Possible to subscribe to business events without using OIC?

Summary:

Are business events (e.g., Purchase order changes) available via other methods - not only Oracle Integration?

Content (please ensure you mask any confidential information):

We have third party vendors interested in the events if they can subscribe without going through the Oracle Integration platform

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):