​
Overview

Flex integrates with RevenueCat to help you manage subscriptions seamlessly across platforms. This guide walks you through connecting your RevenueCat account to Flex, passing a stable customer identifier, saving the integration, and understanding how events map between systems.

​
Installation Guide

1

Add RevenueCat in Flex

Log in to your Flex Dashboard.Go to Integrations → RevenueCat.Enter your RevenueCat App ID and API Key.
  • You can find these in your RevenueCat project under App Settings.
Flex Dashboard → Integrations page with RevenueCat selected
2

Configure in RevenueCat

In your RevenueCat project, open the Apps section.Click + Add and select Other payment provider.Copy your App ID and Secret API Key.Paste these values into the Flex Dashboard RevenueCat fields from Step 1.RevenueCat “Apps” page showing Other Payment Provider selectedRevenueCat “Apps” page showing Other Payment Provider selected
3

Pass a Custom User Identifier to RevenueCat

If you want RevenueCat to reference your own user ID (or a Flex user ID), include it in the checkout session metadata as REVENUE_CAT_CUSTOMER_ID.
{
  "checkout_session": {
    "line_items": [
      {
        "price": "fprice_01k2j2zfnbrs5e0r4c8wqphv29",
        "quantity": 1
      }
    ],
    "success_url": "https://example.com/thank-you?success=true",
    "mode": "subscription",
    "cancel_url": "https://example.com/thank-you?canceled=true",
    "shipping_address_collection": false,
    "defaults": {
      "first_name": "Varsha",
      "last_name": "Parthay",
      "email": "rclivedemo1@gmail.com"
    },
    "metadata": {
      "REVENUE_CAT_CUSTOMER_ID": "1234567890"
    }
  }
}
4

Save and Sync

Click Save in the Flex Dashboard integration page.Flex will begin sending subscription events to RevenueCat so customer status stays in sync.
Tip: If you have existing subscriptions, run an initial sync (or perform a backfill) so historical subscriptions are recognized in RevenueCat.

​
How It Works

After connecting, Flex forwards subscription lifecycle events to RevenueCat so your app logic, entitlements, and paywalls stay accurate. Events include:
  • Trial activations and conversions
  • Renewals and successful payments
  • Payment failures and recoveries
  • Cancellations and expirations
Every Stripe event is mapped to the appropriate RevenueCat (RC) action:
  • Trial Purchase
    Stripe: customer.subscription.created (status: trialing) → RC: trialing (no payment)
  • Trial Conversion
    Stripe: subscription.updated → active + invoice.payment_succeeded → RC: active + payment
  • Renewal
    Stripe: invoice.payment_succeeded (subscription_cycle) → RC: active + payment
  • Billing Issue
    Stripe: invoice.payment_failed (status: past_due) → RC: in_grace_period, no payment, uses next_payment_attempt
  • Recovery
    Stripe: invoice.payment_succeeded after failure → RC: active + payment
  • Cancel at Period End
    Stripe: subscription.updated (cancel_at_period_end) → RC: active, auto_renewal_status: will_not_renew
  • Manual Cancellation
    Stripe: customer.subscription.deleted (no expiry state) → RC: same as “Cancel at Period End”
  • Expiration
    Stripe: final state such as incomplete / expired / unpaid with customer.subscription.deleted → RC: expired, gives_access: false

​
Troubleshooting