payment_setup_required

HTTP 402   title: Payment setup required

What it means

A payment gate on POST <endpoint>/pay: the acting identity has no card on file, so there is nothing to charge. Not a proof-of-work challenge — there is no challenges field.

What it carries

• WWW-Authenticate: Payment — the challenge header naming the scheme.
• No challenges array. A client that assumes one on every 402 is reading the status instead of the code.

What to do next

Call the operator’s payment_setup action and hand the returned setup_url to the human — an AI assistant never automates card entry. Retry pay once the human has saved a card.

On the wire

{
  "type":   "https://kiosk.tech/problems/payment_setup_required",
  "title":  "Payment setup required",
  "status": 402,
  "detail": "… what went wrong on THIS request …",
  "code":   "payment_setup_required"
}

This page documents the RFC 9457 type URI https://kiosk.tech/problems/payment_setup_required. The URI is an identifier, not a locator a client should fetch: branch on the document’s code member. The normative definition lives in the error vocabulary of the Kiosk specification (§9 of the formal spec).