I also often need user agents for various projects (scraping, security purposes, etc). I created a free list and API updated ~ every week that contains a wide range of human browser user agents and bot user agents.

The API with all user agents is available here https://deviceandbrowserinfo.com/api/user_agents/all

If you prefer a more human-readable format you can also use this page https://deviceandbrowserinfo.com/data/user_agents