What problem does it solve? Turning an agreed implementation plan into working code often drifts into scope creep, broken builds, and untested changes. This Skill enforces disciplined, test-driven execution so every step leaves the system green and committable. ## Core Features & Use Cases - Tracer-bullet TDD: Drives each slice with one failing test, minimal passing code, then refactoring only while green, including the Prove-It reproduction pattern for bugs. - Repo-native workflow: Reads AGENTS.md guidance and the repo's own Makefile, package.json, or CI commands instead of assuming a toolchain. - Slice-based commits: Breaks the plan into the smallest independently testable increments and commits each one green, surfacing plan gaps instead of silently redesigning. - Use Case: After a planning phase produces a task list for adding request validation to an API, use this Skill to implement each task with failing tests first, keeping the build green until the full suite passes. ## Quick Start Use the implement skill to execute the plan from the plan phase, building each task test-first and committing only green slices.