Watching what a competitor actually does
Their profile, their whole post history with the numbers attached, and the sounds and playlists their reach is built on.
What serves this
Read from the platform registry, so nothing here is a job the API cannot currently do. Each endpoint links to its own reference.
Reach is built on things you can see
Competitor research usually stops at "they post four times a week and get this many likes", which is the least useful thing about them. The question worth answering is why a particular post worked, and the answer is usually visible: the sound it used, the playlist it sat in, the hashtags, the format, the hour.
Pulling the whole post history with the numbers attached lets you sort it. The top decile of a competitor's posts is a small enough set to look at properly, and the things they have in common are the things worth copying. On TikTok in particular, sounds are the strongest single predictor available publicly, and sound-level endpoints let you find everything else that used the same one.
Do this on a schedule rather than once. A competitor's strategy is a moving thing, and the interesting signal is the change — the week they started posting twice a day, the format they abandoned.