Is there an addon that allows me to add new items to WaniKani's SRS?

WaniKani API And Third-Party Apps
1

For example, non-kanji words or kanji/vocab not normally encountered in WaniKani.

I’m aware that Anki exists, but I personally prefer WaniKani. Visuals wise, format wise, and SRS wise (though maybe I just haven’t used Anki enough to know for sure on that last one)

Plus, it’s nice to have everything in one place.

2

No, it’s not possible to add your own material to Wanikani.

Have you tried checking Kitsun? It’s a SRS website being built by the level 60 WK user @neicul. It incorporates a lot of fresh new ideas that you can see on WK scripts and it’s as user-friendly as Wanikani.

Here’s the forum thread:

The screenshots on the main post aren’t up to date, since a few days ago there was a huge update with a lot of new features + redesign. To see how it looks now, check this post: