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Building an Android App: Create the Project

Three things to say, in order. At the end the app icon appears on a phone or emulator, and it opens. An Android app is one thing — no separate backend, no database, nothing in a browser; the app opens on the phone screen.

Do the setup page first

This page assumes your computer is already prepared — see Start a Project.

Before Step 1 — nothing you must install by hand​

Everything an Android build needs is a language toolchain — a host JDK 17, Google's android CLI and the SDK packages (platforms/android-36, build-tools/36.0.0, platform-tools), all derived from the project you are about to create and installed in Step 2. There is nothing you must install before Step 1.

To do it by hand anyway — on a machine where the agent cannot install anything — run the three steps below, then open a new terminal after the installer finishes. Every line is explained on the Android environment page.

# 1. Host JDK 17 (or: mise use --global java@temurin-17)
winget install --id EclipseAdoptium.Temurin.17.JDK -e
# 2. Google's android CLI
curl.exe -fsSL "https://dl.google.com/android/cli/latest/windows_x86_64/install.cmd" -o "$env:TEMP\android-install.cmd"
& "$env:TEMP\android-install.cmd"
# 3. SDK packages — run this after opening the new terminal
android --sdk="$env:LOCALAPPDATA\Android\Sdk" sdk install platforms/android-36 build-tools/36.0.0 platform-tools

Google publishes no CLI binary for ARM Linux. Prefer the IDE instead? Android Studio's first-run setup bundles the SDK manager, platform tools and an acceptable JDK in one go:

winget install --id Google.AndroidStudio -e

Install the JDK, not the JRE — JDK 21 also works, JDK 11 does not. Step 3 also needs a real phone connected by USB with debugging enabled, or an emulator already running — the agent cannot set that up for you.

Step 1 — Create the project​

Say this

Create a new Android app called my-android in this folder. I only want the Android app itself, nothing else. The tool will stop and ask which pieces to create: read the list it prints and pick the line that says Android.

That is not the default, so the agent must answer the question, not skip it.

What you should see: a confirmation of exactly one piece.

✅ Selected 1 modules:
   - Android

Then ask "which pieces did you actually create?" It should be only the Android app. If anything else appeared, say "delete it and do it again, and this time answer the selection question."

Say the name, never a number

The numbers move as the list changes, so a number you were given once will eventually point at the wrong thing. Have the agent read the list and pick the Android line.

Step 2 — Install what the project needs​

Say this

Set up the environment file and install everything this project needs. I am in mainland China.

Saying where you are matters: the wrong download source makes a short install very long.

What you should see: a settings file at the top of the project and an install that finishes without errors. The Android SDK and JDK also arrive here if missing — deliberately skipped during setup, because nothing knew you wanted an Android app until Step 1 created one. No database step: the app keeps its data on the phone.

Then ask "is the Android app's own code folder there?" If not, the app was never created — go back to Step 1.

Step 3 — Install it on a phone or emulator​

Have a USB-connected phone (debugging enabled) or a running emulator ready before you speak — the agent builds before it checks for a device.

Say this

Build the debug version of the Android app, install it on my device, and tell me when it is ready to open.

What you should see: the app icon appearing on your phone or emulator. Open it and it should launch.

Make sure the device is ready first

If the build finishes but the agent cannot install it, say: "my device is connected — check again and install it."

An emulator is a full phone, not a quick preview

Starting one takes a few minutes and noticeable resources. If you are new to this, a USB phone is simpler — what matters is seeing the app run.

When the icon is on the device and the app opens, the skeleton is done. Next: Create a Feature.

When it goes wrong​

You do not diagnose anything — find your symptom, say the sentence:

What you seeSay this
Extra pieces were created, not just the Android app"You skipped the selection question. Delete it and do it again, answering the list"
A "command not found" error when running a Gradle command"Open a new terminal window and try again — this one has stale information"
The agent says "no device found""The device is connected. Check again — it may need a moment to be recognised"
The app installs but crashes on open"Read the crash log from logcat and tell me what the first error says"
The agent has been silent for a long time"Are you waiting on something that never finishes? Start it the way that lets you keep talking to me, and tell me when it is up"