Insomnia

Insomnia provides a cross‑platform client for designing, testing, and debugging HTTP‑based APIs, supporting REST, GraphQL, gRPC, SOAP, WebSockets and related protocols. It lets developers send requests, inspect responses, and iterate on endpoint definitions within a graphical interface that runs on macOS, Windows and Linux. The tool includes a collection runner for automated testing and integrates with local Git repositories or cloud‑based workflows for version control and collaboration.

The platform is open source and offers a free tier that includes unlimited projects, up to three syncable clients, and core protocol support without requiring an account. Features such as AI‑native capabilities, role‑based access control for teams, and domain capture are highlighted as ways to streamline collaborative API development and security reviews.

Insomnia targets API developers and security‑focused organizations that need a unified environment for building, testing, and sharing API specifications. Its emphasis on extensibility, version‑controlled workflows and multi‑protocol coverage makes it suitable for both individual contributors and larger development teams.