Spec — Define What to Build
CRITICAL: Run HARNESS_DIR=$(epic-harness path) first. NEVER use .harness/ in the project directory.
Process
Understand the request
- Read any existing context (CLAUDE.md, README, codebase structure)
- If the request is vague, ask focused questions (max 3 at a time)
- Never assume — clarify ambiguity before proceeding
Produce the spec Write a concise spec covering:
- Goal: One sentence — what does this achieve?
- Scope: What's included and explicitly excluded
- Requirements: Numbered list (
R1,R2, ...) of concrete, testable behaviors - Acceptance criteria: Numbered list (
AC1,AC2, ...) — observable outcomes that prove each requirement is met - Technical notes: Constraints, dependencies, edge cases
Confirm with user Show the spec in digestible chunks. Get explicit approval before proceeding.
Output
Save the approved spec to $HARNESS_DIR/specs/SPEC-{timestamp}.md using this exact format:
---
status: approved
created: {ISO-8601 timestamp}
goal_slug: {kebab-case-goal-summary}
---
# SPEC-{timestamp}: {Goal}
## Goal
{One sentence}
## Scope
- In: {what is included}
- Out: {what is explicitly excluded}
## Requirements
- R1: {concrete testable behavior}
- R2: {concrete testable behavior}
## Acceptance Criteria
- AC1 (R1): {observable outcome proving R1}
- AC2 (R2): {observable outcome proving R2}
## Technical Notes
{Constraints, dependencies, edge cases}
After saving:
- Count the Requirements (R1, R2, ...). If 3 or more, check team status:
epic team status.- If no team is linked: suggest "This spec has N requirements. Consider running
/teamto set up a project-specific agent team before/go." - If a team is already linked: skip this hint.
- If no team is linked: suggest "This spec has N requirements. Consider running
- Tell the user: "Spec saved. Run
/goto start building."
Anti-Rationalization
| Excuse | Rebuttal | What to do instead |
|---|---|---|
| "It's a small change, I'll just code it" | Small changes still have wrong assumptions | Write the spec — it takes 2 minutes |
| "I'll refine the spec after coding" | Spec after code is documentation, not planning | Spec first, code second |
| "The user didn't give me enough detail" | Then ask — don't invent requirements | Ask focused questions, max 3 at a time |
Evidence Required
- Spec file exists at
$HARNESS_DIR/specs/SPEC-{timestamp}.md - Frontmatter has
status: approved - Every Requirement has at least one Acceptance Criterion
- ACs are observable (can be tested or verified)
Red Flags
- Writing code before the spec is approved
- Assuming requirements that weren't stated
- Producing a 3-page spec for a 1-line change
- Acceptance criteria that cannot be verified by a test or observation
- Skipping this phase for non-trivial features