VapiAI mcp server

Build AI voice assistants and phone agents with Vapi using the Model Context Protocol.

The MCP server requires a Vapi API key. Get one from the Vapi dashboard.

Configure any MCP client that supports local stdio servers to run:

npx -y @vapi-ai/mcp-server

Set VAPI_TOKEN in the server environment. MCP client configuration formats vary, but the server definition generally looks like this:

{
  "mcpServers": {
    "vapi": {
      "command": "npx",
      "args": ["-y", "@vapi-ai/mcp-server"],
      "env": {
        "VAPI_TOKEN": "<your_vapi_token>"
      }
    }
  }
}

Clients that support remote MCP servers can connect directly:

• URL: https://mcp.vapi.ai/mcp
• Header: Authorization: Bearer your_vapi_api_key_here

claude mcp add -e VAPI_TOKEN=your_vapi_token vapi -- npx -y @vapi-ai/mcp-server

Use the local server configuration above in the Claude Desktop configuration file. To connect to the hosted server through an stdio bridge instead:

{
  "mcpServers": {
    "vapi": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://mcp.vapi.ai/mcp",
        "--header",
        "Authorization: Bearer ${VAPI_TOKEN}"
      ],
      "env": {
        "VAPI_TOKEN": "<your_vapi_token>"
      }
    }
  }
}

The skill directory contains reusable instructions for AI coding agents that support Agent Skills. Install it using your host's skill installation process.

For Claude Code:

mkdir -p ~/.claude/skills/vapi
curl -o ~/.claude/skills/vapi/SKILL.md https://raw.githubusercontent.com/VapiAI/mcp-server/main/skill/SKILL.md

Ask your MCP-enabled agent:

I want to build a voice assistant that can schedule appointments

Call +1234567890 using my appointment reminder assistant with these details:
- Customer name: Sarah Johnson
- Appointment date: March 25th
- Appointment time: 2:30 PM

Schedule a call with my support assistant for next Tuesday at 3:00 PM to +1555123456

The create_call action supports passing dynamic variables through assistantOverrides.variableValues. Use double curly braces in your assistant's prompts: {{variableName}}.

Hello {{customerName}}, this is a reminder about your appointment on {{appointmentDate}} at {{appointmentTime}} with {{doctorName}}.

These are automatically available (no need to pass):

• {{now}} - Current date and time (UTC)
• {{date}} - Current date (UTC)
• {{time}} - Current time (UTC)
• {{month}} - Current month (UTC)
• {{day}} - Current day of month (UTC)
• {{year}} - Current year (UTC)
• {{customer.number}} - Customer's phone number

See Vapi documentation for advanced date/time formatting.

Connect to Vapi's hosted MCP server from any MCP client:

• URL: https://mcp.vapi.ai/mcp
• Header: Authorization: Bearer your_vapi_api_key_here

• URL: https://mcp.vapi.ai/sse
• Header: Authorization: Bearer your_vapi_api_key_here

# Install dependencies
npm install

# Build
npm run build

# Test with MCP inspector
npm run inspector

{
  "mcpServers": {
    "vapi-local": {
      "command": "node",
      "args": ["<path>/dist/index.js"],
      "env": {
        "VAPI_TOKEN": "<your_vapi_token>"
      }
    }
  }
}

# Safe default suite (build, mocked execution, contract, and stdio compatibility)
npm test

# Unit tests (mocked public tool execution and catalog contract)
npm run test:unit

# Documentation/tool-catalog consistency lint
npm run test:docs

# Full TypeScript check (production and test code)
npm run typecheck

# Build and run local stdio protocol compatibility tests (no Vapi API calls)
npm run test:stdio

# Pack, install, and launch the package from a clean temporary consumer
npm run test:package

# Live read-only API tests
export VAPI_TOKEN=your_token_here
npm run test:live:readonly

# Live mutating tests (creates and cleans up disposable assistants and tools)
export VAPI_TOKEN=your_test_org_token_here
npm run test:live:mutating

• Vapi Documentation
• Vapi Dashboard
• Vapi Remote MCP Server
• Model Context Protocol