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Test your Retell AI-powered voice agents by connecting them to UserTrace. Our simulated users will interact with your Retell agents through realistic voice conversations.

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Getting Started

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1. Connect Your Retell Agent

In the UserTrace dashboard, navigate to Agent Setup and select Retell AI Integration. Required Information:
  • Retell Agent ID
  • Retell API Key
Example: 
Retell Agent ID: agent_1234567890abcdef

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2. Set Evaluation Context

Define your pass and fail criteria for voice interactions: Example Pass/Fail Criteria: 
Pass Criteria:
- Natural conversation flow
- Quick response times (< 2 seconds)
- Accurate understanding of user requests
- Professional and friendly tone
- Successful task completion

Fail Criteria:
- Robotic or unnatural speech
- Long response delays (> 5 seconds)
- Misunderstanding simple requests
- Inappropriate tone or language
- Failing to complete requested tasks

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Testing Process

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Inbound Agent Testing

For Retell agents that handle incoming calls:
  1. Our test number calls your Retell agent
  2. Retell processes the conversation using your agent configuration
  3. The conversation follows the defined scenario
  4. Results are analyzed and scored

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Outbound Agent Testing

For Retell agents that make outgoing calls:
  1. UserTrace triggers your Retell agent via API
  2. Your agent calls our designated test number (5-minute window)
  3. Our simulated user responds according to the scenario
  4. The conversation continues until completion
  5. Results are analyzed and scored
Key Requirements:
  • Call our number when simulation starts (5-minute window)
  • Use the exact Retell agent you configured in setup
  • Ensure your agent is deployed and accessible

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Retell-Specific Features

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Voice Configuration

Voice Models:
  • Test different Retell voice options
  • Verify voice consistency across calls
  • Check pronunciation and clarity
Language Support:
  • Test multilingual capabilities
  • Verify accent and dialect handling
  • Check language switching functionality

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LLM Integration

Custom Prompts:
  • Test your agent’s custom system prompts
  • Verify behavior consistency
  • Check edge case handling
Function Calling:
  • Test API integrations through voice commands
  • Verify parameter extraction accuracy
  • Ensure proper error handling

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Real-Time Features

Interruption Handling:
  • Test natural conversation interruptions
  • Verify smooth resumption of speech
  • Check context preservation
Live Transcription:
  • Monitor real-time transcription accuracy
  • Test with various accents and speaking speeds
  • Verify noise handling capabilities

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Best Practices

Performance

Response Optimization• Target < 2 second response times • Use Retell’s streaming features • Optimize LLM prompt length • Monitor latency metrics

Conversation Design

Natural Interactions• Design clear conversation flows • Handle ambiguous inputs gracefully • Use appropriate filler words and pauses • Test various speaking styles

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Common Scenarios

Customer Service:
  • Support ticket resolution
  • Order status inquiries
  • Account management
  • Technical troubleshooting
Sales & Marketing:
  • Lead qualification calls
  • Product demonstrations
  • Follow-up conversations
  • Appointment setting
Healthcare & Wellness:
  • Appointment scheduling
  • Symptom assessment
  • Medication reminders
  • Health surveys

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Troubleshooting

Common Issues: Retell Agent Issues:
  • Agent not responding: Check agent deployment status in Retell dashboard
  • Poor voice quality: Verify voice model settings and network connection
  • Function calls failing: Validate API endpoints and authentication
  • Inconsistent responses: Review and optimize system prompts
Call Connectivity:
  • Calls not connecting: Ensure phone number is properly configured
  • Audio issues: Check Retell’s audio settings and network quality
  • Dropped calls: Monitor Retell’s connection stability
  • Latency problems: Optimize LLM response generation

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Advanced Configuration

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Custom Integrations

Webhook Configuration: 
{
  "webhook_url": "https://your-domain.com/retell-webhook",
  "events": ["call_started", "call_ended", "function_called"],
  "authentication": {
    "type": "bearer_token",
    "token": "your-webhook-secret"
  }
}
API Integration Example: 
// Trigger outbound call via Retell API
const response = await fetch('https://api.retellai.com/call', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer ' + RETELL_API_KEY,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    agent_id: 'agent_1234567890abcdef',
    to_number: '+1-555-TEST-NUM',
    from_number: '+1-555-YOUR-NUM'
  })
});
Need help with Retell AI setup? Check the Retell AI documentation or contact [email protected].