---
title: "Use WhatsApp in ChatGPT through a custom MCP app"
description: "Add Kaption’s WhatsApp MCP server to ChatGPT as an app with developer mode. ChatGPT can search chats, summarize conversations and set reminders."
canonical: "https://kaptionai.com/mcp/chatgpt/"
lang: "en"
---

# Use WhatsApp in ChatGPT through a custom MCP app

> Add Kaption’s WhatsApp MCP server to ChatGPT as an app with developer mode. ChatGPT can search chats, summarize conversations and set reminders.

Canonical: https://kaptionai.com/mcp/chatgpt/

ChatGPT can connect to remote MCP servers with OAuth sign-in. Add Kaption’s server and ask ChatGPT to search your chats, summarize a group or find a contact.

## Ask ChatGPT about your WhatsApp

ChatGPT reads the answer from your WhatsApp through Kaption on your computer. Kaption’s relay checks your sign-in and cannot read your messages.

## How to connect

1. **Turn on Cloud MCP in Kaption.** Open WhatsApp Web in Chrome or Edge with the Kaption extension, then AI Assistants (MCP) › Cloud Bridge › Enable. In the Kaption desktop app, switch on Cloud MCP in Settings. Keep it open while the assistant works: the tools only reach WhatsApp while Kaption runs.
2. **Turn on developer mode in ChatGPT.** Open ChatGPT Settings › Apps (Connectors on some plans) › Advanced settings and turn on Developer mode. The menu names vary by plan; OpenAI’s help center has the current path.
3. **Create the app.** Click Create (or Add custom connector), name it WhatsApp, paste the address below and choose OAuth as the authentication.
4. **Sign in with a code on WhatsApp.** The app opens Kaption’s sign-in page. Enter your phone number, type the 6-digit code Kaption sends you on WhatsApp, and choose how long the connection lasts: while you use it (it ends after 90 days without use), 1 year, or until you disconnect it.

MCP server address: `https://mcp.kaptionai.com/mcp` (Streamable HTTP, OAuth 2.1).

## Good to know

- **ChatGPT plans:** Custom MCP apps depend on your ChatGPT plan and workspace settings, and OpenAI changes them often. If you don’t see developer mode, ask your workspace admin or check OpenAI’s help center.
- **Turn it on in a chat:** Pick the WhatsApp app from the tools menu in a conversation, then ask about your chats.
- **What ChatGPT can do:** Search and read chats, summarize conversations, look up contacts and groups, manage labels, notes and reminders, and schedule a message after you confirm it.

## Plan and limits

MCP works on every plan. Free: unlimited for your first 60 days, then 20 tool calls a week. Basic: 20 tool calls a week. Pro: 100 tool calls a week, the plan to pick when an assistant uses WhatsApp every day. Prices: https://kaptionai.com/pricing/ ([pricing.md](https://kaptionai.com/pricing.md)).

## Questions

### Can the assistant send messages on its own?

No message is sent immediately. The assistant can schedule one message to one 1:1 chat, up to 800 characters, and it should confirm the text and the time with you first. Locked chats are never visible to it.

### Does Kaption store my chats on its servers?

No. The relay at mcp.kaptionai.com checks your sign-in and passes each request to Kaption on your computer, which runs it against your WhatsApp and sends back only the answer.

### What does “Extension not connected” mean?

Kaption is closed, or Cloud MCP is off. Open WhatsApp Web with the Kaption extension, or the desktop app, and turn the connection on.