Add a card for numbers
Returns a Stripe Checkout URL that saves a card as the workspace’s default, so numbers can be billed. Buying a number that would be charged without a card returns 402 payment_method_required. Send an Idempotency-Key.
Scopes: billing:write
Authorizations
An API key from Settings → API keys, sent as Authorization: Bearer kb_live_…. A workspace key starts kb_; a personal key starts kbp_ and acts as its owner.
Headers
A unique key (a UUID works) for this request. Retrying with the same key returns the first answer instead of running twice.
255The API version to answer as, a date (YYYY-MM-DD). Leave it out for the current version (2026-11-07). An unknown version is refused with 400 unsupported_api_version.
2026-11-07 "2026-11-07"
Body
Response
Successful Response