Hold voice agents to your standards

Test before release. Then score every live call.

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Hosted or self-hosted options
Built by autonomous vehicle safety engineers

Fail

Standard:

0 calls scored 0 0 0

Own your customer outcomes

What we hear from customer ops teams

Decagon says resolved. The customer called back.
We don’t know how it’s doing.
We changed the ElevenLabs voice. Calls got worse.
QA reviews 2% of calls. What are we missing?
Who told the customer that? We can’t find the call.
Did the prompt or model or Make workflow fail?
A new model came out. Is it safe to switch?
It said booked. There’s no appointment.
We only hear about failures when a customer complains.
Does Sierra or Decagon resolve more customer issues?
The transcript looks fine. The agent talks over customers.
Is it getting better, or are users just hanging up?
GPT Live or ElevenLabs for our agent?
They asked for a human. Vapi never transferred.
We don’t know if a change made it better or worse.
It promised a refund. How many other calls did that happen on?
Sierra says fixed. Has QA checked?
The new prompt fixed transfers but broke cancellations.

Build your quality program with Marker.

Marker turns your service standards into repeatable tests, evaluations, and call scores. You stay in control of the agent development lifecycle.

Define standards
Test before release
Score live calls
Fix failures

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Trust your scores

Review scores
Correct verdicts
Tune judges
Validate changes

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Score every live call.

QA on every call
Don't miss a single issue
Audio and timing issues

Transcript / 9:13AM Call to Help Desk processed

I need to change the address before this ships.

I can update it. Let me confirm the new address first.

tool order.update_address 409

tool order.update_address 204

Deployment: prod / us-east-2
Commit: 3f9c2ba
Trace

trace 8c41d0 · 18.2s · 9 spans

call.session 18.2s

stt.transcribe 5.7s

agent.turn 3.2s

llm.completion 2.6s

tool order.lookup 0.4s

agent.turn 4.3s

tool order.update_address 409

tool order.update_address 0.7s

tts.synthesize 1.4s

Test changes before release.

Realistic test calls
Old and new versions compared

Automated alerting

Teams Slack GitHub

Regression test checkout-agent v25 · 8d21f4c

running

Scenarios

Simulated Users

Simulations

288

Refund after renewal pass

Cancel during upgrade fail

One standard before and after launch.

Pass, warn, and fail checks
A reason for every score

Did the agent verify identity before disclosure?

rev 08 · c41f9ae

LLM Judge Explanation

GPT 5 mini

The agent collected the account postcode before revealing billing details.

Pass

Human‑in‑the‑loop reviewers have the final say.

Correct any score
Every correction sharpens future scores
Full correction history
Or use Marker's trained reviewers

Automated Scoring vs Human Review

93.5% agreement

n = 322 Human pass Human fail Judge pass 214agree 9review Judge fail 12review 87agree

Start with an audit.

We stress test your agent on your most important calls. Then we show you what to fix first.

Connect your agent.
Phone number WebSocket WebRTC
We stress test critical moments.
Identity checks, tool failures, interruptions, and handoffs tested against your standards.
We tell you what to fix first.
Findings ranked by severity, with call recordings and clear recommendations.