This work presents CathSim, an open-source simulator designed to advance machine learning algorithms for autonomous endovascular navigation. By simulating high-fidelity catheter and aorta interactions, including real-time force sensing, CathSim addresses challenges like long training durations and safety concerns. Validation through SAC and PPO algorithms demonstrates its utility for developing reliable and collaborative autonomous catheterization tasks. The simulator is freely accessible at
https://github.com/airvlab/cathsim..