Asynchronous Processing

Asynchronous processing works by queueing SOAP API calls in an async server before they’re processed. Asynchronous processing improves the responsiveness and processing speed of SOAP API calls. API calls aren’t dropped, even if the system is temporarily unavailable. Queued calls can be processed in the order they’re received, scheduled for processing at a specific time, or processed according to their priority.

• When to Use Asynchronous Processing — Asynchronous processing isn’t necessary for all of your API calls. These scenarios can help you understand which API calls are best suited for asynchronous processing.
• Endpoints, Methods, and Objects for Asynchronous Processing — Make sure that the endpoints, methods, and objects you use support asynchronous processing.
• Understand the Options Base Object — To make existing calls asynchronous, include the Options base object parameters and specify that you want to use asynchronous processing.
• Callback Handling for Asynchronous Calls — We recommend that you use an HTTP POST callback to return the results of asynchronous API requests.
• Asynchronous Processing Syntax Guide — View code examples for common asynchronous processing scenarios.

With synchronous call processing, the system processes API calls as soon as they’re received. If the system is temporarily unavailable, synchronous API calls can’t be received and aren’t processed. If calls aren’t processed, it’s difficult to identify when a call is dropped. For example, you can send some calls again with no significant impact to the system or your customers. For processing-heavy actions, such as an email send, duplicating the call isn’t recommended.