My customer would like to secure calls to the Twitter REST api via VPN or IPsec in addition to HTTPS. Can that be done?
My networking is rusty, but afaik, doesn’t matter what kind of setup you’ve got - as long as connections to https://api.twitter.com (on port 443) are getting through.
You’re free to use your own VPN to connect. Twitter does not provide one. As @IgorBrigadir says the key requirement is to be able to access api.twitter.com over HTTPS, if you can do that, you’re all set.
Twitter does not provide additional connection security above TLS. You can include as additional security over connections you control but at some point you will have to terminate the VPN connection upon before the final hop to Twitter’s network.
I use PureVPN. It encrypts my information from start to end, giving me complete privacy and security that’s impossible to beat