#chess #lichess

app fishnet

Distributed Stockfish analysis for lichess.org

17 stable releases

2.4.0 Sep 13, 2021
2.3.3 Jul 4, 2021
2.2.6 Feb 27, 2021
2.2.0 Dec 27, 2020
0.0.1 Nov 21, 2020

#18 in HTTP client

Download history 17/week @ 2021-06-27 15/week @ 2021-07-04 1/week @ 2021-07-11 23/week @ 2021-07-18 22/week @ 2021-07-25 42/week @ 2021-08-01 4/week @ 2021-08-08 42/week @ 2021-08-15 2/week @ 2021-08-22 27/week @ 2021-09-12 6/week @ 2021-09-19 23/week @ 2021-09-26 2/week @ 2021-10-03 29/week @ 2021-10-10

58 downloads per month


25K SLoC

C++ 19K SLoC // 0.2% comments Rust 3.5K SLoC // 0.0% comments JavaScript 703 SLoC // 0.0% comments Shell 565 SLoC // 0.1% comments Python 521 SLoC // 0.1% comments INI 316 SLoC // 0.5% comments

fishnet: distributed Stockfish analysis for lichess.org

crates.io Docker Build


  1. Request your personal fishnet key: https://lichess.org/get-fishnet

  2. Install and run the fishnet client.

    Download standalone binary

    Select the binary for your platform from the latest release and run it.

    # After download:
    chmod +x fishnet-x86_64-unknown-linux-gnu
    ./fishnet-x86_64-unknown-linux-gnu --auto-update

    Useful commands

    ./fishnet-x86_64-unknown-linux-gnu configure              # Rerun config dialog
    ./fishnet-x86_64-unknown-linux-gnu systemd --auto-update  # Print a .service file
    ./fishnet-x86_64-unknown-linux-gnu --help                 # List commands and options

    Other installation methods: From source, AUR, Docker, Kubernetes

  3. Pick an update strategy.

    Automatic updates

    Run with --auto-update as recommended above (will currently still require manual restarts on Windows due to #151).

    Subscribe to release announcements

    With a GitHub account, you can watch this repository (can be set to release announcements only). See the top right corner on this page.

Video introduction

Watch @arex explain fishnet.

Video introduction


Which engine does fishnet use?

fishnet uses Stockfish (hence the name) and Fairy-Stockfish for chess variants.

What are the requirements?

Available for 64-bit Intel and AMD ARMv8 / Silicon
Linux x86_64-unknown-linux-gnu build from source
Windows x86_64-pc-windows-gnu.exe
macOS x86_64-apple-darwin aarch64-apple-darwin
FreeBSD build from source
  • Needs an operating system from around 2016 or later
  • Will max out the configured number of CPU cores
  • Uses about 64 MiB RAM per CPU core
  • A small amount of disk space
  • Low-bandwidth network communication with Lichess servers (only outgoing HTTP requests, so probably no firewall configuration required)

Is my CPU fast enough?

Almost all processors will be able to meet the requirement of ~2 meganodes in 6 seconds. Clients on the faster end will automatically be assigned analysis jobs that have humans waiting for the result (the user queue, as opposed to the system queue for slower clients).

What happens if I stop my client?

Feel free to turn your client on and off at any time. By default, the client will try to finish any batches it has already started. On immediate shutdown, the client tries to inform Lichess that batches should be reassigned. If even that fails, Lichess will reassign the batches after a timeout.

Will fishnet use my GPU?

No, Stockfish is a classical alpha-beta engine. The neural network evaluation of Stockfish NNUE works efficiently on CPUs.

Is fishnet secure?

To the best of our knowledge. However you implicitly trust the authors and the GitHub infrastructure when running with --auto-update.

You can mitigate this by running fishnet as an unprivileged user.

cargo-crev is used to review the trustworthiness of dependencies.

Is there a leaderboard of contributors?

No, sorry, not publically. It would incentivize gaming the metrics.

Can I autoscale fishnet in the cloud?

There is currently no ready-made solution, but an API for monitoring the job queue status is provided.


Sequence diagram

See protocol.md for details. Also supports SSLKEYLOGFILE for inspection at runtime.


fishnet is licensed under the GPLv3+. See LICENSE.txt or ./fishnet-x86_64-unknown-linux-gnu license for the full license text.


~568K SLoC