07",
        "name": "King's Indian Attack, General"
      }
    },
    {
      ... // other game
    }
  ]
}

(1) All game statuses: https://github.com/ornicar/scalachess/blob/master/src/main/scala/Status.scala#L16-L25

GET /api/game/{id} fetch one game by ID

> curl http://en.lichess.org/api/game/x2kpaixn

A single game is returned. All parameters are optional.

name type default description
with_analysis 1 or 0 0 include deep analysis data in the result
with_moves 1 or 0 0 include a list of PGN moves
with_fens 1 or 0 0 include a list of FEN states
token string - security token (unlocks secret game data)
{
  "id": "39b12Ikl",
  "initialFen": "rkrqnnbb/pppppppp/8/8/8/8/PPPPPPPP/RKRQNNBB w KQkq - 0 1" // omitted is standard
  "variant": "chess960", // standard/chess960/fromPosition/kingofthehill/threeCheck
  "speed": "blitz", // bullet|blitz|classical|unlimited
  "perf": "chess960", // bullet|blitz|classical|chess960|kingOfTheHill|threeCheck
  "rated": true,
  "status": "mate", // (1)
  "clock":{          // all clock values are expressed in seconds
    "initial": 300,
    "increment": 8,
    "totalTime": 540  // evaluation of the game duration = initial + 30 * increment
  },
  "timestamp": 1389100907239,
  "turns": 44,
  "url": "http://lichess.org/x2kpaixn",
  "winner": "black",
  "players": {
    "white": {
      "userId": "thibault",
      "name": "Thibault D", // only in the case of imported game
      "rating": 1642,
      "analysis": {
        "blunder": 1,
        "inaccuracy": 0,
        "mistake": 2
      }
    },
    "black": ... // other player
  },
  "analysis": [ // only if the with_analysis flag is set
    {
      "eval": -26, // board evaluation in centipawns
      "move": "e4"
    },
    {
      "eval": -8,
      "move": "b5"
    },
    {
      "eval": -66,
      "move": "Nfe3",
      "variation": "c4 bxc4 Nfe3 c5 Qf1 f6 Rxc4 Bb7 b4 Ba6"
    },
    // ... more moves
  ],
  "moves": "Nf3 d5 g3 e6 Bg2 Be7 d3 Nf6 Nbd2 O-O O-O c6 Rfe1 b6 e4 Bb7", // with_moves flag
  "opening": { // with_opening flag
    "code": "A07",
    "name": "King's Indian Attack, General"
  }
  "fens": [ // only if with_fens flag is set
      "rnbqkbnr/pppppppp/8/8/8/5N2/PPPPPPPP/RNBQKB1R",
      "rnbqkbnr/ppp1pppp/8/3p4/8/5N2/PPPPPPPP/RNBQKB1R",
      "rnbqkbnr/ppp1pppp/8/3p4/8/5NP1/PPPPPP1P/RNBQKB1R",
      "rnbqkbnr/ppp2ppp/4p3/3p4/8/5NP1/PPPPPP1P/RNBQKB1R",
      "rnbqkbnr/ppp2ppp/4p3/3p4/8/5NP1/PPPPPPBP/RNBQK2R",
      "rnbqk1nr/ppp1bppp/4p3/3p4/8/5NP1/PPPPPPBP/RNBQK2R",
      // ... more fens
  ]
}

(1) All game statuses: https://github.com/ornicar/scalachess/blob/master/src/main/scala/Status.scala#L16-L25

GET /game/export/{id}.pgn fetch one game PGN by ID

http://en.lichess.org/game/export/Qa7FJNk2.pgn

This returns the raw PGN for a game.

[Event "Rated game"]
[Site "http://lichess.org/Qa7FJNk2"]
[Date "2014.06.12"]
[White "onpurplesz"]
[Black "LauraSchmidt"]
[Result "1-0"]
[WhiteElo "1516"]
[BlackElo "1698"]
[PlyCount "37"]
[Variant "Standard"]
[TimeControl "1020+0"]
[ECO "C50"]
[Opening "Italian Game, General"]
[WhiteClock ":11:9"]
[BlackClock ":14:6"]
[Annotator "lichess.org"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 { Italian Game, General } Qf6?! { (0.13 → 0.98) Inaccuracy. The best move was Nf6. } (3... Nf6 4. d3 Bc5 5. O-O O-O 6. Bg5 Be7 7. a3 d6 8. h3 a6) 4. d3 h6 5. Be3 d6 6. h3?! { (0.84 → 0.31) Inaccuracy. The best move was Nc3. } (6. Nc3 Be6 7. Nd5 Qd8 8. d4 exd4 9. Nxd4 Nxd4 10. Qxd4 c6 11. Nc3 Bxc4 12. Qxc4 Nf6 13. O-O Be7) 6... a6 7. Nbd2 Be6 8. Qe2 Bxc4 9. Nxc4 Nge7 10. a3 Nd4?! { (0.29 → 0.79) Inaccuracy. The best move was O-O-O. } (10... O-O-O 11. O-O g5 12. a4 Bg7 13. Bd2 Kb8 14. Rae1 Qe6 15. b4 f5 16. b5 fxe4) 11. Bxd4 exd4 12. O-O-O Nc6 13. Rhe1 O-O-O 14. e5 dxe5 15. Nfxe5 Nxe5 16. Qxe5 Qxe5? { (0.35 → 1.78) Mistake. The best move was Qxf2. } (16... Qxf2 17. Re2 Qf6 18. Qxf6 gxf6 19. Rf1 Bg7 20. Nd2 h5 21. Ne4 Rhe8 22. Ref2 Re5 23. b3 Rdd5 24. Kb2) 17. Nxe5 Rg8?! { (1.76 → 2.32) Inaccuracy. The best move was Rd7. } (17... Rd7 18. Nxd7 Kxd7 19. Re4 c5 20. c3 dxc3 21. bxc3 Bd6 22. Kc2 b5 23. a4 Ra8 24. d4 Kc6 25. dxc5) 18. Nxf7 Rd7? { (2.35 → Mate in 2) Checkmate is now unavoidable. The best move was Rd5. } (18... Rd5 19. Re8+ Kd7 20. Rde1 Bb4 21. Rxg8 Bxe1 22. Rxg7 Bxf2 23. Nxh6+ Kc6 24. Kd1 Rb5 25. b3 Rh5 26. Nf7) 19. Re8+ { Black resigns } 1-0

Credits

See the lichess Thanks page

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