LABSCO SUMMARY

One capability, and phone-number format is where it goes wrong.

Every number has to be E.164 — a leading plus and the country code — and anything else comes back with exactly that error. Past that, your Twilio account's rate limits and per-message pricing apply, so an agent that texts freely spends real money.

What it is

A small Node server that lets an assistant send SMS and MMS messages with your Twilio account, plus prompt templates for common messaging situations.

What you get

SMS sent to a number you give, from your Twilio number
MMS as well as plain text messages
Pre-built prompts for the messaging scenarios people ask for most
Credentials read from the environment rather than typed into the conversation

Requirements

Node.js >= 18 and three environment variables: ACCOUNT_SID, AUTH_TOKEN and FROM_NUMBER — your Twilio number in E.164 format, for example +11234567890. Launch it with npx -y @yiyang.1i/sms-mcp-server.

Setup effort

One command plus a key — npx -y @yiyang.1i/sms-mcp-server, then supply credentials

See installation options

USE CASES

01

Sending yourself a reminder from a chat

Ask for the text in plain language and it arrives on your phone, no app switch.

02

Notifying someone at the end of a long task

The assistant sends the message when the work finishes instead of waiting for you to come back to the window.

03

Composing and sending in one step

Have the model write the message and deliver it, rather than producing text you then copy elsewhere.

04

Checking the credentials work

A wrong SID or token comes back as an invalid-credentials error you can fix from the Twilio console.

BEFORE YOU INSTALL

What to know first

Requires

npx on PATH
Node.js >= 18
ACCOUNT_SID in your environment
AUTH_TOKEN in your environment
FROM_NUMBER in your environment

Where it runs

The documented client runs the server on your machine.

INSTALLATION

Connect your client

Server setup

TERMINAL

npx -y @yiyang.1i/sms-mcp-server

MCP Clients

Claude Desktop

CLAUDE DESKTOP · JSON

{
  "mcpServers": {
    "twilio": {
      "command": "npx",
      "args": [
        "-y",
        "@yiyang.1i/sms-mcp-server"
      ],
      "env": {
        "ACCOUNT_SID": "<YOUR_ACCOUNT_SID>",
        "AUTH_TOKEN": "<YOUR_AUTH_TOKEN>",
        "FROM_NUMBER": "<YOUR_FROM_NUMBER>"
      }
    }
  }
}

Twilio MCP Server