Hat	Stage	Upstream gate	Output	Unblocks
Eng	Engineering	SPEC approved	engineering/outputs/tdd/TDD-NNN-<slug>.md	/ralph-workspace-plan

When to Use

SPEC is approved; user wants implementation-ready detail for ralph.

Prerequisites

• SPEC status: approved AND in .workbench-state/approved.json.

Protocol

1. Read SPEC (frontmatter + all sections).
2. For each repo in SPEC target_repos, identify concrete files to create or modify. Read repos/{name}/ (read-only) for existing layout.
3. Write engineering/outputs/tdd/TDD-{NNN}-{slug}.md with 9 sections: Summary, File map per repo (Action / File / Purpose table), Key interfaces (ts code blocks), Sequence diagrams (Mermaid), Data shapes (ref ERD), Failure handling matrix, Test outline, Observability additions, Open questions.
4. Update EPIC-PIPELINE.md — set TDD column.

Output Frontmatter

id: TDD-{NNN}
title: {title}
status: draft
created: {today}
owner: {gh-user}
epic: {EPIC_ID}
prd: PRD-{NNN}
spec: SPEC-{NNN}

File Map Table Shape

Action	File	Purpose
Create	src/adapters/in/http/…ts	REST entry point
Modify	src/core/services/….ts:45-120	new method

Do Not

• Leave “TODO” in the file map. Ask the user if uncertain.
• Copy-paste code from repos/* without citing original file and line range.

Source

skills/tdd/SKILL.md