Insomnia

Insomnia is an open source API client and collaboration platform developed by Kong. It sends and debugs requests over HTTP, gRPC, GraphQL, Socket.io, WebSockets and Server-Sent Events, and also supports MCP servers.

APIs can be designed from OpenAPI specifications, then tested, debugged and mocked in the same application. Projects can be stored locally, in a Git repository or in the cloud, and a Scratch Pad mode lets the client be used without logging in.

Insomnia is distributed under the Apache License 2.0 and is actively developed on GitHub. It integrates with Kong Konnect, Kong’s commercial API platform.