Every integrator gets a sandbox, and you can walk into it

You ship a payments SDK. Every new integrator spends their first day fighting their own environment before they write a line against your API.

Sign-up now clones a container from your integrator template: sample app wired to the sandbox, test keys in place, VS Code at ?folder=/sample&id=0. They're calling your API in the first five minutes. When they file a ticket saying the webhook handler never fires, your developer-relations engineer opens the same URL, stands in their code, and sees they're reading event.type where your payload says type.

Four hundred integrators, four hundred containers, one bare metal box. The ones who gave up in week one cost nothing to keep.