pbl-v8-to-v9-migration

Phase 0: Intent

Announce to the user: "I will migrate this project from PBL 8 to PBL 9."

State the key fact up front so the user calibrates effort correctly: PBL 9.0.0 (released 2026-05-19) removed no APIs. PBL 8.0.0 was the breaking release that deleted the Sku* family, queryPurchaseHistoryAsync, and the parameterless enablePendingPurchases(). PBL 9 builds on that surface with one target SDK bump, two compatibility adjustments, and one optional new feature. RevenueCat characterizes it as a single sprint of work for a v8 app.

If the project still references SkuDetails, querySkuDetailsAsync, SkuType, or the parameterless enablePendingPurchases(), the real baseline is pre-v8. Stop and route the user to pbl-v7-to-v9-migration, which does the v8 work first.

Phase 1: Discovery

Gather the facts before changing anything.

1. Locate the dependency. Open build.gradle, build.gradle.kts, or libs.versions.toml and find com.android.billingclient:billing or billing-ktx. Confirm the version reads 8.x.x. If it reads 7.x or lower, switch to the pbl-v7-to-v9-migration skill.
2. Check androidx.core. Find the androidx.core:core / core-ktx version. v9's error reclassification requires androidx.core 1.9 or later. Record the current value.
3. Check compile and target SDK. Read compileSdk and targetSdk. v9 targets API 35. Note both values.
4. Scan for developer provided billing. Grep for DeveloperProvidedBillingDetails, getLinkUri, enableDeveloperBillingOption, and enableBillingProgram. These are the External Payments APIs from PBL 8.3. If any hit, the nullable getLinkUri() change in Phase 3 applies. If none hit, you can skip that step.
5. Scan error handling. Grep for BillingResponseCode.ERROR and BillingResponseCode.BILLING_UNAVAILABLE. Note every place that branches on a generic ERROR for an unavailable store, because v9 reclassifies the blocked store case.
6. Note in app messaging usage. Grep for showInAppMessages and InAppMessageParams. If present, the optional price increase messaging step applies.