Superhuman Mail MCP Server

Prerequisites
How to connect Claude Code
How to connect Claude Desktop
How to connect ChatGPT
What you can do with the MCP Server
FAQ
Troubleshooting

Overview

The Superhuman Mail MCP Server lets AI tools like Claude and ChatGPT connect directly to your Superhuman inbox and calendar.

Once connected, your AI assistant can search email, draft replies in your voice, manage events, and send messages — all without leaving your AI app.

This eliminates the need to copy and paste between your AI assistant and Superhuman.

Prerequisites

Before you begin, make sure you have all of the following:

A Superhuman Mail account with Ask AI enabled.
The Mail web app installed in Google Chrome.
A Business plan or higher.
- The MCP Server is not available on the Starter plan.
Access to an AI tool that supports MCP (such as Claude Code).

How to Connect

Claude Code — Mac

Prerequisite: You must have Claude Code installed on your device.

Hit Cmd+Space → Terminal to open Terminal.

In Terminal, type or paste the following command:

claude mcp add --transport http superhuman-mail https://mcp.mail.superhuman.com/mcp

Hit Enter.
In Terminal, type the following command to start Claude Code:
```
claude
```
Hit Enter.
Type /mcp and hit Enter.
Hit the down arrow to select superhuman-mail and hit Enter.
Hit the down arrow to select Authenticate and hit Enter.
Complete the OAuth sign-in flow in your browser.

Once authenticated, your AI tool can access your Mail inbox and calendar.

💡 Tip: You can rename superhuman-mail to anything you prefer when adding the MCP server.

Claude Code — Windows

Prerequisite: You must have Claude Code installed on your device.

Hit Win+R to open the "Run dialog" box.
Type cmd and hit Enter to open Command Prompt (or search for PowerShell in the Start menu).

In the terminal, type or paste the following command:

claude mcp add --transport http superhuman-mail https://mcp.mail.superhuman.com/mcp

Hit Enter.
In Terminal, type the following command to start Claude Code:
```
claude
```
Hit Enter.
Type /mcp and hit Enter.
Hit the down arrow to select superhuman-mail and hit Enter.
Hit the down arrow to select Authenticate and hit Enter.
Complete the OAuth sign-in flow in your browser.

Claude Desktop

Prerequisite: You must have Node.js v20.18.1 or higher installed on your device.

To check your version, open Terminal (Mac) or Command Prompt (Windows) and run node --version. If it's below v20.18.1, or you see command not found, see these steps.
Check if you have multiple Node versions by running nvm ls in Terminal (Mac) or nvm list in Command Prompt (Windows). If you see multiple versions, you must follow these steps before continuing — setup will fail otherwise.

Option 1 — Claude Desktop: Open the claude_desktop_config.json file.
1. Open the Claude Desktop app.
2. In the bottom left corner, click on your name and click Settings from the menu that appears
3. On the Settings page, click on Developer.
4. Under Local MCP servers, click Edit Config.
Option 2a — Mac: Open the claude_desktop_config.json file.
1. Open Finder.
2. Hit Cmd+Shift+G to open the "Go to folder" dialog.
3. Copy and paste ~/Library/Application Support/Claude.
4. Hit Enter.
Option 2b — Windows: Open the claude_desktop_config.json file.
1. Open File Explorer.
2. Click the address bar at the top or hit Ctrl+L.
3. Copy and paste %APPDATA%\Claude\.
4. Find the file called claude_desktop_config.json.
Edit the file.
1. If you already have MCP servers in there, edit the file to include this after your previous MCP server definition:
  
  ,
  
  "Superhuman Mail": {
  
        "command": "npx",
  
        "args": [
  
          "-y",
  
          "mcp-remote",
  
    "https://mcp.mail.superhuman.com/mcp"
  
        ]
  
      }
  
  (The command should go after the closing bracket of your last MCP server)
2. If you do not already have MCP servers in there, edit the file to this:
  
  {
  
  "mcpServers": {
  
  "Superhuman Mail": {
  
  "command": "npx",
  
  "args": [
  
  "-y",
  
  "mcp-remote",
  
  "https://mcp.mail.superhuman.com/mcp"
  
  ]
  
  }
  
  }
Hit Cmd+S to save the JSON file.
Restart Claude Desktop.
A Mail authentication window will open in your browser. Complete the authentication process and return to Claude to use the MCP Server!

💡 Tip: If you’re unsure how to edit JSON, you can ask Claude to help update the file.

ChatGPT

Prerequisite: You must have access to Developer Mode in ChatGPT. If you do not have access, request access to Developer Mode from your ChatGPT admin.

Open ChatGPT in your browser.
Click Apps in the left sidebar.
Click the Settings icon in the top right corner.
Scroll to the bottom and select Advanced settings.
Toggle on Developer Mode.
Click Create app.
Enter the following information:
- (Optional) Icon: You do not need to give it an icon, but you may use this if you’d like.
- Name: Superhuman Mail Beta
- Description: Find and draft emails
- MCP Server URL: https://mcp.mail.superhuman.com/mcp
- Authentication: OAuth
Confirm and click Create.

Your ChatGPT app can now connect to Superhuman!

💡 Tip: Claude and ChatGPT both have native Gmail and Outlook connectors. If you want to ensure actions happen in Superhuman, include a prompt like, “Please use Superhuman Mail to do this.”

What you can do with the MCP Server

Once connected, your AI assistant can perform actions across your Mail inbox and calendar.

Examples include:

Search email and events using natural language.
Draft replies in your voice and tone.
Send emails.
Create or update calendar events.
Find availability for meetings.
Summarize important emails and tasks.

These capabilities are powered by MCP tools such as:

query_email_and_calendar: Use natural language (semantic search) to ask a question about your email and calendar
create_or_update_draft: Create or edit an email draft, using your voice and tone.
list_email: Search for and return emails matching specific criteria (To, From, Subject, date.).
create_or_update_event: Create and update calendar events.
get_availability_calendar: Find available meeting times for a group of participants.
send_email: Send an email (From, To, Cc, Bcc, Subject, HTML body).
- Before using this tool, we strongly advise enabling the option to request confirmation each time in your AI assistant, as it can send emails instantly without any delay.
- Smart send is an optional parameter that sends the email at the most likely time the recipient(s) will open it.
get_email_thread: Fetch and display a full email thread's contents.
update_preferences_email_and_calendar: Update writing style, event creation preferences, and facts used to draft emails and calendar events. Updates are made to Superhuman’s Personalization settings.
get_read_statuses: Read the read/unread status for emails that meet specific criteria (time-based, etc.)
update_email: Add or remove a Label, add or remove a Reminder, Star or Unstar, move to or remove from Trash, mark Done or not Done, mark Read or Unread for email thread(s).

💡 Tip: For best results, reference MCP tools explicitly in your prompt when working with your AI assistant.

FAQ

What is the Superhuman Mail MCP Server?

The MCP Server allows AI tools like Claude and ChatGPT to connect directly to your Superhuman inbox and calendar. This allows AI to search, draft, and send emails or manage events without switching apps.

Can IT admins disable MCP access org-wide?

MCP access will be disabled for Enterprise accounts by default. If you are the admin of an Enterprise team and would like to enable or disable Superhuman AI or the MCP Server for your team, please reach out to your Customer Success Manager at Mail.

It's not possible to disable the MCP Server across an organization that's not on an Enterprise plan. However, customers can always choose not to enable the MCP Server for their accounts.

Do MCP drafts appear in Superhuman?

Yes. Drafts created through MCP appear in your Mail drafts folder. In Mail, hit G then D to access your Drafts folder.

Can AI tools send emails on the user's behalf via MCP?

Yes. The MCP server includes a send_email tool that allows AI agents to send email directly, not just draft them. The individual must approve the use of the tool, and they can choose to use the Mail MCP Server in read-only mode.

Before using this tool, we strongly advise enabling the option to request confirmation each time in your AI assistant, as it can send emails instantly without any delay.

Can I send attachments?

Not yet! Attachment support is coming in a future release, and we’ll be sure to update this article once it’s available.

Is there a usage limit?

There is currently no usage limit for the MCP server. This may change in the future, and if it doesn, we’ll update this article.

Is there a send limit?

Yes, send limits are determined by your email provider — Google or Microsoft 365. Since Mail connects to your account through the provider’s API, sends through Mail are limited by Google or Microsoft.

Why can’t I find the MCP Server in Claude or ChatGPT directories?

The Superhuman MCP Server is not yet listed in the ChatGPT or Claude connector directories.

Once listed, setup will be available with one-click installation. For now, you can connect manually using the steps above.

Can I set up the MCP Server using NPM?

Not at this time. When this becomes available, we’ll update this article.

How do I remove the MCP Server from Claude Code?

Run this command in Terminal: claude mcp remove superhuman-mail

If you used a different name when installing, replace superhuman-mail with that name.

How can I tell which MCP server is being used?

Your AI tool will show which MCP tool it calls when performing an action. Expand the reasoning or thinking section to view the server used.

My AI tool didn’t use Mail’s MCP server to complete the action. How can I make sure it does?

As of now, there isn’t a way to set the Mail MCP Server as the default. However, you can add “Please use Superhuman Mail MCP Server” to your prompt.

Is email content sent to third-party AI providers?

Yes. The Mail MCP Server is a remote server hosted by Superhuman Mail — it is not a local-only server. When a user asks their AI tool a question, the AI client calls the MCP Server, which processes the request and returns structured data. That data (e.g., email content, search results, calendar info) is then sent to the AI provider for the model to reason.

This is inherent to the MCP architecture.

Do Mail's Zero Day Data Retention and no-model-training commitments still apply when using MCP?

Mail's existing data protection commitments — including Zero Day Data Retention agreements with AI subprocessors and the policy that no AI subprocessor may use customer data for model training — apply to Superhuman's built-in AI features, where Superhuman controls the contractual relationship with the underlying AI provider.

MCP introduces a different interaction method. When a user connects Mail to an external AI tool such as Claude or ChatGPT via MCP, email and calendar data returned by the Mail MCP Server is transmitted to the AI provider for processing. In this scenario, the user maintains a direct relationship with the AI provider (Anthropic, OpenAI, etc.), and the data protection terms governing that interaction are the AI provider's own policies — not Superhuman's subprocessor agreements.

In practice, this means:

Mail's Zero Day Data Retention commitment governs data processed by Mail's own AI infrastructure (e.g., Ask AI, Smart Compose, Auto Labels).
Data transmitted to external AI providers via MCP is governed by the respective provider's data handling policies.
Superhuman does not send customer data to external AI providers on its own initiative — MCP connections are user-initiated, and each tool invocation requires explicit user approval.

What audit logging exists for MCP? Will I be able to track which activities were done via MCP?

No specific logging for MCP exists, and there are no unique identifiers that will inform whether an action was taken via MCP or a human user.

Troubleshooting

When I try to set up the MCP Server, I get stuck at authentication. How do I fix this?

If you haven't already, make sure you have the Superhuman Mail web app installed in Google Chrome. Once you've installed the web app, try again.

It might also help to make sure Google Chrome is allowed to open the Mail app.

When I try to set up the MCP Server on Claude Desktop, it doesn't work. Any tips for a Mac user?

Claude Desktop requires a tool called Node.js to run the Superhuman Mail connection. This is a one-time setup:

Hit Cmd+Space → Terminal to open Terminal.

In Terminal, type or paste the following command:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Hit Enter.
Terminal will ask for your Mac login password. When you type it, nothing will appear on screen — no dots, no asterisks, nothing. This is completely normal! Just type your password carefully and hit Enter.
Install may take a few minutes. Make sure to pay attention to Homebrew's instructions for next steps. You'll likely need to run three individual commands in your terminal to add Homebrew to your PATH — two start with echo and one starts with eval.
Wait until you see the regular prompt again (ending with % or $). Then install Node.js by pasting the following command:
```
brew install node
```
Hit Enter.
Verify everything installed correcting by pasting the following command:
```
npx --version
```
Hit Enter.
If you see a version number (like 10.8.2), you're good to move on. If it says command not found, try closing and reopening Terminal, then run npx --version again.

I'm getting a "File is not defined," "Cannot find module 'node:path,'" or "Unsupported engine" error when connecting the MCP Server on Claude Desktop. How do I fix it?

This error means the MCP Server is running on an older version of Node.js (v18 or earlier), but it requires v20.18.1 or higher. This can happen if you have multiple Node.js versions installed and your system is defaulting to the wrong one.

Step 1: Find your Node 20 path

Hit Cmd+Space → Terminal to open Terminal.
In Terminal, type or paste the following command:
```
nvm which 20 
```
Hit Enter.

This should print a path like /Users/yourname/.nvm/versions/node/v20.x.x/bin/node. Copy everything up to and including /bin/ — you’ll need it in the next step.

If this command says N/A or fails, you’ll need to install Node 20 first:

nvm install 20

Then run nvm which 20 again.

Step 2: Update your Claude Desktop config

Open the claude_desktop_config.json file using the steps outlined in the Claude Desktop section of this article.
Find the "Superhuman Mail" entry point and update it to match the format below, replacing the example path with the one you copied in Step 1: Find your Node 20 path.

json

"Superhuman Mail": {

"command": "/Users/yourname/.nvm/versions/node/v20.x.x/bin/npx",

"args": [

"-y",

"mcp-remote",

"https://mcp.mail.superhuman.com/mcp"

]

"env": {

"PATH": ""/Users/yourname/.nvm/versions/node/v20.x.x/bin:/usr/local/bin:/usr/bin:/bin"

}

}
Save the file.

Step 3: Clear the npm cache

Hit Cmd+Space → Terminal to open Terminal.
In Terminal, type or paste the following command:
```
rm -rf ~/.npm/_npx 
```
Hit Enter.

Step 4: Restart Claude Desktop

Fully quit and reopen Claude Desktop.
The MCP Server should now connect successfully!

Windows users: The steps are the same, with a few differences:

To find your Node 20 path, run nvm which 20 in Command Prompt (not Terminal):
1. Hit Win+R to open the "Run dialog" box.
2. Type cmd and hit Enter to open Command Prompt (or search for PowerShell in the Start menu).
The path will look like C:\Users\yourname\AppData\Roaming\nvm\v20.x.x.
When updating your config, set "command" to that path followed by npx.cmd, and update the new "PATH" to use that same folder but with semicolons (;) spearating each path instead of colons (:)
To clear the npm cache, run rmdir /s /q %LOCALAPPDATA%\npm-cache_npx

Table of Contents

Overview

Prerequisites

How to Connect

Claude Code — Mac

Claude Code — Windows

Claude Desktop

ChatGPT

What you can do with the MCP Server

FAQ

What is the Superhuman Mail MCP Server?

Can IT admins disable MCP access org-wide?

Do MCP drafts appear in Superhuman?

Can AI tools send emails on the user's behalf via MCP?

Can I send attachments?

Is there a usage limit?

Is there a send limit?

Why can’t I find the MCP Server in Claude or ChatGPT directories?

Can I set up the MCP Server using NPM?

How do I remove the MCP Server from Claude Code?

How can I tell which MCP server is being used?

My AI tool didn’t use Mail’s MCP server to complete the action. How can I make sure it does?

Is email content sent to third-party AI providers?

Do Mail's Zero Day Data Retention and no-model-training commitments still apply when using MCP?

What audit logging exists for MCP? Will I be able to track which activities were done via MCP?

Troubleshooting

When I try to set up the MCP Server, I get stuck at authentication. How do I fix this?

When I try to set up the MCP Server on Claude Desktop, it doesn't work. Any tips for a Mac user?

I'm getting a "File is not defined," "Cannot find module 'node:path,'" or "Unsupported engine" error when connecting the MCP Server on Claude Desktop. How do I fix it?