How to Connect ChatGPT to Your Business Tools

Apps, plugins and developer mode

OpenAI's help centre uses two words. An app connects ChatGPT to an outside service such as Google Drive or Slack. A plugin is a package that can contain one or more apps. Both are managed in Settings > Plugins.

Apps come from two places:

• Built-in apps are listed by OpenAI. You install one and sign in.
• Developer-mode apps are ones you create from a remote MCP server URL. OpenAI's workspace settings call this creating a custom MCP connector. It is how ChatGPT's MCP support reaches a server OpenAI has not listed.

If MCP is new to you, start with what MCP is.

Limits on developer-mode apps

• Remote servers only, over SSE or streaming HTTP. ChatGPT cannot start a server on your computer. For a server on a private network, OpenAI points to its Secure MCP Tunnel.
• Web only. The Help Center says MCP apps are not available on mobile.
• Sign-in can be OAuth, no authentication, or a mix of the two.
• Write actions ask for confirmation by default. You can have ChatGPT remember your approve or deny choice for a tool, and it lasts for that conversation.
• A tool is treated as a write unless the server marks it read-only with the readOnlyHint annotation.
• Agent mode does not use custom apps. Deep research can, for read and fetch actions only.

OpenAI labels the feature "Elevated risk" and names prompt injection and mistaken writes as the things to watch.

Which plans get developer mode

OpenAI's two pages do not say the same thing. Both were read on 5 October 2026.

If you are on Plus or Pro, plan on reads working and test a write before you depend on one. Free and Go appear on neither list.

Workspace accounts have their own rules:

• Business. Only admins and owners can turn on developer mode, and each one turns it on for themselves.
• Enterprise and Edu. An admin grants access under Workspace Settings > Permissions & Roles > Connected Data. Members with access then switch it on in Settings > Apps > Advanced Settings.

The three routes compared

Route 1: Install a built-in app

1. Open Settings > Plugins. OpenAI notes that very old mobile app versions may say Apps instead.
2. Select the app, or the plugin that includes it.
3. Select Install plugin if it is shown.
4. If prompted, select Connect and sign in to the account that already has the data you want.
5. Review the permissions it asks for and approve them.
6. In a chat, mention the app with @, or select + and pick it.

Shopify as an example

Shopify publishes its own plugin for ChatGPT. Installing it sends you to your Shopify admin to approve data access, and Shopify recommends a desktop browser for setup.

The plugin creates and updates products and collections, sets inventory counts and creates percentage-off discount codes. It reads orders and customers without changing them. Refunds and cancellations are blocked even when you approve write access. Bulk status changes cover up to 50 products at a time.

Shopify suggests typing @Shopify in your message, so ChatGPT uses the plugin instead of answering from general knowledge.

Built-in apps need no developer mode, and the vendor supports them. OpenAI says availability depends on the app, your plan, region, workspace and role. You get the actions the vendor chose and no others.

Route 2: Add a vendor's MCP server

Use this when a vendor publishes a remote MCP server and has no ChatGPT app, or when its server does more than its app.

These steps follow OpenAI's developer docs:

1. Find the server URL in the vendor's developer docs. HubSpot's is https://mcp.hubspot.com. HubSpot has you create an MCP connector under Development > MCP Connectors first. That gives you a client ID and a client secret, and the redirect URL you enter there has to match the one your MCP client uses.
2. In ChatGPT on the web, open Settings > Security and login and turn on Developer mode.
3. Go to chatgpt.com/plugins and select the plus button to create a developer-mode app.
4. Enter the server URL and choose the authentication type. With OAuth, ChatGPT uses a client ID and secret if you supply them.
5. Sign in to the tool. The app appears under Drafts in app settings.
6. In a chat, choose Developer mode from the Plus menu and select the app.

For Business, Enterprise and Edu, the Help Center describes a slightly different path. Turn developer mode on under Settings > Apps > Advanced settings, then go to Apps > Create. Enter the endpoint, pick the authentication, click Scan Tools and then Create. The app stays a private draft until an admin or owner publishes it from Workspace settings > Apps > Drafts.

Each vendor is a separate app with its own sign-in. A vendor that requires your own OAuth client adds a setup step before you reach ChatGPT.

Route 3: Add one hosted MCP URL (PopMCP)

A hosted provider runs the MCP servers and holds the credentials. With PopMCP every tool you connect is served from one URL, https://app.popmcp.com/mcp, so ChatGPT needs one developer-mode app.

1. Create a PopMCP account and connect your tools from the MCP server catalog. Check each one shows as Verified.
2. In ChatGPT, turn on Developer mode in Settings > Security and login.
3. Go to chatgpt.com/plugins and select the plus button.
4. Enter https://app.popmcp.com/mcp as the MCP server URL and choose OAuth. There is no token or client ID to paste.
5. Sign in to PopMCP and approve the consent screen, ticking only the connectors ChatGPT should reach.
6. In a chat, pick PopMCP from Developer mode in the composer and ask it to run list_connections. Try a read first.

PopMCP's endpoint uses Streamable HTTP, one of the two transports ChatGPT accepts.

What this route changes

ChatGPT gets one app instead of one per vendor.

You are not held to a short tool list. PopMCP loads a curated set per provider and keeps the rest searchable. QuickBooks has 133 operations, and quickbooks_search_tools finds the ones that are not loaded.

Provider credentials stay in PopMCP, encrypted at rest with AES-256-GCM. ChatGPT holds a PopMCP sign-in and never the provider secret. Tool calls are not metered on any plan.

What it does not change

You still need developer mode, with the same plan rules as Route 2. A paid PopMCP plan cannot add write actions to a ChatGPT plan that only allows read and fetch.

PopMCP's own Free plan is read-only for everyone. Writes start on Starter at $39 a month.

PopMCP does not hold a write for approval. A write runs when ChatGPT calls it, so ChatGPT's confirmation prompt is the check before anything changes. If one built-in app does the job, use that.

Getting ChatGPT to call the right tool

OpenAI's developer docs recommend being explicit. It matters more as the tool list grows.

• Name the app and the tool: "Use the PopMCP app's shopify_get_orders tool to list last week's orders."
• Rule out the alternatives: "Do not use web search. Only use the PopMCP app."
• Before you approve a write, expand the tool call. The full JSON input is there to read.
• When a server adds tools, open the app's details page in app settings and refresh it.

Claude's setup is different, and how to connect Claude to your business tools has those steps. For more than one store or client account, see multiple accounts through one MCP URL.