Payments references
Lookup pages for when a payment is failing and you need the exact answer: what a code means, which test value triggers a scenario, why a verification or signature check fails, what to do next. Not Flint documentation; these cover the payments ecosystem, with a short bridge to how each topic works on Flint.
Card decline codes
Every decline code that matters: what the issuer is saying, whether a retry can work, what to tell the customer, and the network retry rules that make blind retries expensive.
Test card numbers
Every documented test card and failure trigger for Stripe, Square, Adyen, Braintree, PayPal, and Authorize.net, plus the nine cards that matter in every Flint sandbox.
Apple Pay domain verification failed
Every way the well-known file fetch fails: redirects, bot protection, TLS trust, stale files, and the Stripe Connect account trap, with a five minute curl diagnosis.
Stripe webhook signature errors
"No signatures found matching the expected signature for payload" means one of three things: a parsed body, the wrong whsec_ secret, or a mangled header. Fixes per framework.
How to refund a line item in Stripe
Stripe refunds are amount-only. The two real paths: credit notes when an invoice exists, per-unit proration everywhere else, plus the discount, tax, and rounding traps and the metadata that keeps accounting reconciled.
Does Stripe track inventory?
No: Products have no quantity field, Checkout enforces nothing, and the old SKU inventory API is gone. The webhook decrement recipe, the five race windows that oversell during spikes, and what closing them takes.
Does Stripe have an Orders API?
No. Two Orders APIs shipped and both were retired: v1 in October 2019 over SCA, the 2022 beta removed before GA. What ranks under the name now, what replaced the order object, and where the order layer lives today.
Stripe as your source of truth
For payment state, yes, and only from webhooks. For the sale, it can't be: Stripe's own fulfillment guide keeps orders in your database. The domain split, the read-allocation math, and the five drift traps.
Payfac-as-a-service, compared
Finix, Worldpay (Payrix), Rainforest, Tilled, Stax Connect, Payabli, and Stripe Connect on onboarding, registration, economics, API surface, and go-live claims. Vendor-sourced, dated, conflict stated.
Looking for Flint's own documentation? Start at the docs, the API reference, or the Flint error catalog.