spae-build

Run the build phase after STATE.json shows phase build with an active task. The agent reads PLAN.md for the task's intent and acceptance criteria, writes failing tests first, implements minimal code, and sets the phase to check for verification.

Test-driven development for agents means writing a failing test for each acceptance criterion before any production code, then iterating until green. This Skill enforces exhaustive coverage of expected behavior, failure modes, and edge cases before handoff.

Yes, state persists in STATE.json and PLAN.md rather than conversational memory. Any agent harness can re-read these artifacts and resume the workstream at the current phase and active task.

The agent returns to implementation and re-verifies until all criteria pass. It only fails the task for out-of-scope conditions like an infeasible criterion, plan defect, or broken external dependency, making no STATE.json write on failure.

Avoid it for exploratory prototyping or one-off scripts where decomposition overhead exceeds the work itself. It fits structured, multi-task features where verifiability and resumability matter more than speed.