what kind of company can support my business use case?

I am looking for a way to develop a secure business phone line. The idea is to leverage a programmable api where i can execute code on communications inbound and outbound on this phone line.

At first i started off with companies like twilio and telnyx, but the problem is i would have to auto forward calls/SMS instead of proxying. I then thought esims might be a solution, but it seems like they are data only and the goal is to do this without also having to develop an application.

The ideal scenario would be to have a esim compatible with phones with voice and sms and a programmable api; but seems like that doesn't exist, at least from what im finding.

If anyone has any advice on companies or tech that might be able to help here id appreciate it.