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 |
|---|---|---|---|
| apollographql/apollo-kotlin Apollo Kotlin is a strongly-typed, caching GraphQL client for JVM, Android, and Kotlin Multiplatform targets. It provides code generation f… | 97 | 3977 | active |
| Anthropic Python SDK The official Python SDK for accessing the Anthropic Claude API. It provides a typed client for creating messages, streaming responses, and … | 93 | 3951 | stable |
| octokit/octokit.rb Octokit.rb is a Ruby client library for the GitHub REST API, wrapping endpoints in idiomatic Ruby methods. It supports authentication (basi… | 66 | 3951 | stable |
| duolahypercho/codex-router A local model router that lets external LLM providers (Anthropic, Kimi, DeepSeek, xAI, GitHub Copilot, and others) be used inside the Codex… | 79 | 3949 | active |
| release-drafter/release-drafter Release Drafter is a GitHub Action, GitHub App, and Node.js CLI that automatically drafts release notes as pull requests are merged into yo… | 99 | 3948 | active |
| shopizer-ecommerce/shopizer Shopizer is an open-source Java e-commerce platform built on Spring Boot, providing headless commerce with a REST API covering catalog, sho… | 25 | 3942 | active |
| kemalcr/kemal Kemal is a fast, lightweight web framework for the Crystal language with a Sinatra-like DSL for building web applications and JSON APIs. It… | 96 | 3928 | stable |
| Ring Ring is a Clojure library that abstracts HTTP into a simple unified API, inspired by Python's WSGI and Ruby's Rack. It enables modular web … | 74 | 3884 | stable |
| fastly/pushpin Pushpin is a reverse proxy server written in Rust and C++ that adds realtime push capabilities (WebSockets, HTTP streaming, long-polling, S… | 85 | 3863 | active |
| lanqian528/chat2api A Python service that proxies ChatGPT's web interface into an OpenAI-compatible API format, supporting GPT-3.5, GPT-4/4o, O1/O3 models, GPT… | 32 | 3839 | active |
| midday-ai/packrun packrun.dev is a web service and MCP server that scores, compares, and ranks npm packages across 50+ categories using live metrics like dow… | 49 | 3837 | active |
| predibase/lorax LoRAX is a multi-LoRA inference server that serves thousands of fine-tuned LLM adapters on a single GPU by sharing a common base model. It … | 60 | 3835 | active |
| microsoft/kiota Kiota is a Microsoft command-line tool that generates strongly typed HTTP API clients from OpenAPI descriptions. It supports multiple targe… | 99 | 3833 | active |
| jorisvink/kore Kore is an easy-to-use, scalable web application framework for writing web APIs and concurrent web processes in C or Python. It is secure b… | 67 | 3830 | stable |
| thephpleague/oauth2-client A PHP library providing a base client for integrating with OAuth 2.0 service providers per RFC 6749. It includes a GenericProvider for Bear… | 85 | 3819 | stable |
| liujingxing/rxhttp RxHttp is a type-safe HTTP request library for Android built on top of OkHttp, supporting Kotlin Coroutines, RxJava2, and RxJava3. It offer… | 99 | 3816 | active |
| node-oidc-provider A Node.js library implementing an OpenID Certified OAuth 2.0 Authorization Server with full OpenID Connect support. It is highly configurab… | 95 | 3816 | active |
| fern-api/fern Fern is a CLI-based platform that takes OpenAPI (and AsyncAPI, Protobuf, OpenRPC) definitions and generates type-safe SDKs in multiple lang… | 87 | 3813 | active |
| defunkt/gist A Ruby gem providing a `gist` command-line tool for uploading files, clipboard contents, or STDIN to GitHub Gists. It supports creating, up… | 68 | 3807 | active |
| WPGraphQL WPGraphQL is a free, open-source WordPress plugin that exposes an extendable GraphQL schema and API for any WordPress site. It lets develop… | 95 | 3794 | active |
| swar/nba_api A Python API client package for accessing NBA.com's official stats and live game APIs. It wraps NBA.com endpoints with easy methods returni… | 79 | 3789 | active |
| daviddrysdale/python-phonenumbers A Python port of Google's libphonenumber library for parsing, formatting, and validating international phone numbers. It converts phone num… | 76 | 3774 | active |
| Jackson Jackson is the de facto standard JSON parsing and data-binding library for Java and the JVM, providing a streaming parser/generator, POJO-t… | 77 | 3757 | stable |
| 1rgs/claude-code-proxy A Python proxy server that translates Anthropic API requests so Anthropic clients like Claude Code can run against OpenAI, Gemini, or Anthr… | 56 | 3753 | active |
| goccy/go-json goccy/go- is a fast JSON encoder/decoder library for Go that is a drop-in replacement for the standard encoding/ package. It maintains full… | 94 | 3752 | active |
| google/tarpc tarpc is an RPC framework for Rust focused on ease of use, letting you define services directly in code without a separate schema language … | 72 | 3746 | active |
| flasgger/flasgger Flasgger is a Flask extension that extracts OpenAPI (Swagger) specifications from Flask views using docstrings, YAML files, dictionaries, o… | 23 | 3743 | active |
| Julien-cpsn/ATAC ATAC is a feature-full terminal-based API client similar to Postman, Insomnia, or Bruno, built in Rust with a TUI interface. It is free, ac… | 89 | 3740 | active |
| springdoc-openapi springdoc-openapi is a Java library that automatically generates OpenAPI 3 API documentation for Spring Boot applications, with built-in Sw… | 94 | 3738 | stable |
| PHP-CRUD-API A single-file PHP script that automatically exposes a full-featured REST API on top of a MySQL/MariaDB, PostgreSQL, SQL Server, or SQLite d… | 94 | 3736 | stable |
| rs/curlie Curlie is a command-line HTTP client that acts as a frontend to curl while providing the ease of use and output formatting of HTTPie. It ex… | 44 | 3730 | stable |
| thunderclient/thunder-client-support Thunder Client is a lightweight REST API client extension for VS Code and JetBrains IDEs, offering GUI-based request testing, collections, … | 96 | 3725 | active |
| grpc-ecosystem/grpc-spring A Spring Boot starter that integrates the gRPC framework into Spring applications, auto-configuring gRPC servers for @GrpcService beans and… | 67 | 3706 | active |
| async-graphql A high-performance, fully specification-compliant GraphQL server library for Rust built on async/await. It integrates with web frameworks l… | 64 | 3685 | stable |
| schemathesis/schemathesis Schemathesis is a Python-based API testing tool that automatically generates test cases from OpenAPI and GraphQL schemas using property-bas… | 96 | 3680 | active |
| fabric8 A Java client library providing access to the full Kubernetes and OpenShift REST APIs via a fluent DSL. It includes extensions for Knative,… | 98 | 3677 | active |
| AWS SDK for JavaScript The official modular AWS SDK for JavaScript (v3), offering TypeScript-first client packages for each AWS service with a configurable middle… | 96 | 3676 | stable |
| pallets/quart Quart is an async Python web application framework that reimplements Flask's API on top of asyncio and ASGI. It supports HTML templating, J… | 96 | 3673 | stable |
| PublicAffairs/openai-gemini A serverless proxy that translates OpenAI API requests into Google Gemini API calls, letting any OpenAI-only tool use Gemini's free tier. I… | 53 | 3664 | active |
| aws/aws-sdk-go-v2 The official AWS SDK version 2 for the Go programming language, providing clients and utilities for all AWS services such as S3, EC2, and D… | 94 | 3662 | stable |
| AWS SDK for Ruby The official AWS SDK for Ruby (Version 3), providing idiomatic Ruby client libraries for AWS services such as S3, EC2, and DynamoDB. It is … | 67 | 3657 | stable |
| TypeID TypeID is a specification and set of libraries for type-safe, K-sortable, globally unique identifiers that extend UUIDv7 with a snake_case … | 58 | 3653 | active |
| HTTP Toolkit HTTP Toolkit is an open-source desktop application for intercepting, inspecting, and rewriting HTTP(S) traffic on Windows, Linux, and Mac. … | 58 | 3653 | active |
| LangChain A lightweight Python library that adapts Anthropic Model Context Protocol (MCP) tools into LangChain/LangGraph-compatible tools. It provide… | 10 | 3650 | active |
| Elasticsearch .NET client The official, strongly-typed .NET client library for Elasticsearch, maintained by Elastic. It provides typed requests and responses for Ela… | 93 | 3647 | active |
| nesquena/rabl RABL (Ruby API Builder Language) is a Ruby templating system for Rails and Padrino that generates JSON, XML, MessagePack, PList, and BSON A… | 63 | 3627 | stable |
| jsonrainbow/json-schema A PHP library for validating JSON data structures against JSON Schema, supporting Draft-3, Draft-4, Draft-6, Draft-7, and Draft 2019-09. It… | 99 | 3625 | active |
| dtinit/data-transfer-project An open-source framework providing common data models and adapter libraries that enable direct service-to-service transfer of user data bet… | 67 | 3625 | active |
| kennethreitz/responder Responder is a Python HTTP service framework with a Flask/Falcon-style request-response model, built on Starlette and ASGI. It bundles batt… | 85 | 3617 | active |
| ory/oathkeeper Ory Oathkeeper is a cloud native Identity & Access Proxy (IAP) and Access Control Decision API written in Go that authenticates, authorizes… | 74 | 3605 | active |
| dunglas/vulcain Vulcain is a protocol and reference gateway server (a Caddy web server module written in Go) that uses Preload hints, 103 Early Hints, and … | 94 | 3595 | active |
| maticzav/graphql-shield GraphQL Shield is a TypeScript library that lets you build a permission layer for GraphQL servers using an intuitive rule-based API. It wor… | 66 | 3576 | stable |
| WordPress/Requests Requests for PHP is a dependency-free HTTP request library with a simple, Python-requests-inspired API. It abstracts over cURL and fsockope… | 92 | 3574 | stable |
| elliotgao2/toapi A Python library that turns any website into a JSON API by declaring fields with CSS/XPath selectors. It fetches and parses pages on demand… | 73 | 3556 | active |
| MadelineProto MadelineProto is an async PHP library implementing the Telegram MTProto protocol, allowing full client functionality (user or bot login) wi… | 100 | 3536 | active |
| ascending-llc/jarvis-registry Jarvis Registry is an open-source, enterprise-grade MCP and A2A agent gateway and workflow orchestration platform that gives AI copilots an… | 84 | 3531 | active |
| discord-net/Discord.Net Discord.Net is an unofficial asynchronous .NET library for interfacing with the Discord API, with modular packages for REST, WebSocket, com… | 94 | 3517 | active |
| ardatan/graphql-mesh GraphQL Mesh is a GraphQL federation framework and gateway that converts non-GraphQL API services (REST/OpenAPI, gRPC, SOAP, OData, Thrift,… | 95 | 3511 | active |
| openai/openai-go The official Go client library for the OpenAI REST API, providing typed access to models, the Responses API, conversations, and other OpenA… | 87 | 3501 | active |
| Lighthouse Lighthouse is a GraphQL server framework that integrates with Laravel applications, letting you define your API schema using the GraphQL Sc… | 94 | 3498 | active |
| MZCretin/RollToolsApi RollToolsApi is a free, long-maintained aggregated REST API service that provides commonly used data endpoints for developers, hosted on an… | 70 | 3479 | active |
| pistacheio/pistache Pistache is a modern, elegant HTTP and REST framework written in pure C++17. It provides a multi-threaded HTTP server, an asynchronous HTTP… | 71 | 3469 | active |
| svix/svix-webhooks Svix is an open-source, enterprise-ready webhooks-as-a-service platform written in Rust that lets developers send webhooks with a single AP… | 96 | 3457 | active |
| tulios/json-viewer A Chrome browser extension that pretty-prints and syntax-highlights JSON and JSONP responses directly in the browser. It offers 27 themes, … | 32 | 3455 | active |
| json-schema-faker/json-schema-faker A JavaScript library that generates valid, realistic fake JSON data from JSON Schema definitions, supporting JSON Schema 2019-09 and 2020-1… | 86 | 3447 | active |
| TerminusDB TerminusDB is an open-source document graph database with built-in git-like version control, storing JSON/JSON-LD documents in a schema-enf… | 92 | 3435 | active |
| roapi/roapi ROAPI automatically spins up read-only REST, GraphQL, SQL, and FlightSQL query APIs over static or slowly moving datasets without writing a… | 74 | 3434 | active |
| Universal Commerce Protocol The Universal Commerce Protocol (UCP) is an open standard and specification for interoperable, agentic commerce, defining capabilities like… | 77 | 3420 | active |
| zigzap/zap Zap is a fast, robust web microframework for Zig that wraps the facil.io C networking library to build HTTP servers and REST APIs. It provi… | 10 | 3416 | stable |
| google/volley Volley is Google's HTTP networking library for Android that simplifies and speeds up network requests in mobile apps. It provides automatic… | 82 | 3411 | stable |
| ding113/claude-code-hub CC Hub is a self-hosted AI API proxy and gateway service for Claude Code, Codex, and other OpenAI/Claude-compatible APIs, built with Next.j… | 83 | 3402 | active |
| DGS Framework DGS Framework (Domain Graph Service) is a GraphQL server framework for Spring Boot, developed and maintained by Netflix. It provides an ann… | 98 | 3399 | active |
| slackapi/node-slack-sdk The official Slack Developer Kit for Node.js, a collection of single-purpose TypeScript packages covering Slack's Web API, OAuth flows, Inc… | 91 | 3378 | active |
| HiThink-Tech/Financial-API Official Tonghuashun (HiThink) A-share financial data service offering real-time and historical stock quotes, financial statements, valuati… | 78 | 3369 | active |
| akheron/jansson Jansson is a C library for encoding, decoding, and manipulating JSON data. It offers a simple API, full UTF-8 Unicode support, and no depen… | 76 | 3369 | stable |
| Stoat Stoat is the Rust backend software powering Stoat chat, a self-hostable community chat platform descended from Revolt. It consists of modul… | 97 | 3364 | active |
| Metorial Metorial is an open-source identity and access control plane for AI agents, providing 1200+ verified MCP integrations with centralized auth… | 63 | 3356 | active |
| leafo/lapis Lapis is a web framework for Lua and MoonScript that primarily targets OpenResty (Lua embedded in Nginx), with support for other server env… | 89 | 3351 | stable |
| bcherny/json-schema-to-typescript A TypeScript library and CLI (json2ts) that compiles JSON Schema definitions into TypeScript type declarations. It can be used programmatic… | 74 | 3346 | active |
| Sophomoresty/gemini-web2api A single-file Python server that exposes Google Gemini's web interface as an OpenAI-compatible API, supporting chat completions, streaming,… | 54 | 3346 | active |
| awslabs/aws-sdk-rust The official AWS SDK for Rust, providing one generated crate per AWS service plus a shared aws-config crate for credential and region loadi… | 94 | 3343 | stable |
| overtrue/easy-sms A PHP library that provides a unified API for sending SMS messages through dozens of Chinese and international SMS gateway providers (Aliba… | 94 | 3338 | active |
| jsoniter jsoniter is a high-performance JSON serialization and parsing library for Go (with a Java variant) that serves as a 100% compatible drop-in… | 10 | 13859 | maintenance |
| huangxd-/danmu_api A JavaScript-based danmaku (bullet comment) API server that aggregates danmu from major Chinese and international video platforms (Bilibili… | 63 | 3309 | active |
| Apache Avro Apache Avro is a data serialization system providing rich data structures, a compact binary format, container files, and RPC support, with … | 85 | 3307 | stable |
| getkin/kin-openapi A Go library implementing the OpenAPI 2.0, 3.0, 3.1, and (partially) 3.2 specifications. It provides parsing, conversion, and validation of… | 99 | 3302 | active |
| php-curl-class/php-curl-class PHP Curl Class is a PHP library that wraps PHP's cURL extension in a simple object-oriented API for sending HTTP requests. It supports GET,… | 100 | 3298 | active |
| json-c/json-c json-c is a C library implementing a reference-counted object model for constructing, serializing, and parsing JSON, aiming to conform to R… | 83 | 3297 | stable |
| liaohch3/claude-tap claude-tap is a local proxy and trace viewer for AI coding agents like Claude Code, Codex CLI, and Gemini CLI. It intercepts real API traff… | 79 | 3295 | active |
| cyu/rack-cors Rack middleware that adds Cross-Origin Resource Sharing (CORS) support to Rack-compatible Ruby web applications, including Rails. It lets y… | 38 | 3290 | active |
| assetnote/kiterunner Kiterunner is a fast content discovery tool written in Go that bruteforces files, folders, and API routes on web servers. It uses a dataset… | 60 | 3272 | stable |
| zino-hofmann/graphql-flutter A GraphQL client for Dart and Flutter providing queries, mutations, subscriptions, caching, and optimistic updates through a widget-based A… | 82 | 3269 | active |
| postmanlabs/httpbin httpbin is a simple HTTP request and response service written in Python with Flask that echoes back request details as JSON. It is used for… | 23 | 13625 | maintenance |
| microsurging/surging Surging is a distributed microservice engine for .NET Core providing a lightweight, high-performance, modular RPC pipeline with service reg… | 53 | 3264 | active |
| gcui-art/suno-api An unofficial open-source API wrapper for Suno.ai's AI music generation service, exposing endpoints for generating songs, lyrics, and audio… | 53 | 3260 | active |
| openid/AppAuth-Android AppAuth for Android is a client SDK for communicating with OAuth 2.0 and OpenID Connect providers from Android apps. It follows RFC 8252 be… | 62 | 3241 | active |
| alexrudall/ruby-openai A Ruby gem providing a client for the OpenAI API, supporting chat completions, the Responses API, streaming, vision, audio (Whisper), image… | 66 | 3223 | active |
| dotnet/extensions A suite of .NET libraries from Microsoft providing production-ready capabilities such as resilience pipelines, telemetry, diagnostics, comp… | 98 | 3220 | active |
| stoplightio/spectral Spectral is a flexible JSON/YAML linter for creating automated API style guides, with built-in rulesets for OpenAPI v2/v3.x, AsyncAPI v2.x,… | 95 | 3220 | active |
| SteamRE/SteamKit SteamKit2 is a .NET library for interoperating with Valve's Steam network protocol. It provides a simple, extensible interface for performi… | 96 | 3213 | active |