Chat with QuickBooks Online customer data in n8n via MCP server and ChatGPT

Who’s it for

Teams that want an AI chat interface for QuickBooks Online customer data in n8n, and developers who want to expose the same tools to Claude Desktop via MCP with minimal setup.

How it works / What it does

• A Public Chat Trigger receives user messages.
• An AI Agent Orchestrator decides when to call tools and drafts replies.
• OpenAI Chat generates the final response.
• The QBO Customers tool fetches customer records from QuickBooks Online.
• An MCP Server exposes the QBO tools to MCP clients.
• An MCP Client Tool connects to the server’s SSE endpoint so external apps like Claude Desktop can use the same tools.

How to set up

1. Add your OpenAI API key in credentials.
2. Connect QuickBooks Online via OAuth2 with read access to customers.
3. Start the MCP Server Trigger and copy the server URL.
4. In the MCP Client Tool, set sseEndpoint to that exact URL. Without this, the client will not connect.
5. Optionally restrict the Public Chat Trigger if you need access control.

Requirements

• OpenAI API key
• QuickBooks Online company with customer read access
• n8n environment
• Claude Desktop (optional, for MCP usage)

How to customize the workflow

• Add tools for invoices, payments, or items.
• Expose other data sources (Sheets, databases, HTTP APIs) via MCP.
• Adjust prompts, validations, and permissions for your deployment needs.

What is MCP?

MCP (Model Context Protocol) is a standard for securely exposing tools and data to AI models. It lets you connect local or remote systems to AI assistants like Claude Desktop so they can fetch data or perform actions in real time. In this workflow, MCP is used to make QuickBooks customer data accessible to both n8n and Claude Desktop through the same integration.