CLI Development Guidelines

When to activate this skill

• You are designing, implementing, or reviewing a command-line tool.
• The user mentions (explicitly or implicitly): --help, flags, subcommands, exit codes, stdout/stderr, piping, JSON output, color, prompts, config files, env vars, “works in CI”, install/uninstall, telemetry.

What this skill produces

• A CLI contract (what users can rely on): commands, flags, IO behavior, exit codes, config/env, examples, and safety behavior.
• Draft help output and docs structure (example-first).
• A compliance audit (when runnable) using scripts/cli_audit.py.

Non-negotiable CLI citizenship

• Exit codes:
  • 0 on success.
  • Non-zero on failure (and ideally meaningful, documented codes).
• Streams:
  • stdout is for primary output and machine-readable output.