Twilio's Programmable Voice API handles the mechanics of a phone call, dialing out, answering in, routing between numbers, recording, conferencing multiple people in, all controlled through TwiML, a set of instructions Twilio reads to decide what happens next on the call. We build the actual call logic on top of it: the IVR menu that routes based on who's calling, the forwarding rule that checks who's actually available before ringing them, the conference bridge tied to a real appointment instead of a static dial-in number.
TwiML controls the call, step by step. Each instruction, say this, gather a keypress, dial this number, start recording, runs in order as the call progresses, so a basic IVR menu is really just a short script Twilio executes live.
Call forwarding and routing. A number can ring through to a different number, a different person, or branch based on what the caller presses, without the caller ever knowing the call moved.
Conferencing multiple callers. Twilio's conference feature can bridge several callers onto one line, useful for anything from a three-way customer call to a standing team line, with control over who can speak, mute, or get bumped.
A phone tree that just reads options off a static menu is easy to build and starts feeling dumb to callers almost immediately: press 1 for sales doesn't know sales already has four people on hold. The useful version checks something real before routing, who's actually free, what account the caller's number is tied to, whether they already have an appointment today, and that check is logic that lives outside TwiML, in whatever system actually holds that information.
Instead of a fixed menu, the call checks who's actually available in your dispatch or scheduling system before routing, so a caller doesn't land on someone who's out or already on another line.
A conference bridge gets created and its number sent out automatically when an appointment's booked, instead of a standing dial-in number that works for anyone who happens to find it.
Tell us what it needs to check, availability, account history, an appointment, and we'll build the lookup into the call.
Tell us what a caller's call should actually check before it routes, who's free, what account they're on, what they already have booked, and we'll wire that into the call itself. And if voice isn't where your real manual bottleneck is, we build on top of whatever is, anywhere else in the business.
Let's talk →TwiML is the markup language Twilio reads to control a call or message in progress, say this, gather a keypress, dial this number, start recording. Each instruction runs in order, so a simple IVR menu is really just a short TwiML script.
Yes, call forwarding and conditional routing are both built into Programmable Voice: a call can ring through to a different number, or branch based on what the caller presses or says, without the caller noticing the handoff.
Yes, through its conferencing feature: multiple callers can be bridged onto one line, with control over who can speak, who's muted, and who gets removed, useful for anything from a three-way call to a standing team line.
It bills per minute, with rates that vary by whether the call is inbound or outbound and by country, plus the cost of the phone number itself. There's no flat fee for the core Voice API; cost scales directly with call volume.