RevenueCat integration: store subscriptions with your own server records

How do you integrate RevenueCat in-app subscriptions, step by step?

1. 1

   Settle the store rules before choosing a gateway

   LetSlic offers a digital subscription inside an app already published on Google Play, so Play's payments policy required Play Billing, and we asked for an earlier Razorpay branch to be deleted so it could never be merged into a store build. We chose RevenueCat over a hand-written Play Billing integration because it handles receipt checks, renewals and billing retries, and covers Apple's store in the same SDK.

2. 2

   Set the store side up in order

   Create the subscription products in Play Console, then a Google Cloud service account with the required permissions, invite it to Play Console and upload its key to RevenueCat. Google can take up to 36 hours to activate those credentials, and the entitlement, offering and packages wait on that; the webhook and test accounts can be set up meanwhile. Credentials show as active in RevenueCat when the wait is over.

3. 3

   Name entitlements and offerings exactly as the code expects

   LetSlic's code looks for a premium entitlement, a default offering and two exact product IDs, and the setup guide we wrote for the business owner marks each one. Temphera maps store product IDs to its own plans from a table that an environment variable can override without a release, and falls back to the entitlement and the product's period when a product is not listed.

4. 4

   Log the SDK in with your own user ID

   Both apps configure RevenueCat with the backend user's ID as appUserID, so every webhook names a user the server already knows and support can look a customer up in either system.

5. 5

   Authenticate the webhook and fail closed

   RevenueCat sends the Authorization header value you set in its dashboard. Temphera compares it in constant time and rejects every request when no secret is configured, so a missing environment variable cannot open the endpoint.

6. 6

   Store each event once, then process it

   LetSlic stores each webhook first under a unique index on its source and event ID, answers 200, and processes it afterwards, so a redelivered event is recognised and skipped. Temphera checks the event ID, applies the plan change as an idempotent upsert, and records the event as processed only after the work succeeds, so a failure is processed again on RevenueCat's retry.

7. 7

   Map events to plan state without guessing

   A cancellation keeps access until the period ends and only flags it; an expiration removes it; a billing issue marks the plan past due while the store's grace period runs. Trial start and end come from the event's own purchase and expiry times, never from a hard-coded trial length, because the length lives in the store and can change.

8. 8

   Keep your own ledger beside RevenueCat

   LetSlic maps each money event to a ledger type and numbers the entry LE-YYYY-NNNNNN. A Restore Purchases button asks RevenueCat directly for the user's current entitlements, as a safety net if a webhook was missed.

9. 9

   Give existing paying users a plan before the gates go live

   Temphera's old premium flag predates RevenueCat. A script, dry-run by default, grants every legacy premium or lifetime member a complimentary plan before feature gates start reading the plans table, and never overwrites a real store subscription.