cli-configuration

Configuration precedence establishes a layered hierarchy from lowest to highest priority: defaults, system config, user config, project config, environment variables, and CLI arguments. This ensures CLI overrides always win, environment variables override files, and project settings take precedence over system-wide defaults.

Parse multi-format configuration files by detecting format from file extension, then deserializing into a unified structure. Support TOML for simplicity, YAML for readability, and JSON for strict validation, merging all sources into a single resolved configuration object.

XDG Base Directory Specification defines standard paths for config ($XDG_CONFIG_HOME), data ($XDG_DATA_HOME), cache ($XDG_CACHE_HOME), and state ($XDG_STATE_HOME). Use these platform-agnostic directories to store and retrieve CLI configuration files consistently across Linux, macOS, and other Unix-like systems.

Yes. Environment variables occupy a higher precedence layer than config files but lower than explicit CLI arguments. This allows deployment-time overrides without modifying files, while preserving CLI flags as the ultimate override for one-off runs.

The deterministic precedence pipeline resolves conflicts by applying sources in strict order: later layers completely override earlier ones for matching keys. No merging occurs across precedence levels; the highest-priority source wins for each configuration key.

No. A unified configuration management pattern handles all CLI applications consistently: define defaults in code, layer user and project configs via standard directories, inject environment variables, and accept CLI arguments—all following the same precedence rules.