This article explains how to build reliable post-call data extraction for voice AI agents.
By the end, you'll know how to define variables that produce consistent, usable data on every call.
What is post-call data extraction?
After every call, you usually need structured data from it: the caller's name, phone number, what they called about, and whether it was urgent.
You use this data to notify your client, populate a CRM, generate analytics, or trigger follow-up.
Post-call data extraction is the process that produces structured data from the raw call transcript.
You define the variables you want extracted, and a separate system reads the transcript and populates their values. The variables you define become the columns of your structured output.
Understanding extractor in Voice AI.
The extractor is a second LLM that runs after a call ends. It's separate from the voice agent itself.
- The caller talks to your voice agent (one LLM, real-time, voice).
- The call ends and a full transcript is generated.
- The platform sends the transcript to the extractor LLM.
- The extractor reads your variable definitions and the transcript.
- The extractor outputs one value per variable.
- Those values get sent to your webhook and stored in the platform.