mcpField
R
RetellAI MCP Server

RetellAI MCP Server

Local
npmjs.comCommunication40Updated 29w ago

About RetellAI MCP Server

RetellAI MCP Server is an MCP server for the RetellAI voice service, letting AI assistants manage calls, voice agents, phone numbers and voices. It suits users who want MCP clients to configure or operate RetellAI voice features.

Key features

  1. 01Create, list, get and delete calls
  2. 02Create and update voice agents
  3. 03View and configure phone numbers
  4. 04Query available voice options

Use cases

  1. 01Listing phone numbers and voice agents in an account
  2. 02Creating outbound phone calls or web calls
  3. 03Configuring voice agents with different LLM settings

MCP support

This is an MCP server that exposes RetellAI call, agent, phone number and voice tools to MCP clients, so AI assistants can operate the RetellAI service.

Configuration

Local server config is the same for every client. Copy it into your client’s MCP config file.

mcp.json · Universal config
{
"mcpServers": {
"retellai": {
"command": "npx",
"args": [
"-y",
"@abhaybabbar/retellai-mcp-server"
],
"env": {
"RETELL_API_KEY": "<RETELL_API_KEY>"
}
}
}
}
Run commandnpx -y @abhaybabbar/retellai-mcp-server
Environment variables to set
RETELL_API_KEYSecret

Local servers need a runtime on your machine (e.g. Node.js 18+). Config file locations differ by client; see your client’s docs.

Packages
npm@abhaybabbar/retellai-mcp-server

Tools

24

Saved tool list · updated 3w ago

ParameterTypeRequiredDescription
metadataobjectNo
toNumberstringYesThe phone number to call to
directionenumNoinbound | outbound
fromNumberstringYesThe phone number to call from
optInSignedUrlbooleanNo
overrideAgentIdstringNoFor this particular call, override the agent used with this agent id
overrideAgentVersionnumberNoFor this particular call, override the agent version used with this version
retellLlmDynamicVariablesobjectNoDynamic variables to pass to the LLM in key-value pairs
optOutSensitiveDataStoragebooleanNo

Details

From the project README

RetellAI MCP Server

This is a Model Context Protocol (MCP) server implementation for RetellAI, allowing AI assistants to interact with RetellAI's voice services.

Features

The RetellAI MCP server provides tools for:

  • Call Management: Create and manage phone calls and web calls
  • Agent Management: Create and manage voice agents with different LLM configurations
  • Phone Number Management: Provision and configure phone numbers
  • Voice Management: Access and use different voice options

Claude Desktop Setup

  1. Open Claude Desktop and press CMD + , to go to Settings.
  2. Click on the Developer tab.
  3. Click on the Edit Config button.
  4. This will open the claude_desktop_config.json file in your file explorer.
  5. Get your Retell API key from the Retell dashboard (https://dashboard.retellai.com/apiKey).
  6. Add the following to your claude_desktop_config.json file. See here for more details.
  7. Restart the Claude Desktop after editing the config file.
{
  "mcpServers": {
    "retellai-mcp-server": {
      "command": "npx",
      "args": ["-y", "@abhaybabbar/retellai-mcp-server"],
      "env": {
        "RETELL_API_KEY": "<your_retellai_token>"
      }
    }
  }
}
Troubleshooting: "No tools available"

If Claude Desktop shows the server but no tools, upgrade to the latest package version:

npx -y @abhaybabbar/retellai-mcp-server@latest

This issue is typically caused by dependency/version mismatch in older installs.

Example use cases:

  1. List all the numbers I have in retellai
  2. List all the agents I have
  3. Tell me more about pizza delivery agent
  4. Creating agent and calling example:
    1. Create an agent that calls my local pizza shop, make sure to keep the conversation short and to the point.
    2. Order a margeritta pizza
    3. Payment will be done by cash on delivery
    4. Send it to
    5. The agent should pretend to be me. My name is <your_name>
    6. Make an outbound call to my local pizza shop at <phone_number>, using the usa number

Repo Setup

  1. Install dependencies:

    npm i
    
  2. Create a .env file with your RetellAI API key:

    RETELL_API_KEY=your_api_key_here
    
  3. Run the server:

    node src/retell/index.js
    

Available Tools

Call Tools
  • list_calls: Lists all Retell calls
  • create_phone_call: Creates a new phone call
  • create_web_call: Creates a new web call
  • get_call: Gets details of a specific call
  • delete_call: Deletes a specific call
Agent Tools
  • list_agents: Lists all Retell agents
  • create_agent: Creates a new Retell agent
  • get_agent: Gets a Retell agent by ID
  • update_agent: Updates an existing Retell agent
  • delete_agent: Deletes a Retell agent
  • get_agent_versions: Gets all versions of a Retell agent
Phone Number Tools
  • list_phone_numbers: Lists all Retell phone numbers
  • create_phone_number: Creates a new phone number
  • get_phone_number: Gets details of a specific phone number
  • update_phone_number: Updates a phone number
  • delete_phone_number: Deletes a phone number
Voice Tools
  • list_voices: Lists all available Retell voices
  • get_voice: Gets details of a specific voice

License

MIT

Comments

Markdown supported

New to MCP?

From what the protocol is to installing your first server, these answers cover most first questions.

An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.