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Asymptote is a UCI (Universal Chess Interface) chess engine. Currently it does not implement the complete UCI specification, e.g. pondering is currently not supported.

Asymptote does not include a graphical user interface. You need a UCI-compliant GUI like Cutechess or Arena to play against Asymptote.

The UCI options currently supported (as reported by the uci command) are:

> uci
< id name Asymptote 0.6.3
< id author Maximilian Lupke
< option name Hash type spin default 1 min 0 max 16384
< option name Threads type spin default 1 min 1 max 64
< option name ShowPVBoard type check default false
< option name MoveOverhead type spin default 10 min 0
< uciok

Options in general are case-insensitive.

  • Hash: size of the transposition table in megabytes. If it's not a power of two, it will be rounded down to the nearest power of two, i.e. 1000 -> 512.
  • Threads: number of cpu's to use. Whether there is any benefit in using logical (hyperthreading) rather than physical cores is unclear.
  • ShowPvBoard: if set to true, Asymptote will print the board at the end of the current pv (principal variation) each time the pv is updated.

Rust version

Asymptote is developed on the Rust stable channel. There is not guaranteed minimum working version, except the latest stable release.


Several versions of Asymptote have been tested by computer chess engine testers.

Version CCRL 40/4 CCRL 40/40
v0.6 2857 2816
v0.5 2652 2653
v0.4.2 2598 2582
v0.3 2488 2502
v0.2.0 2314 2314
v0.1.8 2176 2179

(last updated July 11, 2019)

Always up-to-date information can be found at the respective websites:

Thanks to every tester!