Insomnia OSS refers to the open-source community forks that emerged after Kong, the company behind Insomnia, introduced mandatory account login requirements in version 2023.5.8, most notably the Insomnium project that stripped out cloud dependencies to provide a fully offline, privacy-focused API testing experience. Insomnium was created as a direct fork of Kong's Insomnia at the last commit before compulsory account creation was introduced, preserving the original offline-first experience that many developers valued. The fork represented the open-source community's response to what they perceived as unwanted commercialization of a tool that many relied on for local API development.
Insomnium maintained all of Insomnia's core capabilities for testing REST, GraphQL, WebSocket, and gRPC APIs while removing cloud sync, telemetry, and login requirements, operating as a 100% local application with no network dependencies for core functionality. The fork attracted developers who specifically needed an API client that worked entirely offline, in air-gapped environments, or in organizations where sending API data through third-party cloud services was prohibited by security policies. Insomnium preserved Insomnia's familiar interface and plugin compatibility while ensuring that no user data left the local machine.
The Insomnium project was archived by its owner on July 19, 2024, with the maintainer citing a shift in focus to another related project. The repository remains publicly available as read-only for anyone who wishes to fork and continue development independently. Since Insomnium's discontinuation, Kong has made significant improvements to Insomnia itself, including reintroducing local-only storage options and Git-based collaboration, addressing some of the concerns that originally motivated the community fork. Developers seeking offline-first API testing have since migrated to alternatives like Bruno and Hoppscotch.