Requirements Engineering Skill

A Claude Code skill that transforms vague or incomplete requirements into well-defined, testable specifications using BDD, Use Cases, Model Specs, Payload Contracts, flowcharts, and architecture diagrams. Based on the Essential Developer methodology.

Who is this for?

Anyone who encounters vague requirements and needs to transform them into implementable specifications:

• Product Managers defining feature requirements
• Software Teams bridging business and technical needs
• Developers needing clear specs before writing code
• Technical Writers structuring project documentation

Installation

Install via skills.sh:

npx skills add SwiftyJourney/requirements-engineering-skill

Compatible Agents

• Claude Code
• Cursor
• GitHub Copilot
• Windsurf
• Any agent supporting the skills/ convention

What the Skill Covers

The 7 Feature Specification Artifacts

Every feature specification includes these artifacts:

1. BDD Narrative — Define who, what, why per user type
2. Acceptance Criteria — Given/When/Then scenarios
3. Use Cases — Step-by-step system behavior (Data/Primary/Error/Cancel)
4. Model Specs — Property/Type tables for domain entities
5. Payload Contract — HTTP method + path + response JSON
6. Flowchart — Decision flow with error branches
7. Architecture Diagram — Module dependency graph

The 6-Step Process

1. Identify — Recognize vague requirements
2. Clarify — Ask Who/What/Where/When/Why/How
3. Specify BDD — Write narratives and acceptance criteria
4. Define Use Cases — Procedural steps with cancel courses
5. Model & Contract — Property/Type tables and JSON payloads
6. Visualize & Document — Diagrams and feature specification

Key Patterns from Essential Developer

• Cancel courses — First-class cancellation requirements for async operations
• Separation of concerns — Extract focused use cases (Load vs Validate vs Cache)
• Domain language alignment — Consistent terminology across all artifacts
• Incremental feature development — Self-contained feature blocks
• Living specification — Requirements evolve with code

Skill File Structure

requirements-engineering/
├── SKILL.md                             # Hub (~140 lines)
└── references/
    ├── _index.md                        # Navigation hub
    ├── bdd-narratives.md                # BDD stories, narratives, acceptance criteria
    ├── use-cases.md                     # Use case structure, courses, separation of concerns
    ├── model-specs-and-contracts.md     # Model specs, payload contracts, JSON examples
    ├── diagrams.md                      # Flowcharts, architecture, sequence, state diagrams
    ├── domain-language.md               # Terminology alignment, renaming patterns
    └── feature-specification-workflow.md # End-to-end workflow, traceability

Related Skills

• ios-architecture-expert — Clean architecture, composition root, generic presenters

Credits

Requirements methodology extracted from the iOS Lead Essentials program by Essential Developer. The Essential Feed Case Study README demonstrates the canonical artifact format.

License

MIT — see LICENSE.