ArgX

argX is a modular software library designed to simplify the handling of command-line arguments and subcommands in applications and scripts. It provides a consistent, language-agnostic approach to defining, parsing, validating, and formatting help text for CLI tools.

Key features include declarative argument schemas, type coercion, constraints and validators, automatic help and usage generation, and robust support for subcommands, mutually exclusive options, and dependencies between arguments. The library aims to reduce boilerplate, improve error messaging, and produce structured results that are easy to consume in host languages.

Architecture-wise, argX centers on a core parsing engine that processes a defined argument specification and returns a structured result. It offers adapters for multiple programming languages and plugin points for validators, formatters, and configuration sources. The design supports integration with environment variables, configuration files, and standard input streams, enabling flexible deployment in diverse environments.

History and scope, argX emerged from a collaborative open-source effort to standardize CLI interfaces and improve developer ergonomics. The project emphasizes backward compatibility within major releases, interoperability with existing tooling through portable schemas, and clear upgrade paths.

Usage typically involves declaring an argument schema in code or in a portable definition file, then running a runtime to parse user input and emit validated data along with detailed error messages when input is invalid. The project focuses on accessibility, consistent help text, and predictable behavior across platforms.