Cart Recovery That Stops After Purchase

An abandoned checkout does not mean the customer should keep getting email. A fixed sequence can keep running after purchase, offer a discount too soon, or match the wrong cart by email address.

That wastes margin and makes the store look careless.

I saved the discount for email three. If the first reminder is enough, the store does not give away margin it did not need to.

Recovery is tied to Shopify’s exact abandoned-checkout identity, not just the customer’s email address. It takes more state, but the stop decision now belongs to the checkout that started the sequence.

PostgreSQL holds the sequence state and prevents duplicate work. The workflow checks Shopify before it writes copy, before Gmail sends, and before it marks a cart lost.

The first purchase-suppression test failed. n8n 2.30.5 returned the Shopify response as a raw HTTP object, so the workflow missed the completed checkout and sent the first email.

I switched the request to native JSON body mode. After that, both the isolated check and the full dispatcher stopped on recovered before AI or Gmail. I kept the failed send out of the successful test count.

All three planned emails arrived in the controlled sequence.

Emails one and two contained no discount. Email three used a verified one-use code.

Shopify recorded one redemption and $47.60 in controlled test recovered value.

Invalid model output retried once, then used approved fallback copy.

A Shopify failure stopped the sequence without sending or advancing state.

This runs against a Shopify development store and stays inactive outside testing. I designed for Gmail and Google Sheets credential failures but did not inject them into the live demo.

A client launch would still need the store’s consent rules, sender domain, schedule, monitoring owner, discount policy, and deliverability setup.