QA for your Retell agents
Your conversation flow describes how calls should go. Zelto grades how they actually went — every production call, every node — and clusters what broke into Findings you can fix.
What actually breaks on Retell in production
Dashboards show you that calls happened. They don't show you the calls that quietly failed — and those are the ones that cost you customers.
Callers falling off the flow
Conversation flows encode the happy path. Real callers interrupt, backtrack, and ask things no node anticipated. Zelto surfaces where callers consistently leave the designed path — and what the agent did when they did.
Function calls that fail mid-call
A booking API errors out, the agent apologizes vaguely, the caller hangs up. Retell logs the error; Zelto tells you how often it happens, what it costs you in failed calls, and which flow node to fix.
Edits that regress working flows
Every flow edit is a deploy. Zelto grades calls continuously, so when Tuesday's edit breaks Monday's working path, it shows up as a new Finding — not as a churned customer three weeks later.
Voicemail and transfer mistakes
Agents leaving pitches on voicemails, transferring to humans too early or not at all, or mishandling the moment a real person picks up. These edge cases are invisible until you grade real traffic at volume.
How Zelto works with Retell
Connect
Connect your Retell API key. Zelto pulls your agents and ingests every completed call with its recording, transcript, and metadata. No changes to your flows.
Zelto listens and diagnoses
Every production call is graded against a rubric Zelto auto-learns from your traffic — your domain, your language, your definition of a good call. No setup, no scorecard to write.
Findings, with the fix drafted
Calls that fail for the same reason are clustered into one Finding, ranked by volume, with example calls, a drafted prompt fix, Slack alerts, and an optional Linear ticket.
Production traffic, not simulations.
Simulation tools grade synthetic conversations against scenarios you wrote. Zelto grades what actually happened with real callers on your Retellagents — because that's where the failures that matter live. Most teams are integrated in under 15 minutes.
Zelto + Retell
The questions teams ask before connecting. Answered honestly.
Other integrations
One week. One agent. Ten findings
Connect one production agent. Zelto listens, then walks you through ten findings with severity, examples, and fixes.
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