play-billing-skills

Use this skill when scoping Google Play alternative billing work with RevenueCat Android SDK 10.x. Documents the current support status, which flows RevenueCat abstracts and which require direct integration at the time the chapter was written.

Use this skill as a quick reference for the RevenueCat Android SDK 10.x and REST API. Covers SDK init, common Purchases calls, CustomerInfo / Offerings access patterns, and the most used REST endpoints.

Use this skill to orient an agent to the RevenueCat Android SDK (10.x) architecture. Covers how RevenueCat reorganizes BillingClient, Google Play Developer API, and RTDN into a single SDK, and how Products, Packages, Offerings, Entitlements, and CustomerInfo connect.

Use this skill when implementing Google Play's alternative billing programs or external offers (introduced across PBL 8.2 to 8.3, current as of PBL 9.x). Covers user choice billing, alternative billing only, external transaction reporting, and the regional program eligibility.

Use this skill when building a backend for Google Play Billing receipt verification. Covers receiving purchase tokens from the client, calling the Google Play Developer API to verify, storing subscription state, and exposing a production ready verification endpoint.

Use this skill as a reference lookup for every Play Billing Library BillingResponseCode and sub response code, with description, category, and handling guidance. Grounded in PBL 9.x.

Use this skill when implementing cancellations, developer initiated revocations, subscription pauses, and winback offers on Google Play. Covers user initiated cancellation, system cancellation, developer revoke/refund, pause resume flow, and winback API tools.

Use this skill when managing Google Play product and subscription catalogs programmatically with the Google Play Developer API. Covers create, update, archive for both inappproducts and monetization.subscriptions endpoints, plus regional pricing automation.

Use this skill when designing error handling and retry strategy for the Play Billing Library. Classifies every BillingResponseCode into recoverable, non recoverable, and user driven categories and builds a retry plan with exponential backoff and circuit breaker patterns.

Use this skill when integrating the Google Play Billing Library client side (adding the dependency, wiring BillingClient, managing its connection lifecycle, and querying product details). Grounded in PBL 9.x.

Use this skill when implementing, acknowledging, or consuming Google Play one time products (consumables and non consumables) with the Play Billing Library. Covers launch, pending transactions, consume for consumables, acknowledge for non consumables.

Use this skill when handling failed subscription renewals on Google Play. Covers Grace Period (user keeps access), Account Hold (access revoked), the RTDN signals that move between stages, and the in app messaging required to drive recovery.

Use this skill when migrating an Android app from Play Billing Library 7.x to 8.x. Covers the full breaking change list, the dependency bump, the required API renames, and the step by step verification flow.

Use this skill when migrating an Android app from Play Billing Library 7.x straight to 9.x. There is no direct path: you do the breaking v7 to v8 work first, then the small v8 to v9 delta. Covers the full rename map, the dependency bump, the two stage plan, and the verification flow.

Use this skill when migrating an Android app from Play Billing Library 8.x to 9.x. Covers the small v9 delta (no API removals): the dependency bump, the targetSdk 35 and androidx.core requirements, the blocked Play Store error reclassification, the nullable getLinkUri change, the optional in app price increase messaging, and the verification flow.

Use this skill when implementing Google Play subscription upgrades, downgrades, or plan switches with setSubscriptionUpdateParams. Covers the six replacement modes (WITH_TIME_PRORATION, CHARGE_PRORATED_PRICE, WITHOUT_PRORATION, DEFERRED, CHARGE_FULL_PRICE, the deprecated UNKNOWN) and when each applies.

Use this skill as a quick reference for billing related Google Play Developer API REST endpoints, covering purchases.products, purchases.subscriptionsv2, purchases.voidedpurchases, and monetization endpoints. Lists paths, auth scopes, and typical request shapes.

Use this skill when changing subscription prices on Google Play. Covers opt out price decreases versus opt in price increases, the 30 to 37 day notification timeline, the SUBSCRIPTION_PENDING state, and the API calls to manage price changes for existing subscribers.

Use this skill when implementing the Play Billing purchase flow end to end. Covers building BillingFlowParams, launching launchBillingFlow(), receiving results in PurchasesUpdatedListener, handling every BillingResult outcome, and posting to your backend.

Use this skill as a quick lookup for all Google Play Real Time Developer Notification (RTDN) types with their integer codes, trigger conditions, and recommended handling. Covers subscription notifications, one time purchase notifications, voided purchase notifications, and test notifications.

Use this skill when setting up Real Time Developer Notifications (RTDN) for Google Play. Covers the full pipeline from Cloud Pub/Sub configuration through message parsing and processing all 22 subscription notification types (renewals, cancellations, revocations, account holds, etc.).

Use this skill when hardening a Google Play Billing integration against fraud. Covers server side receipt verification, replay attack protection, device fingerprinting, velocity checks, and the most common billing fraud patterns.

Use this skill when configuring Play Console, creating products, enabling service account API access, or setting up RTDN before writing billing code. You stand up the full Google Play billing environment so app and backend code can authenticate, query products, and receive server side purchase events.

Use this skill as the pull out reference for the full Google Play subscription state machine, showing every state and every RTDN triggered transition in one diagram.

Use this skill when mapping a Google Play subscription to the seven states (PENDING, ACTIVE, IN_GRACE_PERIOD, ON_HOLD, PAUSED, CANCELED, EXPIRED) and deciding what access your app should grant in each state.

Use this skill when modeling Google Play subscriptions (the three tier Subscription, Base Plan, Offer hierarchy), choosing a catalog shape, and deciding how to map your paywall to base plans and offers. Grounded in Play Billing Library 9.x.

Use this skill when testing a Google Play Billing integration. Covers license test accounts, static test responses, Play Console sandbox purchases, and subscription lifecycle acceleration for renewals, grace period, and account hold.

Use this skill when a developer is new to Google Play Billing or needs to orient themselves before picking an implementation task. Maps their goal to the right pillar (Play Billing Library, Google Play Developer API, Play Console plus RTDNs) and routes them to the concrete skill to invoke next.

Use this skill when your backend needs to read or update RevenueCat state on Android. Covers the RevenueCat REST API (v1 subscribers endpoint, grant/revoke entitlements, attributes), secret vs public SDK API key usage, and why you do not build a receipt verification backend with RevenueCat.

Use this skill when surfacing cancellation, pause, and winback state on Android with RevenueCat. Covers reading unsubscribeDetectedAt, billingIssuesDetectedAt, pause state via periodType, managementURL for deep link, and pause resume date lookup via the REST API.

Use this skill when managing the Android product catalog through the Play Console and the RevenueCat dashboard. Covers the two sided catalog flow (create in Play Console, import or map in RevenueCat), entitlement and offering maintenance, and why you do not call the Google Play Developer API directly.

Use this skill when adding and configuring the RevenueCat Android SDK (purchases-kt/purchases) in an app. Covers the Gradle dependency, Purchases.configure with PurchasesConfiguration, initial app user id strategy, and log level.

Use this skill when handling errors from the RevenueCat Android SDK. Covers PurchasesError, the PurchasesErrorCode enum, the userCancelled flag on PurchasesTransactionException, and the recommended UI response per code.

Use this skill when selling one time products on Android with RevenueCat. Covers fetching offerings, running awaitPurchase on a non subscription package, and relying on the SDK to acknowledge or consume automatically.

Use this skill when handling failed renewals on Android with RevenueCat. Covers how Grace Period and Account Hold are reflected in CustomerInfo automatically, when to prompt the user, and how to trigger Google's in app messaging via showInAppMessages.

Use this skill when implementing subscription upgrades, downgrades, and plan switches via RevenueCat on Android. Covers GoogleProductChangeInfo, picking a Google replacement mode, and letting the SDK manage linkedPurchaseToken chaining.

Use this skill when rolling out subscription price changes on Android with RevenueCat. Covers opt out decreases versus opt in increases, RevenueCat's automatic handling of the change confirmation flow, and the dashboard configuration involved.

Use this skill when implementing a RevenueCat purchase on Android. Covers awaitPurchase, PurchasesTransactionException, reading CustomerInfo entitlements to grant access, restoring purchases, and the six SDK managed steps that happen inside a single call.

Use this skill to decide whether to use RevenueCat or raw Google Play Billing on Android. Provides a side by side reference of what RevenueCat handles versus what remains your responsibility at both client and backend layers.

Use this skill when hardening a RevenueCat integration on Android. Covers Trusted Entitlements response verification (INFORMATIONAL vs ENFORCED), why the server is always the authority, API key hygiene (public SDK key vs secret REST key), anonymous user identity, and purchase token protections RevenueCat provides automatically.