Migrate Desktop GUI to Power Apps Code App

Migrating a PySide6 desktop app to a Vite/TypeScript web app deployable as a Power Apps Code App.

What is a Power Apps Code App?
A Code App is a web app (HTML/CSS/JS) hosted and distributed through Power Apps. It runs inside the Power Apps player, can reference Power Platform connectors, and is managed like any canvas app — sharing, versioning, environments — without requiring a SharePoint or Azure host. Built and deployed with the Power Platform CLI (pac code).

Scenario — Expense Report Currency Converter: load multi-currency expenses + exchange rates from CSV, convert to USD with date-matched rates (fallback to nearest prior date), display summary cards + detail table.

Screenshots

Code App (Power Apps player)

Desktop App (PySide6)

Architecture Mapping

Desktop (Python)	Code App (TypeScript)
core.py	src/core/
ui.py (PySide6 widgets)	index.html + src/main.ts
QTableWidget	HTML <table> + DOM
QFileDialog	<input type="file">
csv module	String.split() parsing

Run

# Desktop
cd desktop-app && pip install pyside6 && python main.py

# Code App (local dev)
cd code-app && npm install && npm run dev

Deploy to Power Platform

cd code-app

# Build
npm run build

# First-time setup: register new app in the active environment
pac auth create --deviceCode           # sign in
pac org select --environment <env-url> # set target environment
pac code init --displayName "Expense Report Calculator" \
              --buildPath "./dist" \
              --fileEntryPoint "index.html"

# Deploy (subsequent pushes)
pac code push

# Verify
pac code list