New open-source tool lets software users build their own mini-apps with AI

Vendo, a YC Summer 2026 startup, open-sourced a tool that lets users of business software create custom mini-apps using AI — without changing the original software's code. Unlike chat-style AI helpers, these mini-apps stick around: users save, share, and copy them across their company. The generated code runs in a locked-down sandbox with no internet or file access.