There is no API access to conversations at this time.
Scraping/crawling the website is prohibited by the Twitter Terms of Service.
You should absolutely not use any application keys that are not your own / owned by your account to access any resources. This is against our developer policy.
We understand that having a public API endpoint for access to conversation metadata is a long-standing request from the developer community, however, this has not yet been prioritised as something we plan to make available in the immediate future. I’d love to have it happen at some stage, as I would with some of the others.
As I’ve explained in other threads in the past, making an endpoint available is not as simple as “just” opening up access to everyone - we need to think about how the endpoint would be used, get it documented, and have it supported and load tested etc.
@gstar2002 the usual way that I’d recommend doing what you want would be to use something like the search API to find replies to the Tweet.