Best API design skills for Claude Code, Codex and other agents.

Designs REST and GraphQL APIs from resource modeling to an OpenAPI 3.1 contract, with versioning, pagination and RFC 7807 error handling.

Jeffallan/claude-skills

This skill should be used when the user is writing Go code and needs guidance on Go-specific pedantry: error wrapping with fmt.Errorf and %w, interface design (accept interfaces return structs)…

chromedp/chromedp

Build production-ready Node.js backend services with Express/Fastify, implementing middleware patterns, error handling, authentication, database integration, and API design best practices.

ever-works/ever-works

Use whenever asked to add, create, or scaffold a CRUD endpoint, router, or entity in this repo's server (create/list/get/update/delete handlers, new…

fosrl/pangolin

Backend architecture patterns, API design, database optimization, and server-side best practices for Node.js, Express, and Next.js API routes.

hellangleZ/burn-in-cceverywhere-ralph

Guides stable API and interface design. An agent skill from dzhalaevd/Donatello.

dzhalaevd/Donatello

REST 및 GraphQL API 설계 원칙 가이드. An agent skill from jh941213/my-cc-harness.

jh941213/my-cc-harness

Reviews or designs an HTTP/JSON API's endpoints, auth, pagination, versioning and deprecations, guarding against inventing a bespoke interface or silently breaking consumers.

AmazingAng/old-coder

Designs REST and GraphQL APIs including endpoints, error handling, versioning, and documentation.

CloudAI-X/claude-workflow-v2

Covers developing the LangBot core backend and web UI: dev setup, repo layout, API auth types, adding endpoints, migrations and keeping the MCP server in step.

langbot-app/LangBot

Design, improve, and review interfaces for websites, apps, dashboards, and components: explore distinct design directions, compare styles side by side, and refine visual hierarchy against real…

oil-oil/oil-ui

Designs GraphQL schemas and Apollo Federation graphs, with DataLoader resolvers, subscriptions, query complexity limits and caching.

Jeffallan/claude-skills

This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or…

OpenHands/OpenHands

Reviews REST API design for correct HTTP verbs, versioning, DTO use, consistent responses and backward compatibility before an API change ships.

decebals/claude-code-java

Applies extend-only design rules to NuGet packages and distributed systems, covering source, binary and wire compatibility and how to deprecate members safely.

Aaronontheweb/dotnet-skills

Comprehensive code review for Java - clean code principles, API contracts, null safety, exception handling, and performance.

piomin/claude-ai-spring-boot

Review changes to Polar's API contract — Pydantic schemas, FastAPI endpoints, OpenAPI output and the generated SDKs.

polarsource/polar

Design or review software architecture, API contracts, data models, and module boundaries for the Static Web Server (SWS) project

static-web-server/static-web-server

A skill your agent uses when: generating TypeScript API layer (type definitions + request functions) from page-spec JSON or Swagger/OpenAPI docs.

ChenyCHENYU/Robot_Admin

A skill your agent uses when reviewing a proposed REST or GraphQL API change before merge — checks contract clarity, backwards compatibility, errors, pagination, auth, and naming.

oxbshw/LLM-Agents-Ecosystem-Handbook

Software design philosophy guide based on John Ousterhout's "A Philosophy of Software Design." Use this skill during: code reviews, architecture discussions, API design, module decomposition…

luoling8192/software-design-philosophy-skill

Step-by-step guide for implementing AndroidX WebKit APIs in frameworks/support/webkit/ after boundary interface roll.

androidx/androidx

Entry point for building an MCP server: asks about the use case, picks a deployment model and tool-design pattern, then hands off to more specialized skills.

anthropics/claude-plugins-official

Guides REST and GraphQL API design, endpoint patterns, request/response schemas, versioning, and API best practices.

CloudAI-X/opencode-workflow

A skill your agent uses when debugging UE C++ crashes, runtime bugs, or unexpected behavior with Rider MCP available.

JasonMa0012/MooaToon

R package development guide covering dependencies, API design, testing, and documentation.

ab604/claude-code-r-skills

Define implementation contracts (APIs and data models) that developers will build against during PRD v0.6 Architecture.

mattgierhart/PRD-driven-context-engineering

Assesses what an API change would break before it is made, finds every usage, documents the impact and plans a deprecation or migration path.

ruby-git/ruby-git

Design or review REST and GraphQL API interfaces. An agent skill from agulli/atlas-agents.

agulli/atlas-agents

API route implementation patterns with RLS, validation, and error handling. Use when creating API routes, implementing CRUD endpoints, adding…

bybren-llc/safe-agentic-workflow

Reviews API design, REST conventions, and backend architecture.

DanielPodolsky/ownyourcode

Maintain portable Feature Track docs for project features. An agent skill from JunsW/feature-track.

JunsW/feature-track

Generate multiple radically different interface designs for a module using parallel sub-agents.

fossasia/eventyay-interpretation

Checklist for adding, changing, deprecating or removing Saleor GraphQL fields, mutations, enums and webhook event types so the change passes review first time.

saleor/saleor

Routes backend work in the Superloopy loop harness to the right reference module, covering API contracts, schema migrations, transactions, background jobs, caching and security.

beefiker/superloopy

Idiomatic Go - package and interface design, error wrapping, table-driven tests, generics, the modern standard library (slices/maps/cmp/errors.Join), current syntax, and logging discipline.

inference-gateway/inference-gateway

A skill your agent uses when optimizing, refactoring, reviewing, or fixing AtomUI controls, including control API contracts, member layout, file splitting, lifecycle, AXAML structure, correctness…

AtomUI/AtomUI

当设计或修改 REST API 响应结构、处理 API 返回值，或生成 Excel/CSV/PDF/对账文件等下游产物时触发。防止 API 设计缺陷导致的字段错位、类型歧义，以及生成产物时关键字段缺失但静默成功的问题。

doccker/cc-use-exp

Apple's approach to interface design and fluid, physical motion, translated for the web.

flornkm/personal-site

Idiomatic Go conventions — naming, error handling, concurrency, interfaces, testing, and API design.

asymmetric-research/solana-exporter

Write modern, high-performance C code using records, pattern matching, value objects, async/await, Span<T/Memory<T, and best-practice API design patterns.

sketch7/FluentlyHttpClient

A skill your agent uses when you need to add or review fuzz testing for Java APIs with CATS — including contract-driven negative testing, malformed payload validation, boundary input exploration, CI…

jabrena/plinth

REST API design principles and best practices. An agent skill from cohen-liel/hivemind.

cohen-liel/hivemind

Guidelines for reviewing API design in the Hex1b codebase. An agent skill from mitchdenny/hex1b.

mitchdenny/hex1b

Builds and designs React Native Nitro Modules with Nitrogen, HybridObject TypeScript specs, Nitro View components, generated native implementations, zero-copy and native-state APIs, Swift/Kotlin/C++…

margelo/react-native-skills

Comprehensive Rust coding guidelines with 265 rules across 26 categories.

JMBeresford/retrom

Evaluates system boundaries and tradeoffs and writes architecture recommendations, option comparisons or ADRs, with a Mermaid diagram when structure changes.

first-fluke/oh-my-agent

Generate, build, and test Azure SDKs locally from TypeSpec with automatic customization.

Azure/azure-sdk-for-android