Retell AI MCP Server

A Model Context Protocol (MCP) server that provides tools for interacting with the Retell AI API. Build, test, deploy, and monitor AI phone agents directly through Claude or other MCP-compatible clients.

Features

This MCP server exposes 45+ tools covering all major Retell AI API endpoints:

Call Management

Create outbound phone calls and web calls
Retrieve call details including transcripts and recordings
List and filter calls with pagination
Update call metadata and data storage settings
Delete calls and associated data

Chat Management

Create chat sessions and SMS conversations
Send messages and receive responses
List and manage chat sessions

Phone Number Management

Purchase/register new phone numbers
Import existing numbers via SIP
Configure inbound/outbound agents per number
List and manage phone numbers

Agent Management

Create and configure voice agents
Create and configure chat agents
Publish agent versions
Manage agent settings (voice, language, behavior)

LLM & Conversation Flow

Create and manage Retell LLM configurations
Design conversation flows with node-based structure
Configure custom prompts and function calling

Knowledge Base

Create knowledge bases for agent context
Add sources (URLs, text, documents)
Manage knowledge base sources

Voice & Batch Operations

List available voices
Schedule batch outbound calls
Run automated agent tests

Account

Check concurrent call limits

Installation

npm install npm run build

Configuration

Environment Variable

Set your Retell AI API key as an environment variable:

export RETELL_API_KEY="your-api-key-here"

Get your API key from the Retell AI Dashboard.

Claude Code Configuration

Option 1: Using the CLI (Recommended)

Add the MCP server using the claude mcp add command:

claude mcp add --transport stdio retell-ai -e RETELL_API_KEY=your-api-key-here -- node /path/to/retell-ai-mcp/dist/index.js

You can also use environment variable expansion:

claude mcp add --transport stdio retell-ai -e RETELL_API_KEY=\${RETELL_API_KEY} -- node /path/to/retell-ai-mcp/dist/index.js

Option 2: Project Configuration File

Create a .mcp.json file in your project root to share with your team:

{ "mcpServers": { "retell-ai": { "command": "node", "args": ["/path/to/retell-ai-mcp/dist/index.js"], "env": { "RETELL_API_KEY": "${RETELL_API_KEY}" } } } }

The ${RETELL_API_KEY} syntax will expand the environment variable at runtime.

Managing the Server

# List configured MCP servers claude mcp list # Get details about the retell-ai server claude mcp get retell-ai # Remove the server claude mcp remove retell-ai

Claude Desktop Configuration

Add this to your Claude Desktop config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{ "mcpServers": { "retell-ai": { "command": "node", "args": ["/path/to/retell-ai-mcp/dist/index.js"], "env": { "RETELL_API_KEY": "your-api-key-here" } } } }

Available Tools

Call Tools

Tool	Description
`retell_create_phone_call`	Create a new outbound phone call
`retell_create_web_call`	Create a new web call session
`retell_get_call`	Retrieve details of a specific call
`retell_list_calls`	List and filter calls
`retell_update_call`	Update call metadata
`retell_delete_call`	Delete a call

Chat Tools

Tool	Description
`retell_create_chat`	Create a chat session
`retell_create_sms_chat`	Start an SMS conversation
`retell_get_chat`	Get chat details
`retell_create_chat_completion`	Send a message
`retell_list_chats`	List all chats
`retell_end_chat`	End a chat session

Phone Number Tools

Tool	Description
`retell_create_phone_number`	Purchase a phone number
`retell_get_phone_number`	Get phone number details
`retell_list_phone_numbers`	List all phone numbers
`retell_update_phone_number`	Update phone number settings
`retell_delete_phone_number`	Delete a phone number
`retell_import_phone_number`	Import via SIP

Voice Agent Tools

Tool	Description
`retell_create_agent`	Create a voice agent
`retell_get_agent`	Get agent details
`retell_list_agents`	List all agents
`retell_update_agent`	Update agent config
`retell_delete_agent`	Delete an agent
`retell_publish_agent`	Publish agent version
`retell_get_agent_versions`	Get version history

Chat Agent Tools

Tool	Description
`retell_create_chat_agent`	Create a chat agent
`retell_get_chat_agent`	Get chat agent details
`retell_list_chat_agents`	List chat agents
`retell_update_chat_agent`	Update chat agent
`retell_delete_chat_agent`	Delete chat agent

LLM Tools

Tool	Description
`retell_create_llm`	Create LLM configuration
`retell_get_llm`	Get LLM details
`retell_list_llms`	List all LLMs
`retell_update_llm`	Update LLM config
`retell_delete_llm`	Delete LLM

Conversation Flow Tools

Tool	Description
`retell_create_conversation_flow`	Create a flow
`retell_get_conversation_flow`	Get flow details
`retell_list_conversation_flows`	List all flows
`retell_update_conversation_flow`	Update a flow
`retell_delete_conversation_flow`	Delete a flow

Knowledge Base Tools

Tool	Description
`retell_create_knowledge_base`	Create knowledge base
`retell_get_knowledge_base`	Get KB details
`retell_list_knowledge_bases`	List all KBs
`retell_delete_knowledge_base`	Delete KB
`retell_add_knowledge_base_sources`	Add sources
`retell_delete_knowledge_base_source`	Remove source

Voice Tools

Tool	Description
`retell_get_voice`	Get voice details
`retell_list_voices`	List available voices

Batch Tools

Tool	Description
`retell_create_batch_call`	Schedule bulk calls
`retell_create_batch_test`	Run agent tests

Account Tools

Tool	Description
`retell_get_concurrency`	Check call limits
`retell_register_phone_call`	Register inbound call

Example Usage

Once configured, you can use Claude to interact with Retell AI:

List available voices:

"Show me all available voices for Retell AI"

Create an agent:

"Create a new voice agent named 'Support Bot' using the voice '11labs-Adrian' with a friendly greeting"

Make a phone call:

"Call +1234567890 from my registered number +0987654321 using the Support Bot agent"

Check call history:

"Show me all calls from the last 24 hours"

Development

# Install dependencies npm install # Build TypeScript npm run build # Watch mode for development npm run dev

License

MIT

Retell AI MCP Server

Retell AI MCP Server

Features

Call Management

Chat Management

Phone Number Management

Agent Management

LLM & Conversation Flow

Knowledge Base

Voice & Batch Operations

Account

Installation

Configuration

Environment Variable

Claude Code Configuration

Option 1: Using the CLI (Recommended)

Option 2: Project Configuration File

Managing the Server

Claude Desktop Configuration

Available Tools

Call Tools

Chat Tools

Phone Number Tools

Voice Agent Tools

Chat Agent Tools

LLM Tools

Conversation Flow Tools

Knowledge Base Tools

Voice Tools

Batch Tools

Account Tools

Example Usage

Development

License

Links

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