Assembled MCP server setup

Plans and permissions:

• Plan: Pro or Enterprise plan
• Connect an AI assistant to Assembled: Admin role, or a custom role with Assembled MCP set to Can access all data via the MCP or Can access and make changes to all data via MCP

Use this guide to connect an AI assistant, such as Claude or ChatGPT, to the Assembled MCP server, so you can ask it questions about your Assembled data. Every assistant uses the same server address and the same sign-in: you add the server to your assistant, then sign in to Assembled when it asks. For what you can do once you’re connected, see Assembled MCP server.

The server address is https://data.mcp.assembledhq.com/mcp.

Before you begin

• Have your Assembled sign-in ready. Your assistant opens the Assembled sign-in page to connect through OAuth, or connects right away if you’re already signed in.
• Use only an AI assistant your organization has approved.

Connect Claude.ai

1. In Claude.ai, go to Settings > Connectors.
2. Select Add custom connector.
3. Enter Assembled as the Name, and https://data.mcp.assembledhq.com/mcp as the Remote MCP server URL. Then select Add.
4. Under Tool permissions, allow at least get_metrics_catalog and query_metrics. Start with Needs approval, and allow more tools as you use them.
5. When Claude asks, sign in to Assembled.
6. Start a new chat and ask “What Assembled metrics can I analyze?”

If Claude answers from your Assembled data, you’re connected.

Important: Some tools create forecast adjustments or publish overtime and voluntary time off. Keep them on Needs approval until you’re ready to let your AI assistant make changes for you.

Connect Claude Code

Claude Code doesn’t have a settings screen for connectors, so you add the server from your terminal. You need Claude Code installed and signed in.

1. In your terminal, outside a Claude Code session, run:

   claude mcp add --transport http assembled https://data.mcp.assembledhq.com/mcp

2. Check that it was added by running claude mcp list. Assembled shows Needs authentication until you sign in.

3. Start Claude Code with claude, then run /mcp in the session.

4. Choose assembled, then Authenticate, and sign in to Assembled in the browser window that opens.

5. Ask “What Assembled metrics can I analyze?” and approve the tool when Claude Code asks.

If Claude answers, you’re connected. In Claude Code’s output, tool calls are labeled with the server name, assembled, so you can tell that an answer came from your Assembled data.

In the command, --transport http means the server is reached at a URL, and assembled is the name Claude Code uses for it. By default, the server is added for you in the current project only. To add it for all your projects, include --scope user:

claude mcp add --scope user --transport http assembled https://data.mcp.assembledhq.com/mcp

To change the scope later, run claude mcp remove assembled, then add the server again with the scope you want.

Keep in mind: Claude Code asks for permission the first time it uses each tool. Approve tools that change data only when you’re ready, and don’t set them to always allow. If you’ve already added Assembled in Claude.ai with the same account, it may be available already: check /mcp before adding it again.

Connect ChatGPT

You need a ChatGPT account that supports custom apps and developer mode.

1. In ChatGPT, select your profile, then Settings.
2. Go to Apps, open Advanced settings, and turn on Developer mode. Read the risk notice first: developer mode allows unverified connectors.
3. Go back to Apps and select Create app. If you don’t see it, refresh the page.
4. Enter a Name, such as Assembled MCP, and https://data.mcp.assembledhq.com/mcp as the MCP server URL. Set Authentication to OAuth.
5. Review Advanced OAuth settings if they appear, acknowledge that custom MCP servers introduce risk, and save the app.
6. When ChatGPT asks, sign in to Assembled.
7. Start a new chat, select your Assembled app if needed, and ask “What Assembled metrics can I analyze?”

If ChatGPT answers from your Assembled data, you’re connected. As in Claude, keep the tools that change data on approval until you’re ready to let ChatGPT make changes for you.

Connect another AI assistant

Any AI assistant that supports remote MCP servers can connect with the same server address and sign-in. See the setup guides for Claude Desktop, Goose, and Dust.

Common issues

• Sign-in fails, or tools return authorization errors: Check that your Assembled role has the Assembled MCP permission, and that you’re signed in to Assembled in the same browser.
• The assistant doesn’t use Assembled to answer: Add “Use Assembled” to your prompt, and check that the Assembled tools are allowed in your assistant’s tool permissions.
• In Claude.ai, tools don’t appear: Check that you allowed them under Tool permissions in the connector’s settings.
• In Claude Code, /mcp shows “No MCP servers configured”: You probably added the server in a different project. Add it again in this project, or add it with --scope user.
• In Claude Code, the browser doesn’t open to sign in: Run /mcp, choose assembled, and choose Authenticate again. If the browser still doesn’t open, copy the address shown in the terminal into your browser.
• In Claude Code, you see “Server already exists”: Run claude mcp remove assembled, then add it again, or use a different name.
• In Claude Code, the server is connected, but no tools appear: Run claude mcp get assembled and check that the address matches the server address above.
• In ChatGPT, the connection fails: In Apps > Advanced settings, check that Developer mode is on. Some setups also need Enforce CSP in developer mode turned off.
• In ChatGPT, there’s no Create app button: Refresh the page after turning on developer mode. If it still doesn’t appear, check that your ChatGPT plan supports custom apps.