Opensource IDE For Exploring and Testing API's (lightweight alternative to Postman/Insomnia)
Newman is a command-line collection runner for Postman
An interactive web UI for gRPC, along the lines of postman
Open source alternatives to paid SaaS apps: Notion, Slack, Auth0, Vercel and more. Curated list with licenses and GitHub stars.
Plugin for converting OpenAPI 3.0 specs to the Postman Collection (v2) format
Javascript module that allows a developer to work with Postman Collections