Answer
No. Two existing APIs are a good starting point, but not yet a finished connection. Data models can use different terms, mandatory fields and states. A “customer” in the shop may have several debtor accounts, delivery addresses and price groups in the ERP. “Stock” may be physically present, reserved, blocked or not yet ready for sale.
In addition, authentication, permissions, rate limits, version changes, failure behaviour and testing options have to be clarified. Some APIs allow reading but not the change that is needed. Others deliver changes only with a delay or without a unique event identifier. Before estimating effort, a specific case should therefore be checked against the actual documentation and, where possible, against a test environment. “Has an API” is not a reliable specification of work.
As of 3 September 2026
Further reading
Related topic: Back ends and interfaces