Open-source apis software
2782 open-source libraries, tools and applications tagged apis, ranked by how closely apis is their primary purpose, then by adoption and maintenance health. Each entry links to a page with sources, use cases and when to choose or avoid it.
2782 products, primary matches first, then adoption-weighted; health v2 shown.
| Product | Health v2 | Stars | Maturity |
|---|---|---|---|
| Exchange API A free currency exchange rates API serving 200+ currencies, including cryptocurrencies and metals, with daily updates and no rate limits. D… | 70 | 2678 | active |
| kordoc An MCP server and CLI that exposes Korea's Ministry of Government Legislation (법제처) open APIs — statutes, precedents, ordinances, treaties,… | 83 | 2653 | active |
| scalatra/scalatra Scalatra is a tiny, Sinatra-inspired web micro-framework for Scala that runs on the JVM. It lets developers build high-performance, asynchr… | 76 | 2647 | active |
| Visual Studio Code A VS Code extension by Microsoft/GitHub that lets developers review and manage GitHub pull requests and issues directly inside the editor. … | 100 | 2636 | active |
| AWS SDK for Java The official AWS SDK for Java, version 2, enabling Java applications to interact with Amazon Web Services such as S3, EC2, and DynamoDB. It… | 96 | 2631 | stable |
| cloudwego/volo Volo is a high-performance, strongly extensible RPC framework written in Rust for building microservices. It provides Thrift, gRPC, and HTT… | 85 | 2630 | active |
| WeChatPadPro/WeChatPadPro WeChatPadPro is a self-hostable WeChat management and automation service built on the unofficial WeChat Pad protocol, written in Go. It exp… | 63 | 2630 | active |
| jeasonlzy/okhttp-OkGo OkGo is an Android network request library built on top of OkHttp, offering a simpler RESTful-style API than Retrofit. It supports RxJava/R… | 23 | 10549 | maintenance |
| http4s Http4s is a minimal, idiomatic Scala library for building HTTP servers and clients, serving as Scala's equivalent to Rack, WSGI, WAI, and S… | 94 | 2626 | stable |
| tus/tus-js-client tus-js-client is a pure JavaScript client library for the tus resumable upload protocol, an HTTP-based protocol for interruptible, resumabl… | 78 | 2625 | stable |
| hayes/pothos Pothos is a plugin-based GraphQL schema builder for TypeScript that uses a strongly typed, code-first approach with no code generation requ… | 91 | 2624 | active |
| ory/fosite Fosite is a security-first, extensible OAuth 2.0 and OpenID Connect SDK for Go, implementing RFC 6749, RFC 6819, PKCE, and OpenID Connect C… | 54 | 2618 | active |
| agentclientprotocol/claude-agent-acp An ACP (Agent Client Protocol) adapter that exposes the Claude Agent SDK to any ACP-compatible client. It bridges protocol features like to… | 80 | 2617 | active |
| firecamp-dev/firecamp Firecamp is an open-source, developer-first API development platform for designing, testing, and documenting REST, GraphQL, WebSocket, and … | 48 | 2615 | active |
| versatica/JsSIP JsSIP is a pure JavaScript SIP (Session Initiation Protocol) library that implements a full SIP user agent for browsers and Node.js. It sup… | 65 | 2608 | stable |
| stephenh/ts-proto ts-proto is a protoc plugin that generates idiomatic, strongly-typed TypeScript code from protobuf schema files, including encode/decode me… | 96 | 2595 | active |
| keikaavousi/fake-store-api FakeStoreAPI is a free hosted REST API that serves pseudo-real e-commerce JSON data including products, carts, users, and JWT login tokens.… | 32 | 2593 | stable |
| HTTPlug HTTPlug is an HTTP client abstraction for PHP built on PSR-7 messages, defining synchronous and asynchronous client interfaces. It lets lib… | 44 | 2588 | stable |
| facet-rs/facet Facet is a Rust reflection ecosystem: a single derive macro gives types a runtime SHAPE description (fields, variants, attributes, layout) … | 81 | 2587 | active |
| Open Wearables Open Wearables is a self-hosted, MIT-licensed platform that unifies wearable health data from providers like Garmin, Whoop, Oura, Fitbit, S… | 82 | 2585 | active |
| API Platform API Platform is a full-stack PHP framework built on Symfony (and Laravel) for creating API-first projects with hypermedia REST or GraphQL A… | 94 | 2577 | stable |
| Azure/azure-sdk-for-java The official Azure SDK for Java, providing client and management libraries for consuming and administering Azure services. It follows the A… | 96 | 2564 | active |
| http-kit http-kit is a minimalist, high-performance, event-driven HTTP client and server for Clojure, fully Ring-compatible as a drop-in replacement… | 63 | 2564 | stable |
| aurora-develop/aurora A Go service that exposes ChatGPT Web capabilities as an OpenAI-compatible API, including chat completions, responses, file Q&A, image gene… | 89 | 2558 | active |
| sparrowapp-dev/sparrow-app Sparrow is an open-source, AI-powered desktop and web application for API testing, debugging, documentation, and team collaboration, positi… | 74 | 2550 | active |
| Autobahn Autobahn|Python is an open-source library implementing the WebSocket protocol and the Web Application Messaging Protocol (WAMP) for Python … | 99 | 2541 | active |
| 3lvis/SwiftSync SwiftSync is a Swift library that syncs JSON API payloads into local SwiftData models and exports them back to JSON. It provides convention… | 75 | 2541 | active |
| Ash Framework Ash is a declarative, extensible application framework for Elixir that lets you model your domain as typed resources and derive APIs, persi… | 96 | 2539 | active |
| circe circe is a JSON library for Scala and Scala.js providing a JSON AST, encoders/decoders (codecs), and automatic derivation for case classes … | 94 | 2539 | stable |
| symfony/serializer The Symfony Serializer component transforms data structures, including object graphs, into array structures or formats like XML and JSON, a… | 93 | 2535 | stable |
| apache/fineract Apache Fineract is an open-source, cloud-ready core banking platform written in Java, providing client management, loan and savings portfol… | 90 | 2533 | stable |
| Alerta Alerta is a monitoring system that consolidates and de-duplicates alerts from multiple monitoring sources into a single view, combining a J… | 69 | 2530 | active |
| RestKit RestKit is an Objective-C framework for building RESTful web service clients on iOS and OS X. It provides an object mapping engine integrat… | 23 | 10084 | maintenance |
| golang/protobuf The legacy Go module providing bindings for Google's protocol buffers, including binary, text, and JSON serialization of protobuf messages.… | 65 | 10077 | maintenance |
| microsoft/CsWin32 A C# source generator that emits strongly-typed P/Invoke and COM interop bindings for Win32 APIs from .winmd metadata. It generates friendl… | 100 | 2524 | active |
| SpectoLabs/hoverfly Hoverfly is a lightweight open-source API simulation and service virtualization tool written in Go. It captures HTTP/HTTPS traffic and repl… | 97 | 2524 | active |
| Cap'n Proto for Rust A Rust implementation of the Cap'n Proto data serialization format and RPC protocol. It generates code from schema files enabling zero-copy… | 77 | 2518 | active |
| CJackHwang/AIstudioProxyAPI A self-hosted proxy server that exposes Google AI Studio's web chat interface as an OpenAI-compatible API using FastAPI and Camoufox/Playwr… | 64 | 2513 | active |
| mitmproxy/pdoc pdoc is a zero-configuration documentation generator that auto-generates API documentation for Python projects from docstrings and type ann… | 69 | 2512 | active |
| Squidex/squidex Squidex is an open-source (MIT) headless CMS and content management hub built with ASP.NET Core and CQRS, exposing content and assets throu… | 95 | 2511 | active |
| pagekit/vue-resource vue-resource is an HTTP client plugin for Vue.js that provides services for making web requests via XMLHttpRequest or JSONP. It supports th… | 10 | 9978 | maintenance |
| Apipie Apipie-rails is a DSL and Rails engine for documenting RESTful APIs in Ruby on Rails applications. It lets developers describe API endpoint… | 79 | 2506 | stable |
| disease.sh (NovelCOVID API) disease.sh is a free, open-source REST API serving JSON statistics on COVID-19, Influenza, and other disease outbreaks, aggregating data fr… | 59 | 2501 | active |
| theoephraim/node-google-spreadsheet A popular JavaScript/TypeScript wrapper library for the Google Sheets API (v4). It provides cell-based and row-based read/write operations,… | 90 | 2494 | active |
| Mercurius Mercurius is a GraphQL adapter for the Fastify web framework for Node.js, providing query parsing/validation caching, JIT execution, subscr… | 95 | 2493 | stable |
| maxmind/GeoIP2-php A PHP library providing a client for MaxMind's GeoIP2 and GeoLite web services and a reader for their MMDB-format geolocation databases. It… | 84 | 2491 | stable |
| php-fig/link php-fig/link provides the PSR-13 standard interfaces for representing hyperlinks and link providers in PHP. It contains only interface defi… | 32 | 2490 | stable |
| trailofbits/graphtage Graphtage is a command-line utility and Python library for semantically diffing and merging tree-structured files like JSON, YAML, XML, HTM… | 96 | 2488 | stable |
| senchalabs/connect Connect is an extensible HTTP server framework for Node.js built around a stack of 'plugins' known as middleware. It provides a minimal cor… | 32 | 9874 | maintenance |
| python-gitlab/python-gitlab python-gitlab is a Python package providing access to the GitLab v4 REST API and GraphQL API, including a CLI tool wrapping REST endpoints.… | 94 | 2476 | stable |
| Google APIs Client Library for PHP The official Google APIs client library for PHP, enabling server-side access to Google APIs such as Gmail, Drive, and YouTube. It is comple… | 93 | 9812 | maintenance |
| confluentinc/schema-registry Confluent Schema Registry is a Java-based serving layer that stores and retrieves Avro, JSON Schema, and Protobuf schemas via a RESTful API… | 77 | 2470 | active |
| stoplightio/elements Stoplight Elements is an open-source set of React and Web Components for building beautiful, interactive API documentation from OpenAPI doc… | 66 | 2466 | active |
| CarterCommunity/Carter Carter is a thin framework layer of extension methods over ASP.NET Core that makes building HTTP APIs more explicit and enjoyable. It adds … | 69 | 2461 | active |
| JMESPath JMESPath is a declarative query language for extracting and transforming elements from JSON documents, with a formal specification and comp… | 64 | 2451 | stable |
| lihengming/spring-boot-api-project-seed A Spring Boot and MyBatis based seed/boilerplate project for quickly building small-to-medium RESTful API projects in Java. It provides bes… | 23 | 9680 | maintenance |
| Saloon Saloon is a PHP library for rapidly building third-party API integrations and SDKs using Connector and Request classes. It is framework-agn… | 96 | 2442 | active |
| lestrrat-go/jwx A comprehensive Go library implementing the full JOSE family of standards (JWA, JWE, JWK, JWS, JWT) for signing, verifying, encrypting, and… | 98 | 2440 | active |
| RubyGems.org RubyGems.org is the Ruby community's central gem hosting service, a Rails application that lets developers publish, search, and install Rub… | 77 | 2439 | active |
| open-webui/pipelines Pipelines is a UI-agnostic, OpenAI API-compatible plugin framework for adding custom Python logic and workflows to any client that speaks t… | 38 | 2437 | active |
| apiDoc apiDoc is a Node.js CLI tool that generates RESTful web API documentation from inline @api annotations in source code comments. It supports… | 10 | 9649 | maintenance |
| Firebase Admin SDK for PHP An unofficial Firebase Admin SDK for PHP that provides access to Firebase services like Authentication, Realtime Database, Firestore, and C… | 97 | 2435 | active |
| Spark Spark is a tiny, expressive web framework for Java 8+ (with a Kotlin DSL) inspired by Sinatra, letting you define routes with lambdas in a … | 32 | 9636 | maintenance |
| timekit-io/booking-js Booking.js is an embeddable JavaScript booking widget by Timekit that lets websites add appointment scheduling in minutes, powered by the T… | 23 | 2428 | active |
| panva/openid-client openid-client is a TypeScript library providing OAuth 2.0 and OpenID Connect client APIs for JavaScript runtimes including Node.js, Deno, b… | 95 | 2419 | stable |
| knowsuchagency/mcp2cli mcp2cli is a Python CLI tool that turns any MCP server, OpenAPI spec, or GraphQL endpoint into a command-line interface at runtime with zer… | 60 | 2418 | active |
| HAPI FHIR HAPI FHIR is a complete open-source Java implementation of the HL7 FHIR standard for healthcare data interoperability, providing APIs for b… | 99 | 2416 | stable |
| dotnet/Docker.DotNet Docker.DotNet is a fully asynchronous .NET (C#) client library for the Docker Remote API, letting applications interact programmatically wi… | 37 | 2414 | active |
| 12306 Ticket Search A Model Context Protocol (MCP) server that exposes 12306 (China Railway) ticket search capabilities to large language models. It provides A… | 78 | 2393 | active |
| SignalR ASP.NET SignalR is a .NET library that makes it simple to add real-time web functionality to ASP.NET (System.Web/Katana) applications, lett… | 38 | 9399 | maintenance |
| dingo/api Dingo API is a PHP package that provides tools for building RESTful APIs on top of the Laravel and Lumen frameworks. It offers content nego… | 23 | 9378 | maintenance |
| Rob--W/cors-anywhere CORS Anywhere is a Node.js reverse proxy that adds CORS headers to proxied requests, allowing browsers to make cross-origin requests to ser… | 32 | 9365 | maintenance |
| nelmio/NelmioApiDocBundle A Symfony bundle that generates OpenAPI/Swagger documentation for REST APIs from PHP 8 attributes and code analysis. It exposes interactive… | 92 | 2368 | active |
| Smithy Smithy is a protocol-agnostic interface definition language (IDL) and a set of tools for modeling services as collections of resources, ope… | 97 | 2365 | stable |
| Countries A Ruby gem providing country objects with data from ISO 3166 (countries and subdivisions), ISO 4217 (currencies), and E.164 (phone numbers)… | 77 | 2364 | active |
| orhanerday/open-ai A community-maintained PHP SDK for accessing the OpenAI API, supporting GPT-3/GPT-4 chat completions, DALL-E image generation, and ChatGPT-… | 24 | 2363 | active |
| gotd/td gotd/td is a full MTProto 2.0 Telegram API client library written in pure Go, supporting both user accounts and bots with generated binding… | 97 | 2358 | stable |
| Neoteroi/BlackSheep BlackSheep is a fast asynchronous ASGI web framework for Python, inspired by Flask and ASP.NET Core. It features built-in dependency inject… | 91 | 2358 | active |
| form-data/form-data A Node.js library for creating readable multipart/form-data streams, inspired by the XMLHttpRequest-2 FormData interface. It supports appen… | 68 | 2356 | stable |
| hashicorp/go-retryablehttp A Go library providing an HTTP client wrapper around net/http with automatic retries and exponential backoff. It exposes a nearly identical… | 65 | 2353 | stable |
| mirumee/ariadne Ariadne is a Python library for building GraphQL servers using a schema-first approach, where the API is defined in SDL and business logic … | 98 | 2345 | stable |
| fruitbars/simple-one-api A single-binary Go gateway that unifies access to multiple LLM providers (Qianfan, iFlytek Spark, Tencent Hunyuan, MiniMax, DeepSeek, etc.)… | 90 | 2345 | active |
| ulule/limiter A dead-simple rate limiting middleware library for Go supporting HTTP, FastHTTP, and Gin. It uses a pluggable store approach with built-in … | 23 | 2343 | stable |
| oschwald/geoip2-golang A Go library for reading MaxMind GeoIP2 and GeoLite2 databases to look up geolocation data for IP addresses. It is built on the maxminddb r… | 95 | 2342 | active |
| OpenSea SDK The official TypeScript SDK for OpenSea, the largest NFT marketplace. It lets developers access the orderbook, create and fulfill listings … | 94 | 2337 | active |
| jwadow/kiro-gateway A self-hosted proxy API gateway for the Kiro API (Amazon Q Developer / AWS CodeWhisperer) that exposes Claude and other models through Open… | 59 | 2325 | active |
| ObjectMapper ObjectMapper is a Swift framework that converts model objects (classes and structs) to and from JSON using the Mappable protocol and the <-… | 23 | 9129 | maintenance |
| Form.io Form.io is an open-source form and data management platform that combines a drag-and-drop JSON-driven form builder with an auto-generated A… | 76 | 2323 | active |
| JSONAPI-Resources/jsonapi-resources JSONAPI::Resources (JR) is a Ruby gem that provides a resource-focused framework for building JSON:API compliant API servers on Rails 5.1+.… | 68 | 2322 | active |
| httpie/http-prompt HTTP Prompt is an interactive command-line HTTP client built on top of HTTPie and prompt_toolkit, featuring fuzzy autocomplete, syntax high… | 23 | 9110 | maintenance |
| cloudflare/meet Cloudflare Meet (formerly Orange Meets) is a demo video-conferencing application built on Cloudflare Realtime SFU (Calls) with WebRTC. It s… | 57 | 2314 | active |
| gotham-rs/gotham Gotham is a flexible web framework for Rust built on Tokio and Hyper, emphasizing stability, safety, security, and speed. It is statically … | 85 | 2312 | active |
| josephburnett/jd jd is a command-line utility and Go library for diffing and patching JSON and YAML values. It supports a native human-readable diff format … | 74 | 2308 | active |
| gnostic gnostic is a Go command-line compiler that converts OpenAPI descriptions between JSON/YAML and Protocol Buffer representations. It provides… | 62 | 2308 | active |
| financial-datasets/mcp-server A Model Context Protocol (MCP) server that exposes the Financial Datasets stock market API to AI assistants like Claude Desktop. It provide… | 28 | 2307 | active |
| Azure/azure-sdk-for-js The official Azure SDK for JavaScript and TypeScript, providing client libraries for consuming Azure services and management libraries for … | 96 | 2302 | active |
| james-6-23/codex2api Codex2API is a self-hosted Go/Gin reverse proxy with an embedded React admin dashboard that turns a pool of Codex accounts into an OpenAI- … | 78 | 2295 | active |
| Verk HTTPoison is an HTTP client library for Elixir built on top of the Erlang hackney HTTP library. It provides a simple, idiomatic API for mak… | 74 | 2287 | stable |
| Easy Mock Easy Mock is a self-hostable persistent web service that generates mock API data quickly and provides a visual interface for defining and m… | 23 | 8953 | maintenance |
| API-Security/APIKit APIKit is a BurpSuite extension (Java plugin) that discovers, scans, and audits leaked API documentation such as GraphQL, OpenAPI/Swagger, … | 23 | 2286 | active |