LABSCO SUMMARY

Real calls and real messages — the account is yours and so is the bill.

Both tools reach the live Vonage APIs, so a wrong number is a number that actually rings. The part people miss is the callback side: voice events only come back if CALLBACK_SERVER_URL points at something Vonage can reach from the internet, which on a laptop means a tunnel rather than localhost.

What it is

A Python server that puts two Vonage telephony actions in front of an assistant: dialling a number and speaking to it, and sending a text message. A callback server runs alongside it on port 8080 to receive Vonage's voice events.

What you get

A voice call placed to a number, with language and style parameters so the spoken text can carry a chosen accent — voice_call
A text message sent from your Vonage virtual number — send_sms
A record of what Vonage reported back: the callback server stores voice events and exposes them at GET /events, GET /events/{event_id} and DELETE /events

Requirements

A Vonage account with an API key, secret, application ID and private key. Environment variables carry them and the endpoints: VONAGE_API_KEY, VONAGE_API_SECRET, VONAGE_APPLICATION_ID, VONAGE_PRIVATE_KEY_PATH, VONAGE_LVN, VONAGE_API_URL, VONAGE_SMS_URL and CALLBACK_SERVER_URL. Python 3.13+. Run python telephony_server.py, or the bundled docker compose up --build. In production CALLBACK_SERVER_URL has to be a public URL Vonage can reach; in development it defaults to http://localhost:8080.

Setup effort

Run a container — build the image from the repository, then point your client at it

See installation options

USE CASES

01

Calling someone with a message you just drafted

Ask for the call in plain language and have the assistant read out the text it wrote a moment ago, with the accent and speaking style passed as parameters.

voice_call

02

Falling back to text when a call is the wrong move

Send the same content as a text message from your Vonage number instead of dialling.

send_sms

03

Checking what actually happened on a call

Read the stored Vonage events for that call — initiated, completed, or error — instead of inferring it from the tool's return value.

2 tools

Listed in project docs. Your client may show a different list.

voice_call

send_sms

BEFORE YOU INSTALL

What to know first

Tools you get

2 tools named in the project's documentation. voice_call places a real phone call and send_sms sends a real SMS, billed to your Vonage account. Call events go to a separate callback server on port 8080, not an MCP tool.

Requires

docker on PATH
A Vonage account: API key, API secret, application ID, private key and a virtual number (VONAGE_LVN) in the .env file

Where it runs

The documented client runs the server on your machine.

INSTALLATION

Connect your client

Build the image from the repository, then point your client at it.

Server setup

TERMINAL

git clone https://github.com/Vonage-Community/telephony-mcp-server
cd telephony-mcp-server

Create a .env file in the clone with your Vonage credentials (VONAGE_API_KEY, VONAGE_API_SECRET, VONAGE_APPLICATION_ID, VONAGE_PRIVATE_KEY_PATH, VONAGE_LVN), and put your Vonage application's private.key next to it — the Dockerfile copies both into the image.

TERMINAL

docker build -t telephony-mcp-server .

MCP Clients

Claude Desktop

CLAUDE DESKTOP · JSON

{
  "mcpServers": {
    "telephony": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "--init",
        "-e",
        "DOCKER_CONTAINER=true",
        "telephony-mcp-server"
      ]
    }
  }
}

The client configuration passes no Vonage credentials: the image reads them from the .env file and private.key that the Dockerfile copies in at build time, so create both before docker build.

Telephony MCP Server