UseThatApp Documentation

How It Works

UseThatApp uses a two-phase server-to-server webhook handoff. No iframes, no client-side JavaScript, no shared secrets — just two backend calls:

1. Launch. When a user clicks Launch app on usethatapp.com, the marketplace POSTs an encrypted, signed envelope to your app's launch URL. Your backend calls get_user (Python) or getUser (JavaScript) to verify and decrypt it, and gets back an opaque user_key to persist against its own session.
2. Query. Whenever your app needs the user's current tier, it calls get_version / getVersion. The SDK signs the request with your private key, hits https://usethatapp.com/licensing/getversion/, and returns the product name (e.g. "Pro") or null.

Quick Example

Two server-side calls — verify the launch envelope, then look up the live tier whenever you need it:

from usethatapp import get_user, get_version

# In your launch route — your framework's request shape may vary:
uta_user = get_user(request.form["uta_payload"])
session["uta_user_key"] = uta_user.user_key

# Anywhere else:
version = get_version(session["uta_user_key"])
if version == "Pro":
    ...  # serve paid content

import { getUser, getVersion } from "usethatapp";

// In your launch route:
const user = getUser(req.body.uta_payload);
req.session.utaUserKey = user.user_key;

// Anywhere else:
const version = await getVersion(req.session.utaUserKey);
if (version === "Pro") {
  // serve paid content
}

Why UseThatApp?

Supported Frameworks

Choose your language to see the full list of framework guides, or jump straight to the Quick Start.