What problem does it solve? Teams with an approved technical plan often struggle to execute it with disciplined test-first development, losing track of progress across phases or writing tests after the code already exists. This Skill drives a plan from context/changes/<change-id>/plan.md through red-green-refactor cycles, one phase at a time, while keeping execution state in the plan's Progress section. ## Core Features & Use Cases - Phase-by-phase TDD loop: For each eligible phase, writes a failing test first, implements the minimal code to pass, then refactors while staying green. - Eligibility gating: Detects phases where implementation already exists or where test-first does not fit (scaffolding, infra, visual polish) and redirects them to /10x-implement instead of forcing low-value tests. - Shared progress tracking: Mutates the same ## Progress section as /10x-implement, so phases can be interleaved between the two skills without losing state, with commit SHAs written back at phase end. - Use Case: A developer has an approved plan for adding OAuth login with four phases. They run /10x-tdd oauth-login phase 1, and the Skill writes failing tests for the token validation logic, implements it minimally, commits the phase, and hands off a resume command for the next phase. ## Quick Start Run /10x-tdd with a change-id such as "/10x-tdd oauth-login phase 1" to start driving that approved plan test-first from its Progress section.
