Create a customer
Creates a customer, usually at signup, keyed by your own ID in external_id. A customer is charged once it has a subscription.
Authentication
A secret key (rl_sk_test_..., rl_sk_live_...) or a restricted key with limited scopes (rl_rk_test_..., rl_rk_live_...). A restricted key can carry agent: true and an expires_at, and is what a coding agent should hold. Keys end in a checksum so secret scanners can recognize them. People create, roll and revoke keys in the dashboard; GET /v1/api_keys lists them, masked.
Request
Sandbox only. Attach the customer to this test clock (clock_...).
Always use this connected provider (by name) for this customer, ahead of the routing rules. While a customer names a provider, that provider can’t be removed. The removal returns 409 invalid_state with this customer in blocked_by.
Response
Present once the customer has saved a payment method. unusable means the provider that holds it was removed: the method is kept on record, marked unusable and never charged, and the customer needs to save a new one. Left out before they save one.