Google In-App Purchase
When your Android app sells digital products — premium features, credits, subscriptions — Google requires those purchases to go through Google Play Billing, not your website's payment gateway. The Google IAP bridge is what connects your existing website purchase flow to Google Play's native payment sheet.
How It Works
- The user taps a purchase button on your website.
- Your website sends a message to the app via the bridge, specifying the product to purchase.
- The app opens Google Play's native payment sheet.
- Google processes the payment.
- The app sends the result back to your website.
- Your website delivers the product (or shows an error).
Triggering a Purchase
javascript
appilix.postMessage(JSON.stringify({
type: "google_iap_init",
props: {
product_id: "com.example.app.premium_monthly",
product_type: "subscription",
app_account_token: "550e8400-e29b-41d4-a716-446655440000"
}
}));Parameters
| Parameter | Required | Description |
|---|---|---|
product_id | Yes | The Product ID exactly as created in Google Play Console |
product_type | Yes | "consumable", "non-consumable", or "subscription" |
app_account_token | No | An obfuscated account ID linking the purchase to your internal user account. Included with the order for server-side verification |
The product_id must match exactly what you created in Google Play Console — including capitalization and any dots or underscores.
Handling the Response
Set up the listener before triggering the purchase:
javascript
appilix.onmessage = function(event) {
const data = JSON.parse(event.data);
if (!data || data.type !== 'google_iap_init') return;
if (data.response.status === true) {
const { product, purchase } = data.response;
// Send the purchase token to your backend for verification before unlocking anything
fetch('/api/unlock-premium', {
method: 'POST',
body: JSON.stringify({
product_id: product.id,
order_id: purchase.id,
verification_data: purchase.verification_data,
verification_source: purchase.verification_source
})
});
} else {
// Purchase failed or cancelled
console.log('Purchase failed:', data.response.message);
}
appilix.onmessage = null;
};Response Fields
| Field | Present When | Description |
|---|---|---|
status | Always | true if the purchase succeeded, false otherwise |
message | status is false | Reason for the failure (e.g. user cancelled, payment failed) |
product | status is true | Details of the purchased product, as returned by Google Play Console |
purchase | status is true | Details of the completed transaction |
product object
| Field | Description |
|---|---|
id | The Product ID, matching what you passed in product_id |
title | Localized product name from Google Play Console |
description | Localized product description from Google Play Console |
price | Localized, formatted price string (e.g. "$4.99") |
rawPrice | Price as a number, useful for calculations or analytics |
currencyCode | ISO currency code (e.g. "USD") |
purchase object
| Field | Description |
|---|---|
id | The Google order ID. Keep this for support requests, refund lookups, and to avoid double-crediting the same purchase |
transaction_date | When the transaction completed |
verification_data | The purchase token. Send this to your backend to verify with the Play Developer API before granting any entitlement |
verification_source | Identifies which Google verification flow produced the token |
Never grant the purchased entitlement based on the client-side response alone — always verify verification_data against the Play Developer API from your backend first.
Product Types
| Type | Description |
|---|---|
consumable | Can be purchased multiple times. Use for credits, coins, or one-time boosts. |
non-consumable | Purchased once and owned permanently. Use for lifetime access or removing ads. |
subscription | Renews automatically on a schedule. Use for monthly or yearly plans. |
Important Notes
- This bridge is for Android only. On iOS, see the Apple In-App Purchase JS Bridge article.
- Always verify the purchase on your backend before delivering the product. Do not rely solely on the client-side response.
- Test purchases using Google Play's license testing or internal testing tracks before publishing.
- Implementing this correctly requires modifying your website's purchase button logic and handling the bridge response. Involve a developer if needed.
For Google Play Console product setup instructions, see the Google In-App Purchase article.