🏭 zopcua

A Zig wrapper for open62541, an open-source OPC UA implementation.

⚠️ Development Status

This library is under active development and NOT ready for production use.

• Requires Zig 0.14
• APIs are unstable and subject to change
• Limited feature coverage of the underlying open62541 library

Project Goals

This wrapper aims to make working with open62541 feel native to Zig by:

1. Adopting Zig idioms - Using error return types, tagged unions, and other Zig patterns instead of C conventions
2. Abstracting C complexities - open62541 uses bitfields extensively in some structs, requiring C wrapper functions for safe access

This library will not reach full feature parity with open62541 for some time. If you need functionality that isn't yet wrapped, please open an issue!

Documentation

📚 View the full API documentation

Installation

Add zopcua to your project:

zig fetch --save git+https://github.com/xentropic-dev/zopcua.git

Then in your build.zig:

const ua = b.dependency("zopcua", .{
    .target = target,
    .optimize = optimize,
});
exe.root_module.addImport("ua", ua.module("ua"));

mbedTLS Dependency

zopcua requires mbedTLS for cryptographic operations and secure communication. By default, mbedTLS is statically linked from vendored sources - no system installation required.

If you prefer to use system-installed mbedTLS libraries instead:

const ua = b.dependency("zopcua", .{
    .target = target,
    .optimize = optimize,
    .mbedtls = .system,  // Use system mbedTLS instead of vendored
});
exe.root_module.addImport("ua", ua.module("ua"));

When using system mbedTLS, ensure the libraries are installed:

• macOS: brew install mbedtls
• Ubuntu/Debian: sudo apt install libmbedtls-dev
• Other Linux: Use your distribution's package manager

Usage

const std = @import("std");
const ua = @import("ua");

pub fn main() !void {
    var server = try ua.Server.init();
    defer server.deinit();

    try server.runUntilInterrupt(); // Blocks here until Ctrl-C
}

Building

# Build the library (uses vendored mbedTLS by default)
zig build

# Build with system mbedTLS
zig build -Dmbedtls=system

# Run tests
zig build test

# Generate documentation
zig build docs

License

This wrapper library is licensed under the MIT License. See LICENSE for details.

The underlying open62541 library is licensed under the Mozilla Public License 2.0. See the open62541 repository for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.