Project
Weiawaga
Weiawaga is a UCI chess engine written in Rust which plays at superhuman strength. You can face it yourself on Lichess, where it has played well over a hundred thousand rated games. The current release is around 3400 Elo on the CCRL scale, although since I so infrequently release new “official” versions the CCRL Elo is usually significantly weaker than the development version Elo. The engine’s name comes from the Rhinemaidens’ first line in Wagner’s Das Rheingold.
The site and the engine share a name. Whichever one you were looking for, you found it.
On Lichess
The bot account has been on Lichess since September 2020. It runs on a Raspberry Pi and plays through asyncLio-bot, my own bridge between UCI engines and Lichess. Its opponents are almost always other engines.
Releases
Releases are rare, and so each one has tended to be a large jump in strength.
- v4.0, January 2022. The first release with multithreading.
- v5.0, April 2022. The first release with a neural network evaluation, about 350 Elo stronger than v4.0.
- v6.0, August 2025. The first release in a few years, with a new network and a long list of search changes.
Building and running
The network is embedded in the binary at compile time. The build script reads a pinned filename and SHA-256 from net.txt, downloads that network from nets.weiawaga.me if it is not already cached, verifies the hash, and compiles it in, so a release build is fully self-contained. Point any UCI interface at the binary, or use a prebuilt release. v6.0 ships baseline and AVX2 builds for Linux and Windows and a baseline build for macOS.
Links
- Repository
- Lichess bot profile
- Releases
- Mimir, the NNUE trainer
- asyncLio-bot, the Lichess client
Licensed under the GPL, version 3 or later.