While idtracker.ai’s job ends when the trajectory files are validated. There is an extra tool (not part of but compatible with idtracker.ai) called trajectorytools.
It is a Python package to perform basic trajectory analysis and it is available at fjhheras/trajectorytools.
You can find some analysis routines from  implemented with trajectorytools in the Jupyter Notebook trajectories.ipynb in polavieja_lab/idtrackerai_notebooks. Here we present some of the analysis we get using a 10 juvenile fish video:
Smoothed trajectories (left) and density of neighbors around a focal fish (right)