Open-source test harness for voice agent workflows.

• Simulate conversations — LLM-powered users talk to your agent, LLM judges score the results
• Test any platform — Retell, VAPI, LiveKit, Bland, Telnyx, or custom agents
• Convert between formats — Import from one platform, export to another via a unified graph IR
• Diagnose failures — Auto-fix broken prompts with an LLM-powered repair loop
• Run anywhere — CLI, Web UI, REST API, CI/CD

Installation

uv tool install voicetest

Or add to a project (uv run voicetest to run):

uv add voicetest

Or with pip:

pip install voicetest

Quick start

Try voicetest with a sample healthcare receptionist agent and 8 test cases:

# Set up an API key (free, no credit card at https://console.groq.com)
export GROQ_API_KEY=gsk_...

# Load demo and start web UI
voicetest demo --serve

Tip: If you have Claude Code installed, skip API key setup and use claudecode/sonnet as your model. See Claude Code Passthrough.

Web UI

voicetest serve

Agent import, graph visualization, test execution with real-time streaming transcripts, run history, diagnosis, and more at http://localhost:8000.

Platform support

Import from any supported format, convert through the unified AgentGraph, and export to any other:

Retell CF ─────┐                  ┌───▶ Retell LLM
               │                  │
Retell LLM ────┼                  ├───▶ Retell CF
               │                  │
VAPI ──────────┼                  ├───▶ VAPI
               │                  │
Bland ─────────┼───▶ AgentGraph ──┼───▶ Bland
               │                  │
Telnyx ────────┤                  ├───▶ Telnyx
               │                  │
LiveKit ───────┤                  ├───▶ LiveKit
               │                  │
XLSForm ───────┤                  ├───▶ Mermaid
               │                  │
Custom ────────┘                  └───▶ Voicetest JSON

Platform	Import	Push	Sync	API Key Env Var
Retell	✓	✓	✓	RETELL_API_KEY
VAPI	✓	✓	✓	VAPI_API_KEY
Bland	✓	✓		BLAND_API_KEY
Telnyx	✓	✓	✓	TELNYX_API_KEY
LiveKit	✓	✓	✓	LIVEKIT_API_KEY + LIVEKIT_API_SECRET

CI/CD

Run voice agent tests in GitHub Actions to catch regressions before production:

name: Voice Agent Tests
on:
  push:
    paths: ["agents/**"]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: astral-sh/setup-uv@v5
      - run: uv tool install voicetest
      - run: voicetest run --agent agents/receptionist.json --tests agents/tests.json --all
        env:
          GROQ_API_KEY: ${{ secrets.GROQ_API_KEY }}

Configuration

Settings are stored in .voicetest/settings.toml:

[models]
agent = "groq/llama-3.1-8b-instant"
simulator = "groq/llama-3.1-8b-instant"
judge = "groq/llama-3.1-8b-instant"

[run]
max_turns = 20
audio_eval = false
streaming = false

Any LiteLLM-compatible model works — OpenAI, Anthropic, Google, Ollama, and more. See the full configuration reference.

Documentation

Full documentation is at voicetest.dev/docs.

Topic	Description
Getting Started	Install, demo, first test walkthrough
Core Concepts	Agent graphs, node types, test cases
CLI Reference	All commands and options
Features	Format conversion, diagnosis, audio eval, snippets, and more
Configuration	Models, settings, Claude Code, platform credentials
Architecture	Engine internals, DI, storage
Development	Contributing, Docker setup, code quality

Contact

Questions, feedback, or partnerships: hello@voicetest.dev

License

Apache 2.0