What problem does it solve? When extending a CLI with deterministic, model-free commands, the command documentation, the skill wrapper, and the underlying script can drift apart — signatures mismatch, exit codes go undocumented, and parsing logic leaks into the wrong layer. This Skill enforces the authoring discipline that keeps the provenance file, the wrapper, and the script consistent. ## Core Features & Use Cases - Provenance file authoring: Records the exact invocation signature — every argument, flag, and default — matching the script character-for-character. - Thin wrapper discipline: Keeps all parsing, validation, and rendering logic in the invoked script while the wrapper only resolves context (feature directory, target script) and shells out. - Exit-code contract mapping: Maps every documented exit code to a real script path and every script failure to a documented code, including fail-loudly-on-unsupported-input behavior and explicit hook registration statements. - Use Case: When adding a new /speckit-git-cleanup-style command to a Spec Kit extension, use this Skill to produce the speckit.<name>.md provenance file and the paired SKILL.md wrapper with a complete, verifiable exit-code table. ## Quick Start Author the command provenance file and thin skill wrapper for a new deterministic CLI command that resolves the feature directory and shells out to its script.
