Connecting Claude and other AI tools

You can connect an AI tool you already use, such as Claude or ChatGPT, to your Letterhead account. Once it’s connected, you ask it questions in plain English and it answers from your live Letterhead data, and it can make some changes for you too. You don’t need to be a developer to set it up.

This is separate from Penpal, the assistant built into Letterhead. A connected AI tool works from its own app; Penpal works inside Letterhead. See Working with Penpal.

Before you start

• You need to be a company administrator. Anyone else sees an authorization error when they sign in.
• Your AI tool needs to support custom connectors (sometimes called MCP servers). Claude and ChatGPT both do.
• There’s no API key to paste. You connect by signing in to Letterhead with your normal login.

Find your connection URL

1. In Letterhead, go to Settings → MCP.
2. Under Server URL, click Copy URL.

Each company has its own URL, so copy it from your own account. Paste the whole URL, including the /mcp at the end.

Connect your AI tool

The menu names vary by tool, but the steps are the same:

1. Open your AI tool’s connector settings. In Claude, this is usually Settings → Connectors → Add custom connector. In ChatGPT, look under Settings → Connectors.
2. Add Letterhead as a custom connector and paste the URL you copied. Add it as a connector or MCP server, not as a generic API integration; if your tool asks for an API key, that’s the sign you’ve picked the wrong option.
3. Sign in to Letterhead when prompted, and approve access for your AI tool.

Once you’ve approved it, your AI tool can work with your Letterhead account.

What you can ask it to do

• Answer questions about your channels and letters, newsletter and campaign performance, transactional email performance grouped by tag, and subscriber and engagement numbers, including a company-wide audience rollup.
• Draft newsletters from a plain-language description.
• Set and adjust goals for engagement, clicks or growth. See setting goals.
• Schedule recurring reports on your key metrics, emailed daily, weekly or monthly to the people you name, and edit or cancel existing ones. See scheduling a recurring report.
• Check and rescue automations: see which are running, paused, stuck or erroring, and send a stuck one now or put it back on schedule. See Working in Automations.
• Manage promotions: list them and their schedules, reschedule, pause, reactivate, or edit their headline, content and link. See managing promotions.
• Browse your company’s curated content across channels.

For example:

• “Set a goal to increase click rates by 10% this quarter”
• “Schedule a weekly engagement report every Monday to the team”
• “Which automations won’t send on their own? Send the stuck ones now”
• “What’s our overall audience growth across all channels?”

When to contact us

If you’re signed in as a company administrator, you’ve pasted the full URL from Settings → MCP, and the connection still fails, contact support and we’ll look into it.

Related

• Working with Penpal
• Working in Integrations
• Using the Letterhead API