OpenAI recently launched Developer Mode in ChatGPT, introducing full Model Context Protocol (MCP) client support. This enables direct integration with external tools and data sources through custom connectors. With Lemonado's MCP server, you can give ChatGPT secure, real-time access to your business data, including databases, spreadsheets, and business applications, directly from the chat interface.

Many MCP servers support both read and write functions, allowing models to query data and perform actions within connected systems. While this enables powerful capabilities, it also introduces risks, particularly with unverified connectors that could accidentally alter or delete your data.

Lemonado takes a different approach. It operates as a remote, read-only MCP server. ChatGPT can securely access and analyze your connected data sources (like Stripe, Google Ads, Sheets, or Postgres) without any ability to modify them. This design prioritizes data integrity and safety while still providing ChatGPT with advanced analytical capabilities and natural language to SQL translation.

This guide walks you through enabling Developer Mode, adding Lemonado as a custom connector in ChatGPT, and running your first test query. It assumes you've already created a Lemonado account and connected at least one data source in your workspace.

Step 1: Enable Developer Mode

1. Go to chatgpt.com in your browser.

2. Click your profile icon → Settings

3. Navigate to Apps & connectors → Scroll down to Advanced Settings

4. Toggle on Developer Mode (beta)

Note: Developer Mode is currently only available in beta for Plus, Pro, Business, Enterprise, and Education accounts on the web.

Step 2: Add your Lemonado Connector

1. Go to the Connectors tab in your ChatGPT settings.

2. Click Create in the top right corner.

3. Enter the following details:

(These are also available in your Lemonado workspace under AI Connectors)

• Name: Lemonado

• Remote MCP Server URL: https://mcp.lemonado.io/mcp

• Authentication: Select OAuth (recommended).

4. Click Create. You'll be redirected to Lemonado to log in and authorize access to your chosen AI Connector.

After successful authentication, Lemonado will appear as a connected tool under Developer Mode.

Technical Note: ChatGPT supports SSE and streaming HTTP connector protocols. Authentication options include OAuth or none (for public endpoints).

Step 3: Test Your Connection

1. Start a new chat in ChatGPT.

2. Click the plus (+) icon in the message box, then hover over More (…).

3. Select Lemonado from the list of available connectors to activate inside your chat.

4. Try a test query, for example:

If successful, Claude will return data directly from your connected Lemonado workspace.

Step 4: Start Querying Your Data

Once connected, ChatGPT can use Lemonado as a read-only data layer for natural language analysis. Try prompts such as:

“Show this week’s revenue compared to last month.”
“Which Google Ads campaigns drove the most Stripe subscriptions this year?”
“Find HubSpot contacts who haven’t been reached in the last 30 days.”

All queries run through Lemonado's unified SQL engine, allowing you to combine and analyze data from multiple sources in a single request, securely and in real time.

Best Practices

• Scope each connector appropriately.
  Keep each connector limited to the specific data it needs to access.

• Monitor access regularly.
  Review Lemonado's audit logs to track how Claude interacts with your data.

• Maintain security hygiene.
  Rotate or revoke OAuth tokens periodically to keep your connections secure.

You've now connected ChatGPT to Lemonado MCP, enabling secure, real-time access to your business data through natural language. Lemonado ensures every connection remains read-only, audited, and secure, so you can explore insights confidently without risk to your underlying data.

Have questions or need help? Contact our support team at hello@lemonado.io.