Voice agents that get better every week.
Zelto is QA for voice AI agents. It catches the failures a scorecard can't, and hands you the fix.
From thousands of calls to a handful of fixes
Every production call comes in. Zelto groups the ones that fail for the same reason, ranks them by impact, and drafts the fix. Each one moves a number you already report on.
01 Calls in
- vapi · 0:42
- retell · 1:18
- livekit · 2:03
- vapi · 0:54
- bland · 1:51
- vapi · 1:09
- retell · 0:38
- pipecat · 2:24
Every production call streamed in real time
02 Diagnosed
Clusters detected146 calls- Voicemail not detected47
- DTMF narrated, not sent23
- Number stutter on amounts12
- Greeting too slow8
- Missed customer interrupt18
- Hallucinated callback time6
- PII read pre-auth9
- Compliance disclosure skipped11
- Wrong date format readback7
- Long pause after price5
Zelto grades every call and groups the ones that fail for the same reason
03 Findings
- highF-104247 calls
Voicemail not detected · payment data leaked
- mediumF-104323 calls
Agent narrated key press instead of DTMF
- lowF-104412 calls
Number enunciation glitch on dollar amounts
- highF-10459 calls
PII spoken before caller authentication
- mediumF-104614 calls
Greeting tempo drifts after 30s of silence
- lowF-10476 calls
Regional last name confuses TTS
- highF-104811 calls
Missed required compliance disclosure
- mediumF-104917 calls
Callback time committed agent can't honor
- lowF-10508 calls
Date repeated back in wrong format
- mediumF-10515 calls
Long pause after price quote
Ranked by how many calls are affected. Fix the patterns, not the noise
04 Outcomes
Last 30 days- +12%Collection rate
- +8%Sales conversion
- +18%First-call resolution
- −37%Bad calls / day
- +9%CSAT
- −14%Avg. handle time
- −52%Compliance flags
- −21%Refund requests
- +22%Containment
- −28%Escalations
- −16%Repeat callers
- −9%Avg. quote-to-close
The metric your business runs on starts moving
More than just findings
Findings are the core. Everything around them gets the fix into the tools your team already lives in: Slack, Linear, and the coding agent of your choice.
- highF-1042Voicemail not detected · payment data leaked47
- mediumF-1043Agent narrated key press instead of DTMF23
- mediumF-1044Greeting tempo drifts after 30s of silence14
- lowF-1045Number enunciation glitch on dollar amounts12
- highF-1046PII spoken before caller authentication9
- mediumF-1047Callback time committed agent can't honor17
Findings
Every recurring failure, grouped by the calls that share it.
Zelto clusters every call that fails for the same reason into one Finding, ranked by call volume. Fix the patterns that touch the most production traffic first.
Fix: acknowledge frustration before offering next steps
Fix
Drafted fixes, ready for your agent.
Every finding ships with a prompt and a Linear ticket. Hand it off to Claude, Codex, Cursor, or whatever coding agent you already use.
Alerts
Per-customer alerts in Slack.
Route findings to a dedicated channel per customer. The team that owns the account hears about a regression the moment it happens.
Ask Zelto
An AI that knows your voice ops.
"Which agent regressed this week?" The in-product copilot answers in plain English.
Listen to the moment
Jump to the failing seconds, not the full call.
Each finding pins the exact range that triggered it.
Greeting tempo drifts after 30s of silence
Learning
Gets sharper every time your team gives feedback.
Mark a finding wrong or lower its severity. Zelto applies the correction across every call that shares the pattern.
One API, every voice stack you already use.
Native integrations with the big voice platforms. Or connect using our API.
- Custom / API
- Custom / API
Voice AI debt collection startup
“Zelto reduces the time our engineers and solution architects spend reviewing calls, now they can focus on making the agent for our customers better.”
Pricing that scales with your calls
Every plan analyzes 100% of your production calls, clusters recurring failures, and ships the fix. Pick the volume that fits, and only pay for the calls you actually analyze.
+ $0.02 per call analyzed
- Calls included5,000
- Voice agents3
- Slack alerts
- 100% of calls analyzed
- Prioritized issues
- Reports
- Automatic fixes
- Private Slack channel
- Custom integrations
+ $0.01 per call analyzed
- Calls included60,000
- Voice agentsUnlimited
- Slack alerts
- 100% of calls analyzed
- Prioritized issues
- Reports
- Automatic fixes
- Private Slack channel
- Custom integrations
Starting at $2,500
- Calls included+370,000
- Voice agentsUnlimited
- Slack alerts
- 100% of calls analyzed
- Prioritized issues
- Reports
- Automatic fixes
- Private Slack channel
- Custom integrations
Pay as you go
You stay in control of spend
Set your limit
Cap how many calls we analyze each month, so your spend never runs past what you set.
Filter what counts
Analyze only the calls that matter to you, and filter out the ones you'd rather we skip.
Never overpay
The moment a higher plan would cost you less at your volume, we tell you to switch.
What you'll ask us
The questions that come up on every first call. Answered honestly.
One week. One agent. Ten findings
Connect one production agent. Zelto listens, then walks you through ten findings with severity, examples, and fixes.
Book a demo