Resources
Programmable voice with FlexML
Create interactive voice applications using high-level instructions, integrate HTTP applications, and make or receive phone calls. FlexML is the CarrierX markup language that describes what happens on each call.
Incoming call
<Say>“Press 1 for sales, 2 for support.”
<Gather>Waits for the caller's key press
If the caller presses Key 1
<Dial>Sales team
If the caller presses Key 2
<Dial>Support team
If the caller presses no key
<Record>Takes a message
Why FlexML
Voice that follows your business logic
A FlexML application is a short set of XML instructions that controls a call: routing, media playback and interactive voice response. CarrierX's interpreter carries them out in real time, while the caller is on the line.
Add voice to your applications
Make and receive phone calls from your own software, and look up customer records while a call is in progress.
No SIP server to run
Build interactive voice applications without running your own SIP server. Host call flows on CarrierX's cloud platform or serve them from your own.
Familiar if you are migrating
FlexML stays compatible with familiar standards such as TwiML, and CarrierX publishes guides for moving from Twilio or Plivo.
Use cases
What you can build
FlexML handles the call flow; CarrierX's conference and Mediator products cover meetings and private forwarding.
IVR and call routingFlexML
Menus that gather key presses and move callers through prompts, with conditional logic that responds to what they enter.
Notifications and alertsFlexML
Outbound calls that deliver a message by text to speech or a recorded audio file.
ConferencingConference
A hosted conference bridge for up to 1,000 callers per meeting, secured with access codes and user roles.
Number masking and forwardingMediator
Forward calls from a rented number while masking the number that appears on the destination phone, preserving caller privacy.
Voice messaging and recordingFlexML
Capture messages and conversations as call recordings, in multiple formats.
AI-powered voice assistantsFlexML
Stream call audio to the application behind your assistant.
Features
What FlexML gives you
FlexML integrates with CarrierX's telephony infrastructure, and the FlexML API manages the accounts, calls and phone numbers behind it.
REST API
Endpoints for managing accounts, calls and phone numbers (DIDs).
Webhooks
Serve call instructions from your own servers through webhook callbacks, or host them on CarrierX.
Phone numbers
Rent phone numbers to connect to the PSTN, and place or receive calls on them.
Text to speech
Speak any text to the caller using simple markup.
Audio playback
Play audio files or remotely hosted streaming media.
Recording
Create call recordings in multiple formats.
Key-press input
Gather and respond to DTMF, the tones callers send.
Answering machine detection
Detect when an answering machine picks up a call.
Call control
Dial out, hang up or reject calls, with conditional routing and callbacks.
Questions
Common questions
Programmable voice
Talk through your voice application
Book a call with the CarrierX team to walk through the call flow you want to build on FlexML.