How do I install Ghub?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Ghub need an API key?

No required environment variable is listed on this record.

When was Ghub last checked?

Last checked 2026-10-28. MCP server and JSON CLI for Gmail, Drive, Sheets, Docs and Calendar across multiple Google accounts, with built-in OAuth.

Ghub MCP 서버

ghub

Gmail, Drive, Sheets, Docs, and Calendar for AI agents, across several Google accounts, as an MCP server and a JSON CLI.

$ ghub call search_emails --json '{"account":"work","query":"is:unread","max_results":10}' \
    --fields emails.id,emails.subject --limit 10
{"ok":true,"data":{"emails":[{"id":"...","subject":"..."}]},"meta":{"version":1}}

ghub is a local server that gives an AI assistant access to your Google accounts. It speaks the Model Context Protocol (MCP) over stdio or SSE, and the same 60 tools are also available as short CLI calls that print one JSON object. You sign in once per account with a built-in OAuth flow. After that, an agent can read and search across all your inboxes at once, or act on one account you name.

It is for people who run agents (Claude Code, Codex, Claude Desktop, or their own) and use more than one Google account. It exists because most Gmail MCP servers handle one account and need manual token setup.

Features

Multi-account: Configure as many Google accounts as you want. Read and search tools merge results from all enabled accounts when you leave account out. Write tools require an explicit account.
Five Google services: 60 tools across Gmail, Drive, Sheets, Docs, and Calendar.
Built-in OAuth: Onboard an account with begin_account_auth and finish_account_auth. Refreshed tokens are saved automatically.
Attachments: get_all_attachments extracts text from PDF, Word, and Excel files. Images are read with a small macOS Vision OCR helper when swiftc is available at install time.
Agent CLI: ghub tools, ghub schema TOOL, and ghub call TOOL give structured JSON, bounded output, validation-only --dry-run, and fixed exit codes. See docs/agent-cli.md.
Two MCP transports: stdio by default, or HTTP with SSE for hosted setups.

Install

You need Node.js 20 or newer.

From a clone (the compiled dist/ is committed, so this works without a build step):

git clone https://github.com/tszaks/ghub.git
cd ghub
npm install
npm run build
node dist/index.js tools

Or from a release tarball (see docs/releases.md):

npm install -g ./ghub-1.7.0.tgz
ghub tools

npm install runs scripts/build-ocr.sh, which compiles the OCR helper only if swiftc is found (macOS). Without it, image attachments are saved to disk but no text is extracted.

ghub is not published to the npm registry.

Quick start

Create Google OAuth credentials (see Google Cloud setup) and download the JSON file.
Add ghub to your MCP client (see Client configuration).
Ask your agent to call begin_account_auth, open the URL it returns, then pass the code to finish_account_auth. Details are in OAuth onboarding.
Call list_accounts to check that each account has a valid token.

Client configuration

ghub runs as node /absolute/path/to/ghub/dist/index.js (or ghub mcp if installed from the tarball). With no arguments it starts the MCP server on stdio.

Claude Code

claude mcp add ghub -- node /absolute/path/to/ghub/dist/index.js

Codex (~/.codex/config.toml)

[mcp_servers.ghub]
command = "node"
args = ["/absolute/path/to/ghub/dist/index.js"]

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "ghub": {
      "command": "node",
      "args": ["/absolute/path/to/ghub/dist/index.js"]
    }
  }
}

The server starts and lists its tools over stdio with no extra setup. Google calls begin only after you onboard an account.

Configuration

Variable	Default	Purpose
`GMAILMCPCONFIG_DIR`	`~/.gmail-multi-mcp`	Where account files and tokens are stored.
`GMAIL_MCP_CONFIG_DIR`	none	Older name for the same setting. `GMAILMCPCONFIG_DIR` wins if both are set.
`MCP_TRANSPORT`	`stdio`	Set to `sse` to serve MCP over HTTP.
`PORT`	none	If set, the server switches to SSE mode and listens on it. Falls back to `RAILWAY_PORT`, then `3000`, when SSE is forced.
`HOST`	`0.0.0.0`	Bind address in SSE mode.

To pass a variable to the server, add it to the client config, for example claude mcp add ghub -e GMAILMCPCONFIG_DIR=/custom/path -- node /absolute/path/to/ghub/dist/index.js.

Where data is stored

Default configuration location: ~/.gmail-multi-mcp/

~/.gmail-multi-mcp/
├── accounts.json           # Master account list
└── accounts/
    ├── personal/
    │   ├── credentials.json  # OAuth client credentials
    │   ├── token.json       # Access/refresh tokens
    │   └── meta.json        # Account metadata
    └── work/
        ├── credentials.json
        ├── token.json
        └── meta.json

accounts.json format

{
  "defaultAccount": "personal",
  "accounts": [
    {
      "id": "personal",
      "email": "[email protected]",
      "displayName": "Personal Gmail",
      "enabled": true,
      "credentialPath": "~/.gmail-multi-mcp/accounts/personal/credentials.json",
      "tokenPath": "~/.gmail-multi-mcp/accounts/personal/token.json"
    },
    {
      "id": "work",
      "email": "[email protected]",
      "displayName": "Work Email",
      "enabled": true,
      "credentialPath": "~/.gmail-multi-mcp/accounts/work/credentials.json",
      "tokenPath": "~/.gmail-multi-mcp/accounts/work/token.json"
    }
  ]
}

Google Cloud setup

Before using ghub, you need to set up a Google Cloud project:

1. Create a Google Cloud Project

Go to Google Cloud Console
Create a new project or select an existing one
Note your project ID

2. Enable Gmail API

In your project, go to APIs & Services > Library
Search for "Gmail API"
Click Enable
Enable Google Drive, Google Sheets, Google Docs, and Google Calendar APIs for the corresponding tools you plan to use.

3. Create OAuth 2.0 Credentials

Go to APIs & Services > Credentials
Click + CREATE CREDENTIALS > OAuth client ID
If prompted, configure the OAuth consent screen:
- Choose "External" user type
- Fill in required fields (app name, support email)
- Add your email to test users
For application type, select Desktop app
Give it a name (e.g., "Gmail MCP Client")
Click Create
Download the JSON file - you'll need this for authentication

4. OAuth Consent Screen Setup

Go to APIs & Services > OAuth consent screen
Review the existing broad scopes requested by GHub:
- https://mail.google.com/
- https://www.googleapis.com/auth/gmail.settings.basic
- https://www.googleapis.com/auth/drive
- https://www.googleapis.com/auth/spreadsheets
- https://www.googleapis.com/auth/documents
- https://www.googleapis.com/auth/calendar
Add your Gmail address(es) as test users

These scopes permit writes and are unchanged by the CLI. Human consent is required during the separate OAuth onboarding flow.

SSE deployment

Set MCP_TRANSPORT=sse to force HTTP/SSE mode. If PORT is present, SSE mode starts automatically.
The SSE endpoint is /sse and message posts go to /messages. GET / returns a plain text health line.
For Railway, point the start command at npm start or node dist/index.js and let Railway provide PORT.

The SSE server has no authentication of its own. Anyone who can reach the port can use every configured account. Run it only on a private network or behind your own access control.

OAuth onboarding

Authenticate accounts directly through MCP tools:

Step 1: Start Authentication

Call the begin_account_auth tool with your OAuth credentials:

{
  "account_id": "personal",
  "email": "[email protected]",
  "credentials_json": {
    "installed": {
      "client_id": "YOUR_CLIENT_ID.apps.googleusercontent.com",
      "client_secret": "YOUR_CLIENT_SECRET",
      "redirect_uris": ["http://localhost"]
    }
  }
}

Or use a file path:

{
  "account_id": "personal",
  "email": "[email protected]",
  "credentials_path": "/path/to/credentials.json"
}

The tool returns a Google OAuth URL. Open this URL in your browser.

Step 2: Complete Authentication

In your browser, sign in with the Gmail account
Grant the requested permissions
Google redirects you to a localhost URL with a code parameter
Copy the authorization code from the URL

Call finish_account_auth:

{
  "account_id": "personal",
  "authorization_code": "4/0AfJoh..."
}

Your account is now authenticated and ready to use.

Usage

Example 1: Read Recent Emails from All Accounts

// Aggregates across all enabled accounts
{
  "max_results": 20,
  "include_body": true
}

// Returns emails with source account indicated

Example 2: Search Across Multiple Accounts

{
  "query": "from:[email protected] is:unread",
  "max_results": 10
}

// Searches all enabled accounts, merges and sorts results

Example 3: Send Email from Specific Account

{
  "account": "work",
  "to": "[email protected]",
  "subject": "Project Update",
  "body": "Here's the latest on the project...",
  "html": false
}

Example 4: Read Only from One Account

{
  "account": "personal",
  "max_results": 10,
  "query": "label:important"
}

Example 5: Manage Labels

// Create a new label
{
  "account": "personal",
  "name": "Urgent-2026"
}

// Add label to messages
{
  "account": "personal",
  "message_ids": ["msg123", "msg456"],
  "label_ids": ["Label_789"]
}

Example 6: Delete Drafts

// Delete one or more drafts by their draft IDs (returned by create_draft)
{
  "account": "personal",
  "draft_ids": ["r5457071851533655344", "r774137312565667821"]
}

Tools

All 60 tools, taken from the live registry (ghub tools). Kind is read, write, or auth. Parameters for the first Gmail tools are in docs/api-reference.md. For the exact input schema of any tool, run ghub schema TOOL.

Accounts and auth

Tool	Kind	What it does
`list_accounts`	read	List all configured Gmail inbox accounts and their authentication/health status.
`begin_account_auth`	auth	Start OAuth onboarding for an account.
`finish_account_auth`	auth	Complete OAuth onboarding by exchanging authorization code and storing token.json.

Gmail

Tool	Kind	What it does
`read_emails`	read	Read emails from one account or aggregate across all enabled accounts when account is omitted.
`search_emails`	read	Search Gmail using query syntax.
`get_email_thread`	read	Get a full email thread for one account.
`get_labels`	read	List labels for one account.
`mark_as_read`	write	Mark messages as read in one account.
`add_labels`	write	Add labels to messages in one account.
`remove_labels`	write	Remove labels from messages in one account.
`archive_emails`	write	Archive messages in one account by removing INBOX label.
`trash_emails`	write	Move messages to trash in one account.
`create_label`	write	Create a new Gmail label in one account.
`delete_label`	write	Delete a Gmail label in one account.
`block_sender`	write	Block a sender by creating a Gmail filter (same mechanism as Gmail's native "Block" button).
`list_blocked_senders`	read	List all Gmail filters for an account.
`unblock_sender`	write	Remove a Gmail filter.
`unsubscribe_from_email`	write	Unsubscribe from a mailing list by invoking the List-Unsubscribe header (RFC 2369/8058).
`mute_thread`	write	Mute a conversation: archives the thread now and (with scope="subject") installs a subject-based filter so future replies auto-archive.
`create_draft`	write	Create a draft email in one account.

Drive

Tool	Kind	What it does
`search_drive_files`	read	Search Google Drive file metadata.
`list_drive_files`	read	List Google Drive files.
`get_drive_file`	read	Get full metadata for a specific Google Drive file including size, parents, export links.
`get_drive_file_content`	read	Download a Drive file and extract its text content.
`upload_drive_file`	write	Upload a local file to Google Drive.
`create_drive_folder`	write	Create a new folder in Google Drive.
`update_drive_file`	write	Update a Drive file: rename it, move it between folders, star/unstar, or update its description.
`trash_drive_file`	write	Move a Google Drive file to trash.
`share_drive_file`	write	Share a Google Drive file by adding a permission.

Sheets

Tool	Kind	What it does
`sheets_get`	read	Get Google Sheets spreadsheet metadata: title, sheet tabs, row/column counts.
`sheets_read`	read	Read cell values from a Google Sheet range (e.g., "Sheet1!A1:D10" or "A1:D10" for the first sheet).
`sheets_write`	write	Write values to a Google Sheet range.
`sheets_append`	write	Append rows to a Google Sheet after the last row with data.
`sheets_create`	write	Create a new Google Sheets spreadsheet.
`sheets_add_tab`	write	Add a new sheet tab to an existing spreadsheet.
`sheets_rename_tab`	write	Rename a sheet tab in a spreadsheet.
`sheets_delete_tab`	write	Delete a sheet tab from a spreadsheet.
`sheets_format`	write	Apply formatting to a range of cells: bold, italic, font size, background/text color, alignment, number format, wrap strategy.
`sheets_add_chart`	write	Create a chart in a Google Sheet from a data range.
`sheets_insert_dimension`	write	Insert rows or columns into a sheet at a specified position.
`sheets_delete_dimension`	write	Delete rows or columns from a sheet.

Docs

Tool	Kind	What it does
`docs_get`	read	Get the full text content and title of a Google Doc.
`docs_create`	write	Create a new Google Doc.
`docs_append`	write	Append text to the end of a Google Doc.
`docs_replace_text`	write	Find and replace all occurrences of text throughout a Google Doc.
`docs_insert_table`	write	Insert an empty table at the end of a Google Doc.
`docs_apply_style`	write	Apply a heading or paragraph style to a text range in a Google Doc by character indices.

Calendar

Tool	Kind	What it does
`list_calendars`	read	List all Google Calendars for one or all enabled accounts.
`list_events`	read	List calendar events.
`get_event`	read	Get full details of a single calendar event.
`create_event`	write	Create a new calendar event.
`update_event`	write	Update an existing calendar event.
`delete_event`	write	Delete a calendar event.

Permissions and privacy

Scopes requested: full Gmail access (https://mail.google.com/), Gmail settings (filters), full Drive, Sheets, Docs, and Calendar. These allow reading and writing. ghub does not narrow them per tool.
What it can read: mail, attachments, Drive files, spreadsheets, documents, and calendar events in every account you onboard.
What it can change: send mail, delete drafts, trash mail, create and delete filters, upload, move, share, and trash Drive files, edit Sheets and Docs, and create, update, and delete events. There is no confirmation prompt in the server. Your MCP client's tool approval is the safety check.
Where data goes: ghub talks to Google's APIs and nothing else. It sends no telemetry. Content you read is returned to your MCP client or CLI caller, and from there to whichever model that client uses.
Where credentials live: OAuth client files and tokens are stored in plain JSON under the config directory (~/.gmail-multi-mcp by default). Protect that folder. credentials.json and token.json are git-ignored.
Local files: send_email and create_draft read attachment paths you give them, upload_drive_file reads a local file, and attachment tools save files to disk.

Using with agents

An agent can discover everything it needs at run time:

ghub tools                    # names, descriptions, read/write/auth kind
ghub schema search_emails     # input schema, output envelope, example
ghub call send_email --dry-run --input - <<'JSON'
{"account":"work","to":"[email protected]","subject":"Example","body":"Hello"}
JSON

Use --dry-run to validate a write before running it. Mutations never pick a default account. See docs/agent-cli.md for the JSON contract and exit codes, and docs/agent-cli-spec.md for the specification.

FAQ and troubleshooting

"Invalid grant" Error

This usually means your authorization code has expired. Authorization codes are single-use and expire after a few minutes.

Solution: Run begin_account_auth again to get a fresh OAuth URL and authorization code.

"Token has been expired or revoked"

Your refresh token is no longer valid.

Solution:

Delete the token.json file for the affected account
Run the OAuth flow again (begin_account_auth then finish_account_auth)

"Insufficient permissions"

The OAuth token doesn't have the required scopes.

Solution:

Check your Google Cloud OAuth consent screen has all required scopes
Review the current requested scopes, API enablement, and access to the specific resource.
If the grant is missing required scopes, have a human review consent and complete the separate OAuth flow again. CLI calls do not start this automatically.

Account Not Found

The specified account ID doesn't exist in accounts.json.

Solution:

Run list_accounts to see available accounts
Ensure you completed OAuth onboarding for the account
Check that the account is enabled: true in accounts.json

Rate Limiting

Gmail API has rate limits (daily quota and per-user quotas).

Solution:

Check your quota at Google Cloud Console
Implement exponential backoff in your application
Consider applying for increased quota if needed

Contributing

Read CONTRIBUTING.md. Report security problems as described in SECURITY.md. Everyone taking part follows the Code of Conduct. Agents working on the code should read AGENTS.md.

Docs: Agent CLI, CLI spec, API reference, Releases, Changelog.

License

MIT

Acknowledgments

Built with the Model Context Protocol SDK
Uses the Google APIs Node.js Client

Built by Tyler Szakacs.

이 서버 추가

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Ghub?

Does Ghub need an API key?

What transport does Ghub use?

When was Ghub last checked?

Documentation

ghub

Features

Install

Quick start

Client configuration

Configuration

Where data is stored

accounts.json format

Google Cloud setup

1. Create a Google Cloud Project

2. Enable Gmail API

3. Create OAuth 2.0 Credentials

4. OAuth Consent Screen Setup

SSE deployment

OAuth onboarding

Step 1: Start Authentication

Step 2: Complete Authentication

Usage

Example 1: Read Recent Emails from All Accounts

Example 2: Search Across Multiple Accounts

Example 3: Send Email from Specific Account

Example 4: Read Only from One Account

Example 5: Manage Labels

Example 6: Delete Drafts

Tools

Accounts and auth

Gmail

Drive

Sheets

Docs

Calendar

Permissions and privacy

Using with agents

FAQ and troubleshooting

"Invalid grant" Error

"Token has been expired or revoked"

"Insufficient permissions"

Account Not Found

Rate Limiting

Contributing

License

Acknowledgments