Echolon

Echolon is a local-first API client designed for developers and teams who need a powerful, privacy-conscious alternative to cloud-based tools. It enables you to design, test, and debug APIs across multiple protocols while keeping your data on your own machine. By focusing on performance, offline access, and robust collaboration workflows, Echolon streamlines everyday API development and testing tasks without locking you into a proprietary ecosystem.

The tool supports HTTP, WebSocket, and other common protocols, allowing you to work with REST, GraphQL, and real-time APIs in a single interface. Git integration is built in, so collections, environments, and requests can be version-controlled alongside your codebase, enabling code reviews, branching, and rollbacks for API workflows. Offline support ensures you can continue to inspect, run, and modify requests without an internet connection, which is especially useful for secure or air-gapped environments. As an open-source project, Echolon offers transparency, extensibility, and the flexibility to adapt it to your existing tooling and CI/CD pipelines.