go/interface-design

Design lean Go interfaces with consumer-side definitions and concrete return types.

3|1|Updated Feb 10, 2026
One-click install
npx skills add https://github.com/deandum/claude-resources --skill go-interface-design-deandum
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: go/interface-design
Source: https://github.com/deandum/claude-resources/tree/main/skills/go/interface-design
Command: npx skills add https://github.com/deandum/claude-resources --skill go-interface-design-deandum

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Go interface design guides developers to create lean, consumer-focused interfaces and prefer concrete return types to improve testability and maintainability.

Core Features & Use Cases

  • Small, focused interfaces reduce coupling and enable flexible implementations.
  • Guidance on when to introduce interfaces, how to compose them, and how to evolve APIs safely.
  • Use case: refactor a large interface into smaller, consumer-facing interfaces to simplify testing and composition.

Quick Start

Replace bloated interfaces with small, consumer-facing interfaces and prefer returning concrete types where possible.

Frequently Asked Questions about go/interface-design

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

FAQPage Schema
How do I design lean Go interfaces for better testability?▼

Design lean Go interfaces by creating small, consumer-focused interfaces and preferring concrete return types. This approach reduces coupling, improves maintainability, and enables flexible implementations in Go codebases.

When should I introduce interfaces in Go codebases?▼

Introduce interfaces in Go when you need to decouple components for testing or composition. Refactoring large interfaces into smaller, consumer-facing abstractions simplifies APIs and ensures compile-time correctness through static checks.

What is the best way to refactor a large Go interface?▼

The best way to refactor a large Go interface is to split it into smaller, consumer-facing interfaces. Apply interface segregation to reduce coupling, and prefer returning concrete types where possible to simplify testing and composition.

Why do my Go interfaces cause tight coupling?▼

Go interfaces cause tight coupling when they are bloated and defined on the producer side. Moving to small, consumer-side interfaces and returning concrete types reduces coupling and improves code maintainability.

Can I use generics to improve type safety in Go interface design?▼

Yes, using generics improves type safety in Go interface design. Combined with consumer-side interfaces and concrete return types, generics help verify correctness at compile time and ensure simple, well-typed APIs.