Retellai MCP Server

RetellAi MCP Server

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What is the Retellai MCP server?

Most AI and media services work still happens through a UI a human drives. Retellai MCP server moves it into the conversation instead. RetellAi MCP Server.

The short version

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

  • 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

The tools it exposes

The server publishes 14 tools. What each one is for:

  • 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
  • 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
  • list_phone_numbers — Lists all Retell phone numbers

Getting it running

The server ships on npm as @abhaybabbar/retellai-mcp-server, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

What it needs from you

Configuration is passed through the environment: RETELL_API_KEY. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

How it compares

This sits in the AI and media services group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Retellai's toolset — list_calls, create_phone_call, create_web_call and 11 more — is a fair guide to whether it matches your workflow. It is maintained by abhaybabbar; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Things to watch

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • With 14 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Retellai.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
list_callsLists all Retell calls
create_phone_callCreates a new phone call
create_web_callCreates a new web call
get_callGets details of a specific call
delete_callDeletes a specific call
list_agentsLists all Retell agents
create_agentCreates a new Retell agent
get_agentGets a Retell agent by ID
update_agentUpdates an existing Retell agent
delete_agentDeletes a Retell agent
get_agent_versionsGets all versions of a Retell agent
list_phone_numbersLists all Retell phone numbers
create_phone_numberCreates a new phone number
get_phone_numberGets details of a specific phone number

How to install the Retellai MCP server

{
  "mcpServers": {
    "retellai-mcp-server": {
      "command": "npx",
      "args": ["-y", "@abhaybabbar/retellai-mcp-server"],
      "env": {
        "RETELL_API_KEY": "<your_retellai_token>"
      }
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Configuration

VariableDescriptionRequired
RETELL_API_KEYCredential the server authenticates with.Yes

Example prompts to try

  • Use Retellai to list calls.
  • Use Retellai to create phone call.
  • Use Retellai to create web call.

Frequently asked questions

It connects Retellai to MCP-compatible AI assistants such as Claude and Cursor, exposing 14 tools (list_calls, create_phone_call, create_web_call, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Retellai directly.