Specify - Functional Specifications

Overview

Create detailed functional specifications focusing on what you're building and why, not the technical implementation details.

Announce at start: "I'm using the specify skill to create functional specifications."

When to Use

• •After establishing project constitution
• •Before creating technical implementation plans
• •When defining new features or requirements
• •When clarifying user needs and business requirements

The Process

Step 1: Understand Requirements

1. •Review project constitution (.specify/memory/constitution.md)
2. •Understand the user's intent and requirements
3. •Focus on WHAT and WHY, not HOW

Step 2: Create Specification

Create specification in specs/<feature-id>/spec.md following the template:

Required Sections:

1. •

   Feature Overview

   • •Feature name and ID
   • •High-level description
   • •Business value and motivation
2. •

   User Stories

   • •As a [user type]
   • •I want to [action]
   • •So that [benefit]
   • •Acceptance criteria
3. •

   Functional Requirements

   • •Core functionality
   • •Edge cases
   • •Error handling
   • •Data validation rules
4. •

   Non-Functional Requirements

   • •Performance requirements
   • •Security requirements
   • •Accessibility requirements
   • •Compatibility requirements
5. •

   Constraints and Assumptions

   • •Technical constraints
   • •Business constraints
   • •Assumptions about users/environment
6. •

   Review & Acceptance Checklist

   • •Requirements completeness
   • •Clarity and specificity
   • •Testability
   • •Consistency with constitution

Step 3: Create Feature Branch

• •Create git branch: 001-<feature-name> (or next sequential number)
• •Commit specification to branch
• •Use Superpowers/using-git-worktrees if needed for isolated workspace

Step 4: Validate Specification

Ask user to review:

• •Are all requirements captured?
• •Are user stories clear and testable?
• •Are edge cases covered?
• •Does it align with project constitution?

Example Prompt

/speckit.specify Build an application that can help me organize my photos in separate 
photo albums. Albums are grouped by date and can be re-organized by dragging and dropping 
on the main page. Albums are never in other nested albums. Within each album, photos are 
previewed in a tile-like interface.

Output Structure

specs/
└── 001-<feature-name>/
    └── spec.md

Key Principles

• •Be explicit: Describe WHAT and WHY clearly
• •Don't specify tech stack: Leave implementation details for planning phase
• •User-centric: Focus on user needs and benefits
• •Testable: Requirements should be verifiable
• •Complete: Cover all aspects (happy path, edge cases, errors)

Integration with Other Skills

After creating specification:

• •Use SpecKit/clarify to clarify any underspecified areas
• •Use SpecKit/plan to create technical implementation plan
• •Use Superpowers/brainstorming if design exploration is needed

Common Mistakes to Avoid

• •❌ Specifying implementation details (tech stack, algorithms)
• •❌ Vague requirements ("should be fast", "user-friendly")
• •❌ Missing edge cases or error scenarios
• •❌ Mixing requirements with design decisions
• •❌ Skipping user stories or acceptance criteria