QAlert Scraper is apparently the scraper used by Qanon aggregator sites like qanon.pub and qmap.pub. The scraper pulls information from special pages hosted on 8kun in the form of JSON objects. If the data presented to the scraper on these special pages is a faithful representation of the posts on 8chan then what the scraper would be doing is collecting all the posts made by a specific list of tripcodes on a specific list of 8kun boards. For instance if the scraper ran through the https://8kun.top/qresearch/catalog.json JSON object it would apparently make a list of post ids. With that list of post IDs it would search through the posts JSON object by adding the ID to the end of the url like this: https://8kun.top/qresearch/res/(postidnumberhere).json. The scraper would then search for a "trip" property that matched one of the approved tripcodes.
It's important to note that this data could easily tampered with by administrators of 8kun, all it would take is one command to the database to change a trip or change the time of a post, or even change the content of a post.