# Building a Hup Mini App You are building a **mini app** for Hup (https://hup.social) — a small web app that runs inside a sandboxed iframe embedded in a social post, and transacts through the viewer's existing Hup wallet session. This document is self-contained: everything needed to build, test, and list a mini app is here. ## What a mini app is - A normal web page, hosted anywhere, served over **https** (http only for localhost testing). - Hup renders it inside `