About API processing messages

Hi ​@YUKIS,

It depends on whether the API operation is synchronous or asynchronous. In a synchronous API call, the response is returned once the request has been fully processed. For example, in IFS Connect outbound messaging, Invoke_Outbound_Message is synchronous,  it waits for a response from the receiving endpoint before returning.

Post_Outbound_Message, on the other hand, is asynchronous. It queues the message as an Application Message and immediately returns a message ID, while the actual processing happens in the background.

Regards

Hi ​@YUKIS,

For a standard synchronous IFS API call (for example, a Projection action, REST API, or PL/SQL API invoked directly), the response is returned only after the API processing has completed. The caller waits for the transaction to finish, and then receives either the result or an error. This aligns with IFS Integration API guidance that integration APIs are designed to complete a logical business process within a call.

Therefore, the correct statement is: The message is sent after the API process is completed.

The second statement would only apply to asynchronous processing, such as Application Messages, IFS Connect queues, background jobs, or event-driven integrations. In those cases, IFS may acknowledge receipt immediately while the actual processing continues in the background. The integration documentation explicitly mentions both synchronous and asynchronous messaging patterns.

In short:

• Synchronous API → Response returned after processing completes.
• Asynchronous API / Messaging → Acknowledgement may be returned immediately, while processing continues in the background.