Skill UI

This skill helps design and review API contract tests between providers and consumers. It focuses on verifying wire-level behavior during schema changes, compatibility regressions, and client integration failures. By using local fixtures and existing tools, it ensures type assertions alone are not validation. It classifies changes as breaking or compatible, builds test matrices for various scenarios, and verifies boundaries without provisioning new services.

Design and verify runtime progress output for Python, PowerShell, and Node.js batch scripts. Covers start, progress, per-item failures, summaries, stdout separation, and exit-status consistency.