I plan to create a MongoDB database which will store information that is obtained from an external API. I need to integrate this MongoDB database with my AEM project in such a way that I can generate OAK indexes that will be obtained from that database, this in order to create a search in my AEM project. I have reviewed the following documentation:
I understand that OAK indexes the content stored in my project's repository. Is there a way to store external content in the repository? If this option is possible it could save me having to integrate from MongoDB.
If I understand you correctly, you want some application approaching directly the MongoDB and that this content then shows up in AEM/Oak and is reachable through its API.
This is not possible, because Oak does not know of the documents you added outside of its control to the MongoDB. Therefor it will never show up in the indexes. If you want to content to be indexed within Oak, you need to insert into the repository by regular means (Oak/Sling APIs).