Official Retell AI Integration

Test Your Retell Agents
Before They Talk
to Customers

VoxGrade connects directly to your Retell account. Import agents, run 25+ automated tests, get a grade in 60 seconds.

No credit card 14-day free trial Works in 60 seconds
Before
0%
F
Untested agent
VoxGrade
After
0%
A
After optimization

How It Works

Three Steps to a Graded Agent

No SDK. No code changes. Just connect your Retell API key and VoxGrade handles everything.

1
🔑

Connect Your Retell API Key

Paste your Retell API key into VoxGrade. We automatically import your agents, their LLM config, and voice settings.

retell_api_key = "sk-ret_..."
// Auto-imports all agents
2
🎯

Select Your Agent, Click Test

Pick any agent from the dropdown. Choose a scenario pack or let VoxGrade auto-generate adversarial tests based on your agent's prompt.

agent: "Appointment Setter v3"
scenarios: 25 auto-generated
3
📊

Get Your Grade + Auto-Fix

Receive a detailed scorecard with letter grade, metric breakdown, and one-click fix suggestions for every failed test.

Grade: A (91/100)
// 23/25 tests passed

What VoxGrade Tests

25+ Quality Metrics, Fully Automated

Every test simulates a real caller scenario against your Retell agent. No manual review needed.

👋

Greeting Quality

Is the opening natural, warm, and on-brand? Does it set the right context for the call?

🛡

Objection Handling

Can your agent handle pushback, price concerns, and "not interested" gracefully?

🧠

Memory Persistence

Does the agent remember details from earlier in the conversation without repeating questions?

🚨

Hallucination Detection

Catches your agent making up facts, inventing policies, or promising things it shouldn't.

Compliance

Verifies required disclosures, consent collection, and regulatory language are present.

Interruption Handling

How does the agent respond when the caller talks over it or cuts it off mid-sentence?

🤐

Silence Recovery

Tests what happens when the caller goes silent. Does the agent recover naturally or freeze?

📞

Transfer Logic

Validates hand-off to human agents happens at the right moment with proper context.

📅

Booking Accuracy

Confirms the agent captures dates, times, and details correctly when scheduling appointments.

Emotional Intelligence

Measures empathy, tone matching, and appropriate responses to frustrated or confused callers.


Built for Retell

Deep Integration, Not a Generic Wrapper

VoxGrade understands Retell's architecture. Every test is optimized for how Retell agents actually work.

Direct API Integration

Import all your Retell agents in one click. VoxGrade reads your agent configs, voice settings, and webhook URLs directly from the Retell API. No copy-pasting prompts.

One-click agent import
📝

LLM Prompt Analysis

VoxGrade reads your Retell LLM configuration and system prompt to generate targeted test scenarios. Tests are specific to what your agent is supposed to do, not generic.

Reads your Retell LLM config
🎙

Voice-Specific Testing

Tests actual call behavior including interruption handling, latency, silence detection, and turn-taking. Not just text-based checks -- real voice interaction patterns.

Tests real call behavior
🔄

CI/CD Pipeline

Add VoxGrade to your deployment pipeline. Every time you update your Retell agent's prompt or config, automated tests run and block deploys that regress quality.

Test on every deploy
ci-pipeline.yml
# Grade your Retell agent on every deploy
- name: Run VoxGrade Tests
  run: |
    curl -X POST https://app.voxgrade.ai/api/v1-test \
      -H "Authorization: Bearer $VOXGRADE_API_KEY" \
      -d '{"platform":"retell","agent_id":"ag_xxx"}'

- name: Check Grade
  run: |
    # Fails pipeline if grade < B
    test $(jq '.grade' result.json) != "F"

0+
Voice agents tested
0+
Quality metrics per test
0s
Average time to grade
Get Started

Grade Your Retell Agent Free

Enter your email to start a 14-day free trial. Connect your Retell API key and get your first grade in under a minute.

You're in! Check your inbox for next steps.

No credit card required. Cancel anytime.

✓ 14-day free trial ✓ No credit card ✓ Works with any Retell agent ✓ SOC 2 compliant