Feature

Open Source

Source code published under an open license.

124 providers 1639 APIs 119 declared variants

The implementation is openly licensed and publicly readable, so integrators can audit behavior, fork, and contribute. Also changes the risk calculus on vendor continuity.

124 API providers on the APIs.io network offer open source. The highest-rated are APIs.io, Airbyte, GitLab, Pipedream, Buildkite.

Providers

Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.

Exemplar 16 Complete, well-documented, and agent-ready
APIs.io APIs.io is an open-source API search engine and federated discovery network built on the APIs.json specific... 11 APIs 81.8 Airbyte Airbyte is an open-source data integration platform that enables businesses to easily and efficiently move ... 44 APIs 75.7 GitLab GitLab Inc. is an open-core company that develops GitLab, a DevOps software platform for building, securing... 44 APIs 74.3 Pipedream Pipedream is a developer-centric integration platform providing three product lines: Workflows (code-level ... 16 APIs 72.8 Buildkite Buildkite is a hybrid CI/CD platform that combines a hosted control plane (pipelines.buildkite.com) with se... 23 APIs 71.8 Canvas LMS Canvas is the open, AGPLv3-licensed learning management system created and maintained by Instructure, Inc. ... 16 APIs 71.7 Daytona Daytona is open-source, secure, and elastic infrastructure for running AI-generated code. Daytona sandboxes... 28 APIs 70.3 ibm-quantum IBM Quantum is IBM's quantum computing program — the operator of the IBM Quantum Platform (quantum.cloud.ib... 11 APIs 69.7 Commerce Layer Commerce Layer is the headless, multi-market commerce API used by global brands to sell everywhere — web, m... 148 APIs 69.5 Highlight (highlight.io) Highlight (highlight.io) is the open-source, full-stack monitoring platform — session replay, error monitor... 8 APIs 68.7 Stytch Stytch is an authentication and identity infrastructure provider. Its Consumer and B2B APIs cover passwordl... 47 APIs 67.8 fireblocks Fireblocks is an institutional digital-asset and stablecoin infrastructure company providing MPC-secured cu... 35 APIs 67.2 Pocket Network Pocket Network is the decentralized RPC layer of Web3 — a permissionless, fully open data delivery protocol... 16 APIs 67.2 sensible-so Sensible is a document-automation API platform that extracts structured data from PDFs, images, spreadsheet... 7 APIs 67.1 Cumulocity Cumulocity is an enterprise AIoT (Artificial Intelligence of Things) platform that connects, manages, and a... 39 APIs 66.7 E2B E2B (e2b-dev) provides secure, isolated cloud sandboxes for AI agents and AI-generated code, built on a for... 14 APIs 66.6
Strong 27 Solid coverage with minor gaps
D-Wave D-Wave Quantum Inc. (NYSE: QBTS) is the leader in commercial quantum annealing computing and developer of t... 6 APIs 65.5 Hyperbolic Hyperbolic is an open-access AI cloud and decentralized GPU marketplace serving 200,000+ builders with affo... 6 APIs 65.0 Recraft Recraft is a London-based AI design platform — founded in 2023 by Anna Veronika Dorogush (creator of the Ca... 5 APIs 64.8 ankr Ankr is a Web3 infrastructure provider whose multichain RPC, Advanced API, liquid staking, contract automat... 9 APIs 64.5 Microsoft Azure Quantum Microsoft Azure Quantum is Microsoft's cloud quantum computing service — an open, multi-vendor platform tha... 8 APIs 64.3 Mews Mews is a cloud-native hospitality operating system serving 15,000+ hotels, hostels, and vacation-rental pr... 78 APIs 64.2 Leonardo.AI Leonardo.AI is an Australian generative-AI company (acquired by Canva in July 2024) offering a Production A... 14 APIs 64.0 Nanonets Nanonets is a no-code document AI and OCR platform that combines a custom-model OCR API, pre-built document... 10 APIs 63.5 WooCommerce WooCommerce is the world's most popular open-source eCommerce platform, built on WordPress. It provides a c... 21 APIs 63.4 Outbrain Outbrain Inc. (NASDAQ: OB), which closed its acquisition of Teads in early 2025 and now operates public... 10 APIs 63.2 Civitai Civitai is the largest open community for Stable Diffusion, SDXL, Flux, and video AI models — hosting over ... 12 APIs 62.4 Paperspace Paperspace is a GPU cloud platform for AI, ML, and 3D rendering workloads, acquired by DigitalOcean in 2023... 25 APIs 62.3 Lichess Lichess is a free, ad-free, open-source online chess server operated by a French nonprofit and powered enti... 23 APIs 61.7 TIDAL TIDAL is a high-fidelity music streaming service owned by Block (Square's parent, acquired 2021) offering H... 65 APIs 61.7 Inworld AI Inworld AI is a real-time voice AI infrastructure provider. The Inworld platform delivers text-to-speech, s... 7 APIs 61.6 Encore Encore is a backend application framework and developer cloud that lets engineering teams build type-safe d... 6 APIs 61.4 Google Quantum AI Google Quantum AI is Google's quantum-computing research and engineering arm, building superconducting quan... 15 APIs 61.1 Chroma Chroma (Chroma DB) is an open-source AI-native embedding database designed to make it easy to build LLM app... 8 APIs 60.3 Vespa Vespa is an open-source AI search engine, big-data serving engine, and vector database originally developed... 9 APIs 59.9 ThingsBoard ThingsBoard is an open-source IoT platform for device connectivity, data collection, processing, and visual... 58 APIs 59.5 Triton One Triton One is a high-performance Solana RPC and blockchain infrastructure provider operating globally distr... 13 APIs 59.5 Backpack Backpack is a Solana-first crypto company founded by Armani Ferrante and Tristan Yver — the same team behin... 15 APIs 59.3 Continue Continue is the open-source AI code assistant for VS Code and JetBrains, distributed under Apache 2.0. The ... 5 APIs 58.9 ServiceTitan ServiceTitan is the operating system for the trades — all-in-one field service management software for resi... 55 APIs 58.9 N8n Build with the precision of code or the speed of drag-n-drop. Host with on-prem control or in-the-cloud con... 15 APIs 58.6 Typesense Typesense is a fast, typo-tolerant, open-source search engine designed for developer productivity. It provi... 25 APIs 56.7 Packagist Packagist is the default package repository for Composer, the PHP dependency manager. It indexes over 454,0... 5 APIs 56.5
Developing 26 Usable, with meaningful gaps to close
Conekta Conekta is a Mexico-based payment processor that lets businesses accept credit and debit cards, OXXO cash v... 25 APIs 55.9 1NCE 1NCE is a Cologne-headquartered global IoT connectivity provider best known for the IoT Lifetime Flat — a s... 22 APIs 55.1 Beatoven.ai Beatoven.ai is an Indian generative-music startup (Bengaluru, founded 2021) building text-to-music and text... 2 APIs 54.6 LangWatch LangWatch is an open-source LLM observability, evaluation, and AI agent testing platform. Built around Open... 28 APIs 54.0 arXiv arXiv is the open-access e-print repository operated by Cornell Tech, hosting more than two million preprin... 4 APIs 52.9 Octopus Energy Octopus Energy is a UK-founded retail energy supplier and the parent of Kraken Technologies, the AI-powered... 9 APIs 52.9 Forethought Forethought is a San Francisco-based generative AI customer-support platform. Its multi-agent product suite... 3 APIs 52.3 Tensor Tensor is the Solana-native NFT marketplace and trading protocol founded by Tensor HQ and now stewarded by ... 9 APIs 52.0 Cerbos Cerbos is an open-core, language-agnostic, scalable authorization platform that decouples access control fr... 13 APIs 51.3 Nango Nango.dev is a developer infrastructure platform that simplifies building product integrations with externa... 6 APIs 50.8 AgStack Foundation AgStack Foundation is a Linux Foundation project providing open-source digital infrastructure for the agric... 7 APIs 50.1 Formant Formant is a San Francisco–based robotics and physical-operations cloud platform that lets companies operat... 7 APIs 49.0 Descope Descope is a customer and agentic identity access management (CIAM) platform founded in 2022 by veterans of... 16 APIs 48.2 Casdoor Casdoor is an open-source, AI-first identity and access management (IAM) and MCP gateway authentication ser... 15 APIs 46.9 Children's Hospital of Philadelphia Founded in 1855 as the first hospital in the United States dedicated to the healthcare of children, Childre... 8 APIs 46.9 VA Lighthouse VA Lighthouse is the US Department of Veterans Affairs' developer API platform. Published at developer.va.g... 35 APIs 46.6 crates.io crates.io is the official package registry for the Rust programming language, operated by the crates.io tea... 5 APIs 46.5 Umami Umami is an open source, privacy-first web analytics platform that provides website traffic insights withou... 7 APIs 46.1 Redis Redis is an open source, in-memory data structure store used as a database, cache, message broker, and stre... 4 APIs 44.4 Docling Docling is an open-source toolkit for parsing diverse document formats — PDF, DOCX, PPTX, XLSX, HTML, image... 18 APIs 44.0 Frankfurter Frankfurter is an open-source (MIT) currency exchange rates API that blends foreign-exchange reference rate... 6 APIs 43.9 PokéAPI PokéAPI (pokeapi.co) is a free, open-source RESTful and GraphQL API serving comprehensive Pokémon data — in... 12 APIs 43.9 ACI.dev ACI.dev (Aipolabs Agent-Computer Interface) is an open-source tool-calling platform that hooks AI agents in... 4 APIs 43.5 Radio Browser Radio Browser is a free, community-driven directory of internet radio stations. The project publishes a pub... 4 APIs 43.1 OpenHands OpenHands (by All Hands AI, formerly OpenDevin) is an open-source autonomous coding agent platform. Ships a... 14 APIs 42.8 American Airlines American Airlines is one of the world's largest airlines, operating an extensive domestic and international... 2 APIs 42.0
Thin 20 Limited public surface area
Unity Unity is a real-time 3D content creation platform — the Unity engine powers cross-platform games, simulatio... 19 APIs 40.6 Medusa Medusa is an open-source headless commerce platform written in Node.js and TypeScript, distributed under th... 17 APIs 39.9 Jaeger Jaeger is an open-source, end-to-end distributed tracing platform for monitoring and troubleshooting transa... 3 APIs 38.6 ipify ipify operates two complementary IP APIs. The free Public IP Address API (api.ipify.org, api6.ipify.org, ap... 3 APIs 38.4 Krea Krea is a real-time AI creative suite that lets designers, filmmakers, brand teams, and everyday creators g... 7 APIs 38.3 Cypress Semiconductor Cypress Semiconductor was a US-based semiconductor company known for its PSoC programmable system-on-chip m... 6 APIs 37.0 Turborepo Turborepo is a high-performance build system for JavaScript and TypeScript codebases, built by Vercel and w... 2 APIs 36.3 Quote Garden Quote Garden is a free, open-source REST API that serves more than 75,000 famous quotes. Built by Prathames... 3 APIs 36.1 Audiomack Audiomack is an on-demand music streaming and audio discovery platform that lets artists and creators uploa... 8 APIs 35.4 Syndica Syndica is a Solana-only infrastructure company building developer infrastructure for Web3. Its production ... 4 APIs 34.5 Random User Generator Free random user data API for generating realistic fake user profiles with names, addresses, photos, and co... 1 API 34.2 Analog Devices Analog Devices (ADI) is a global semiconductor company designing high-performance analog, mixed-signal, and... 3 APIs 32.9 Academy Software Foundation The Academy Software Foundation (ASWF) is a Linux Foundation project that supports open source software dev... 14 APIs 32.2 BMW ConnectedDrive BMW ConnectedDrive is BMW Group's umbrella for connected vehicle services spanning navigation, remote servi... 4 APIs 31.8 Deutsche Telekom Deutsche Telekom AG is Europe's largest telecommunications operator, headquartered in Bonn, Germany, servin... 50 APIs 31.1 Apiary Apiary is an API design and documentation platform, now part of Oracle Cloud Infrastructure. With 486,000+ ... 2 APIs 30.6 Three.js Three.js is an open-source JavaScript 3D library originally created by Ricardo Cabello (mrdoob) in 2010 and... 6 APIs 30.4 Yarn Yarn is an open-source JavaScript package manager and project manager originally created at Facebook in 201... 10 APIs 30.0 Jitsi Jitsi is a collection of free and open-source projects for secure, simple, and scalable real-time video con... 10 APIs 28.8 Volvo Cars Volvo Cars is a Swedish premium automotive OEM (headquartered in Gothenburg, owned by Geely) that operates ... 4 APIs 28.6
Emerging 28 Early or largely undocumented
Pasqal Pasqal is a French neutral-atom quantum computing company headquartered in Palaiseau, France and co-founded... 8 APIs 27.4 Glama Glama is an all-in-one AI workspace combining an MCP server marketplace and registry, a managed MCP gateway... 7 APIs 27.2 Firely Firely is an Amsterdam-based health IT company and one of the original co-developers of the HL7 FHIR (Fast ... 3 APIs 26.6 Signifyd Signifyd is an ecommerce fraud prevention, chargeback protection, and revenue optimization platform. Its Co... 8 APIs 26.4 Cielo Cielo is one of the largest Brazilian card acquirers and a publicly traded company (B3:CIEL3), originally f... 13 APIs 26.3 Apache Software Foundation The Apache Software Foundation (ASF) is a 501(c)(3) nonprofit organization that provides open source softwa... 1 API 25.9 McKinsey & Company McKinsey & Company is the senior partner of the MBB triumvirate of global strategy and management consultin... 25.8 Renovate Renovate is an open source automated dependency update bot maintained by Mend. It scans repositories for re... 6 APIs 25.7 Eyevinn Technology Eyevinn Technology is a Stockholm, Sweden based video streaming consultancy and open source company special... 8 APIs 25.3 Raken Raken is a San Diego-based construction technology company providing a field-first daily reporting and fiel... 1 API 24.7 Automatisch Automatisch is an open source business automation tool and self-hosted alternative to Zapier that connects ... 1 API 24.6 Xanadu Xanadu is a Toronto-based photonic quantum computing company building cloud-accessible continuous- variable... 10 APIs 24.6 CHAOSS CHAOSS (Community Health Analytics in Open Source Software) is a Linux Foundation project that develops met... 4 APIs 24.4 Xanadu Xanadu is a Canadian photonic quantum computing company building room-temperature, fault-tolerant, scalable... 14 APIs 21.7 Changelog Changelog is a media company and podcast network for developers covering open source and software developme... 4 APIs 21.3 Satellogic Satellogic is an Argentine-founded, U.S.-listed (NASDAQ: SATL) vertically integrated Earth observation comp... 6 APIs 21.2 Sony Sony Group Corporation is a Japanese multinational spanning electronics, gaming, entertainment, image senso... 4 APIs 21.1 Promptfoo Promptfoo is an open-source CLI and TypeScript/Node.js library for evaluating, red-teaming, and security-te... 20.9 Scenario Scenario is a Paris- and San Francisco-headquartered AI platform for game asset generation founded in 2021 ... 5 APIs 20.5 pnpm pnpm is a fast, disk space efficient package manager for JavaScript and Node.js projects. It uses a content... 5 APIs 19.6 GSK GSK plc (formerly GlaxoSmithKline, rebranded in May 2022) is a global biopharma headquartered in the United... 18.6 QuEra Computing QuEra Computing is a Boston-based neutral-atom quantum computing company (founded 2018) that operates Aquil... 8 APIs 18.4 CHIPS Alliance CHIPS Alliance is a Linux Foundation project (founded in 2019) that develops open-source hardware (silicon)... 18.1 Apivault Apivault is an open-source directory and gateway for discovering public APIs. The platform catalogs thousan... 1 API 17.9 Refact.ai Refact.ai is an open-source, local-first AI coding assistant and autonomous software-engineering agent buil... 2 APIs 17.4 Quantinuum Quantinuum is an integrated quantum computing company formed by the 2021 merger of Honeywell Quantum Soluti... 9 APIs 17.2 WhyLabs WhyLabs was an AI observability platform focused on data and model monitoring for both classical ML and LLM... 3 APIs 15.7 Comet Comet is Perplexity's AI-native browser built on Chromium (Blink), integrating Perplexity Search and an age... 13.3
Minimal 7 Almost no public developer surface
Bosch Bosch is a German multinational engineering and technology company producing automotive components, industr... 5 APIs 12.1 Schrödinger Schrödinger is a New York-headquartered (NASDAQ: SDGR) computational science company that develops a physic... 10.0 Fox Corporation Fox Corporation (NASDAQ: FOXA, FOX) is a US media company spun out of 21st Century Fox in 2019 when the res... 9.9 SST SST is an open source TypeScript framework for building full-stack applications on your own infrastructure.... 2 APIs 8.8 ether.fi ether.fi is a non-custodial, decentralized Ethereum liquid restaking protocol where stakers retain control ... 8.7 OctoAI OctoAI (formerly OctoML) was a Seattle-based AI inference platform founded in 2019 as a University of Washi... 5 APIs 8.5 Rolls-Royce Rolls-Royce plc is a British multinational aerospace and defense company manufacturing aero engines (Trent ... 6.4

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.

100% open source under Apache 2.0 (with separate commercial license for `highlight.io/` and `enterprise/` directories)150+ pre-built configurations in the open-source sensible-configuration-library covering common document types (1040, W-2, 1099, ACORD forms, loss runs, bank statements, rate confirmations)25+ open-source inference models — Llama 3.1 8B/70B/405B, Qwen 2.5, DeepSeek V3, DeepSeek R1, Hermes 3, Mistral, Llama 3.2 Vision, Qwen2-VL300+ Open Source Projects3D Scene module with custom-layer extensibility (open-source 3d-viewer-module)AGPL-3.0 Open SourceAll Google Quantum AI open-source software is Apache 2.0 licensedApache 2.0 LicenseApache 2.0 Open Source LicenseApache 2.0 licensed; governance via GOVERNANCE.md and MAINTAINERS.mdApache 2.0 open-source licensing for pytket, qnexus, lambeq, Guppy, Selene, QermitAutoChain — open-source lightweight framework for building and testing LLM agents (1.8k+ GitHub stars)Browser-side background-removal JS library and Blender texturing plugin available as open sourceC# scripting with hot-reload, the Unity Scripting API, and full source available via UnityCsReferenceCompanion BMW Car IT open-source stack (joynr, ramses, MoCOCrW, python-dlt) underpinning connected-vehicle middlewareCore: free open-source self-managedFirely .NET SDK — official open-source C# FHIR library (de-facto reference SDK)Free open-source MCP server hostingFree open-source WordPress pluginFree, ad-free, open-source online chess server operated by a French nonprofit, funded by donationsGSK Biostatistics Open SourceHosted Flow app (React) with full source available for self-hostingHosted micro frontends: checkout, cart, my-account, microstore, identity — each open-source on GitHubKrea Realtime experience with sub-50ms image generation and an open-source Realtime 14B autoregressive video model distilled from Wan 2.1 (CC BY-NC-SA 4.0)Local MCP server (Node.js, billed against API units) — open source on GitHubMIT LicenseMIT licensed, no required runtime dependencies, runs in browser, Node.js, Electron, Tauri, Deno, and React NativeMIT licensed, open source on GitHub (vercel/turborepo)MIT-licensed open sourceMIT-licensed open source codebase (composer/packagist) — operated, not designed for reuseMulti-turn agent simulations with User Simulator and Judge Agents (open-source `scenario` framework)Ocean SDK — Python open-source SDK covering dimod, dwave-system, dwave-cloud-client, hybrid, samplersOfficial OpenAPI 3.1 specification published under MIT license at github.com/conekta/openapiOn-chain programs are open-source (Apache-2.0) Anchor programs published as IDLs, npm packages, and Rust cratesOpen SourceOpen Source (BSD-3-Clause)Open Source (MIT)Open Source Cloud (OSC)Open Source EcosystemOpen Source Focus

Showing 40 of 119 declared variants