Modify Calls In Progress

This guide teaches the basics required for the following use cases:

You can use this guide to dynamically manage automated broadcast or alert calls while they are in progress. For example, you can programmatically redirect a notification call to a live agent queue if a customer requests immediate assistance, or terminate a call early once an urgent message has been acknowledged. To learn more advanced features that you can use with notifications, see Voice notifications.

Together with your IVR workflows, you can use this guide to interrupt automated self-service paths based on real-time events. Seamlessly break a caller out of an automated data-gathering script if they request a human agent, or modify the call's direction dynamically when a backend database updates during the session. To learn more advanced features that you can use with self-service automation, see Voice self-service automation.

You can use this guide to implement essential call center features like warm transfers, supervisor barge-ins, and call holds. Modify active calls to pull customers out of queues as agents become available, bridge multiple parties together, or redirect callers to different departments based on live agent availability. To learn more advanced features that you can use with inbound call centers, see Voice inbound call centers.

Together with Twilio live audio streaming, you can use this guide to control transcription services dynamically during a conversation. Programmatically start or stop transcription streams to protect user privacy when sensitive information is being spoken, or inject new routing rules into a call based on live keywords detected by your transcription engine. To learn more advanced features that you can use with AI or ML transcription, see Voice AI and ML transcription.

You can use this guide to manage interactions between human callers and autonomous voice bots in real time. Create human-in-the-loop takeover mechanisms that instantly intercept an active call and redirect it to a human supervisor if the AI agent detects frustration or encounters a complex request. To learn more advanced features that you can use with AI agents, see Voice AI agents.

You can use this guide to optimize live outbound interactions and agent utilization. Instantly modify the path of an outbound call to play a prerecorded message the moment an answering machine is detected, or dynamically shift active outbound legs between agent tiers based on shifting campaign priorities. To learn more advanced features that you can use with outbound call centers, see Voice outbound call centers.

You can use this guide to power advanced click-to-talk workflows and lead response systems. Initiate a call to a sales representative first, and then dynamically modify that call in progress to dial and bridge the prospect the exact moment the agent goes off-hook and is ready to talk. To learn more advanced features that you can use with sales dialers, see Voice sales dialers.

You can use this guide to control proxy routing and number masking on active lines. Modify live call parameters to dynamically mask phone numbers for privacy, track campaign attribution data mid-flight, or update routing metrics as a call moves through various marketing touchpoints. To learn more advanced features that you can use with call tracking, see Voice call tracking.

After following this guide, you can programmatically modify live phone calls using Twilio Programmable Voice and the Twilio SDKs. You will have built code that can dynamically update call directions or explicitly update the call status to complete active sessions on your account.

Explore the following guides to build on what you've learned in this guide:

• Make outbound phone calls: Learn how to spin up completely new outbound calls from your web application.
• Respond to incoming phone calls: Learn how to handle incoming webhooks from Twilio to start initial phone call routines.

Find reference documentation for the topics on this page.

• Call resource