SOTA CLI & Developer-Tool UX

Purpose

Expert-level rules for building and auditing command-line tools: the grammar of commands/flags/args, config layering, human-vs-machine output, TTY-aware interaction, exit codes, signal handling, lifecycle behavior, and distribution. The core thesis: a CLI has three users — a human at a TTY, a script in CI, and an AI agent driving the tool (a stricter script) — and every design decision must serve all three without flags-gymnastics. Rules are imperative with rationale and good/bad terminal examples; every rules file ends with an audit checklist. Load only the files relevant to the task via the index below.

BUILD mode

When designing or implementing a CLI: