1,418 free skills
API Design skills
Skills for designing APIs — REST conventions, GraphQL schema design, versioning strategy, rate limiting, and OpenAPI contracts.
Sourced from real, public repositories — synced daily, never invented.
1,418 free skills
Skills for designing APIs — REST conventions, GraphQL schema design, versioning strategy, rate limiting, and OpenAPI contracts.
Sourced from real, public repositories — synced daily, never invented.
15 tools across six categories
13 of them never send your data anywhere
Free · No signup · No trial clock
SEE THE DIRECTORY
lark-event
larksuite/cli
Lark/Feishu real-time event listening / subscribing / consuming: stream events as NDJSON via `lark-cli event consume <EventKey>` (covers IM messages/reactions/chat changes, Approval status changes, Task updates, VC meeting started/joined/ended, Minutes generated, Whiteboard updated, etc.). Use for Lark bots, real-time message processing, long-running subscribers, streaming webhook/push handlers. Supports `--max-events` / `--timeout` bounded runs and a stderr ready-marker contract — designed for AI agents running as subprocesses.
lark-contact
larksuite/cli
飞书 / Lark 通讯录:按姓名 / 邮箱解析成 open_id,或按 open_id 反查姓名 / 部门 / 邮箱 / 联系方式 / 个人状态 / 签名,以及按关键词搜索当前用户可见的机器人 / 智能体(agent)。当用户提到一个名字要下一步发消息 / 排日程,或拿到 open_id 想查具体信息时使用。不负责部门树遍历、按部门列员工、组织架构图,这类需求走原生 OpenAPI。
lark-openapi-explorer
larksuite/cli
飞书/Lark 原生 OpenAPI 探索：从官方文档库中挖掘未经 CLI 封装的原生 OpenAPI 接口。当用户的需求无法被现有 lark-* skill 或 lark-cli 已注册命令满足，需要查找并调用原生飞书 OpenAPI 时使用。
azure-aigateway
microsoft/azure-skills
Configure Azure API Management as an AI Gateway for AI models, MCP tools, and agents. WHEN: semantic caching, token limit, content safety, load balancing, AI model governance, MCP rate limiting, jailbreak detection, add Azure OpenAI backend, add AI Foundry model, test AI gateway, LLM policies, configure AI backend, token metrics, AI cost control, convert API to MCP, import OpenAPI to gateway.
lark-apps
larksuite/cli
妙搭（Spark/Miaoda）应用开发与托管：应用创建、本地全栈开发、云端生成迭代、创意设计（UI mockup / 可交互原型 / 线框图 / 落地页 / 仪表盘 / 幻灯片 deck / 视觉探索）、AI相关能力和飞书平台能力或者其他外部能力集成、日志/Trace/监控指标/PV/UV 查询、环境变量管理、应用协作者与协作权限设置、应用角色与成员管理、自动化触发器（定时/记录变更/Webhook/飞书审批）。当用户要开发/新建一个系统·工具·平台·应用，或要本地开发 / 云端开发 / 修改 / 部署 / 发布 / 上线 / 拿可分享链接，或用 HTML 做页面·网站·部署到妙搭，或要设计 / design / mockup / prototype / wireframe / 做 PPT / deck / 视觉探索，或提到妙搭/Spark/Miaoda（应用运行时域名形如 *.aiforce.cloud）、应用数据库、应用文件存储、开放 API Key、可见范围、应用协作者/开发权限、应用角色/角色成员、线上日志、接口请求量、错误量、延迟、访问量、环境变量、给妙搭应用配自动化任务/定时触发/审批通过后自动触发时使用。不负责普通云盘文件上传（lark-drive）、飞书文档编辑（lark-doc）、原生幻灯片创建（lark-slides）。
convex
get-convex/agent-skills
Convex is the backend agents get right on the first try: an all-TypeScript reactive platform where the database, server functions, scheduling, file storage, auth, and realtime sync are one type-safe system, every function is a transaction, and `tsc` catches most mistakes before deploy. Ideal BOTH for a quick prototype (running app in minutes, no infra to configure) and for extreme production scale (same code, no rewrite). Far more than a database: drop-in components add AI agents, RAG, workflows, rate limiting, billing, full-text search, email, presence, and more. Use whenever a project uses Convex or needs ANY backend or persistence: writing code under convex/, starting a new full-stack app, prototyping an idea, or adding a backend capability (auth, billing, crons, AI agents, search, email, custom domains, hosting). Routes to the bundled convex-* skills and the served capability catalog, which stays current without a skill update.
cloudflare-email-service
cloudflare/skills
Send and receive transactional emails with Cloudflare Email Service (Email Sending + Email Routing). Use when building email sending (Workers binding or REST API), email routing, Agents SDK email handling, or integrating email into any app — Workers, Node.js, Python, Go, etc. Also use for email deliverability, SPF/DKIM/DMARC, wrangler email setup, MCP email tools, or when a coding agent needs to send emails. Even for simple requests like "add email to my Worker" — this skill has critical config details.
nodejs-backend-patterns
wshobson/agents
Build production-ready Node.js backend services with Express/Fastify, implementing middleware patterns, error handling, authentication, database integration, and API design best practices. Use when creating Node.js servers, REST APIs, GraphQL backends, or microservices architectures.
clerk-backend-api
clerk/skills
Clerk Backend REST API explorer and executor. Browse tags, inspect endpoint schemas, and execute authenticated requests. Use when listing users, managing organizations, or calling any Clerk API endpoint.
clerk-webhooks
clerk/skills
Clerk webhooks for real-time events and data syncing. Verify with verifyWebhook
golang-swagger
samber/cc-skills-golang
Golang OpenAPI/Swagger documentation with swaggo/swag — annotation comments (@Summary, @Param, @Success, @Router, @Security), swag init code generation, framework integrations (gin, echo, fiber, chi, net/http), security definitions (Bearer/JWT, OAuth2, API key), and struct tags (swaggertype, enums, example, swaggerignore). Apply when adding or maintaining Swagger/OpenAPI docs in a Go project, or when the codebase imports github.com/swaggo/swag, github.com/swaggo/gin-swagger, github.com/swaggo/echo-swagger, github.com/swaggo/http-swagger, or github.com/swaggo/files.
golang-graphql
samber/cc-skills-golang
Implements GraphQL APIs in Golang using gqlgen or graphql-go. Apply when building GraphQL servers, designing schemas, writing resolvers, handling subscriptions, or integrating GraphQL with existing Go HTTP services. Also apply when the codebase imports `github.com/99designs/gqlgen` or `github.com/graph-gophers/graphql-go`.
api-design-principles
wshobson/agents
Master REST and GraphQL API design principles to build intuitive, scalable, and maintainable APIs that delight developers. Use when designing new APIs, reviewing API specifications, or establishing API design standards.
better-auth-security-best-practices
better-auth/skills
Configure rate limiting, manage auth secrets, set up CSRF protection, define trusted origins, secure sessions and cookies, encrypt OAuth tokens, track IP addresses, and implement audit logging for Better Auth. Use when users need to secure their auth setup, prevent brute force attacks, or harden a Better Auth deployment.
flutter-use-http-package
flutter/agent-plugins
Use the `http` package to execute GET, POST, PUT, or DELETE requests. Use when you need to fetch from or send data to a REST API.
api-and-interface-design
addyosmani/agent-skills
Guides stable API and interface design. Use when designing APIs, module boundaries, or any public interface. Use when creating REST or GraphQL endpoints, defining type contracts between modules, or establishing boundaries between frontend and backend.
sanity-best-practices
sanity-io/agent-toolkit
Sanity development best practices for schema design, GROQ queries, TypeGen, Visual Editing, images, Portable Text, Studio structure, localization, migrations, Sanity Functions, webhooks, Blueprints, and framework integrations such as Next.js, Nuxt, Astro, Remix, SvelteKit, Angular, Hydrogen, and the App SDK. Use this skill whenever working with Sanity schemas, defineType or defineField, GROQ or defineQuery, content modeling, Presentation or preview setups, Sanity-powered frontend integrations, event-driven content automation, documentEventHandler, defineDocumentFunction, defineMediaLibraryAssetFunction, @sanity/functions, @sanity/blueprints, sanity.blueprint.ts, event-driven content automation, or when reviewing and fixing a Sanity codebase.
resend
resend/resend-skills
Use when working with the Resend email API — sending transactional emails (single or batch), receiving inbound emails via webhooks, managing email templates, tracking delivery events, managing domains, contacts, broadcasts, webhooks, API keys, automations, events, viewing API request logs, or setting up the Resend SDK. Always use this skill when the user mentions Resend, even for simple tasks like "send an email with Resend" — the skill contains critical gotchas (idempotency keys, webhook verification, template variable syntax) that prevent common production issues.
extension-http-outcalls
caffeinelabs/skills
HTTP outcalls performed by the backend canister (not in the frontend), including mandatory local verification of external REST API requests.
openapi-spec-generation
wshobson/agents
Generate and maintain OpenAPI 3.1 specifications from code, design-first specs, and validation patterns. Use when creating API documentation, generating SDKs, or ensuring API contract compliance.
wecomcli-smartsheet
wecomteam/wecom-cli
企业微信智能表格内容操作技能——专注于智能表格（smartsheet）的数据、结构与样式管理：读取表结构与记录、管理子表/字段/记录/视图/图表，以及修改行列样式（填色/高亮）；记录新增或更新遇到 851003 / no authority 时通过 Webhook 兜底写入。触发条件：用户提到智能表格、企微表格、smartsheet 的内容操作或样式修改，或链接形如 https://doc.weixin.qq.com/smartsheet/s3_xxx。企业微信表格分为「智能表格」和「在线表格」两种类型，本文档介绍的是智能表格的相关技能。智能表格包含子表（sheet）、视图（view）、字段/列（field），每条记录（record）以 `record_id` 作为主键，结构类似关系型数据库。当用户未明确说明使用「在线表格」时，一律默认使用功能更强大的智能表格（本技能）。
php-pro
jeffallan/claude-skills
Use when building PHP applications with modern PHP 8.3+ features, Laravel, or Symfony frameworks. Invokes strict typing, PHPStan level 9, async patterns with Swoole, and PSR standards. Creates controllers, configures middleware, generates migrations, writes PHPUnit/Pest tests, defines typed DTOs and value objects, sets up dependency injection, and scaffolds REST/GraphQL APIs. Use when working with Eloquent, Doctrine, Composer, Psalm, ReactPHP, or any PHP API development.
shopify-admin
shopify/shopify-ai-toolkit
Write or explain **Admin GraphQL** queries and mutations for apps and integrations that extend the Shopify admin. Use when the user wants to **understand, design, or generate** the operation itself—even before deciding how to run it. Do **not** choose `admin` first for **app or extension config validation** —use **`use-shopify-cli`**. Do **not** choose `admin` first to **execute** Admin GraphQL **now via Shopify CLI** or for CLI setup/troubleshooting on store workflows—use **`use-shopify-cli`** (store auth/execute, handle/SKU/location lookups, inventory changes).
convex-billing
get-convex/agent-skills
Add Stripe billing/payments to the Convex app via @convex-dev/stripe (checkout + webhook + gating).
readout
warpdotdev/common-skills
Produce a polished, self-contained HTML "readout" document under ~/.readouts (with an auto-maintained index page), either by snapshotting the findings accumulated in the current conversation or — when invoked fresh, e.g. "/readout on how github webhook events are processed" — by sharpening scope with clarifying questions and researching the codebase before documenting. The work runs in a child agent so the main conversation's context stays clean. Use whenever the user invokes /readout, says "write this up", "turn this into a doc/page", "make a readout", or asks for a readable, shareable document capturing findings or explaining how something works.
stripe-integration
wshobson/agents
Implement Stripe payment processing for robust, PCI-compliant payment flows including checkout, subscriptions, and webhooks. Use when integrating Stripe payments, building subscription systems, or implementing secure checkout flows.
java-spring-boot
pluginagentmarketplace/custom-plugin-java
Build production Spring Boot applications - REST APIs, Security, Data, Actuator
springboot-patterns
affaan-m/ecc
Spring Boot architecture patterns, REST API design, layered services, data access, caching, async processing, and logging. Use for Java Spring Boot backend work. Use when building or reviewing a Spring Boot backend — REST layer, services, data access, caching, or async work.
api-design
affaan-m/ecc
REST API design patterns including resource naming, status codes, pagination, filtering, error responses, versioning, and rate limiting for production APIs. Use when designing or reviewing REST endpoints, resource names, status codes, pagination, or versioning.
django-patterns
affaan-m/ecc
Django architecture patterns, REST API design with DRF, ORM best practices, caching, signals, middleware, and production-grade Django apps. Use when building or reviewing Django apps, DRF APIs, ORM queries, or caching.
n8n-workflow-patterns
czlonkowski/n8n-skills
Proven workflow architectural patterns from real n8n workflows. Use when building new workflows, designing workflow structure, choosing workflow patterns, planning workflow architecture, or asking about webhook processing, HTTP API integration, database operations, AI agent workflows, batch processing, or scheduled tasks. Always consult this skill when the user asks to create, build, or design an n8n workflow, automate a process, or connect services — even if they don't explicitly mention 'patterns'. Covers webhook, API, database, AI, batch processing, and scheduled automation architectures. Also use when optimizing a slow workflow or speeding up large-item-count processing (node count, batchSize, all-items vs per-item).
shopify-storefront-graphql
shopify/shopify-ai-toolkit
Use for custom storefronts requiring direct GraphQL queries/mutations for data fetching and cart operations. Choose this when you need full control over data fetching and rendering your own UI. NOT for Web Components - if the prompt mentions HTML tags like <shopify-store>, <shopify-cart>, use storefront-web-components instead.
springboot-security
affaan-m/ecc
Spring Security best practices for authn/authz, validation, CSRF, secrets, headers, rate limiting, and dependency security in Java Spring Boot services. Use when reviewing Spring Security authn/authz, validation, CSRF, secrets, headers, or rate limiting.
openapi-to-application-code
github/awesome-copilot
Generate a complete, production-ready application from an OpenAPI specification
aspnet-minimal-api-openapi
github/awesome-copilot
Create ASP.NET Minimal API endpoints with proper OpenAPI documentation
copilot-usage-metrics
github/awesome-copilot
Retrieve and display GitHub Copilot usage metrics for organizations and enterprises using the GitHub CLI and REST API.
flutter-handling-http-and-json
flutter/skills
Executes HTTP requests and handles JSON serialization in a Flutter app. Use when integrating with REST APIs or parsing structured data from external sources.
api-security-best-practices
sickn33/agentic-awesome-skills
Implement secure API design patterns including authentication, authorization, input validation, rate limiting, and protection against common API vulnerabilities
wordpress-pro
jeffallan/claude-skills
Develops custom WordPress themes and plugins, creates and registers Gutenberg blocks and block patterns, configures WooCommerce stores, implements WordPress REST API endpoints, applies security hardening (nonces, sanitization, escaping, capability checks), and optimizes performance through caching and query tuning. Use when building WordPress themes, writing plugins, customizing Gutenberg blocks, extending WooCommerce, working with ACF, using the WordPress REST API, applying hooks and filters, or improving WordPress performance and security.
shopify-use-shopify-cli
shopify/shopify-ai-toolkit
Choose when the user needs **Shopify CLI** to run or fix something now: validate app or extension config on disk (`shopify.app.toml`, `shopify.app.<name>.toml`, `shopify.extension.toml`); run or troubleshoot store workflows (`shopify store auth`, `shopify store execute`); or perform explicit store-scoped reads/writes on a named store domain (for example, show/list/find the first 10 products on my store at `foo.myshopify.com`, or inventory and product changes by handle, SKU, or location name). Emphasize **commands and operational steps**, not only authoring GraphQL. Skip for API-only understanding or codegen with no CLI execution, and skip for brand-new merchant asks to start a Shopify store or try Shopify before they have an account. Examples: validate configuration before deploy; run an existing query via CLI; show the first 10 products on `foo.myshopify.com`; missing `shopify store execute`.
agentmemory-rest-api
rohitg00/agentmemory
The agentmemory HTTP REST API surface, the primary protocol for talking to the memory server. Use when calling agentmemory over HTTP, when MCP is unavailable and you need a fallback, or when integrating a host that does not speak MCP.
shopify-hydrogen
shopify/shopify-ai-toolkit
Hydrogen storefront implementation cookbooks. Some of the available recipes are: B2B Commerce, Bundles, Combined Listings, Custom Cart Method, Dynamic Content with Metaobjects, Express Server, Google Tag Manager Integration, Infinite Scroll, Legacy Customer Account Flow, Markets, Partytown + Google Tag Manager, Subscriptions, Third-party API Queries and Caching. MANDATORY: Use this API for ANY Hydrogen storefront question - do NOT use Storefront GraphQL when 'Hydrogen' is mentioned.
email-best-practices
resend/resend-skills
Use when building email features, emails going to spam, high bounce rates, setting up SPF/DKIM/DMARC authentication, implementing email capture, ensuring compliance (CAN-SPAM, GDPR, CASL), handling webhooks, retry logic, making emails accessible (alt text, headings, contrast, screen readers), or deciding transactional vs marketing.
spring-boot-engineer
jeffallan/claude-skills
Generates Spring Boot 3.x configurations, creates REST controllers, implements Spring Security 6 authentication flows, sets up Spring Data JPA repositories, and configures reactive WebFlux endpoints. Use when building Spring Boot 3.x applications, microservices, or reactive Java applications; invoke for Spring Data JPA, Spring Security 6, WebFlux, Spring Cloud integration, Java REST API design, or Microservices Java architecture.
upstash-redis-js
upstash/skills
Work with the Upstash Redis TypeScript/JavaScript SDK for serverless Redis operations. Use for caching, session storage, rate limiting, leaderboards, full-text search (querying, filtering, aggregating) with Upstash Redis Search (different from regular FT.SEARCH), and all Redis data structures. Supports automatic serialization/deserialization of JavaScript types. Upstash Redis Search also available via @upstash/search-redis and @upstash/search-ioredis adapters for TCP clients.
email-best-practices
resend/email-best-practices
Use when building email features, emails going to spam, high bounce rates, setting up SPF/DKIM/DMARC authentication, implementing email capture, ensuring compliance (CAN-SPAM, GDPR, CASL), handling webhooks, retry logic, making emails accessible (alt text, headings, contrast, screen readers), or deciding transactional vs marketing.
step-parts
earthtojake/text-to-cad
Find, evaluate, and download common purchasable CAD parts from step.parts, including named off-the-shelf actuators, servos, motors, electronics boards, connectors, screws, bolts, nuts, washers, bearings, standoffs, and other catalog components. Use when Codex needs to search the hosted step.parts catalog before creating simplified placeholder geometry, resolve fuzzy part names, standards, aliases, or dimensions, choose a matching part, fetch a canonical .step file, verify checksums, or use the step.parts API/OpenAPI/catalog endpoints for standard part discovery.
create-web-form
github/awesome-copilot
Create robust, accessible web forms with best practices for HTML structure, CSS styling, JavaScript interactivity, form validation, and server-side processing. Use when asked to "create a form", "build a web form", "add a contact form", "make a signup form", or when building any HTML form with data handling. Covers PHP and Python backends, MySQL database integration, REST APIs, XML data exchange, accessibility (ARIA), and progressive web apps.
flutter-use-http-package
flutter/skills
Use the `http` package to execute GET, POST, PUT, or DELETE requests. Use when you need to fetch from or send data to a REST API.
agents
elevenlabs/skills
Build voice AI agents with ElevenLabs. Use when creating voice assistants, customer service bots, interactive voice characters, or any real-time voice conversation experience, and when configuring an agent's tools, workflows, or procedures, including creating, editing, compiling, and publishing procedure drafts on an agent branch over the SDKs or REST API.
printing-press
mvanhorn/cli-printing-press
Set up a new integration, connector, or CLI binding for any API. Wrap or generate a ship-ready Go CLI from an OpenAPI, HAR, or Postman spec via the lean research -> generate -> build -> shipcheck loop. Use when the user says build a CLI, wrap this API, set up a new integration, add a connector, integrate with a service, or names an API by domain.
msw-search
msw-git/msw-ai-coding-plugins-official
MSW search integration — (1) vector search for API docs and implementation guides via the msw-mcp MCP server (mlua_api_retriever / mlua_document_retriever), (2) REST API search for resources (sprite / animation / sound / resource pack / avatar). Use for 'find details, examples, or related APIs not in .d.mlua', 'need a SpriteRUID', 'monster sprite', 'background image', 'find a sound', 'avatar item lookup', etc. Keywords: document search, API details, examples, guide, retriever, resource, sprite, animation, sound, RUID, resource pack, avatar.
zod
pproenca/dot-skills
Zod schema validation best practices for type safety, parsing, and error handling. This skill should be used when defining z.object schemas, using z.string validations, safeParse, or z.infer. This skill does NOT cover React Hook Form integration patterns (use react-hook-form skill) or OpenAPI client generation (use orval skill).
n8n-expression-syntax
czlonkowski/n8n-skills
Validate n8n expression syntax and fix common errors. Use when writing n8n expressions, using {{}} syntax, accessing $json/$node variables, troubleshooting expression errors, mapping data between nodes, or referencing webhook data in workflows. Use this skill whenever configuring node fields that reference data from previous nodes — expressions are how n8n passes data between nodes, and getting the syntax wrong is the most common source of workflow errors. Also use when asked whether a complex expression hurts performance.
supabase-server
supabase/server
Use when planning or writing server-side code that uses `@supabase/server` — Edge Functions, Hono apps, webhook handlers, or any backend that creates Supabase clients or validates inbound auth. Trigger **before** writing or modifying any file that imports from `@supabase/server` (or sub-paths like `@supabase/server/core`); calls `withSupabase`, `createSupabaseContext`, `createAdminClient`, `createContextClient`, `verifyAuth`, `verifyCredentials`, or `extractCredentials`; configures an `auth:` mode (`'none'` | `'publishable'` | `'secret'` | `'user'`, or keyed variants like `'secret:*'`); or lives under `supabase/functions/` and authenticates an inbound request. Also trigger during planning — if a plan mentions any of the above, load the skill before drafting code; do not extrapolate `auth:` values or auth modes from neighboring functions. Also trigger when you see legacy patterns to migrate to this package — `Deno.serve`, `createClient(Deno.env.get('SUPABASE_URL'))`, imports from `esm.sh/@supabase` or `deno.land/std`, usage of `SUPABASE_ANON_KEY` / `SUPABASE_SERVICE_ROLE_KEY`, or the deprecated `allow:` config option / removed `'always'` / `'public'` mode values / removed `authType` field.
api-designer
jeffallan/claude-skills
Use when designing REST or GraphQL APIs, creating OpenAPI specifications, or planning API architecture. Invoke for resource modeling, versioning strategies, pagination patterns, error handling standards.
cargo-storage
getcargohq/cargo-skills
Work with the data inside a Cargo workspace — models (Companies, Contacts, Deals…), datasets, columns, relationships, records, and SQL over workspace storage. Triggers: \"what models do I have\", \"show me the schema\", \"add a column for\", \"how many contacts do I have\", \"SELECT … FROM\", \"query my companies table\", \"join contacts to companies\", \"what is the DDL\", \"set up a webhook-fed model\", \"where does this field live\", \"import this into a model\", \"unify these models\", \"merge duplicate accounts\", \"link contacts to companies\", \"set up a relationship between\". Skip when: querying run or batch telemetry rather than business data — use cargo-orchestration; naming a reusable filtered audience — use cargo-segmentation.
fastapi-expert
jeffallan/claude-skills
Use when building high-performance async Python APIs with FastAPI and Pydantic V2. Invoke to create REST endpoints, define Pydantic models, implement authentication flows, set up async SQLAlchemy database operations, add JWT authentication, build WebSocket endpoints, or generate OpenAPI documentation. Trigger terms: FastAPI, Pydantic, async Python, Python API, REST API Python, SQLAlchemy async, JWT authentication, OpenAPI, Swagger Python.
cargo-hosting
getcargohq/cargo-skills
Put something on the internet from Cargo — Vite single-page apps served at https://<slug>.cargo.app and serverless edge workers that answer HTTP requests, plus the deployments that build and promote them. Triggers: \"build me a dashboard for this\", \"host this app\", \"give me a URL to share\", \"deploy this\", \"I need a webhook endpoint\", \"make it live\", \"promote to production\", \"put it on cargo.app\", \"ship a UI for my team\". Skip when: the app or worker should be declared as committed workspace code — use cargo-cdk.
chat-sdk
vercel/chat
Build multi-platform chat bots with Chat SDK (`chat` npm package). Use when developers want to scaffold a bot with create-chat-sdk, build a Slack, Teams, Google Chat, Discord, Telegram, GitHub, Linear, or WhatsApp bot, handle mentions, direct messages, subscribed threads, reactions, slash commands, cards, modals, files, or AI streaming, set up webhook routes or multi-adapter bots, send rich cards or streamed AI responses to chat platforms, or build a custom adapter or state adapter.