Vapi MCP Server

What is Vapi MCP Server?

Vapi MCP Server lets you build AI voice assistants and phone agents with Vapi using the Model Context Protocol. It is for developers who want to create, manage, and call voice assistants directly from MCP‑compatible clients like Claude Code or Claude Desktop.

How to use Vapi MCP Server?

Install via npx and add to your MCP client configuration. For Claude Code, run claude mcp add vapi -- npx -y @vapi-ai/mcp-server and authenticate via browser on first use. For Claude Desktop, add the server to mcpServers in claude_desktop_config.json using either OAuth (no API key) or a VAPI_TOKEN environment variable from the Vapi dashboard. A remote configuration is also available.

Key features of Vapi MCP Server

• Full CRUD for assistants, calls, and phone numbers
• Outbound calling (immediate or scheduled)
• Custom tool creation for API integration
• Dynamic variable substitution in assistant prompts
• OAuth login and logout for authentication
• Remote MCP server via Streamable HTTP or SSE

Use cases of Vapi MCP Server

• Create a voice assistant that can schedule appointments
• Make an outbound call to a customer with appointment reminders
• Schedule a future call with a support assistant
• Manage phone numbers (buy, update, release)
• Build and test voice‑agent workflows from Claude

FAQ from Vapi MCP Server

What tools does Vapi MCP Server provide?

It provides tools for assistants, calls, phone numbers, custom tools, and authentication – over 15 actions including create, read, update, delete, and login/logout.

How do I authenticate with Vapi MCP Server?

You can use OAuth (browser login, no API key needed) or a Vapi API key via the VAPI_TOKEN environment variable. For remote access, pass the token as a Bearer token in the Authorization header.

Can I use variable values in assistant prompts?

Yes. Use double curly braces like {{customerName}} in your assistant prompts and pass values via assistantOverrides.variableValues when creating a call. Several default variables ({{now}}, {{date}}, {{customer.number}}, etc.) are automatically available.

Where is data stored?

Data (assistants, calls, phone numbers) lives in your Vapi account. The server acts as a stateless MCP bridge and does not store data locally.

What transports are supported?

Local use runs over stdio. For remote clients, Streamable HTTP (recommended) and SSE (deprecated) are supported at https://mcp.vapi.ai/mcp and https://mcp.vapi.ai/sse respectively.