Spec Driven Development Skill
Use this skill when the user asks to implement a feature. This workflow ensures proper planning and approval before any code is written.
Workflow
Follow these steps in order. Do not skip steps. Always ask for explicit approval before moving to the next step.
Step 1: Create Feature Directory
Create a feature directory under .specs/{feature_name} using kebab-case for the name.
Step 2 (Optional): Create Requirements Document
This step is opt-in and must be explicitly requested by the user.
If the user requests requirements, create requirements.md in the feature directory with:
- Introduction - Brief context and purpose of the feature
- User Stories & Acceptance Criteria - Written in EARS (Easy Approach to Requirements Syntax) style
Example EARS patterns:
- Ubiquitous: "The [system] shall [action]"
- Event-driven: "When [event], the [system] shall [action]"
- State-driven: "While [state], the [system] shall [action]"
- Optional: "Where [condition], the [system] shall [action]"
- Unwanted behavior: "If [condition], then the [system] shall [action]"
Example structure:
# Requirements
## Introduction
[Brief context about what this feature addresses and why it's needed]
## User Stories & Acceptance Criteria
### US-1: [User Story Title]
**As a** [role], **I want** [goal], **so that** [benefit].
**Acceptance Criteria:**
- When [user action], the system shall [expected behavior]
- While [state], the system shall [maintain condition]
- Where [optional condition], the system shall [handle appropriately]After creating the requirements document, refine it:
- Scan for missing requirements — Review the document for gaps such as missing edge cases, undefined behavior, unspecified error handling, unclear scope boundaries, missing performance constraints, or unaddressed user roles/permissions.
- Identify ambiguities — Flag any requirements that could be interpreted in multiple ways, have vague language (e.g., "fast", "simple", "flexible"), or lack concrete acceptance criteria.
- Ask clarifying questions — Present the user with a clear list of questions covering the missing and ambiguous areas. Group them logically and explain why each question matters.
Do not proceed until all critical ambiguities are resolved. Minor open questions can be noted as assumptions in the design document.
If requirements are created, get approval before proceeding to the design document.
Step 3: Create Design Document
Create design.md in the feature directory with:
- Overview - High-level description of the solution
- Architecture / Components - System structure and component interactions
- Data Models - Schemas, types, and data structure
- Testing Strategy - Approach to testing the feature
Show the code snippets of the core parts of the implementation in the design.
We prioritize integration testing, and show a couple of test snippets as example of testing strategy.
After creating the design document, refine it:
- Scan for missing requirements — Check whether the design covers all stated requirements and user stories. Identify any requirements that were dropped, under-specified, or only partially addressed.
- Identify ambiguities — Flag design decisions that are vague or leave open questions about behavior, data flow, or component responsibilities.
- Ask clarifying questions — Present the user with questions about any gaps or ambiguities discovered. Explain how each gap could affect implementation.
Do not proceed until all critical gaps are resolved. Minor open questions can be noted as assumptions.
Step 4: Design Approval Gate
Ask the user: "Does the design look good? If so, we can move on to the implementation plan."
Wait for explicit approval before proceeding.
Step 5: Create Tasks Document
Once design is approved, create tasks.md in the feature directory with:
- Numbered checklist of coding tasks
- Each task should reference specific design components
- Include only coding tasks - no deployment, documentation, or other non-coding tasks
Example structure:
# Implementation Tasks
## Tasks
- [ ] 1. Create data model for [entity]
- [ ] 2. Add API endpoint for [action]
- [ ] 3. Implement validation logic
- [ ] 4. Add unit tests for [component]
- [ ] 5. Add integration tests for [feature]Step 6: Tasks Approval Gate
Ask the user: "Do the tasks look good?"
Wait for explicit approval.
Step 7: Stop
Do not implement any code. The workflow ends here. Implementation should be a separate activity initiated by the user.
Important Rules
- Never skip steps - Each step builds on the previous one
- Always get approval - Do not proceed without explicit user confirmation
- No implementation - This workflow is for planning only
- Kebab-case naming - Feature directories use kebab-case (e.g.,
user-authentication)