Feature
OpenAPI Specification
A machine-readable OpenAPI/Swagger contract.
55 providers
260 APIs
55 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.
55 API providers on the APIs.io network offer openapi specification. The highest-rated are Postman, Automation Anywhere, Speakeasy, Appian, Auth0.
Providers
Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.
Exemplar 6 Complete, well-documented, and agent-ready
PostmanPostman is the world's leading API platform, used by 35+ million developers to design, build, test, documen...Automation AnywhereAutomation Anywhere is an enterprise robotic process automation (RPA) platform that enables organizations t...SpeakeasySpeakeasy provides an AI control plane platform that lets enterprises govern, secure, and observe AI agents...AppianAppian is a low-code automation platform that accelerates the creation of high-impact business applications...Auth0Auth0 (now part of Okta) is a leading identity-as-a-service platform providing authentication and authoriza...Microsoft Azure QuantumMicrosoft Azure Quantum is Microsoft's cloud quantum computing service — an open, multi-vendor platform tha...
Strong 9 Solid coverage with minor gaps
Apollo.ioApollo.io is a sales intelligence and go-to-market platform combining a database of 240M+ contacts and 30M+...APIMaticAPIMatic is a developer experience platform for APIs that specializes in automated SDK generation, API docu...WalmartWalmart is a multinational retail corporation that operates a chain of hypermarkets, discount department st...RaygunRaygun is an application monitoring platform that combines Crash Reporting, Real User Monitoring (RUM), and...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...PineconeWith its vector database at the core, Pinecone is the leading knowledge platform for building accurate, sec...LALAL.AILALAL.AI is an AI-powered audio separation and voice technology platform operated by OmniSale GmbH. It uses...Commerce LayerCommerce Layer is the headless, multi-market commerce API used by global brands to sell everywhere — web, m...WowzaWowza is a Denver, Colorado-based video streaming infrastructure provider that has been simplifying live an...
Developing 18 Usable, with meaningful gaps to close
Adafruit IOAdafruit IO is a cloud Internet of Things platform from Adafruit Industries built for makers, hobbyists, st...LichessLichess is a free, ad-free, open-source online chess server operated by a French nonprofit and powered enti...IonQIonQ (NYSE IONQ) is a College Park, Maryland-based public trapped-ion quantum computing company. IonQ desig...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...TrueworkTruework operates a unified income and employment verification platform for mortgage lenders, credit unions...Rigetti ComputingRigetti Computing (Nasdaq, RGTI) is a Berkeley, California-based quantum computing company building superco...PolyAPIPoly, built using cutting-edge AI and Kubernetes-native technology, accelerates development and simplifies ...ContinueContinue is the open-source AI code assistant for VS Code and JetBrains, distributed under Apache 2.0. The ...Octopus EnergyOctopus Energy is a UK-founded retail energy supplier and the parent of Kraken Technologies, the AI-powered...AsyncAPIAsyncAPI is a Linux Foundation project that improves the state of event-driven architectures by providing a...Apache OFBizApache OFBiz is an open-source enterprise resource planning (ERP) system providing a suite of integrated bu...ApiaryApiary is an API design and documentation platform, now part of Oracle Cloud Infrastructure. With 486,000+ ...LangflowLangflow is an open-source low-code visual builder for AI agents, RAG pipelines, and LangChain-based workfl...TheTVDBTheTVDB is a community-driven television and movie metadata database founded in 2006. It supplies structure...NOAA — National Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration (NOAA) is the United States scientific and regulatory a...AmadeusAmadeus for Developers is the self-service developer program from Amadeus IT Group, the leading technology ...MarqoMarqo is an open-source, multimodal vector search engine that lets developers index text and images, genera...
Thin 16 Limited public surface area
KreaKrea is a real-time AI creative suite that lets designers, filmmakers, brand teams, and everyday creators g...JeticJetic is the first and only cloud-native API & Integration Platform based on Apache Camel. An iPaaS solutio...AutoRestAutoRest is an open source tool from Microsoft (MIT License) that generates client libraries for accessing ...APIClarityAPIClarity is an open source (Apache-2.0) API security and observability tool that captures API traffic in ...Ron Swanson QuotesA community-built, open source HTTP API that returns Ron Swanson quotes from the NBC television series Park...TrinoTrino is an open-source, distributed SQL query engine built for lightning-fast analytics over large, hetero...Vert.xEclipse Vert.x is a toolkit for building reactive applications on the JVM, providing support for multiple l...CrestaCresta (legally Cresta Intelligence, Inc.) is a Palo Alto, California enterprise Customer Experience AI com...APIs.guruAPIs.guru is an open source, community-driven directory of public REST API definitions in OpenAPI 2.0/3.x f...Lex MachinaLex Machina is a legal analytics platform owned by LexisNexis that transforms raw court documents and docke...Volvo CarsVolvo Cars is a Swedish premium automotive OEM (headquartered in Gothenburg, owned by Geely) that operates ...API-FiddleAPI-Fiddle is an interactive, collaborative API design platform for creating professional APIs based on Ope...EventsEvent-driven APIs catalog. Documents the landscape of brokers, streaming platforms, schema registries, and ...Deutsche TelekomDeutsche Telekom AG is Europe's largest telecommunications operator, headquartered in Bonn, Germany, servin...42Crunch42Crunch is a leading API security company that specializes in protecting and securing APIs. They provide i...Pie InsurancePie Insurance is a Washington, DC and Denver-based insurtech founded in May 2017 that makes commercial insu...
Emerging 4 Early or largely undocumented
QuantinuumQuantinuum is an integrated quantum computing company formed by the 2021 merger of Honeywell Quantum Soluti...FastMCPFastMCP is the fast, Pythonic framework for building Model Context Protocol (MCP) servers, clients, and app...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...
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)AsyncAPI DescriptionAsyncAPI SpecificationAuto-generated soracom CLI built directly from the OpenAPI specConnected 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.FastAPI 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 specificationManagement 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 Upload and URL InputOpenAPI and FastAPI importOpenAPI spec availableOpenAPI-First DesignOpenAPI/Swagger SupportPostman and Swagger ToolingPrepare OpenAPIPrivate, gated API and SDK — no public OpenAPI, no public SDK release, no self-service developer signupPublic OpenAPI 3.0 specification covering 53 operations across 12 resource tagsPublic OpenAPI 3.1.0 spec at https://docs.krea.ai/api-reference/openapi.json plus Postman import and an interactive in-browser playgroundPublic OpenAPI specs published from truework.docs.buildwithfern.comREST + JSON over HTTPS; OpenAPI 3.1.0 specification at /docs
Showing 40 of 55 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.