Echolon

Echolon is an open‑source API client designed for developers who need a local‑first tool with full Git integration. It stores collections, variables, and settings on the local file system, allowing work offline and without requiring cloud logins. The client supports multiple protocols, including REST and WebSocket, and plans to add GraphQL, letting users interact with any API from a single workspace.

The request editor offers rich content previews, JSON‑Path filtering, and live schema validation against OpenAPI specifications. A powerful variable system lets users define dynamic values—such as timestamps, UUIDs, and random data—at global, workspace, or collection level, with support for JavaScript expressions. Authentication methods cover Basic, Bearer, API Key, Digest, OAuth 2.0, AWS v4, and JWT, and a one‑click mocking feature can generate responses via a local or cloud proxy.

Version control is built in: users can stage, commit, push, and pull changes directly within the interface, view visual diffs, and manage branches, with optional GitHub integration. The client also provides a one‑click publishing workflow for API documentation and supports both light and dark themes.