WhatsApp Business API by Wassenger

WhatsApp MCP Server for the official WhatsApp Business API

A hosted Model Context Protocol server that lets Claude, Cursor, VS Code, the OpenAI API and any other MCP client work with WhatsApp through the official WhatsApp Business API: send and read messages, reply with approved templates, run campaigns, manage contacts and run a shared team inbox.

It is run by Wassenger. There is nothing to install: point your client at https://api.wassenger.com/mcp and send your Wassenger API key in the Authorization header. Claude and ChatGPT on the web have no field for a header, so there the key goes in the address instead.

Remote URL:  https://api.wassenger.com/mcp
Transport:   Streamable HTTP
Auth:        Authorization: Bearer <WASSENGER_API_KEY>
             or https://api.wassenger.com/mcp?key=<WASSENGER_API_KEY> for clients without headers

Business API or personal account?

There are two kinds of WhatsApp MCP servers, and they solve different problems.

If you only want Claude to read and search your own personal chats, a personal-account server is the simpler choice. If WhatsApp is how your business talks to customers, use the Business API.

Quick start

1. Create a Wassenger account and connect your WhatsApp Business number.
2. Copy your API key from app.wassenger.com/apikeys.
3. Add the server to your client with one of the configurations below.
4. Ask: "Which of my WhatsApp numbers are connected?" to check it works.

Connect your client

Claude (web and desktop app)

Open Customize → Connectors, click +, choose Add custom connector, give it a name and paste the address with your key:

https://api.wassenger.com/mcp?key=YOUR_WASSENGER_API_KEY

Click Add. In a chat, open the + menu, choose Connectors and switch it on. On Team and Enterprise plans only an owner can add a custom connector, and everyone who uses it shares that key.

ChatGPT (web)

ChatGPT reaches a custom MCP server from the web app, on the plans where OpenAI enables developer mode, and a workspace admin has to turn it on. Go to Apps → Create, paste the same address, choose No authentication, click Scan tools and then Create. Choosing OAuth fails, because this server publishes no OAuth metadata.

Claude Code

claude mcp add --transport http wassenger https://api.wassenger.com/mcp \
  --header "Authorization: Bearer YOUR_WASSENGER_API_KEY"

Clients that only run local servers

Some clients only start local processes, like Claude Desktop configured through claude_desktop_config.json. Use the npm bridge from this repository (mcp-wassenger): it connects to the hosted server and sends your key in the Authorization header.

{
  "mcpServers": {
    "wassenger": {
      "command": "npx",
      "args": ["-y", "mcp-wassenger", "YOUR_WASSENGER_API_KEY"]
    }
  }
}

Cursor

~/.cursor/mcp.json:

{
  "mcpServers": {
    "wassenger": {
      "url": "https://api.wassenger.com/mcp",
      "headers": { "Authorization": "Bearer YOUR_WASSENGER_API_KEY" }
    }
  }
}

VS Code

.vscode/mcp.json. VS Code asks for the key the first time and stores it securely:

{
  "inputs": [
    { "type": "promptString", "id": "wassenger-key", "description": "Wassenger API key", "password": true }
  ],
  "servers": {
    "wassenger": {
      "type": "http",
      "url": "https://api.wassenger.com/mcp",
      "headers": { "Authorization": "Bearer ${input:wassenger-key}" }
    }
  }
}

OpenAI API (Responses API and Agents SDK)

import OpenAI from 'openai'

const openai = new OpenAI()

const response = await openai.responses.create({
  model: 'gpt-6.1-sol',
  input: 'Summarize the unread WhatsApp chats from today',
  tools: [{
    type: 'mcp',
    server_label: 'wassenger',
    server_url: 'https://api.wassenger.com/mcp',
    headers: { Authorization: `Bearer ${process.env.WASSENGER_API_KEY}` },
    require_approval: 'always'
  }]
})

Any other client

Use the remote URL with Streamable HTTP and the Authorization header. If your client has no field for headers, use the ?key= address; if it only runs local servers, use the npm bridge: npx -y mcp-wassenger YOUR_WASSENGER_API_KEY.

What you can ask

• "Show me the unread chats from today and draft a reply to each one."
• "Assign every chat that mentions 'invoice' to the billing department."
• "Send the order_shipped template to +1 555 555 0100 with tracking number 1Z999."
• "Which customers asked about pricing this week and got no answer?"
• "Create a campaign with the spring_offer template for contacts labelled 'VIP'."
• "Move the deal for Acme to 'Proposal sent' and add a note with today's call summary."
• "Check whether these 20 numbers have WhatsApp before I import them."
• "How many chats did we open, resolve and leave pending this week?"

Tools

More than 50 tools, grouped by what they work on:

Groups, Channels and Status updates only work on numbers connected by QR code, because the official Business API doesn't offer them.

Security

• Use the Authorization header whenever your client has a field for it. A key in the address (?key=) ends up in access logs, proxy logs, error reports and browser history, so treat it as exposed: for Claude and ChatGPT on the web, create a key used only there and revoke it if the address leaks.
• An agent with this server can read your customers' messages and send messages in your name. Treat untrusted message content as untrusted input: keep approval on for tools that send or delete, as in the OpenAI example above.
• Revoke a key at any time from app.wassenger.com/apikeys.

FAQ

Is there a WhatsApp MCP server I can use with Claude? Yes. This one works in Claude on the web and in the desktop app as a custom connector, in Claude Code and in any MCP client, on top of the official WhatsApp Business API. Setup takes a URL and an API key.

How do I connect WhatsApp to Claude or ChatGPT as an AI agent? Connect your number to Wassenger, then add this server: as a custom connector in Claude, as an app in ChatGPT's developer mode, or as an MCP tool in an agent built on the OpenAI API, with the configurations above. The agent can then read chats, reply, send templates and hand conversations to people on your team.

Do I need to keep a phone or computer switched on? No. Numbers on the Business API run in Meta's cloud and the MCP server is hosted.

Can it message customers who haven't written in the last 24 hours? Yes, with a template approved by Meta. Free-form messages are only allowed within 24 hours of the customer's last message; that is a WhatsApp rule for every provider.

Is it free? The hosted server comes with your Wassenger account, and the npm bridge in this repository is open source under the MIT license. You need a Wassenger account with a connected number: see pricing. Meta bills template messages directly.

Links

• Wassenger · Pricing · API documentation
• Connect WhatsApp to Claude: step-by-step guide
• Model Context Protocol

License

MIT