Whop Invoice Sync

How Flexprice pushes invoices to Whop and reconciles payment status automatically

The Flexprice–Whop integration is bidirectional and fully asynchronous. Invoice creation and finalization in Flexprice are never blocked by Whop sync.

• Whop to Flexprice: When a customer pays through Whop, Flexprice is notified and marks the invoice paid automatically.
• Flexprice to Whop: Finalized invoices are pushed to Whop with one of two collection methods:
  • Send Invoice (default): Customer receives a hosted checkout link and pays on their own timeline.
  • Charge Automatically: After the first payment, subsequent invoices are charged automatically using the saved payment method.

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Pushing Invoices to Whop

Every finalized Flexprice invoice is automatically pushed to Whop. This applies to all invoice types: subscription billing, one-off invoices, and credit topup invoices.

Conditions for sync:

1. Invoice status transitions to finalized
2. Whop connection is active
3. Invoice Sync toggle is enabled on the connection

What gets created in Whop:

Field	Value
Product	From connection config, or auto-created Flexprice Billing Product
Plan type	one_time
Amount	Invoice amount_due, rounded to 2 decimal places
Collection method	send_invoice or charge_automatically (see Charge Automatically)
Payment method	Only set when using charge_automatically; omitted otherwise
Due date	Invoice due date if in the future; defaults to 30 days from now
Customer name	Customer name from Flexprice
Email	Customer email from Flexprice

After the Whop invoice is created, Flexprice fetches the hosted checkout URL and stores it under invoice.metadata["whop_checkout_url"]. Share this link with your customer for payment.

Product handling: If no product ID is configured on the connection, Flexprice auto-creates a Flexprice Billing Product (visibility: quick_link). Its ID is stored on the connection and reused for all future invoices.

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Charge Automatically

For returning customers, Flexprice skips the checkout link and charges their saved payment method directly.

First invoice: Customer receives a hosted checkout link and pays through Whop.

All subsequent invoices: Whop charges the saved payment method automatically. No action required from the customer.

If no saved payment method is found (e.g. customer has not paid through Whop before), the invoice falls back to a hosted checkout link.

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Reconciling Payments from Whop

On payment through Whop, an invoice.paid webhook is fired to Flexprice. Flexprice identifies the corresponding invoice and, if not already paid, marks the payment status as succeeded.

For credit topup invoices, the customer’s wallet is credited immediately on reconciliation.

Without the webhook configured in Whop, payments will not automatically reconcile in Flexprice and Charge Automatically will not activate. See Connection Setup for instructions.

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Marking an Invoice Paid Offline

When a Flexprice invoice is marked paid via an admin action or an offline payment, Flexprice automatically marks the corresponding Whop invoice as paid. If the Whop invoice is already paid, the call is skipped.

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Troubleshooting

Scenario	Behavior
No Whop connection configured	Sync skipped silently
Invoice sync toggle off	Sync skipped silently
Customer has no email address	Sync fails immediately. Add an email to the customer and re-sync
Invoice already synced to Whop	Skipped; duplicate creation is prevented
Whop invoice already paid	Skipped; duplicate mark-paid call is prevented
First-time customer with no Whop payment history	Falls back to hosted checkout link
Customer has no saved payment methods	Falls back to hosted checkout link
Payment method fetch fails	Falls back to hosted checkout link; Whop API errors are retried with backoff
Whop API temporarily unavailable	Retried automatically with backoff

Whop sync failures never block invoice creation or finalization in Flexprice. All sync happens asynchronously.

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Related Documentation

• Connection Setup: Set up your Whop connection and configure the webhook