Yet Another API Development Environment delivers a self-hosted alternative to Postman designed from the ground up for teams that need secure, collaborative API development without sending sensitive credentials through third-party cloud services. The multi-user system manages team members with role-based permissions and supports external authentication through OAuth2 and OIDC providers, while all data persists in an H2 file-based database that survives container and server restarts. REST and WebSocket request testing includes environment variable substitution, request chaining, and Markdown documentation for each endpoint. The JavaScript scripting engine runs request and response scripts for automated testing and data extraction, with cron job scheduling and API-triggered execution for continuous integration workflows. Collections import directly from OpenAPI specifications and Postman exports, while outbound export generates request code in multiple languages and frameworks. The browser extension proxy for Chrome and Firefox routes requests through the user's browser to bypass CORS restrictions when testing localhost and internal APIs, with an alternative server-side proxy for headless environments. Single-file data import and export simplifies backup and migration between instances. The React and Vite frontend ships with dark mode enabled by default. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.