Migrating an Existing Play App Onto Wired-In BillingClient 6.2.0 (Aura Pro Takeover Notes)

Most "sell your Android app" writeups stop at upload an APK. The part that actually decides whether the app makes money starts after the listing goes live: the subscription products exist, the billing client is wired, and a purchase made on a phone you hold reaches your merchant account without you touching it.

This is a technical walkthrough of that second half — using the Aura Pro package ($299.99, https://reggiebro.github.io/WorkflowAlpha.ai/landing/) as the concrete example, because it's the only Android app package I've seen that ships the billing integration as finished code rather than a TODO comment.

Every product page on https://reggiebro.github.io/WorkflowAlpha.ai/ has a working interactive demo you can type into before paying. Worth using: the prompt generator on the Aura Pro page runs the same generation logic the app runs on-device.

What "billing already wired" actually means

A lot of app codebases say "billing" and mean "we left the product IDs in a constants file." Aura Pro ships BillingClient 6.2.0 integration with two subscription products declared up front:

• com.auraprompt.app.premium_monthly
• com.auraprompt.app.premium_annual

That sounds like a detail. It isn't. The failure mode it prevents is the one where you finish the migration, a test purchase succeeds, and you still can't tell which product the receipt belongs to — because the ID in your code never matched the ID in the Console, so the server-side acknowledgement has nothing to key on.

Migration order: keep the existing package identity

The first decision is the package name, and it's the one you can't reverse cheaply. Google Play treats the package name as the app's identity. Changing com.oldname.app to com.newname.app is not a rename — it's a brand-new app with zero ratings, zero reviews, zero install history, and a new store listing.

So the migration keeps the original package name and moves everything else underneath it:

1. Import the existing app into your Console. You need ownership of the original signing key (or the original developer's cooperation). The package name only becomes reusable if it's yours to sign.
2. Wire the billing client against the existing package name. The product IDs are new, but the package they live under is the one you already have users in.
3. Create the subscription products in the Console first. Product creation is manual in Play Console — the API can't do it. play_takeover.py handles APK upload, store listing, store images, in-app products, subscription products, track activation, and publishing, but the Console-side product records have to exist first or the client has nothing to query.
4. Release to internal testing, buy with a license-tester account, check the acknowledgement. This is the real test. A purchase that shows up in the test account but isn't acknowledged server-side is the bug you find here, not in production.

The isDemo toggle, and why you don't want to skip it

The APK ships with isDemo=true, which unlocks every premium feature with no paywall and no API key. Install it on your own phone, click through all 11 categories, and confirm the output is actually structured rather than a templated string with your topic pasted in.

Then rebuild with isDemo=false and that same phone is your billing test device. Skipping this and testing billing blind against a live release is how you end up with a real card charged against a half-wired client.

The 6 Console steps the API can't do

play_takeover.py --key key.json covers everything the Play Developer API allows. What's left is manual and unavoidable:

Step	Where
Data Safety declaration	Play Console
Content rating (IARC)	Play Console
Category / primary audience	Play Console
Pricing per country	Play Console
Store listing review submission	Play Console
Push notifications setup (if used)	Console / Firebase

None of these are reasons not to do the migration. They're the reason the takeover takes an afternoon and not a weekend.

Test before you pay

• Site: https://reggiebro.github.io/WorkflowAlpha.ai/ (Aura Pro page: /landing/)
• Other products with live demos: Veloce-Engine /veloce-engine/, Mentary AI /mentary-ai/, USB Coding Expert /usb-coding-expert/, Faceless Video /faceless-video/
• PayPal: send to [e-mail] — write a note naming the product, seller confirms in the inbox
• Crypto: 0x078fE079A9440631Bc6AD722D7143dC382b4ea4f on Base (ETH / USDC / USDT)
• Also accepted: Western Union / MoneyGram

No discount is being offered and there's no quota on how many copies go out — this is a flat price for a finished app. The thing to test is whether the demo does what you need it to do before you send anything.

Honest scope note: the interactive demo on the page exercises the prompt-generation engine and UI in the browser. The Play Store takeover path and the live billing acknowledgement are covered by the buyer documentation (README-TAKOVER.md, README-PLAY-SETUP.md), not by the browser demo.