Introduction to args.zig

args.zig is a modern, high-performance command-line argument understanding library for Zig, designed to be powerful yet easy to use. Inspired by Python's argparse, it brings a fluent and intuitive API to the Zig ecosystem while maintaining zero-allocation efficiency where possible.

Why args.zig?

Building a CLI tool should be straightforward. You shouldn't have to fight with complex boilerplate or compromise on features just to parse flags and options. args.zig fills the gap by providing a production-grade parser that handles:

• Complex parsing logic: Flags, options with values, subcommands, and mixed arguments.
• Developer experience: Fluent builder pattern, clear error messages, and automatic help generation.
• End-user experience: Auto-suggestions for typos ("Did you mean...?"), colored output, and shell completions.
• Performance: Optimized utility functions to minimize allocations and overhead.

Key Features

• 🚀 Lightning Fast: Built with efficiency in mind.
• 🎯 Intuitive and Fluent API: Readable code that clearly defines your CLI structure.
• 📋 Declarative Structs: Parse directly into Zig structs with parseInto for rapid prototyping.
• 🔄 Subcommands: Infinite nesting of commands (e.g., git remote add ...).
• 🔤 Shell Completions: Generate scripts for Bash, Zsh, Fish, Nushell and PowerShell.
• 🌍 Environment Variables: Seamless fallback to specific environment variables.
• ✨ Auto-Generated Help: Beautiful, consistent, and colorized help text.
• 🛡️ Robust Validation: Type checking, choices, numeric ranges, and custom validation functions.
• 🔔 Update Checker: Optional integration to notify users of new releases.

Design Philosophy

The library is built around a few core principles:

1. Correctness first: Strict parsing rules by default (with permissive options).
2. Helpful errors: When a user makes a mistake, guide them to the solution.
3. Zig-idiomatic: Uses standard Zig patterns for memory management (allocators) and error handling.

Who is this for?

Whether you are building a small utility script, a complex developer tool, or a large-scale application, args.zig scales with your needs.

Ready to start? Check out the Installation guide.