Feature
OpenAPI Specification
A machine-readable OpenAPI/Swagger contract.
62 providers
284 APIs
62 declared variants
The API ships an OpenAPI (or Swagger) description, which unlocks generated clients, mocks, linting, and import into every major API tool. The single highest-leverage artifact a provider can publish.
62 API providers on the APIs.io network offer openapi specification. The highest-rated are Canvas LMS, Commerce Layer, S&P Global, Postman, Raygun.
Providers
Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.
Exemplar 4 Complete, well-documented, and agent-ready
Canvas LMSCanvas is the open, AGPLv3-licensed learning management system created and maintained by Instructure, Inc. ...Commerce LayerCommerce Layer is the headless, multi-market commerce API used by global brands to sell everywhere — web, m...S&P GlobalS&P Global (NYSE SPGI) is the parent of S&P Global Ratings, S&P Global Market Intelligence, S&P Dow Jones I...PostmanPostman is the world's leading API platform, used by 35+ million developers to design, build, test, documen...
Strong 14 Solid coverage with minor gaps
RaygunRaygun is an application monitoring platform that combines Crash Reporting, Real User Monitoring (RUM), and...Adafruit IOAdafruit IO is a cloud Internet of Things platform from Adafruit Industries built for makers, hobbyists, st...LALAL.AILALAL.AI is an AI-powered audio separation and voice technology platform operated by OmniSale GmbH. It uses...AppianAppian is a low-code automation platform that accelerates the creation of high-impact business applications...Microsoft Azure QuantumMicrosoft Azure Quantum is Microsoft's cloud quantum computing service — an open, multi-vendor platform tha...Apollo.ioApollo.io is a sales intelligence and go-to-market platform combining a database of 240M+ contacts and 30M+...IonQIonQ (NYSE IONQ) is a College Park, Maryland-based public trapped-ion quantum computing company. IonQ desig...LichessLichess is a free, ad-free, open-source online chess server operated by a French nonprofit and powered enti...Rigetti ComputingRigetti Computing (Nasdaq, RGTI) is a Berkeley, California-based quantum computing company building superco...TrueworkTruework operates a unified income and employment verification platform for mortgage lenders, credit unions...Auth0Auth0 (now part of Okta) is a leading identity-as-a-service platform providing authentication and authoriza...ContinueContinue is the open-source AI code assistant for VS Code and JetBrains, distributed under Apache 2.0. The ...WalmartWalmart is a multinational retail corporation that operates a chain of hypermarkets, discount department st...Octopus EnergyOctopus Energy is a UK-founded retail energy supplier and the parent of Kraken Technologies, the AI-powered...
Developing 18 Usable, with meaningful gaps to close
SocketSocket is a developer-first supply-chain security platform that protects applications from malicious depend...TIDALTIDAL is a high-fidelity music streaming service owned by Block (Square's parent, acquired 2021) offering H...SoracomSoracom is a global IoT cellular connectivity and platform provider headquartered in Tokyo, founded in 2014...AmadeusAmadeus for Developers is the self-service developer program from Amadeus IT Group, the leading technology ...SpeakeasyThe platform to Build APIs your users love. Best in class API tooling for robust SDKs, API docs, Terraform ...PineconeWith its vector database at the core, Pinecone is the leading knowledge platform for building accurate, sec...APIMaticAPIMatic is a developer experience platform for APIs that specializes in automated SDK generation, API docu...TheTVDBTheTVDB is a community-driven television and movie metadata database founded in 2006. It supplies structure...PolyAPIPoly, built using cutting-edge AI and Kubernetes-native technology, accelerates development and simplifies ...WowzaWowza is a Denver, Colorado-based video streaming infrastructure provider that has been simplifying live an...StackOneStackOne is an AI-powered embedded integration platform as a service (iPaaS) designed to simplify and accel...Apache OFBizApache OFBiz is an open-source enterprise resource planning (ERP) system providing a suite of integrated bu...LoopsLoops is a modern email platform purpose-built for software companies, combining product, marketing, and tr...UnityUnity is a real-time 3D content creation platform — the Unity engine powers cross-platform games, simulatio...MarqoMarqo is an open-source, multimodal vector search engine that lets developers index text and images, genera...NOAA — National Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration (NOAA) is the United States scientific and regulatory a...JeticJetic is the first and only cloud-native API & Integration Platform based on Apache Camel. An iPaaS solutio...KreaKrea is a real-time AI creative suite that lets designers, filmmakers, brand teams, and everyday creators g...
Thin 20 Limited public surface area
LangflowLangflow is an open-source low-code visual builder for AI agents, RAG pipelines, and LangChain-based workfl...TrinoTrino is an open-source, distributed SQL query engine built for lightning-fast analytics over large, hetero...Automation AnywhereAutomation Anywhere is an enterprise robotic process automation (RPA) platform that enables organizations t...AutoRestAutoRest is an open source tool from Microsoft (MIT License) that generates client libraries for accessing ...Ron Swanson QuotesA community-built, open source HTTP API that returns Ron Swanson quotes from the NBC television series Park...LAPISLAPIS (Lightweight API Specification for Intelligent Systems) is a compact, LLM-native API description form...Lex MachinaLex Machina is a legal analytics platform owned by LexisNexis that transforms raw court documents and docke...API-FiddleAPI-Fiddle is an interactive, collaborative API design platform for creating professional APIs based on Ope...APIs.guruAPIs.guru is an open source, community-driven directory of public REST API definitions in OpenAPI 2.0/3.x f...Test FirstA software development approach where tests are written before the implementation code, ensuring code quali...Deutsche TelekomDeutsche Telekom AG is Europe's largest telecommunications operator, headquartered in Bonn, Germany, servin...Vert.xEclipse Vert.x is a toolkit for building reactive applications on the JVM, providing support for multiple l...APIClarityAPIClarity is an open source API security and observability tool that analyzes API traffic to reconstruct O...CrestaCresta (legally Cresta Intelligence, Inc.) is a Palo Alto, California enterprise Customer Experience AI com...Volvo CarsVolvo Cars is a Swedish premium automotive OEM (headquartered in Gothenburg, owned by Geely) that operates ...42Crunch42Crunch is a leading API security company that specializes in protecting and securing APIs. They provide i...AsyncAPIAsyncAPI is a Linux Foundation project that improves the state of event-driven architectures by providing a...FastMCPFastMCP is the fast, Pythonic framework for building Model Context Protocol (MCP) servers, clients, and app...Pie InsurancePie Insurance is a Washington, DC and Denver-based insurtech founded in May 2017 that makes commercial insu...EventsEvent-driven APIs catalog. Documents the landscape of brokers, streaming platforms, schema registries, and ...
Emerging 5 Early or largely undocumented
ApiaryApiary is an API design and documentation platform, now part of Oracle Cloud Infrastructure. With 486,000+ ...QuantinuumQuantinuum is an integrated quantum computing company formed by the 2021 merger of Honeywell Quantum Soluti...ApiNotesApiNotes is an interactive API documentation tool that generates developer portals with live endpoint testi...SpecLynxSpecLynx provides enterprise-ready API tooling for authors and maintainers of OpenAPI, AsyncAPI, and Arazzo...API InsightsAPI Insights is a free online tool powered by Treblle that provides advanced API analysis and monitoring by...
Minimal 1 Almost no public developer surface
What Providers Actually Declared
This feature is a canonical term. These are the free-text strings
providers wrote in their own apis.yml that map onto it.
5 public REST OpenAPI surfaces (LLM-ready, Extract, NERD, Scribe v1 batch, Scribe v2 batch)API Contract DefinitionAsyncAPI DescriptionAsyncAPI SpecificationAuto-generated soracom CLI built directly from the OpenAPI specBuilt-in OpenAPI 3.0 generator via the `rake doc:openapi` task using swagger_yardConnected Vehicle API v2 — read vehicle status, diagnostics, statistics, and metadata, and send commands (lock/unlock, climate start/stop, flash lights, sound horn, engine start/stop) backed by a public OpenAPI specification.Deterministic OpenAPI ConversionFastAPI runtime exposing live `/openapi.json` and Swagger UI at `/docs`FastAPI-based REST API with OpenAPI 3.1 spec served at /docs and /openapi.json on every deploymentFull OpenAPI 3.1 specification with 185 operations across 23 tags published at github.com/lichess-org/apiGenerate OpenAPIGitHub-hosted Swagger documentationHybrid REST + gRPC API surface — OpenAPI 3.0 HTTP API for management + gRPC for translation and executionIngest OpenAPIJSON:API (jsonapi.org/format/) compliant Core API with 917 path operations across 130+ top-level resources on a single OpenAPI 3.1 specKraken developer portal at developer.octopus.energy with REST API Reference generated from an OpenAPI specificationLive OpenAPI spec served from https://api.socket.dev/v0/openapiManagement API (OpenAPI 3.1 Beta, 221 paths, 2,567 schemas)National Weather Service api.weather.gov — alerts (CAP), gridded forecasts, observations, aviation (SIGMETs/AIRMETs/TAFs), radar, zones, points, glossary — 66 documented endpoints in OpenAPI 3.9.2No maintained first-party SDK; both walmartlabs repos are archived (2019, 2020). Walmart directs developers to OpenAPI GeneratorOfficial OpenAPI 3.1 spec served at /api/v1/openapi.json with Swagger-style explorer at /api/v1/docs/Open OpenAPI Specifications RepositoryOpenAPIOpenAPI Contract SecurityOpenAPI Contract ValidationOpenAPI DirectoryOpenAPI ExportOpenAPI Linter GitHub AppOpenAPI ProcessingOpenAPI Spec ReconstructionOpenAPI SupportOpenAPI ToolsOpenAPI Upload and URL InputOpenAPI and FastAPI importOpenAPI spec availableOpenAPI-First DesignOpenAPI/Swagger SupportPostman and Swagger ToolingPostman, OpenAPI-style REST docs, and the UGS CLI as primary integration surfaces for the backend services
Showing 40 of 62 declared variants
Work with this as data
Every feature here is available over the APIs.io API and to AI agents over MCP. Features is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.