Vapi

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Vapi is an API-first platform for building, testing, and deploying AI voice agents. It handles telephony, orchestration, and integrations so you can focus on your agent’s behavior. Paired with Rime’s ultra-realistic voices, you get natural-sounding conversations with sub-200ms latency. This guide walks you through creating a basic voice assistant with Vapi and Rime.

Prerequisites

To follow this guide, you need:

• A Vapi account
• A Rime API key (optional)

Step 1: Create the assistant

From the Vapi Dashboard, navigate to Assistants and click Create Assistant.

1.1 Select a template

Give your assistant a name, select Blank Template, and click Create Assistant.

1.2 Configure the model

In the Model tab, select your preferred LLM provider. Any option should work, but models with lower latency enable better conversational flow.

Add a First Message to enable your assistant to begin conversations.

Configure a System Prompt to define your agent’s personality and behavior. The system prompt can be as complex or simple as you like. For example:

You are a helpful voice assistant.
Keep your responses short and conversational. No more than 2-3 sentences.
Be friendly and natural.

Alternatively, use the Generate button and get AI help to create a well-structured prompt.

1.3 Configure the voice

In the Voice tab, configure your assistant to use Rime AI as the Provider.

Select the Voice that you want your assistant to use. Learn more about Rime’s voices on the Voices page.

Set the Model to Arcana to use the latest Rime model with the most realistic voices.

1.4 Configure the transcriber

Finally, in the Transcriber tab, select your preferred speech-to-text (STT) Provider and click Publish.

1.5 Publish the assistant

In the publishing popup window, select Skip and Publish.

Step 2: Add your API keys to Vapi (optional)

Vapi provides API access to all its supported models via its billing plans. However, if you already have a subscription plan for one or more of your assistant’s configured providers, you can enable the assistant to access them instead of using integrated Vapi billing:

Under the Build heading, click More and select Integrations. Then, find your providers and add your API keys.

Vapi stores API keys securely and automatically grants your assistants access to them.

Step 3: Test your assistant

The above steps create the most basic assistant using Rime’s voices.

Click Talk to Assistant in the dashboard to start a conversation in your browser.

Next steps

To further customize your assistant, you can:

• Try different voices: Audition other voices like celeste, orion, and andromeda at app.rime.ai.
• Add a phone number: Provision a contact number in the Vapi dashboard and assign it to your assistant for telephony
• Create a workflow: Program your assistant to do complex tasks using Vapi Workflows.
• Customize the personality: Update the system prompt to match your use case.