https://www.iatatravelcentre.com https://www.iatatravelcentre.com is my goto when it comes to visas. Not sure though if they provide this data over an API. and

https://www.iatatravelcentre.com https://www.iatatravelcentre.com is my goto when it comes to visas. Not sure though if they provide this data over an API. and I heard that this is what airlines usually use.