Background (What, Why, Solution overview) | Installation | Usage

A comprehensive testing and evaluation framework for voice agents across language models, prompts, and agent personas.

Background

What

Voice Lab streamlines the process of evaluating and iterating on LLM-powered agents. Whether you're looking to optimize costs by switching to a smaller model, test newly-released models, or fine-tune prompts for better performance, Voice Lab provides the tools you need to make data-driven decisions with confidence.

While optimized for voice agents, Voice Lab is valuable for any LLM-powered agent evaluation needs.

Why

Building and maintaining voice agents often involves:

• Manually reviewing hundreds of call logs
• Refining prompts without clear metrics
• Risking a performance hit when switching to new language models
• Limited ability to test edge cases systematically

Solution & Use Cases

Voice Lab enables you to tackle common challenges in voice agent development:

Metrics & Analysis

• Define your custom metrics in JSON format and use LLM-as-a-Judge to score those metrics
• Track performance metrics across different configurations
• Monitor and intelligently choose the most cost-effective model

Model Migration & Cost Optimization

• Confidently switch between models (e.g., Claude Sonnet to GPT-4, or GPT-4 to GPT-4 Mini)
• Evaluate smaller, more efficient models for better cost-latency balance
• Generate comprehensive comparison tables across different models

Prompt & Performance Testing

• Test multiple prompt variations systematically
• Simulate and verify performance across diverse user types and interaction styles

Installation

1. Clone the repository:

   git clone https://github.com/saharmor/voice-lab.git
   cd voice-lab

2. Create a virtual environment:

   python3 -m venv venv
   source venv/bin/activate
   pip install -r requirements.txt

3. Set up your environment variables by creating a .env file in the project root directory and adding the following environment variables:

   OPENAI_API_KEY=your_openai_api_key
   

Usage

Basic

For now, this library only supports the text part of a voice agent, i.e. testing the underlying language model and prompt. The the example_test.py to execute the pre-defined test:

python llm_testing/example_test.py

For more advanced configuration, you can use the Voice Lab Configuration Editor to generate the json config files.

Adding New Test Scenarios

You can generate test scenarios using the Voice Lab Configuration Editor or edit test_details.json:

1. Open the test_details.json file located in the llm_testing directory.

2. Add a new entry for the scenario. Here’s a template you can use:

   "chill pharmacy clerk": {
       "system_prompt": "You are a friendly pharmacy clerk assisting customers with their medication needs. Make sure to provide clear information and answer any questions.",
       "initial_message": "Hello! How can I assist you today?",
       "tool_calls": [
           {
               "type": "function",
               "function": {
                   "name": "end_conversation",
                   "description": "Call ONLY when conversation reaches clear end state by both sides exchanging farewell messages or one side explicitly stating they want to end the conversation.",
                   "strict": true,
                   "parameters": {
                       "type": "object",
                       "properties": {
                           "reason": {
                               "type": "string",
                               "description": "The specific reason why the conversation must end.",
                               "enum": [
                                   "explicit_termination_request",
                                   "service_not_available",
                                   "customer_declined_service"
                               ]
                           },
                           "who_ended_conversation": {
                               "type": "string",
                               "enum": ["agent", "callee"]
                           },
                           "termination_evidence": {
                               "type": "object",
                               "properties": {
                                   "final_messages": {
                                       "type": "array",
                                       "items": {
                                           "type": "string"
                                       }
                                   },
                                   "termination_type": {
                                       "type": "string",
                                       "enum": ["successful_completion", "early_termination"]
                                   }
                               },
                               "required": ["final_messages", "termination_type"]
                           }
                       },
                       "required": ["reason", "who_ended_conversation", "termination_evidence"]
                   }
               }
           }
       ],
       "success_criteria": {
           "required_confirmations": ["medication_info", "price"]
       },
       "persona": {
           "name": "Chill Clerk",
           "initial_message": "Hi there! What can I help you with today?",
           "description": "A relaxed pharmacy clerk who enjoys helping customers.",
           "role": "pharmacy_clerk",
           "traits": [
               "friendly",
               "patient",
               "helpful"
           ],
           "mood": "CHILL",
           "response_style": "CASUAL"
       }
   }

Contribution ideas

• Support providing agents with additional context via json, e.g. credit card details, price range, etc.
• Dynamic metrics for json (e.g. metrics.json)
• Voice analysis (interruptions, pauses, etc.)
• Support more language models via LiteLLM
• Integrate Tencent's 1B Personas for more detailed and complex scenarios
• Use Microsoft's new TinyTroupe for more extensive simulations
• Integrate Qwen2-Audio for audio analysis
• Batch processing for lower cost (50% off)
• Suggest fine-tuned models for better adherence/style/etc. evaluation (e.g., defining what is concise vs. length)
• Improve test framework
  • Create a DB of agents and personas, each with additional context (e.g. address) according to scenarios (e.g. airline, commerce)
  • Add parallel test execution
  • Add detailed test reporting
  • Add conversation replay capability
• Generated test report
  • Add the eval_metrics.json and test_scenarios that were used for the test run

Attribution

If you use this project, please provide attribution by linking back to this repository: https://github.com/saharmor/voice-lab.