API Banking and Open Banking

What You Can Do After This Chapter

Learning objective. Learner explains API banking and open banking, including consent, authentication, and third-party access, and writes API requirements for a payment initiation use case. Learner demonstrates this skill using realistic banking examples, explaining each step clearly and using correct terminology throughout.

Practical assessment. Learner writes functional requirements for an API that lets a third-party app initiate a 300 euro payment with customer consent, covering authentication, consent scope, idempotency, and error handling. Learner then draws the consent flow from app request to bank approval, and lists five error cases with the correct HTTP status and customer message for each. Learner submits the work with all calculations, sources, and assumptions stated clearly, and checks the result against the chapter checklist before final submission.

Expected deliverables.

• API requirements document for payment initiation
• Consent flow diagram
• Error case table with five errors
• Idempotency and retry design note

Completion criterion. Learner covers consent, authentication, idempotency, and errors in the requirements, draws the consent flow correctly, and assigns the right status to each error. Completion is judged on accuracy, completeness, and clear reasoning throughout the submitted work.