In their defence, there is a fairly nice website too, not sure why it needs to have its own logo though

https://bwt.cbp.gov/

That's border wait times, not what the OP was looking for.

TSA used to have an API [0]. But, of course while the deprecation page still lives on the service does not.

Edit: Also looks like TSAWaitTimes.com [1] is an option, I'm sure their API works. o_O

[0] https://www.dhs.gov/archive/mytsa-api-documentation [1] https://www.tsawaittimes.com/