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 |
|---|---|---|---|
| FastAPI FastAPI is a modern, high-performance Python web framework for building APIs, based on standard Python type hints and built on Starlette an… | 94 | 103093 | active |
| Hoppscotch Hoppscotch is an open-source API development ecosystem for building, testing, and documenting HTTP, REST, GraphQL, and WebSocket requests. … | 98 | 80634 | active |
| typicode/json-server A Node.js CLI tool that turns a JSON file into a full fake REST API with CRUD endpoints, filtering, and pagination in seconds. It is widely… | 73 | 75711 | active |
| OpenBB OpenBB's Open Data Platform (ODP) is an open-source Python toolset that integrates proprietary, licensed, and public financial data sources… | 85 | 73550 | active |
| Plane Plane is an open-source project management platform offering issue tracking, cycles/sprints, kanban boards, roadmaps, and an integrated wik… | 97 | 61193 | active |
| CLIProxyAPI A Go-based proxy server that exposes OpenAI/Gemini/Claude/Codex-compatible API endpoints backed by CLI AI assistant accounts (Claude Code, … | 82 | 54756 | active |
| psf/requests Requests is a widely-used Python library for making HTTP/1.1 requests with a simple, human-friendly API. It handles connection pooling, ses… | 90 | 54342 | stable |
| New API New API is a self-hosted LLM gateway and AI asset management system that aggregates 30+ model providers behind a single unified endpoint. I… | 88 | 48905 | active |
| Bruno Bruno is an open-source desktop IDE for exploring and testing REST and GraphQL APIs, positioned as a lightweight alternative to Postman and… | 98 | 47313 | active |
| Hyperswitch Hyperswitch is an open-source, composable payments orchestration platform written in Rust by Juspay, connecting to 300+ payment processors,… | 95 | 45357 | active |
| Wei-Shaw/sub2api Sub2API is a self-hosted AI API gateway written in Go that converts Claude, OpenAI, Gemini, and Grok subscriptions into unified API access.… | 80 | 44264 | active |
| lysine-dev/retrofit Retrofit is a type-safe HTTP client for Android and the JVM that turns REST APIs into Java or Kotlin interfaces using annotations. It gener… | 79 | 43934 | stable |
| curl Docker images curl is a command-line tool and libcurl is a C library for transferring data to or from servers using URL syntax, supporting dozens of prot… | 95 | 43152 | stable |
| httpie/cli HTTPie CLI is a modern, user-friendly command-line HTTP client written in Python for testing, debugging, and interacting with APIs and HTTP… | 23 | 38644 | stable |
| ASP.NET Core ASP.NET Core is the open-source, cross-platform web framework for .NET, used to build modern cloud-based web applications, APIs, IoT apps, … | 97 | 38467 | stable |
| songquanpeng/one-api One API is a self-hosted LLM API gateway and key management system that unifies OpenAI, Azure, Anthropic Claude, Google Gemini, DeepSeek, a… | 52 | 37040 | stable |
| jq jq is a lightweight command-line JSON processor written in portable C with zero runtime dependencies. It lets users slice, filter, map, and… | 82 | 35854 | stable |
| github/github-mcp-server GitHub's official Model Context Protocol (MCP) server that connects AI tools like Claude, Cursor, and VS Code directly to GitHub's platform… | 83 | 33620 | active |
| binarywang/WxJava WxJava is a comprehensive Java SDK for WeChat backend development, covering WeChat Pay, Mini Programs, Official Accounts, Open Platform, En… | 72 | 33138 | active |
| Hono Hono is a small, ultrafast web framework built on Web Standards APIs with zero dependencies. It runs on any JavaScript runtime including Cl… | 95 | 32549 | stable |
| SWR SWR is a React Hooks library for data fetching, named after the stale-while-revalidate caching strategy. It returns cached data first, then… | 90 | 32493 | stable |
| Antigravity Tools Antigravity Tools is a desktop application built with Tauri v2, React, and Rust that manages multiple AI service accounts and provides one-… | 80 | 32370 | active |
| Hasura GraphQL Engine Hasura GraphQL Engine is an open-source engine that auto-generates instant, realtime GraphQL APIs (and REST endpoints) over existing databa… | 98 | 32132 | active |
| googleworkspace/cli A single command-line tool (`gws`) for interacting with all Google Workspace APIs — Drive, Gmail, Calendar, Sheets, Docs, Chat, Admin, and … | 72 | 31505 | active |
| decolua/9router 9Router is a self-hosted AI gateway/router that connects AI coding tools like Claude Code, Cursor, Codex, and Cline to 60+ LLM providers th… | 74 | 30634 | active |
| spf13/viper Viper is a comprehensive configuration library for Go applications that reads from files, environment variables, command-line flags, and re… | 54 | 30475 | stable |
| encode/django-rest-framework Django REST framework is a powerful and flexible toolkit for building Web APIs on top of Django. It provides serializers, class-based views… | 98 | 30205 | stable |
| swagger-api/swagger-ui Swagger UI is a collection of HTML, JavaScript, and CSS assets that dynamically generate interactive API documentation from an OpenAPI (Swa… | 93 | 29025 | stable |
| PostgREST PostgREST is a standalone web server that automatically exposes any existing PostgreSQL database as a fully RESTful HTTP API. Written in Ha… | 98 | 27693 | stable |
| tokio-rs/axum Axum is an HTTP routing and request-handling library for Rust built on Tokio, focusing on ergonomics and modularity. It integrates deeply w… | 89 | 27309 | stable |
| discord.js discord.js is a powerful, object-oriented Node.js library for interacting with the Discord API, covering gateway events, REST calls, slash … | 90 | 26819 | stable |
| Agent2Agent (A2A) Protocol Agent2Agent (A2A) is an open protocol, hosted under the Linux Foundation, that standardizes communication and interoperability between opaq… | 80 | 26020 | active |
| rwf2/Rocket Rocket is an async web framework for Rust focused on usability, security, extensibility, and speed. It provides macro-based routing, compil… | 46 | 25783 | stable |
| TOON TOON (Token-Oriented Object Notation) is a compact, human-readable encoding of the JSON data model designed to reduce token usage in LLM pr… | 78 | 25440 | active |
| ranaroussi/yfinance yfinance is a Python library that fetches financial and market data from Yahoo! Finance's publicly available APIs, returning data as pandas… | 95 | 25373 | stable |
| gorilla/websocket gorilla/websocket is a fast, well-tested Go implementation of the WebSocket protocol (RFC 6455) for both clients and servers. It is part of… | 25 | 24876 | stable |
| Actix Web Actix Web is a powerful, pragmatic, and extremely fast asynchronous web framework for Rust. It provides type-safe routing, flexible respond… | 100 | 24864 | stable |
| Guzzle Guzzle is an extensible PHP HTTP client for sending HTTP requests and integrating with web services. It supports synchronous and asynchrono… | 98 | 23445 | stable |
| go-chi/chi chi is a lightweight, idiomatic HTTP router for Go that is 100% compatible with net/http and built around the context package. It supports … | 95 | 22952 | stable |
| SwiftyJSON SwiftyJSON is a Swift library that simplifies parsing and manipulating JSON data with convenient subscript access and automatic optional ha… | 63 | 22939 | stable |
| whatsapp-web.js whatsapp-web.js is a Node.js client library that connects to WhatsApp through the WhatsApp Web browser app using Puppeteer, exposing nearly… | 90 | 22673 | active |
| gorilla/mux gorilla/mux is a powerful HTTP request router and URL matcher for Go web servers, implementing the standard http.Handler interface. It supp… | 23 | 21833 | stable |
| Dgraph Dgraph is a distributed, horizontally scalable graph database with native GraphQL support, written in Go. It provides ACID transactions, co… | 97 | 21804 | stable |
| Parse Platform Parse Server is an open-source Backend-as-a-Service (BaaS) that runs on Node.js with the Express framework, providing REST and GraphQL APIs… | 96 | 21398 | active |
| graphql/graphql-js GraphQL.js is the official reference implementation of GraphQL for JavaScript. It provides tools to build a GraphQL schema and execute quer… | 97 | 20340 | active |
| grpc-gateway A protoc plugin that reads protobuf service definitions with google.api.http annotations and generates a reverse-proxy server translating R… | 100 | 20006 | stable |
| lionsoul2014/ip2region ip2region is an offline IP-to-region localization library and IP data management framework supporting both IPv4 and IPv6 with city-level re… | 98 | 19713 | stable |
| Elysia Elysia is a TypeScript backend web framework built for Bun, emphasizing end-to-end type safety, schema-driven validation, and ergonomic dev… | 93 | 19239 | active |
| Keploy Keploy is a developer-centric API and integration testing platform that records real application traffic, database queries, and streaming e… | 96 | 18641 | active |
| Sanic Sanic is a fast, asynchronous Python web framework and web server supporting async/await syntax and ASGI compliance. It bundles a productio… | 78 | 18634 | stable |
| ory/hydra Ory Hydra is an OpenID Certified OAuth 2.0 and OpenID Connect provider server written in Go, handling token issuance, client management, an… | 72 | 17563 | stable |
| Apache APISIX Apache APISIX is a dynamic, high-performance cloud-native API gateway and AI gateway built on NGINX and etcd, offering load balancing, dyna… | 94 | 17201 | stable |
| julienschmidt/httprouter HttpRouter is a lightweight, high-performance HTTP request router (mux) for Go that supports path variables and method matching using a com… | 23 | 17132 | stable |
| LibreTranslate/LibreTranslate LibreTranslate is a free and open source machine translation API that is fully self-hosted and offline capable, powered by the Argos Transl… | 92 | 17127 | stable |
| Ky Ky is a tiny, zero-dependency JavaScript HTTP client built on the Fetch API, offering a simpler API with method shortcuts, automatic retrie… | 95 | 17095 | stable |
| yhirose/cpp-httplib A C++11 single-file header-only HTTP/HTTPS server and client library supporting HTTP/1.1 with SSL/TLS via OpenSSL, MbedTLS, or wolfSSL. It … | 96 | 16913 | active |
| graphql/graphiql GraphiQL is the official GraphQL Foundation reference IDE for exploring and testing GraphQL APIs in the browser, plus a monorepo ecosystem … | 94 | 16913 | active |
| forwardemail/superagent SuperAgent is a small, progressive HTTP request library for Node.js and browsers with an elegant, chainable API supporting callbacks, promi… | 93 | 16628 | stable |
| aiohttp aiohttp is an asynchronous HTTP client and server framework for Python built on asyncio. It supports client and server WebSockets out of th… | 99 | 16572 | stable |
| hyperium/hyper hyper is a fast, correct, low-level HTTP implementation for Rust providing both client and server APIs with HTTP/1 and HTTP/2 support. It i… | 95 | 16362 | stable |
| scalar/scalar Scalar is an open-source API platform centered on rendering beautiful interactive API references from OpenAPI/Swagger documents, with a bui… | 91 | 16250 | active |
| Rapptz/discord.py discord.py is a modern, async-ready Python library wrapping the Discord API, including a commands extension for building bots. It handles r… | 74 | 16187 | stable |
| rjsf-team/react-jsonschema-form A React component library that declaratively builds and validates web forms from JSON Schema. It supports multiple UI themes (MUI, Bootstra… | 98 | 15909 | stable |
| HTTPX HTTPX is a fully featured HTTP client library for Python 3 with sync and async APIs, HTTP/1.1 and HTTP/2 support, and a requests-compatible… | 78 | 15639 | stable |
| Moya/Moya Moya is a Swift network abstraction layer that encapsulates Alamofire calls behind typed, enum-based API endpoints. It provides compile-tim… | 61 | 15354 | stable |
| corsairdev/corsair Corsair is an open-source TypeScript integration layer that lets applications and AI agents connect to 200+ third-party services (GitHub, S… | 58 | 15309 | active |
| Feathers Feathers is a full-stack framework for building web APIs and real-time applications in TypeScript or JavaScript. It provides a service-orie… | 97 | 15257 | stable |
| ZITADEL ZITADEL is an open-source identity and access management (IAM) platform providing authentication and authorization out of the box, includin… | 94 | 15193 | active |
| languagetool-org/languagetool LanguageTool is an open-source proofreading engine that checks grammar, spelling, and style in 25+ languages. It ships as a Java library, a… | 77 | 15163 | stable |
| OpenWA OpenWA is a free, MIT-licensed, self-hosted WhatsApp API Gateway that wraps WhatsApp connections in a REST API with webhooks, a React dashb… | 78 | 15142 | active |
| sindresorhus/got Got is a human-friendly and powerful HTTP request library for Node.js, offering JSON mode, retries, pagination, hooks, and stream support. … | 95 | 14949 | stable |
| Ajv Ajv is the fastest JSON Schema validator for JavaScript, compiling declarative schemas into optimized validation functions. It supports JSO… | 84 | 14852 | stable |
| hapijs/hapi @hapi/hapi is a mature Node.js web framework for building HTTP servers and APIs with secure defaults, a rich plugin system, and zero extern… | 66 | 14786 | stable |
| Ktor Ktor is an asynchronous web framework for Kotlin, built by JetBrains on top of coroutines, for creating servers, microservices, and multipl… | 98 | 14548 | stable |
| Drogon Drogon is a C++14/17/20-based HTTP web application framework for building high-performance web application servers. It uses non-blocking I/… | 82 | 14326 | active |
| Netflix/zuul Zuul is Netflix's L7 application gateway service providing dynamic routing, monitoring, resiliency, and security for microservices. It is a… | 93 | 14083 | active |
| OpenResty OpenResty is a full-fledged web platform that bundles an enhanced Nginx core, LuaJIT, and many Nginx modules and Lua libraries into a singl… | 79 | 14044 | stable |
| apollographql/apollo-server Apollo Server is a spec-compliant, production-ready GraphQL server library for Node.js that supports schema-first development. It integrate… | 90 | 13952 | stable |
| quicktype quicktype is a code generation tool that produces strongly-typed models and serializers from JSON samples, JSON Schema, TypeScript, and Gra… | 94 | 13889 | active |
| MeterSphere MeterSphere is an open-source continuous testing platform with a built-in AI assistant for generating test cases. It combines test case man… | 94 | 13541 | active |
| HackerNews/API Official documentation and samples for the Hacker News public API, hosted on Firebase. It describes how to access HN items (stories, commen… | 32 | 13357 | stable |
| Cap'n Proto Cap'n Proto is an extremely fast binary data interchange format and capability-based RPC system, designed so data can be read directly from… | 76 | 13210 | stable |
| nock/nock Nock is an HTTP server mocking and expectations library for Node.js. It intercepts HTTP requests made by code under test and returns predef… | 94 | 13126 | stable |
| Portkey AI Gateway Portkey AI Gateway is an open-source, TypeScript-based AI gateway that routes requests to 1,600+ LLMs across many providers through a singl… | 71 | 13079 | active |
| ShishirPatil/gorilla Gorilla is a UC Berkeley research project for training and evaluating LLMs to make function/tool calls, including the OpenFunctions fine-tu… | 52 | 13044 | active |
| Swag (Go Swagger generator) Swag converts Go source code annotations into Swagger 2.0 (OpenAPI) documentation, with a CLI generator and integrations for popular Go web… | 85 | 13039 | stable |
| graphile/crystal Graphile's Crystal monorepo containing Grafast, a planning and execution engine for GraphQL.js, and PostGraphile, which auto-generates high… | 95 | 12935 | active |
| fullstorydev/grpcurl grpcurl is a command-line tool for invoking RPC methods on gRPC servers, accepting JSON input and converting it to binary protobuf encoding… | 86 | 12855 | active |
| dio dio is a powerful HTTP client library for Dart and Flutter supporting global configuration, interceptors, FormData, request cancellation, t… | 94 | 12840 | stable |
| NangoHQ/nango Nango is an open-source integration platform for building product integrations with 900+ pre-built API providers. It handles OAuth/API-key … | 95 | 12694 | active |
| Kludex/starlette Starlette is a lightweight, production-ready ASGI framework and toolkit for building async web services in Python. It provides HTTP and Web… | 100 | 12674 | stable |
| Play Framework Play Framework is a high-velocity, reactive web framework for Java and Scala running on the JVM. It offers a stateless, non-blocking archit… | 90 | 12617 | active |
| darrenburns/posting Posting is a terminal-based (TUI) HTTP client for testing and working with REST APIs, similar to Postman or Insomnia but keyboard-centric. … | 91 | 12509 | active |
| grpc/grpc-rust Tonic is a Rust implementation of gRPC over HTTP/2, providing async/await client and server support built on hyper and tokio, with prost-ba… | 91 | 12495 | stable |
| Sinatra Sinatra is a Ruby DSL for quickly creating web applications with minimal effort, built on Rack. It provides routing, filters, sessions, and… | 70 | 12454 | stable |
| Slim Framework Slim is a PHP micro-framework for quickly writing simple yet powerful web applications and APIs. It provides a fast HTTP router, concentric… | 86 | 12275 | active |
| expressjs/multer Multer is Node.js middleware for handling multipart/form-data, primarily used for file uploads, built on top of busboy. It integrates with … | 93 | 12087 | stable |
| LonamiWebs/Telethon Telethon is a pure Python 3 asyncio MTProto library for interacting with Telegram's full API, either as a user account or a bot, serving as… | 10 | 12067 | active |
| seanmonstar/reqwest Reqwest is an ergonomic, batteries-included HTTP client library for Rust built on hyper. It supports async and blocking clients, JSON/multi… | 96 | 11845 | stable |
| go-resty/resty Resty is a simple HTTP, REST, and SSE client library for Go with a fluent API. It provides middleware, retries with backoff, circuit breaki… | 93 | 11814 | active |
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