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Introduction

Ultravox provides two ways to create voice conversations: Agents (recommended) and Direct Calls. For all new projects, we strongly recommend starting with agents as they provide better consistency, reusability, and maintainability.

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Agents vs Direct Calls

Agents (Recommended)


Reusable templates that define assistant behavior, personality, and capabilities. Create once, use for multiple calls.
Best for: Production applications, consistent experiences, team collaboration.

Direct Calls


One-time configurations where you specify all settings for each individual call.
Best for: Quick testing, very simple one-off use cases.

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Why Start with Agents?

Agents provide a way to define voice assistants that can be reused across multiple calls, ensuring consistent behavior and capabilities. This enables you to maintain a cohesive user experience with minimal configuration overhead at call creation time. Each agent includes a call template that defines system prompts, voice settings, available tools, and more. Key benefits of using Agents: Reusable Configuration → Create a single agent definition and use it for multiple calls without repeating configuration settings. Consistent Experience → Ensure your voice experience maintains the same personality, capabilities, and behavior across all interactions. Version Control → Update an agent’s configuration in one place and have changes apply to all future calls. Simplified Deployment → Reduce the complexity of starting calls by referencing an existing agent instead of providing all configuration details.
Time-Saving FeatureAgents are ideal for production applications where you want consistent behavior across multiple user interactions.

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Next Steps

Build Your First Agent

Create reusable voice assistant templates

Start Making Calls

Use agents or direct calls to create conversations

Advanced Techniques

Learn sophisticated conversation control