api-and-interface-design

Define typed API contracts, error semantics, and boundary validation before implementation.

2|Updated May 3, 2026
One-click install
npx skills add https://github.com/Rosetears520/aili-workflows --skill api-and-interface-design-rosetears520
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: api-and-interface-design
Source: https://github.com/Rosetears520/aili-workflows/tree/main/skills/api-and-interface-design
Command: npx skills add https://github.com/Rosetears520/aili-workflows --skill api-and-interface-design-rosetears520

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

It solves the problem of fragile, inconsistent, or poorly defined interfaces that cause downstream breakage and misuse as your product evolves.

Core Features & Use Cases

  • Contract-first API design: Define typed inputs/outputs and interface behavior before implementation to reduce ambiguity and coupling.
  • Consistent error semantics: Standardize error formats and status-code mappings so consumers can reliably handle failures.
  • Boundary validation: Validate untrusted inputs and third-party responses only at system edges to keep internal logic clean and safe.
  • Backward-compatible evolution: Prefer additive changes over breaking modifications, aligning with real-world consumer expectations influenced by Hyrum's Law.

Quick Start

Use the api-and-interface-design skill to help you define a version-stable REST or GraphQL interface with typed contracts, consistent errors, and clear boundary validation for your new or changing endpoint.

Frequently Asked Questions about api-and-interface-design

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

FAQPage Schema
How do I design a stable REST or GraphQL API that doesn't break existing consumers?

Design a stable API by defining typed contracts and error semantics before implementation, preferring additive backward-compatible changes over breaking modifications to reduce consumer breakage risks.

What is boundary validation and when do I need it for API interface design?

Boundary validation in API interface design is the practice of validating untrusted inputs and third-party responses only at system edges to keep internal logic clean and safe.

How do I standardize error handling and status code mappings for my endpoints?

Standardize error handling by defining consistent error formats and status-code mappings during contract-first API design, ensuring consumers can reliably parse and handle failures across endpoints.

What's the best way to evolve an API version without causing downstream breakage?

The best way to evolve an API version without downstream breakage is to use additive backward-compatible changes, aligning modifications with real-world consumer expectations influenced by Hyrum's Law.

Does contract-first API design work for defining module boundaries and component props?

Yes, contract-first API design works for defining module boundaries and component prop interfaces by establishing explicit typing conventions and interface behavior before implementation.