ws

a lightweight WebSocket library for Zig ⚡

Features

• Only allocates for WebSocket handshake, message parsing and building does not allocate
• Ease of use, can be used directly with net.Stream
• Does buffered reads and writes (can be used with any other reader/writer too)
• Supports streaming output thanks to WebSocket fragmentation

Example

By default, ws uses the Stream interface of net namespace. You can use your choice of stream through ws.Client interface.

test "Simple connection to :8080" {
    const allocator = std.testing.allocator;

    var cli = try connect(allocator, try std.Uri.parse("ws://localhost:8080"), &.{
        .{"Host",   "localhost"},
        .{"Origin", "http://localhost/"},
    });
    defer cli.deinit(allocator);

    while (true) {
        const msg = try cli.receive();
        switch (msg.type) {
            .text => {
                std.debug.print("received: {s}\n", .{msg.data});
                try cli.send(.text, msg.data);
            },

            .ping => {
                std.debug.print("got ping! sending pong...\n", .{});
                try cli.pong();
            },

            .close => {
                std.debug.print("close", .{});
                break;
            },

            else => {
                std.debug.print("got {s}: {s}\n", .{@tagName(msg.type), msg.data});
            },
        }
    }

    try cli.close();
}

Planned

• WebSocket server support
• TLS support out of the box (tracks std.crypto.tls.Client)
• Request & response headers
• WebSocket Compression support

Acknowledgements

This library wouldn’t be possible without these cool projects & posts:

• truemedian/wz
• frmdstryr/zhp
• treeform/ws
• openmymind.net/WebSocket-Framing-Masking-Fragmentation-and-More
• Writing WebSocket servers

License

MIT License, check out.