IN THIS SECTION
- What is MCP and why it's useful
- Joiin's MCP Server
- Connecting to Joiin MCP
- What You Can Ask
- Multiple Clients
- Disconnect
- Troubleshooting
MAX: The Joiin MCP connection for AI assistants is available in our MAX package.
What is MCP and why it's useful
MCP (Model Context Protocol) is an open standard that lets AI assistants — such as Claude, ChatGPT, or Cursor — connect directly to external tools and data sources. Rather than copying data into a chat window or switching between applications, your AI client can query Joiin in real time and work with your actual financial data as part of a natural conversation. For finance teams already using AI tools day-to-day, it means Joiin becomes a native part of that workflow — ask a question, get an answer backed by live consolidated data, without leaving the tools you're already in.
Joiin's MCP Server
Joiin provides an MCP server that you can connect to your AI assistant of choice — including Claude, ChatGPT, and Cursor. Once connected, you can ask natural language questions about your financial data: run consolidated reports, search transactions, check sales by customer, and more. You can also query Joiin's help guides directly from within your AI client. Because MCP works alongside whatever else your AI assistant has access to, your Joiin financial data becomes part of a broader, connected conversation — not a separate lookup.
Connecting to Joiin MCP
Joiin MCP Server follows the MCP open standard and so can be connected to by any tool that works with that standard.
The steps are the same for every app:
- In Joiin, go to Integrations > AI Connections and copy the MCP Server URL.
- In your AI app, add a custom MCP server (some apps call it a connector) and paste in the URL. Each app does this differently, so follow the app's own instructions. Links to latest instructions for three of the most popular AI Apps:
- Claude: https://support.claude.com/en/articles/11175166-get-started-with-custom-connectors-using-remote-mcp
- ChatGPT: https://help.openai.com/en/articles/12584461-developer-mode-apps-and-full-mcp-connectors-in-chatgpt-beta
- Cursor: https://cursor.com/docs/context/mcp - Sign in with your Joiin account when asked.
- Check what the app will be able to read, then click Allow (see Approving the connection below).
- Joiin tools are now available in your AI app.
Approving the connection
When an app connects for the first time, you sign in to Joiin and see Allow access to your Joiin data?. The screen shows the app's name, the website it is Connecting to, and what it will be able to read:
- your Joiin clients, companies and groups;
- Profit & Loss, Balance Sheet, Cashflow, KPIs and Trial Balance;
- Chart of Accounts;
- Sales By Customer and Purchases By Supplier;
- A/R Ageing and A/P Ageing;
- Transactions and Journals.
Access is read-only: the app cannot change or delete anything in your Joiin account. Click Allow to connect, or Cancel to stop. Check that the website under Connecting to is the app you expect, because an app chooses its own name.
A web app shows its website (for example chatgpt.com). An app on your own computer shows a local address such as 127.0.0.1. The ChatGPT desktop app may show as Codex - Codex is part of OpenAI, the company behind ChatGPT.
What You Can Ask
Financial Reports
- "Show me last month's P&L"
- "What's our balance sheet?"
- "Run a KPI report - revenue, profit, margins"
- "Cash flow for the last 6 months"
- "Compare this year's P&L vs last year"
- "Show P&L by month for the last 12 months"
- "Revenue broken down by company"
- "Show budget vs actual for this quarter"
Sales & Purchases
- "Who are our top customers?"
- "Show supplier spending for last year"
- "How much did we buy from [supplier name]?"
- "Customer revenue breakdown for Q1"
Outstanding Invoices & Bills
- "Show overdue invoices"
- "What bills are unpaid?"
- "AR ageing by customer"
- "How much do we owe suppliers?"
Transactions
- "Find invoice INV-1234"
- "Search for payments to [contact name]"
- "Look up transactions for 5000"
Account Details
- "What accounts do we have related to depreciation?"
- "Break down marketing expenses for January"
- "Why is Other Expenses so high last month?"
Joiin Help
- "How do I set up eliminations?"
- "How to connect Xero?"
- "What is group consolidation?"
- "How do I set up multi-currency?"
Multiple Clients
If your Joiin account has access to multiple clients, the assistant will ask which one to use. If you only have one client, it's selected automatically. You can ask your assistant to switch clients at any time.
Disconnect
To disconnect, remove the Joiin connector or MCP server in your AI app's settings.
This removes the connection immediately. Your Joiin data and account are not affected.
Troubleshooting
"Connection failed" when adding the server
- Check the URL is exactly https://app-api.joiin.co/mcp
- Make sure you can reach app.joiin.co in your browser
"Access denied" when running a tool
You may not have access to the requested client. Ask your Joiin admin to add you.
"Dynamic period not available"
The requested time period has no data. Try a different date range or check that your companies have synced data for that period.
Reports show no data
Your companies may be CSV-only uploads without transaction-level data. Connect via Xero or QuickBooks for full reporting (Sales by Customer, Purchases by Supplier, Ageing reports).
Session expired
Most apps refresh your session automatically. If it stops working, remove and re-add the Joiin server in your AI app.
"Access denied" when connecting
Cancel was clicked on the Joiin consent screen. Connect again and click Allow.