posture posture

Open Source

Score 43.0 / 100 1106 providers +93 via APIs 309 APIs Search apis.io →

Providers using this tag (1105)

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

Exemplar 31 Complete, well-documented, and agent-ready

AppwriteApplicationBackendMobile2 APIs83.2 WSO2API ManagementGatewaysAPI Lifecycle7 APIs79.9 The Things Network / The Things StackLoRaWANIoTNetwork Server9 APIs79.2 MedplumHealthcareFHIRDeveloper Platform1 API79.1 FlagsmithFeature FlagsRemote ConfigRelease ManagementA/B Testing2 APIs78.5 RudderStackCustomer Data PlatformCDPData Pipeline1 API78.5 GhostPublishingNewslettersMembershipSubscription3 APIs78.0 SwetrixAnalyticsCookieless TrackingGDPR Compliant2 APIs77.0 SvixWebhookWebhooks As A ServiceWebhook DeliveryWebhook Sending1 API76.7 CanonicalCanonicalCloudLinux13 APIs76.3 DifyArtificial IntelligenceLLMOpsBackend-as-a-ServiceAgents2 APIs75.3 PlunkEmailTransactional EmailMarketingAutomation2 APIs75.1 GatiFlowMarket IntelligenceDeveloper SignalsTrendsHiring2 APIs74.6 ClickHouseClickHouseAnalyticsCloud DatabaseColumn-Oriented2 APIs73.5 KongKongAPI GatewayAI GatewayAI Connectivity2 APIs73.2 GiteaGiteaGitSource ControlDevOps2 APIs72.5 AuthentikAuthenticationAuthorizationIdentity ProviderLDAP1 API71.6 Virto CommerceB2B eCommerceCatalog ManagementOrder ManagementPricing14 APIs71.4 NovuNotificationMessagingIn-AppEmail1 API71.1 GrafanaObservabilityMonitoringDashboardsLogs1 API71.0 Red HatRed HatCloudContainersEnterprise6 APIs70.6 AirbyteData IntegrationETLELT1 API70.3 MatomoAnalyticsWeb AnalyticsPrivacy61 APIs70.0 Crawl4AIAI AutomationWeb CrawlingWeb ScrapingData Extraction1 API68.6 CanvasCanvasEducationEdTechGraphQL146 APIs68.2 RybbitAnalyticsWeb AnalyticsProduct AnalyticsPrivacy1 API68.2 Microsoft .NET.NETC#CloudCross-Platform10 APIs67.7 Blnk FinanceFintechFinancial ServicesLedgerdouble-entry-accounting1 API67.4 Synadia CommunicationsCompanyMessagingEvent StreamingNATS2 APIs67.0 AppsmithLow-CodeInternal ToolsWorkflow Automation1 API66.9 Canvas LMSLearning ManagementEducationEdTechLMS1 API66.9

Strong 65 Solid coverage with minor gaps

Developing 242 Usable, with meaningful gaps to close

Thin 371 Limited public surface area

Emerging 280 Early or largely undocumented

Minimal 113 Almost no public developer surface

Unrated 3 Not yet scored

Concord SystemsCompanyStream ProcessingReal-TimeData Processing ImpiraCompanyDocument AIIntelligent Document ProcessingMachine Learning NeuralMagicCompanyArtificial IntelligenceMachine LearningInference

APIs with this tag (304)

Ranked by the provider's API Evangelist rating — the Kin Score is scored per provider, not per API, so every API of a provider shares its band. How the rating works →

Exemplar 19 Complete, well-documented, and agent-ready

Svix Open Source Server APIThe self-hostable open source Svix server (svix-webhooks repo). Smaller surface area than the hosted produc...76.7 Launchpad Web Services APILaunchpad exposes a RESTful Web Services API over its project hosting, bug tracking, code, builds, translat...76.3 Kong GatewayKong Gateway is the open-source, lightweight, cloud-native API gateway optimized for microservices, deliver...73.2 Kong InsomniaKong Insomnia is an open-source API development platform for designing, debugging, and testing APIs. It sup...73.2 Arcade MCP FrameworkThe arcade-mcp open-source Python framework — "MCP Server Framework and Tool Development library for buildi...72.9 New Relic Telemetry SDKsThe New Relic Telemetry SDKs are open source client libraries for sending metrics, events, logs, and traces...72.3 Adobe Campaign Classic JavaScript SDKAn open-source JavaScript SDK that wraps Adobe Campaign Classic SOAP APIs in a simple, expressive, JavaScri...72.0 Stoplight CLIThe Stoplight CLI enables programmatic linting of API descriptions and pushing analysis results to the Stop...71.8 Stoplight ElementsElements is an open-source toolkit for building beautiful, interactive API documentation from OpenAPI speci...71.8 Stoplight PrismPrism is an open-source HTTP mock and proxy server that turns any OpenAPI v2/v3 or Postman Collection file ...71.8 Stoplight SpectralSpectral is an open-source JSON and YAML linter for creating automated API style guides and governance rule...71.8 Scalar API ClientScalar API Client is a fully open-source, offline-first REST API client built on the OpenAPI standard. Supp...71.7 Scalar CLIThe Scalar CLI is a command-line interface for managing OpenAPI files, generating documentation, running mo...71.7 IBM Watsonx.data APICollect, store, query, and analyze structured and unstructured enterprise data with a unified data lakehous...69.1 Crawl4AI Self-Hosted APIThe Apache-2.0 API server that ships inside the crawl4ai project and the unclecode/crawl4ai Docker image, s...68.6 Q# Quantum Programming LanguageQ# is Microsoft's open-source, hardware-agnostic quantum programming language. The Modern QDK compiler is w...68.1 Blnk Cloud APIManaged Cloud REST surface covering OAuth auth, a Proxy API to a Core instance, Data API, Filters API, Aler...67.4 Blnk Watch APIRule-based transaction monitoring API (transaction evaluation, instruction management, Git-backed rule sync...67.4 NextGen Mirth Connect Integration Engine APIAPI for NextGen Mirth Connect, an open-source healthcare integration engine supporting HL7 v2, FHIR, and ot...66.7

Strong 36 Solid coverage with minor gaps

Hermes Search Engine gRPC APISelf-hosted, MIT-licensed Rust search engine published by Space Frontiers (github.com/SpaceFrontiers/hermes...65.5 Medusa Core RepositoryMonorepo with the Medusa server, Admin, Commerce Modules, Framework, and packages. MIT-licensed reference f...65.4 Gravitee Kafka GatewayThe Gravitee Kafka Gateway brings full API management discipline to Apache Kafka. It sits in front of one o...65.2 Gravitee Kubernetes OperatorThe Gravitee Kubernetes Operator (GKO) is a Go-based Kubernetes operator that lets platform teams declare G...65.2 Red5 Agent-Native SurfacePublicly hosted llms.txt providing a structured index of Red5 products, use cases, and documentation for AI...65.1 Red5 Pro Server APIREST/JSON API embedded in the Red5 Pro media server providing server info/ping/statistics, applications, st...65.1 Stream Manager 2.0 APIREST/JSON API used by both Red5 Pro clusters and Red5 Cloud for Auth, Admin, Proxy, Streams, Streams Provis...65.1 Janssen ProjectThe Janssen Project is the upstream Linux Foundation open-source identity platform that powers Gluu Flex. I...63.9 Highlight Self-Hosted DeploymentSelf-hosted deployment of the open-source Highlight stack. Three tiers — Dev (single-host docker-compose), ...63.6 Data API BuilderOpen source configuration-based engine that creates REST and GraphQL APIs for SQL Server, Azure SQL, Azure ...62.7 Data API Builder for SQL ServerOpen-source tool that generates REST and GraphQL endpoints for SQL Server and Azure SQL databases from conf...62.7 Refuel Autolabel (Open Source)Autolabel is the open-source Python library (pip install refuel-autolabel) to label, clean, and enrich text...61.6 OpenZeppelin Contracts API ReferenceThe OpenZeppelin Contracts library provides a comprehensive collection of modular, reusable, and secure Sol...60.2 OpenZeppelin Monitor APIOpenZeppelin Monitor is an open-source blockchain monitoring service that watches for specific on-chain act...60.2 Hugging Face Transformers LibraryOpen-source Python library that provides pretrained models, tokenizers, and pipelines for inference and fin...60.0 Gloo EdgeGloo Edge is a feature-rich, Kubernetes-native ingress controller and API gateway built on Envoy Proxy, sup...57.8 CirqCirq is an Apache 2.0 Python framework for designing, manipulating, simulating, and executing Noisy Interme...57.7 OpenFermionOpenFermion is an Apache 2.0 library for translating quantum chemistry and materials science problems (elec...57.7 qsimqsim is a high-performance C++ state-vector simulator with a Python (qsimcirq) binding that plugs directly ...57.7 QualtranQualtran provides abstractions (Bloqs) for expressing, decomposing, and resource-estimating fault-tolerant ...57.7 ReCirqReCirq is a research-grade collection of reproducible Cirq experiments and applications published by Google...57.7 Redox HL7 v2 Libraryredox-hl7-v2 is Redox's open-source JavaScript library for parsing and generating HL7 v2 messages, useful f...57.7 StimStim is a fast stabilizer-circuit simulator and detector-error-model toolchain that underpins Google Quantu...57.7 TensorFlow QuantumTensorFlow Quantum (TFQ) is a hybrid quantum-classical machine learning library that integrates Cirq circui...57.7 Tesseract DecoderTesseract is a search-based maximum-likelihood decoder for quantum error correction that accompanies Stim. ...57.7 UnitaryUnitary is an API library for adding quantum behaviours (superposition, entanglement, measurement) into cla...57.7 Traefik MeshLightweight service mesh built on Traefik Proxy. Offers traffic management and observability for service-to...57.0 Traefik ProxyTraefik Proxy is the flagship open-source (MIT) cloud-native reverse proxy, ingress controller, and load ba...57.0 Yaegi (Go Interpreter)Embeddable Go interpreter maintained by Traefik Labs. Powers the Traefik plugin system - plugins are upload...57.0 Fasten OnPremFasten OnPrem is an open-source, self-hosted, personal and family electronic medical record manager written...56.1 Drupal.org REST APIThe read-only REST API the Drupal Association operates on drupal.org itself, exposing Drupal.org’s own node...55.8 Goalkeeper MCP ServerStateless Streamable HTTP MCP service shipped with Goalkeeper, exposing 11 tools for creating and reading g...55.5 agentsmd (agentcontext) APILive, free, unauthenticated endpoint behind the agentsmd wedge: POST /normalize accepts {source_format, con...55.2 stripesig Webhook Signature Debugger APILive, free, unauthenticated endpoint behind the stripesig wedge: POST /check accepts {provider (stripe|gith...55.2 Unified ID 2.0 (UID2)Unified ID 2.0 is an open-source, deterministic identity framework seeded by The Trade Desk and now governe...55.1 Prefect Server REST APIThe Prefect Server REST API is the self-hosted variant of the Prefect orchestration API for managing workfl...54.6

Developing 61 Usable, with meaningful gaps to close

Arazzo EngineOpen-source Python engine that executes Arazzo workflow specifications alongside OpenAPI operation definiti...53.9 Jentic API AI-Readiness Framework (JAIRF)Technical specification for evaluating how interpretable, operable, and trustworthy an API is for AI system...53.9 Jentic MiniFree, open-source, self-hosted API execution layer that sits between an agent and the outside world. The ag...53.9 Jentic Standard AgentOpen-source composable reasoning agent framework that plans, acts, and recovers from failures, preconfigure...53.9 AURA Agent FrameworkMezmo's open-source agentic orchestration framework. Apache 2.0 Rust framework for composing AI agents from...52.0 Mezmo Agent (logdna-agent-v2)Open-source Rust log collection agent (logdna-agent-v2). Tails files, journald, and Kubernetes pod logs and...52.0 Bruno API ClientBruno is an open-source API client for exploring and testing REST, GraphQL, and gRPC APIs. Collections are ...51.9 Penn Medicine Open Source Health InformaticsPenn Medicine and the Perelman School of Medicine publish open-source health-informatics software across se...50.7 agentgatewayagentgateway is an open-source data plane for agentic AI — it secures, observes and governs the connections...50.4 Goose AI Agentgoose is a general-purpose, open-source AI agent that runs locally. Originally from Block and now governed ...50.4 Parallax Evaluation APISelf-hosted HTTP API of Parallax, the Apache-2.0 runtime security engine Scalarr publishes for AI agents. T...50.2 Odin MCP ServerFirst-party Model Context Protocol server (stdio transport) published by Dream Horizon that exposes Odin — ...49.7 Brightlayer UI (Design System)Eaton's open-source design system and component library used to build Brightlayer applications. Ships theme...49.5 Semgrep CLIOpen-source command-line static analysis engine. Runs locally and in CI to scan code with community and cus...49.5 Semgrep Community RulesCommunity and Semgrep-maintained rule packs covering security, correctness, best-practice, and supply chain...49.5 Semgrep DocumentationSource for the Semgrep product documentation site, including CLI reference, rule-writing guides, AppSec Pla...49.5 Semgrep InterfacesShared interface definitions (ATD-generated types) used between the Semgrep CLI, AppSec Platform, and langu...49.5 Lance FormatApache 2.0 open lakehouse format for multimodal AI. Columnar Parquet replacement offering 100x faster rando...48.6 AWX APIAWX is the open-source upstream project for Ansible Automation Platform, providing a web-based UI, REST API...47.8 Nittei Scheduler APINittei is MeetsMore's self-hosted calendar and scheduler server, written in Rust (Axum + SQLx + PostgreSQL)...47.8 use-ai Serveruse-ai is MeetsMore's open-source (BUSL-1.1) React client and Node/Bun server for letting an LLM drive a we...47.8 Continue CLIOpen-source command-line interface powering Continue's source-controlled AI checks. Checks are markdown fil...47.2 Continue IDE ExtensionsOpen-source IDE plugins shipping for VS Code and JetBrains. Provide chat, edit, apply, autocomplete, and ag...47.2 PyOD (Python Outlier Detection)PyOD is a comprehensive and scalable Python library for detecting outliers/anomalies in multivariate data. ...46.9 Ansible Semaphore APIAnsible Semaphore is an open-source modern web UI and REST API for running Ansible playbooks. It provides p...46.8 AWX APIAWX is the open-source upstream project for Ansible Automation Platform, providing a web-based UI, REST API...46.8 API DashAPI Dash is an open source AI-powered cross-platform API client built with Flutter for desktop and mobile. ...45.5 ApimanApiman is an open source API management platform with a developer portal, API gateway, and management UI su...45.5 NGINXNGINX is a versatile open-source software for web serving, reverse proxying, caching, load balancing, media...44.9 Sidequest Commons Guide (A2A)A2A agent (JSON-RPC; 0.3 message/send by default, 1.0 SendMessage with A2A-Version 1.0) that returns determ...44.4 CoolifyThe Coolify platform - an open-source, Apache-2.0 licensed, self-hostable PaaS written in PHP (Laravel) tha...44.1 Trieve Open Source ServerSelf-hostable Trieve server (Rust / Actix-web), dashboard, search and chat UIs, ingestion / file / delete w...44.0 API BlueprintAPI Blueprint is a high-level API design language created by Apiary for designing and documenting web APIs....43.9 Telegram TDLib (Telegram Database Library)TDLib is a cross-platform, fully functional Telegram client library for third-party developers. TDLib takes...43.2 Macquarie University Library Open-Source ToolingThe Macquarie University Library publishes six public repositories on GitHub as the mqlibrary organisation ...43.1 Pocket Network PATH Gateway APIPATH (Pocket API and Toolkit Harness) is an open-source framework for deploying permissionless gateways on ...43.1 Streamlit Python APIThe Streamlit Python library API provides a rich set of functions for building interactive data application...43.1 Rokwire Core Building Block APIThe identity, account and authorization service at the centre of UIUC's Rokwire platform — accounts, profil...42.9 Rokwire Gateway Building Block APIThe Rokwire service that fronts external and campus systems for the Illinois app — wayfinding and building/...42.9 TimeFusion (Timeseries Engine)Rust-based timeseries database for events, logs, traces, and metrics using a PostgreSQL dialect over S3 / D...42.8 OP StackOpen-source, modular Ethereum L2 rollup stack. The monorepo at github.com/ethereum-optimism/optimism contai...42.2 Rentberry Geocoder (gRPC)Open-source gRPC geocoding and timezone-lookup service Rentberry built and runs for its own property search...42.2 TraceeTracee is a runtime security and forensics tool for Linux that uses eBPF technology to trace system events ...42.1 TrivyTrivy is a comprehensive open source security scanner for containers, Kubernetes, code repositories, clouds...42.1 Promptfoo CLIThe Promptfoo CLI is the primary entry point for running prompt and model evaluations from the command line...41.7 Signal Android SDKSignal-Android is the open-source Android client for the Signal encrypted messaging platform. It provides t...41.6 Signal Desktop SDKSignal-Desktop is the open-source desktop client for the Signal encrypted messaging platform, built with El...41.6 Signal iOS SDKSignal-iOS is the open-source iOS client for the Signal encrypted messaging platform. It delivers end-to-en...41.6 Open-Source LibraryThe original open-source cleanlab Python library for data-centric AI - finds and fixes label errors, outlie...41.2 EvolutionaryScale ESM Python SDKOfficial Python SDK packaging ESM3 and ESM Cambrian model loaders, the `ESMProtein` multi-track data model,...41.1 Emory Libraries Digital Repository SoftwareEmory Libraries (Library Technology and Digital Strategies) maintains a large public open-source GitHub org...40.3 Fluentd Plugin APIThe Fluentd Plugin API allows developers to write custom input, output, filter, parser, formatter, and buff...40.2 OpenInferenceOpenInference is Arize's open-source set of OpenTelemetry conventions and instrumentation libraries for LLM...40.1 PhoenixPhoenix is Arize's open-source LLM observability platform offering local tracing, evaluation, experiments, ...40.1 RPA FrameworkThe RPA Framework is an open-source collection of Python libraries for robotic process automation designed ...40.1 OpenSCOW / CraneSched research-computing APIsOpenSCOW ("Super Computing On Web") is an HPC portal and management system authored at Peking University; C...39.9 BentoML REST APIBentoML is an open-source unified inference platform for deploying and scaling AI models. It auto-generates...39.5 MLflow Model Registry REST APIMLflow is an open source platform for managing the ML lifecycle, including experiment tracking, reproducibi...39.5 NVIDIA Triton Inference Server HTTP APINVIDIA Triton Inference Server is an open-source inference serving software that implements the KServe Open...39.5 Ray Serve REST APIRay Serve is a scalable model serving library built on Ray, designed for building online inference APIs. Su...39.5 vLLM OpenAI-Compatible APIvLLM is a high-throughput and memory-efficient inference engine for LLMs, implementing PagedAttention for e...39.5

Thin 95 Limited public surface area

DBHi Biomedical and Health InformaticsCHOP's Department of Biomedical and Health Informatics (DBHi) maintains 168 public repositories covering he...39.0 umd.io — student-run University of Maryland data APIA read-only REST API over UMD course, section, professor, campus bus, building/map and major data, covering...38.7 Agent Foundry — Strands Base Agent APIThe HTTP and A2A surface of Booz Allen's Agent Foundry agent baseline, an Apache-2.0 composition root that ...38.4 Lingo.dev CLIOpen-source command-line tool that localizes JSON, YAML, Markdown, CSV, and PO files in one command, tracki...37.9 Lingo.dev CompilerOpen-source build-time React localization. The Compiler detects translatable strings and generates localize...37.9 Spree Core Repository (spree/spree)Monorepo with the Spree Rails engine, Admin, Store/Admin/Platform/ Storefront APIs, OpenAPI specs, TypeScri...37.8 Tsinghua University TUNA Open Source MirrorThe TUNA open-source software mirror is the one surface Tsinghua publishes that behaves like a public API. ...37.7 CaboLabs EHRServer REST APIEHRServer is CaboLabs' Apache-2.0 open source, service-oriented openEHR clinical data repository. It expose...37.6 Quix Streams (Open Source)Apache 2.0 open source Python library (pip install quixstreams) for building containerized stream-processin...37.6 AnyscaleAnyscale is the production-scale AI platform built on Ray by the creators of Ray, supporting LLM inference ...37.4 Apache APISIX AI ProxyThe Apache APISIX ai-proxy plugin streamlines integration with LLMs by converting plugin settings into the ...37.4 Envoy AI GatewayEnvoy AI Gateway is an open-source extension to Envoy Proxy and Envoy Gateway, providing a Kubernetes-nativ...37.4 GentraceGentrace was an AI evaluation and observability product; the company has shut down and its codebase is now ...37.4 HeliconeHelicone is an open-source AI observability and routing platform centered on requests, sessions, prompts, d...37.4 LiteLLMLiteLLM (BerriAI) is an open-source LLM gateway that exposes 100+ LLM providers — OpenAI, Anthropic, Azure,...37.4 PortkeyPortkey is a production-grade AI gateway and control plane that fronts 1,600+ LLMs with unified routing, fa...37.4 Haystack Framework (Open Source)Apache-2.0 licensed Python framework for composable LLM orchestration. Build modular Pipelines from Compone...37.1 Saleor Core (Server) RepositorySource repository for the Saleor server - the Django / Python backend that implements the GraphQL API, busi...36.8 GraphQL Inspector CLICommand-line tool for comparing two GraphQL schemas and generating a detailed list of breaking, non-breakin...36.7 GraphQL Mesh APIGraphQL federation framework that composes any API service — REST, OpenAPI, gRPC, SOAP, OData, JSON Schema,...36.7 GraphQL Scalars APIOpen-source TypeScript/JavaScript library providing 80+ custom GraphQL scalar types (DateTime, EmailAddress...36.7 Syndica Sig Validator RPC APISig is Syndica's open-source Solana validator client implemented in Zig, built for performance, modular RPC...36.4 Opentrons Python Protocol APIThe Opentrons Python Protocol API is an open-source Python framework for writing automated biology lab prot...36.3 GPT4AllOpen-source ecosystem for running large language models locally on consumer hardware. Ships a desktop chat ...36.2 Estuary Flow ConnectorsOpen-source library of source and destination connectors for SaaS apps, databases, message queues, warehous...35.7 TueFind subject discovery services (ixTheo, RelBib, KrimDok)Three national subject-information discovery services built and operated by Tübingen University Library on ...35.7 GS Quant Python ToolkitGS Quant is Goldman Sachs' open-source Python toolkit for quantitative finance, distributed on GitHub and P...35.6 OpenDBM REST APIThe OpenDBM REST API is a self-hosted FastAPI service published inside AiCure's open-source OpenDBM reposit...35.6 Emissary-IngressEmissary-Ingress is an open-source, Kubernetes-native API gateway built on Envoy Proxy and a CNCF incubatin...35.4 MOSTLY AI Synthetic Data SDKOpen-source Python SDK (mostlyai, Apache 2.0) for training generators and producing synthetic data. Runs in...35.0 Sejda ConsoleCommand-line shell over the Sejda SDK for running PDF tasks (merge, split, etc.) from a terminal or scripts...34.8 Sejda SDKOpen-source (AGPLv3) Java library for PDF manipulation - merge, split, rotate, encrypt, watermark, and more...34.8 Lightly Self-Supervised Learning SDK (OSS)The open-source (Apache-2.0) lightly Python library for self-supervised representation learning on images (...34.5 Surge Python SDKOfficial Python SDK (surge-api on PyPI) wrapping the Surge API. Requires Python 3.10+, MIT-licensed, and la...34.5 Kubescape In-Cluster Component API (Open Source)The open-source Kubescape Operator's in-cluster components (storage, kubevuln, gateway, operator, node-agen...34.3 Orama Open Source EngineThe open-source @orama/orama library (Apache 2.0) - a complete in-memory search engine and RAG pipeline tha...34.2 Vocode Open Source Libraryvocode-core, the MIT-licensed Python library for building voice-based LLM agents with pluggable STT, LLM, a...34.0 Runcrunc is a CLI tool for spawning and running containers on Linux according to the OCI (Open Container Initia...33.9 Brave BrowserPrivacy-first Chromium-based browser for Windows, macOS, Linux, Android, and iOS, with built-in tracker and...32.9 Open-Source Snorkel LibraryThe free, open-source snorkel Python library (Apache-2.0) for programmatically building and managing traini...32.9 IKEA DIRIGERA Smart Home Hub API (Unofficial, Local)The DIRIGERA hub is IKEA's next-generation smart home gateway (replacing TRADFRI). It exposes a private, lo...32.7 Conductor MCP ServerConductor MCP is an official Model Context Protocol server for Orkes Conductor that exposes workflow execut...32.6 Apicurio RegistryApicurio Registry is a high-performance, runtime registry for schemas and API designs. It stores and manage...32.3 Maastricht University Institute of Data Science (Open Source)The Institute of Data Science maintains an active public GitHub organization (220 public repositories) with...32.3 Maastricht University Library Open SourceThe University Library publishes 46 public repositories of research-data-management support material, open ...32.3 Wander (formerly Brocade) — library platform built by UAntwerpen Library & ArchiveWander is the integrated library, collection and research-information platform the University of Antwerp Li...32.1 Manifold Creator Core Smart ContractsOpen-source Solidity smart contract framework for deploying ERC721 and ERC1155 creator-owned NFT contracts....32.0 Manifold Royalty RegistryOn-chain smart contract registry that serves as a single source of truth for NFT royalties across all major...32.0 Tailcall GraphQL RuntimeHigh-performance GraphQL runtime for composing multiple upstream REST, gRPC, and GraphQL APIs into a unifie...31.9 Confidential Computing Consortium ProjectsA portfolio of open source projects governed by the Confidential Computing Consortium covering Trusted Exec...31.5 Deepchecks Open-Source TestingThe AGPL-3.0 licensed open-source Python package for continuous validation of tabular, computer-vision, and...31.4 Port Ocean Integration FrameworkOpen-source framework used to build Port integrations that ingest data from third-party systems into the ca...31.4 Carbone Render Engine (Open Source)Open-source Node.js library that powers the rendering engine. Embed directly in your application; render te...31.3 RepolinterRepolinter is an open source linting tool for repositories that validates compliance with open source best ...31.3 Apache JMeterApache JMeter is the most widely-used open-source load testing tool. It supports HTTP, HTTPS, FTP, JDBC, LD...31.2 Gatling Load TestingGatling is an open-source load testing framework built on Akka and Netty, providing high performance with a...31.2 Locust Load TestingLocust is a scalable, distributed open-source load testing framework written in Python. Test scenarios are ...31.2 Bloomberg HTTP APIHTTP wrapper making the Bloomberg Open API available via HTTP and WebSockets, allowing clients to access re...31.1 KUCARS Open-Source Robotics Research (GitHub)Public open-source repositories from the Khalifa University Center for Autonomous Robotic Systems (KUCARS) ...31.1 HoppscotchHoppscotch is a lightweight open-source browser-based API client supporting REST, GraphQL, WebSockets, SSE,...30.7 LlamaIndex Python FrameworkLlamaIndex is an open-source Python framework for building LLM-powered applications including agents, RAG p...30.4 LlamaIndex TypeScript FrameworkLlamaIndex TypeScript is the JavaScript and TypeScript implementation of the LlamaIndex framework for build...30.4 FiftyOne SDK (Python)The open-source FiftyOne Python SDK is the primary interface for building and curating visual AI datasets -...30.3 what3words API Docs and OpenAPI RepositoryPublic repository hosting the OpenAPI specification, LLM files, and reference material for the what3words P...29.7 Publicis Sapient KnowHOWKnowHOW is Publicis Sapient's open-source (Apache-2.0) engineering measurement platform — a KPI dashboard t...29.4 Blender Extensions PlatformThe Blender Extensions Platform (extensions.blender.org) provides a curated repository of addons, themes, a...29.3 Blender Python APIThe Blender Python API (bpy) provides Python access to Blender's internal data, operators, and UI component...29.3 Frankfurter APIFree and open-source API for current and historical forex rates.29.3 Model Context Protocol (MCP)The Model Context Protocol (MCP) is an open-source standard for connecting AI applications to external syst...29.1 Apache KafkaOpen-source distributed event streaming platform governed by the Apache Software Foundation. Described as u...28.8 Apache PulsarOpen-source distributed messaging and streaming platform built for the cloud. Top-10 Apache Software Founda...28.8 Apicurio RegistryOpen-source schema and API artifact registry backed by Red Hat (Apache 2.0). Stores OpenAPI, AsyncAPI, Avro...28.8 NATSCNCF incubating high-performance, lightweight messaging system designed for cloud, edge, and IoT. Supports ...28.8 StorybookStorybook is an open-source frontend workshop for building UI components and pages in isolation. Supports R...28.4 Storybook MCP ServerThe Storybook MCP (Model Context Protocol) server enables AI agents to interact with a running Storybook in...28.4 Software Engineering Daily Backend APIThe Software Engineering Daily Backend API is an open-source REST API that powers the platform's web, iOS, ...28.2 Software Engineering Daily Mobile AppThe Software Engineering Daily mobile application is an open-source React Native app available on iOS and A...28.2 Qodo Merge (PR-Agent)AI pull-request reviewer. Available as the Apache-2.0 open-source PR-Agent (CLI, GitHub Action, Docker, sel...28.1 Renovate CLIThe open source Renovate CLI is a Node.js application distributed via npm and as Docker images on Docker Hu...28.1 Score SpecificationThe Score Specification (score.yaml) is a declarative, platform-agnostic workload definition format that ca...28.1 GoReplayGoReplay captures live HTTP traffic with libpcap and replays it against a test target, letting teams valida...28.0 Aider Python ModuleAider exposes a Python module entrypoint (`python -m aider`) and an importable package (`aider.main.main`) ...27.9 NUSMods API (student-operated, not endorsed)The only public machine-readable description of NUS course data that exists — module lists, module informat...27.9 TaxiQL Query APITaxiQL is a declarative query language for federated data retrieval across multiple APIs and data sources. ...27.9 DeepEvalDeepEval is an open-source Python framework for evaluating LLM applications as unit tests. It ships with re...27.3 DeepTeamDeepTeam is Confident AI's open-source red teaming framework for stress-testing LLM applications against ad...27.3 KlickerUZH GraphQL APIKlickerUZH is the university's open-source audience-response and interactive-learning platform, developed a...27.2 Testcontainers Open-Source LibrariesA family of open-source libraries providing a programmatic API for spinning up and tearing down Docker cont...27.2 PyAnsysOpen-source Python ecosystem for Ansys products. The pyansys metapackage bundles 45+ libraries including Py...27.1 Qrlew Server APIQrlew is Sarus's open-source (Apache 2.0) SQL manipulation and differential-privacy engine, written in Rust...26.9 Garden Core CLIOpen-source command-line tool and engine that turns a Garden project configuration into a graph of Build, D...26.6 University of Copenhagen Web Platform Source (ku-kom)github.com/ku-kom is the university's GitHub account — a User account rather than an Organization, named "U...26.4 MorphirMorphir is a universal language for business and technology that captures business logic in a portable, tec...26.3 OpenTofu CLIOpenTofu is a CLI-driven infrastructure-as-code tool forked from Terraform. The opentofu binary reads Hashi...26.3 SWAPI REST API (swapi.tech)The Node/MongoDB community rebuild of SWAPI, maintained by @semperry at swapi.tech. Wraps the canonical SWA...26.3

Emerging 86 Early or largely undocumented

AWS CLIThe AWS CLI v2 is the official command-line interface for Amazon Web Services, providing unified access to ...26.1 University of Alberta Library Open Source (GitHub)The University of Alberta Library's GitHub organization, ualbertalib, holds 138 public repositories and is ...26.1 Galaxy Project APIThe open-source Galaxy bioinformatics workbench exposes a REST API for managing histories, datasets, workfl...26.0 Terminal-BenchPublic benchmark / task-submission framework published by Mercor (terminal-bench-3 on GitHub) for evaluatin...25.6 Open Hub API (Ohloh)The REST API for Black Duck Open Hub (formerly Ohloh). Returns XML wrapped in a root element that always carr25.5 Carolina Digital Repository Services API (box-c)Public, keyless JSON API behind the Carolina Digital Repository, UNC Libraries' institutional repository fo...25.4 Apache ThriftApache Thrift is a lightweight, language-independent software stack for point-to-point RPC implementation. ...25.0 RequestsRequests is a simple and elegant HTTP library for Python, designed for human beings. It provides a clean, h...25.0 Kata ContainersKata Containers is an open source container runtime that uses lightweight virtual machines to provide the s...24.3 gVisorgVisor is an open-source application kernel written in Go that provides an additional layer of isolation be...24.2 SuperTestSuperTest is a Node.js library for testing HTTP servers by providing a high-level abstraction for HTTP asse...24.2 Stack Auth Self-Hosted (stack-auth/stack)Open-source monorepo containing the Stack Auth backend (Next.js + Postgres) and dashboard. Deployable on cu...24.1 RocksDB Embedded APIRocksDB C++ library API providing key-value storage operations including Get, Put, Delete, Merge, iterators...23.6 Web Summit Developer ProgrammeThe Web Summit Developer Programme provides free ticket access for active developers and open source contri...23.5 Open Policy Agent (OPA)Open Policy Agent is a CNCF-graduated open source general-purpose policy engine that enables unified, conte...23.2 SPIFFE - Secure Production Identity Framework for EveryoneSPIFFE is a CNCF-graduated open standard for workload identity in dynamic environments. It provides a frame...23.2 SPIRE - SPIFFE Runtime EnvironmentSPIRE is the reference implementation of SPIFFE, a CNCF-graduated production-ready toolchain for establishi...23.2 WgetGNU Wget is a free command-line utility for non-interactive downloading of files from the web using HTTP, H...23.0 Wget2GNU Wget2 is the next-generation successor to GNU Wget, built from scratch around libwget. It is multi-thre...23.0 Superduper FrameworkOpen-source Python framework (superduper-framework) for declaring AI models, embeddings, vector indexes, RA...22.7 k0sk0s is a single-binary, lightweight, certified Kubernetes distribution that runs on any infrastructure from...22.1 TripoSR (Open Source)Open-source single-image 3D reconstruction model released by VAST AI Research in collaboration with Stabili...22.0 Thymeleaf CoreThe core Thymeleaf template engine library providing HTML, XML, TEXT, JavaScript, and CSS template mode pro...21.2 RestfoxRestfox is a lightweight, offline-first web HTTP client for testing REST APIs, similar to Postman but brows...21.1 RestSharpRestSharp is a simple REST and HTTP API client library for .NET, wrapping HttpClient with a fluent API for ...20.7 WiresharkWireshark is a free and open-source network protocol analyzer that captures and interactively browses netwo...20.6 Arize AI (Phoenix)Arize AI provides an AI observability and evaluation platform centered on Arize AX (the commercial product)...20.5 DeepEval (Confident AI)DeepEval is an open-source LLM evaluation package, paired with Confident AI as the hosted observability/eva...20.5 HeliconeHelicone is an open-source observability and monitoring platform for LLM applications. The homepage states ...20.5 Inspect AIInspect AI is an open-source framework for large language model evaluations developed and maintained by the...20.5 MLflow LLM EvaluateMLflow LLM evaluate extends MLflow's experiment tracking with mlflow.evaluate() support for LLM tasks. The ...20.5 OpenAI EvalsOpenAI Evals is the open-source framework released by OpenAI for evaluating large language models and LLM-b...20.5 PromptfooPromptfoo is an open-source CLI and library for evaluating and red-teaming LLM applications. The docs descr...20.5 RagasRagas is an open-source evaluation library focused on retrieval-augmented generation, described in its own ...20.5 TruLensTruLens is an open-source evaluation and tracing platform for AI agents that helps developers "move from vi...20.5 Overture Maps Python CLIOpen-source Python command-line tool and library for downloading and querying Overture data. Maintained at ...19.7 Overture SchemaCanonical open schema specification for all Overture themes, maintained in the OvertureMaps/schema GitHub r...19.7 Overture TilesOpen tile-generation tooling that builds vector tilesets from Overture data for rendering and downstream ap...19.7 GliderGlider is Patronus's small judge model for evaluating reasoning chains and rubric-based scoring with low la...19.6 LynxLynx is Patronus's open-weights hallucination detection model published on Hugging Face. It is positioned a...19.6 baytrends Water Quality Trend APIbaytrends is an open-source R package developed by Tetra Tech for evaluating long-term trends in Chesapeake...19.5 Tetra Tech Data Discovery Tool APIThe Data Discovery Tool (DDT) is an open-source environmental data analysis platform developed by Tetra Tec...19.5 Step CIStep CI is an open source API Quality Assurance framework that is language-agnostic and configured using YA...18.9 Kisee — Identity Provider ServerKisee is an open-source HTTP API server published by Melty Group that exchanges valid username/password pai...18.8 Pasee — Identity Management ServerPasee is an open-source HTTP API server published by Melty Group that layers group and user management over...18.8 Maximum Independent Set SolverMaximum Independent Set (MIS) solver library that exploits the natural mapping of MIS onto Rydberg-blockade...18.7 Pulser SDKPulser is Pasqal's open-source (Apache-2.0) Python framework for composing, simulating, and executing pulse...18.7 Qadence SDKQadence is Pasqal's higher-level digital-analog quantum programming interface for writing variational quant...18.7 QoolQit SDKQoolQit is Pasqal's Python package for simplified algorithm development in the Rydberg Analog Model on neut...18.7 Quantum Evolution Kernel (QEK)QEK is Pasqal's open-source graph machine learning library that uses quantum-driven similarity metrics deri...18.7 QUBO SolverQuadratic Unconstrained Binary Optimization solver library that combines classical heuristics with quantum ...18.7 Open Technology FundThe Open Technology Fund (OTF) is a U.S. government-funded independent nonprofit that supports the developm...18.6 Apache Software FoundationThe Apache Software Foundation hosts 300+ open source projects spanning big data, cloud, messaging, databas...18.1 RetrofitRetrofit is a type-safe HTTP client for the JVM that turns annotated Java/Kotlin interfaces into HTTP API c...18.1 Sony gobreaker Circuit Breakergobreaker is a Go implementation of the Circuit Breaker pattern, widely used in microservice resilience des...17.4 Sony Neural Network Libraries (NNabla)NNabla is Sony's open-source deep-learning framework with Python and C++ bindings, dynamic and static compu...17.4 Sonyflake Distributed ID GeneratorSonyflake is a Go library producing 63-bit unique IDs inspired by Twitter's Snowflake but tuned for longer ...17.4 Public APIs DirectoryA collective list of free APIs organized by category including Animals, Finance, Weather, Geocoding, Govern...17.3 Lura FrameworkThe Lura Framework is an open-source Go library for building ultra-high-performance API gateways with middl...17.0 Lura ProjectLura Project is an open source framework for building ultra-performant API gateways with middlewares.17.0 DapperDoxDapperDox is an open-source API documentation generator that renders beautiful, customizable reference docs...16.2 ReqnrollReqnroll is the open-source community continuation and fork of SpecFlow, maintaining full backward compatib...16.1 Cline VS Code ExtensionOpen-source autonomous coding agent for VS Code. Reads/writes files, runs commands, browses the web, calls ...14.8 ETWAnalyzer Command Line ToolC# command-line tool published by Siemens Healthineers for analyzing Event Tracing for Windows (ETW) captur...14.7 K2s Kubernetes Distribution for Windows HostsOpen-source Kubernetes distribution built specifically for Windows hosts, published from the Siemens-Health...14.7 Patch-CLIP Embedding ModelPython research project from the Siemens-Healthineers GitHub org that extends the CLIP architecture with pa...14.7 SHIELD-DAVE Medical Device Cybersecurity PlatformPHP-based platform from the Siemens-Healthineers GitHub org focused on medical device cybersecurity and US ...14.7 Llama Models (open weights)Open-weight Llama model family available for direct download and self-hosted inference, distributed under M...14.5 Llama StackOpen-source framework standardizing the building blocks for Llama-based generative AI applications, includi...14.5 PurpleLlamaOpen-source project providing tools and evaluations for assessing and improving the safety and security of ...14.5 Genmo Mochi Pipeline (Self-Hosted OSS)The first-party access surface is the open-source model itself. The Mochi repo (Apache-2.0) ships a "simple...14.4 CNCF Hosted Projects (Standards Steward)CNCF stewards an open-source project portfolio whose APIs underpin much of modern cloud infrastructure - Ku...14.2 RTSP ImplementationsCommon open-source RTSP server and client implementations used in production. MediaMTX (formerly rtsp-simpl...13.9 Software Discovery ToolSoftware Discovery Tool helps match developer requirements with available open source software tested on th...13.9 zopen Communityzopen is a community-driven catalog and build framework that ports and packages popular open source tools f...13.9 Changelog Open Source Platform (GitHub)The Changelog platform is an open source Elixir and Phoenix application that powers changelog.com. The sour...13.4 The Changelog Podcast RSS FeedThe Changelog podcast RSS feed provides access to all episodes of The Changelog, a weekly podcast covering ...13.4 Adept Fuyu-8B ModelOpen-source 9B-parameter image-text-to-text multimodal model designed for digital agents - simple architect...13.0 Adept Persimmon-8B Base ModelOpen-source 8B-parameter base text generation model with permissive license. Self-hosted only - no managed ...13.0 Adept Persimmon-8B Chat ModelOpen-source chat-tuned variant of Persimmon-8B. Self-hosted only - no managed API.13.0 Linux Foundation ProjectsProgrammatic access to Linux Foundation project resources, member data, and open source ecosystem informati...11.9 pvfactorspvfactors is an open-source Python library for modeling diffuse shading and bifacial photovoltaic (PV) irra...11.9 PVMismatchPVMismatch is an open-source Python library for calculating mismatch losses in photovoltaic systems. It mod...11.9 SolarUtilsSolarUtils is an open-source Python package providing solar position algorithms and utility functions for s...11.9 O-RAN Software Community APIProgrammatic access to O-RAN Software Community open interface specifications, RAN intelligence APIs, near-...11.6 LF Research APIProgrammatic access to LF Research publications, open source trend data, and industry analysis resources.11.5

Minimal 7 Almost no public developer surface

LF Edge APIProgrammatic access to LF Edge project resources, APIs, and edge computing framework tools.10.6 TruLens (Open Source)Open-source Python library for evaluating and tracking LLM applications. Provides feedback functions (groun...10.6 LF Networking APIProgrammatic access to LF Networking project resources, APIs, and open networking infrastructure tools.9.8 Open edX REST APIOpen-source REST API surface across the Open edX platform: Enrollment API, Courses API, User API, Catalog A...8.8 Maya Hydra APIMaya plugin API that replaces the main Maya viewport with a Hydra viewer, enabling custom render delegate i...7.9 LangKitLangKit is an open-source toolkit that extracts telemetry from LLM prompts and responses including relevanc...0.0 whylogswhylogs is an open-source data logging library that creates approximate statistical profiles of datasets, e...0.0

Companies reaching this through an API (93)

These companies publish an API, specification or operation carrying “Open Source” but do not classify their business under it. Listed unranked and kept out of the count above, because one tagged operation is not a statement about what a company does.

Adept Adobe Campaign Agent Skills AI Gateway Ambassador Anomaly Detection Ansible Playbooks Ansys Apiary APIToolkit (Monoscope) Aqua Security Arcade Booz Allen Hamilton Brave CaboLabs Children's Hospital of Philadelphia Cleanlab Deepchecks Eaton Emory University Estuary Flow Evals Events EvolutionaryScale Forex Garden Goldman Sachs Google Quantum AI IBM Jentic Khalifa University Life Sciences Lightly Lingo.dev Maastricht University Macquarie University Manifold Maya Mercor Mezmo Microsoft Azure Quantum Microsoft SQL Server Mirantis MOSTLY AI National University of Singapore New Relic NextGen Healthcare OpenZeppelin Optimism Pasqal

Show all 93 companies ↓

Patronus AI Peking University Penn Medicine Pocket Network Port Prefect Qodo Quix Red5 Redox Refuel Rentberry RTSP Scalability Testing Scalable Inference Serving Scalar Sejda Semgrep Siemens Healthineers Snorkel AI Sony Space Frontiers SpecFlow Stoplight Surge AI Syndica Telegram Testcontainers Tetra Tech The Trade Desk Tripo AI TruEra (Snowflake) U.S. Agency for Global Media University of Alberta University of Antwerp University of Maryland College Park University of Tübingen University of Zurich Vocode Voxel51 Web Summit what3words Zero Trust Architecture

Score breakdown

Frequency

74.0

log-scaled weighted occurrences

Breadth

6.5

spread across providers

Quality lift

78.5

mean composite of providers using it

Cohesion

47.7

strength of nearest seed neighbor

Where this tag comes from

Provider tag1106

Api tag309

Cohort brief

Auto-generated

The 1083 providers in the APIs.io catalog tagged Open Source, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.

Providers

1083

of 1106 on the roster

Mean Kin Score

32.5

+9.6 vs catalog 22.9

Mean Agent Readiness

17.3

+5.4 vs catalog 11.9

Spread

0–83.2

median 32.1 · σ 15.8

How the 1083 split by band

Exemplar 31Strong 65Developing 242Thin 371Emerging 278Minimal 96

Facet averages, against the whole catalog

Facet	This cohort	Catalog	Difference	Scored
Operational Transparency	27.4	13.7	+13.7	1083
Developer Ergonomics	36.7	23.2	+13.5	1083
Contract Quality	29.7	17.6	+12.1	1083
Contract Governance	10.7	6.3	+4.4	1083
Discoverability	61.5	58.1	+3.4	1083
Access Clarity	27.3	26.5	+0.8	1083

A facet is averaged over the members that carry it, not over the whole cohort — the “Scored” column is that count. Averaging an absent facet as zero would score our own coverage gaps as the providers’ posture.

What this cohort publishes

Artifact	This cohort	Catalog	Difference
MCP server (any)	18%	14%	+4
MCP server (first-party)	15%	12%	+3
Agent Skills	0%	0%	0
OAuth scopes	9%	11%	-2
Security	97%	98%	-1
Arazzo workflows	3%	2%	+1
Governance rules	34%	14%	+20

mcp_pct counts any mcp/ artifact including ones API Evangelist derived from the provider OpenAPI; mcp_first_party_pct counts only servers the provider publishes. Prefer the latter.

Top by Kin Score

1 Appwrite 83.2
2 WSO2 79.9
3 The Things Network / The Things Stack 79.2
4 Medplum 79.1
5 Flagsmith 78.5
6 RudderStack 78.5
7 Ghost 78
8 Swetrix 77
9 Svix 76.7
10 Canonical 76.3

Work with this as data

Every tag here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for tags

7 MCP tools reach this

find_tagsBrowse and filter every tag in the catalog.
get_cohortThis tag as a scored cohort — every provider carrying it, with scores.
cohort_statsPRO — the distribution across this tag: mean, median, band split, adoption rates.
cohort_rankingsPRO — the leaderboard, on composite AND agent-readiness axes.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This tag

curl "https://apis.io/api/v1/tags/open-source"

All tags

curl "https://apis.io/api/v1/tags?limit=25"

As a scored cohort

curl "https://apis.io/api/v1/cohorts/tag/open-source"

The distribution (Pro)

curl "https://apis.io/api/v1/cohorts/tag/open-source/stats" \
  -H "X-API-Key: $APIS_IO_KEY"

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