api-and-interface-design

Name: api-and-interface-design
Availability: InStock
Author: cookeyholder

Define stable REST or GraphQL API contracts before implementation.

Updated Apr 9, 2026

Search Tags:#interfaces #validation #rest #graphql #contract-first #api-design

Ready to run

npx skills add https://github.com/cookeyholder/django-devcontainer-template --skill api-and-interface-design-cookeyholder

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: api-and-interface-design
Source: https://github.com/cookeyholder/django-devcontainer-template/tree/main/.agent/skills/api-and-interface-design
Command: npx skills add https://github.com/cookeyholder/django-devcontainer-template --skill api-and-interface-design-cookeyholder

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Design stable, well-documented interfaces that reduce misuse and coupling across services, teams, and components by establishing clear contracts before implementation.

Core Features & Use Cases

Contract-first design: define the interface before implementation to set the public surface.
Consistent error semantics: align error responses to a single, predictable format across endpoints.
Boundary validation: validate inputs at the API boundary to prevent internal leakage and ensure correctness.
Versioning and extension: prefer additive changes to maintain backward compatibility and minimize breaking changes.
REST/GraphQL guidance: standardize resource design, naming, pagination, and contracts across surfaces.

Quick Start

Define a sample contract-first interface for a REST or GraphQL endpoint to outline the public API before coding.

Frequently Asked Questions about api-and-interface-design

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is contract-first API design and when should I use it?▼

Contract-first API design defines the interface and public surface before implementation to reduce misuse and coupling. Use it when designing REST or GraphQL endpoints, module boundaries, or public interfaces across teams to establish clear contracts.

How do I design REST and GraphQL APIs that maintain backward compatibility?▼

Design REST and GraphQL APIs for backward compatibility by preferring additive changes over breaking modifications. This approach maintains stable contracts, standardizes resource design and pagination, and minimizes disruptions across services.

How do I standardize error responses across API endpoints?▼

Standardize API error responses by aligning them to a single, predictable format across all endpoints. This consistent error semantics approach reduces misuse and ensures predictable behavior across REST and GraphQL surfaces.

How do I validate API inputs at the boundary to prevent internal leakage?▼

Validate API inputs at the boundary to prevent internal leakage by enforcing contract-first rules. This boundary validation ensures correctness, stops invalid data from reaching internal services, and maintains interface stability.

Can I use this approach for defining module boundaries across teams?▼

Yes, you can use this approach for defining module boundaries across teams. It establishes clear public interfaces and stable contracts before implementation, reducing coupling and preventing misuse between different services and components.

What is the best way to version API contracts without breaking changes?▼

The best way to version API contracts without breaking changes is to prefer additive changes. This extension method maintains forward compatibility, stabilizes the public surface, and minimizes disruptions across REST or GraphQL endpoints.