Stripe event: checkout.session.completed, check payment_status before you fulfill

TL;DR

Wait for checkout.session.async\payment\succeeded instead. Use it to release anything you held, not this handler.

Steps

1. Wait for checkout.session.async\payment\succeeded instead.
2. Use it to release anything you held, not this handler.

When to use

You are seeing this: The customer finished the Checkout Session. Use this skill when you run into "Stripe event: checkout.session.completed, check payment_status before you fulfill".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Stripe's event reference says checkout.session.completed occurs when a Checkout Session has been successfully completed. Stripe's fulfillment guide (verified live at https://docs.stripe.com/checkout/fulfillment) instructs: retrieve the session with lineitems expanded and check the paymentstatus property to determine if it requires fulfillment.