Citi Authorize API
The Citi Authorize API handles the OAuth 2.0 authorization-code and customer-consent flows required for third-party applications to gain scoped access to a customer's Citi account data and to initiate payments. It is the security and consent layer underpinning the rest of the Citi Developer Hub retail catalog, issuing the access and refresh tokens consumed by the Accounts, Money Movement, and Customers APIs. Documentation is HTML-only on the Citi developer surface; no public OpenAPI is published.