Specify

Specify - Requirements Before Design

Formalize requirements into structured specifications before architecture/planning. Focus exclusively on WHAT and WHY - never HOW.

Position in flow: /brainstorming → /specify → /clarify (auto) → /architecture-tech-lead → /task-planner

Arguments

• /specify "feature description" - Create new specification
• /specify --update - Update existing spec with new info
• /specify --status - Show spec completeness

Output

Creates .claude/specs/{YYYY-MM-DD}-{slug}/spec.md

Structure:

.claude/specs/2025-01-29-user-auth/
├── spec.md          # Main specification
└── clarifications/  # Resolved uncertainty log (created by /clarify)

Specification Process

1. Extract Short Name

From description, derive 2-4 word slug:

• Action-noun format: user-auth, email-validation, payment-flow
• Preserve technical terms
• Lowercase, hyphenated

2. Explore Context

Before writing spec:

• Check existing specs: ls .claude/specs/
• Review related code areas
• Understand current state

3. Write Specification

Load references/spec-template.md and populate sections.

Critical constraint: Spec describes WHAT users need and WHY. NO implementation details:

• No tech stack mentions
• No API designs
• No database schemas
• No framework references
• No code patterns

If tempted to write HOW, mark as [NEEDS CLARIFICATION: technical approach TBD] and move on.

4. Mark Uncertainties

For ANY ambiguity, use marker syntax:

- FR-003: System MUST validate user input [NEEDS CLARIFICATION: validation rules undefined]

Categories of uncertainty:

• Business logic - rules, thresholds, behaviors
• Scope boundaries - what's in/out
• Edge cases - error states, limits
• Technical - feasibility questions (arch-lead resolves these)
• User expectations - unclear acceptance criteria

5. Auto-Trigger Clarify

After writing spec, count markers:

grep -c "NEEDS CLARIFICATION" .claude/specs/*/spec.md

If count > 3: Invoke /clarify before proceeding.

If count <= 3: Note markers for arch-lead to address during research phase.

Spec Template Reference

See references/spec-template.md for full template. Key sections:

User Scenarios (Required)

## User Scenarios

### US1: [P1] Account Creation
**As a** new user
**I want to** create an account with email
**So that** I can access personalized features

**Why P1:** Core functionality, blocks all other features

**Acceptance Scenarios:**
- Given valid email and password, When I submit, Then account is created and confirmation sent
- Given existing email, When I submit, Then error shown with login link
- Given weak password, When I submit, Then requirements shown inline

Priority levels:

• P1 - Must have, blocks other work
• P2 - Should have, significant value
• P3 - Nice to have, defer if needed

Functional Requirements (Required)

## Functional Requirements

- FR-001: System MUST allow email/password registration
- FR-002: System MUST send confirmation email within 60 seconds
- FR-003: System MUST enforce password policy [NEEDS CLARIFICATION: policy rules]
- FR-004: System SHOULD support OAuth providers [NEEDS CLARIFICATION: which providers?]

Use MUST/SHOULD/MAY (RFC 2119):

• MUST - Absolute requirement
• SHOULD - Strong recommendation, exceptions need justification
• MAY - Optional, nice-to-have

Success Criteria (Required)

## Success Criteria

- SC-001: 95% of registrations complete without error
- SC-002: Confirmation emails delivered within 60 seconds (p95)
- SC-003: Password validation feedback in <100ms
- SC-004: Zero accounts created with invalid email format

Criteria MUST be:

• Measurable - specific numbers, not "fast" or "reliable"
• Verifiable - can write test/metric for it
• Technology-agnostic - no "Redis cache hit rate"

Out of Scope (Required)

## Out of Scope

Explicitly NOT part of this feature:
- Social login (separate spec)
- Account deletion (future work)
- Profile editing (separate spec)
- Admin user management

Prevents scope creep during implementation.

Quality Checks

Before finalizing spec, verify:

Handoff to Architecture

When spec is ready (markers <= 3 or clarified):

1. Commit spec: git add .claude/specs/ && git commit -m "spec: {slug}"
2. Invoke arch-lead: /architecture-tech-lead
3. Arch-lead reads spec, produces plan with technical decisions

Arch-lead resolves technical uncertainties during research phase.

Constraints

• NEVER include implementation details
• NEVER skip User Scenarios section
• NEVER use vague success criteria ("fast", "reliable")
• ALWAYS mark uncertainties explicitly
• ALWAYS include Out of Scope section
• Auto-trigger /clarify if >3 markers