Apache Camel is an open source integration framework with 350+ connectors. Write routes in Java, YAML, or XML. Run on Spring Boot, Quarkus, or standalone. Apache License 2.0.
Swagger UI is a collection of HTML, JavaScript, and CSS assets that dynamically generate beautiful documentation from a Swagger-compliant API.
GOWA - WhatsApp REST API with support for UI, Multi Account, Webhooks, and MCP, and Chatwoot. Built with Golang for efficient memory use.
Headless open-source eCommerce platform on top of PHP/Symfony/API Platform
📱The official Wikipedia app for Android!
Tools for working with Ghost's APIs
Go RESTful API starter kit with Gin, JWT, GORM (MySQL, PostgreSQL, SQLite), Redis, Mongo, 2FA, email verification, password recovery
gRPC to JSON proxy generator following the gRPC HTTP spec
Open-source, self-hosted enterprise & site search server built on OpenSearch. Crawls web / file / DB / cloud sources, 20+ languages, REST API, and AI/RAG & semantic search. Apache-2.0.
MikoPBX — free open-source PBX for small business, built on Asterisk 22, PHP 8.4, and Phalcon 5. Deploy as ISO, Docker, LXC, or in the cloud.
Open-source, self-hosted file-processing tool. Convert, compress, OCR, transcribe & run local AI across image, video, audio, PDF & documents, via UI, REST API & pipelines. Your files never leave your network.
Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.
Javinizer written in Go and Svelte. This is a modern replacement for the original Javinizer. (NSFW) Organize your local Japanese Adult Video (JAV) library.
OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)
AI-powered code analysis tool with bug detection, code explanations, and AI-powered suggestions.
A virtual stock market and trading platform. Includes a fully simulated stock market, with dynamic price changes and news events. Simulation models a real calendar with time sped up
A ready-to-use Template for Rest API using spring-boot-microservices, MongoDB as Database, Integrated with codecov and sonarqube, deployable to cloud.
A curated list of free public APIs — searchable, community-maintained, with a free JSON API.
Open Source API List and Testing Tools