Api Design Principles

What it does

This skill helps you design, refactor, and review REST and GraphQL APIs to ensure they are intuitive, scalable, and maintainable. It guides you through key considerations like defining consumers, choosing API styles, specifying errors, and establishing versioning strategies. The skill leverages a detailed implementation playbook with patterns, checklists, and templates to aid in the process.

When to use it

• Designing new REST or GraphQL APIs from scratch.
• Refactoring existing APIs to improve usability and maintainability.
• Establishing API design standards for your development team.
• Reviewing API specifications before implementation begins.
• Migrating between different API paradigms, such as from REST to GraphQL.

Key capabilities

• Guidance on defining consumers, use cases, and constraints for APIs.
• Assistance in choosing appropriate API styles (REST or GraphQL).
• Support for specifying error handling, versioning, pagination, and authentication strategies.
• Access to detailed patterns, checklists, and templates via the resources/implementation-playbook.md file.

Example prompts

• "I'm designing a new REST API for managing user profiles. What are some key design principles I should consider?"
• "We want to migrate our existing REST API to GraphQL. Can you guide me through the process and highlight potential challenges?"
• "Our team needs to establish API design standards. What are some essential elements we should include?"

Tips & gotchas

• This skill is most effective when designing or modifying APIs, not for implementation guidance within a specific framework.
• Always validate the output with environment-specific testing and expert review – do not treat it as a complete solution.
• If you're unsure about inputs, permissions, safety boundaries, or success criteria, stop and ask for clarification.