cutechess-engines.json(5)

CUTECHESS-ENGINES.JSON(5)

File Formats Manual

CUTECHESS-ENGINES.JSON(5)

NAME

cutechess-engines.json — Cute Chess engine configuration file

DESCRIPTION

cutechess-engines.json is the chess engine configuration file for cutechess-cli(6). An engine configuration defines a name, a command, a working directory and many other options. Engine configurations can be used in cutechess-cli(6) with the conf command-line option.

Engine configurations are defined in JavaScript Object Notation (JSON) format. See JSON FORMAT.

JSON FORMAT

JavaScript Object Notation (JSON) is a text-based format for structured data. JSON is a subset of ECMAScript (JavaScript).

Values

A JSON value must be one of: object, array, number, string, false, true or null.

Objects

An object is structure of name-value pairs enclosed in curly brackets. A name is a string. Name and value are separated by a single colon. Pairs are separated by commas.

Example objects would be:

{ "Finland" : ".fi", "Sweden" : ".se" }

{
  "firstName" : "JC",
  "lastName"  : "Denton",
  "age"       : 28,
  "languages" : [ "English", "French", "Spanish" ]
}

Arrays

An array is a structure of zero or more values enclosed in square brackets. Values are separated by commas.

Example arrays would be:

[ "Cute", "Chess" ]

[
  [ 1, 0, 0 ],
  [ 0, 1, 0 ],
  [ 0, 0, 1 ]
]

Numbers

A number consists of an integer part and optional fractional and/or exponent part. The integer part can be prefixed with a minus sign. Fractional part is a decimal point followed by one or more digits. Exponent part begins with a letter E in upper or lowercase which may be followed by a plus or minus sign. The E and optional sign are followed by one or more digits.

Octal and hex forms are not allowed.

Example numbers would be:

128
-1.04
2e32
-18E-20

Strings

A string is sequence of characters enclosed in quotation marks. All Unicode characters may be placed within the quotation marks except for the characters that must be escaped: quotation mark, backslash, and control characters.

Available two-character escape sequences are as follows:

\\: Backslash character.
\/: Forward slash character.
\": Quotation mark.
\b: Bell character.
\f: Form feed character.
\n: Line feed character.
\t: Vertical tab character.
\unum: Unicode character where num is a four hexadecimal digits that encode the character's code point.

Example strings would be:

"Hello, world!"

"Please place all items \"carefully\" in bins."

"\u03a6 is one of the letters of Greek alphabet."

ENGINE CONFIGURATION

The configuration file consist of an array of objects. Each object defines a single engine configuration. Required options for each engine configuration are:

name : string: The name of the engine.
command : string: The engine command.
protocol : "uci" | "xboard": The chess engine protocol used by this engine.

Other available options for an engine configuration are:

workingDirectory : string: The working directory of the engine.
stderrFile : string: File where the engine's standard error output is redirected.
initStrings : array of string: Array of strings sent to the engine's standard input at startup.
whitepov : true | false: When true invert the engine's scores when it plays black. The default is false.
This option should be used with engines that always report scores from white's perspective.
ponder : true | false: When true enable pondering if the engine supports it. The default is false.

EXAMPLES

A minimal engine configuration file for the Sloppy chess engine:

[
  {
    "name": "Sloppy",
    "command": "sloppy",
    "protocol": "xboard"
  }
]

Using the above engine configuration file with the conf command-line option:

$ cutechess-cli -engine conf=Sloppy
  -engine conf=Sloppy -each tc=40/60 -rounds 10