This project is based on mattnite/zig-zlib. I also used [LukasKastern](Title fork for making project compatibile with 0.11 zig master.

There is existing deflate/gzip compressor/decompressor in zig standard library. For using it in websocket implementation I was missing ability to set window size (it is fixed on 32k) and sliding window functionality in decompressor.
It seams that most other websocket implementations are using zlib for deflate.

Refrences

Compression Extensions for WebSocket
zlib 1.2.13 Manual

Link

There is empty zig project (made with 'zig init-exe') in example/exe which illustrates how to link zlib library using zig package manager.

Add dependency in build.zig.zon:

    .dependencies = .{
        .zlib = .{
            .url = "https://github.com/ianic/zig-zlib/archive/9186b0f5fdfd6c29cd04f7ada7b0113fe1f63611.tar.gz",
            .hash = "122001cc3da638f9315f08fb51fe5aace68c254b59bcac3457e20d746565bad7fe04",
        },
    },

In build.zig link 'z' library and 'zlib' module:

    // Define dependencies
    const zlib = b.dependency("zlib", .{});

    ...

    // Link z library and zlib module.
    exe.linkLibrary(b.dependency("zlib", .{
        .target = target,
        .optimize = optimize,
    }).artifact("z"));
    exe.addModule("zlib", zlib.module("zlib"));

Notes

get zlib source into zlib folder:

wget https://github.com/madler/zlib/releases/download/v1.2.13/zlib-1.2.13.tar.gz
tar xvf zlib-1.2.13.tar.gz
rm zlib-1.2.13.tar.gz
mv zlib-1.2.13 zlib