A Model Context Protocol (MCP) server that enables Claude and other AI assistants to initiate and manage voice calls using Twilio and OpenAI (GPT-4o
Voice Call MCP server exists for a simple reason — assistants are far more useful when they can act on Voice Call directly instead of describing what you should do. A Model Context Protocol (MCP) server that enables Claude and other AI assistants to initiate and manage voice calls using Twilio and OpenAI (GPT-4o Realtime model).
Installation goes through your MCP client rather than a global install: point it at npm on npm and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.
Once Voice Call is connected, these are the calls the assistant has available:
Real — time language switching during calls 🌐Pre — built prompts for common calling scenarios (like restaurant reservations) 🍽️TWILIO_ACCOUNT_SID — Your Twilio account SIDTWILIO_AUTH_TOKEN — Your Twilio auth tokenTWILIO_NUMBER — Your Twilio numberOPENAI_API_KEY — Your OpenAI API keyNGROK_AUTHTOKEN — Your ngrok authtokenRECORD_CALLS — Set to "true" to record calls (optional)Double — check your TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN. You can copy them from the Twilio ConsoleYou will need 5 environment variables: TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, TWILIO_NUMBER, OPENAI_API_KEY, NGROK_AUTHTOKEN. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.
nvm (Node Version Manager): - Twilio account with API credentials - OpenAI API key - Ngrok AuthtokenAmong the AI and media services options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Voice Call's toolset — Real, Pre, TWILIO_ACCOUNT_SID and 6 more — is a fair guide to whether it matches your workflow. It is maintained by popcornspace; worth a glance at recent repository activity before you build anything load-bearing on it.
SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.
| Tool | What it does |
|---|---|
| Real | time language switching during calls 🌐 |
| Pre | built prompts for common calling scenarios (like restaurant reservations) 🍽️ |
| TWILIO_ACCOUNT_SID | Your Twilio account SID |
| TWILIO_AUTH_TOKEN | Your Twilio auth token |
| TWILIO_NUMBER | Your Twilio number |
| OPENAI_API_KEY | Your OpenAI API key |
| NGROK_AUTHTOKEN | Your ngrok authtoken |
| RECORD_CALLS | Set to "true" to record calls (optional) |
| Double | check your TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN. You can copy them from the [Twilio Console](https://console.twilio.com) |
{
"mcpServers": {
"voice-call": {
"command": "node",
"args": ["/path/to/your/mcp-new/dist/start-all.cjs"],
"env": {
"TWILIO_ACCOUNT_SID": "your_account_sid",
"TWILIO_AUTH_TOKEN": "your_auth_token",
"TWILIO_NUMBER": "your_e.164_format_number",
"OPENAI_API_KEY": "your_openai_api_key",
"NGROK_AUTHTOKEN": "your_ngrok_authtoken"
}
}
}
}Configuration as documented by the project. Restart the client after saving.
nvm (Node Version Manager): - Twilio account with API credentials - OpenAI API key - Ngrok Authtoken| Variable | Description | Required |
|---|---|---|
| TWILIO_ACCOUNT_SID | Configuration value read at startup. | Optional |
| TWILIO_AUTH_TOKEN | Credential the server authenticates with. | Yes |
| TWILIO_NUMBER | Configuration value read at startup. | Optional |
| OPENAI_API_KEY | Credential the server authenticates with. | Yes |
| NGROK_AUTHTOKEN | Credential the server authenticates with. | Yes |
Build a programmable telecommunications stack for connecting telephony services with the Internet via a cloud-based utility.
Search built for AI, not humans — semantic web search that returns model-ready content, plus code context.
Answers, not links — delegate questions to Perplexity's search-grounded models and get cited responses back.
Give your assistant a voice — text-to-speech, voice cloning and audio tools from the ElevenLabs API.
Give your assistant a real code sandbox — isolated cloud VMs for actually running the code it writes.
The ML hub in your context window — search models, datasets, papers and run Spaces from the official server.