🔁 Best Open-Source API Tools in 2026

A curated list of free APIs for use in software and web development, enabling easy discovery of public API resources.

A powerful fair-code workflow automation platform with native AI capabilities. It combines visual workflow building with the ability to include custom code. Self-host or use the cloud version with over 400+ integrations available.

Supabase is an open-source alternative to Firebase, offering a rich Postgres database solution tailored for building efficient web, mobile, and AI applications.

Model Context Protocol Servers provide a framework for managing and deploying machine learning models effortlessly across various environments.

Open source API development ecosystem, serving as an efficient and open-source alternative to Postman and Insomnia.

RAGFlow is a leading open-source Retrieval-Augmented Generation (RAG) engine that combines advanced RAG methods with Agent capabilities, delivering a superior, context-rich experience for Large Language Models (LLMs). It enables efficient information retrieval and contextual augmentation, optimizing generative AI pipelines.

A comprehensive guide with examples for using the OpenAI API effectively.

A natural language interface for computers that enhances human-computer interaction through voice and text commands.

A powerful Cloud Native Application Proxy designed for ease of use and automation. It seamlessly integrates with your infrastructure components and configures itself automatically and dynamically.

An open-source, realtime backend system condensed into a single file. It provides instant APIs and a stylish admin UI for managing your apps effortlessly.