Connect Nylas Email and Calendar to Manus MCP

What this guide covers

manus-mcp-cli is the command-line interface built into the Manus AI sandbox for managing Model Context Protocol (MCP) server connections. MCP is a standard that lets AI agents call external tools through a typed, discoverable interface. In this guide, the specific goal is to register nylas mcp serve so Manus can discover Nylas email and calendar tools automatically. If you need generic Manus MCP coverage for other servers, this page is intentionally narrower than that.

Confirm manus-mcp-cli is available in Manus

manus-mcp-cli comes pre-installed in every Manus sandbox environment. You do not need to install it separately. When Manus creates a sandbox for your task, the binary is already on the PATH. You can verify it is available by asking Manus to check the version, or by running the command directly in a Manus code block.

# Verify manus-mcp-cli is available
manus-mcp-cli --version

# List currently registered servers
manus-mcp-cli list servers

If you are working outside the Manus sandbox (for example, testing locally), you will not have access to manus-mcp-cli directly. In that case, use the Nylas CLI's own nylas mcp install command to register with your local AI assistant instead. See the MCP setup guide for local configuration.

Register the Nylas MCP server with manus-mcp-cli

Registering an MCP server tells Manus where to find the Nylas binary, what arguments to pass, and what environment variables it needs. Once registered, Manus automatically discovers the Nylas tools and makes them available during your conversation. The registration uses a JSON configuration object that follows the MCP server specification.

# Register a server with inline JSON config
manus-mcp-cli register server --config '{
  "name": "nylas",
  "command": "nylas",
  "args": ["mcp", "serve"],
  "env": {}
}'

You can also register from a configuration file, which is cleaner for complex setups with multiple servers or environment variables.

# Register from a config file
manus-mcp-cli register server --config-file /path/to/mcp-config.json

After registration, verify the server appears in the list and that Manus can discover its tools:

# List registered servers
manus-mcp-cli list servers

# List tools exposed by the nylas server
manus-mcp-cli list tools --server nylas

Install and register Nylas CLI as a Manus MCP server

The Nylas CLI has a built-in MCP server mode that exposes 16 email and calendar tools through the Model Context Protocol. To use it with manus-mcp-cli, you first install and configure the Nylas CLI inside the Manus sandbox, then register it as an MCP server. This gives your Manus agent full email and calendar access through structured tool calls.

# Step 1: Install the Nylas CLI in the Manus sandbox
curl -fsSL https://cli.nylas.com/install.sh | bash
export PATH="$PATH:$HOME/.nylas/bin"

# Step 2: Configure your Nylas API key
nylas auth config --api-key YOUR_NYLAS_API_KEY

# Step 3: Register the Nylas CLI as an MCP server
manus-mcp-cli register server --config '{
  "name": "nylas",
  "command": "nylas",
  "args": ["mcp", "serve"],
  "env": {
    "PATH": "/usr/local/bin:/usr/bin:/bin:$HOME/.nylas/bin"
  }
}'

The full JSON configuration for the Nylas MCP server looks like this. Save it as nylas-mcp.json for reuse across sessions:

{
  "name": "nylas",
  "command": "nylas",
  "args": ["mcp", "serve"],
  "env": {
    "PATH": "/usr/local/bin:/usr/bin:/bin:$HOME/.nylas/bin"
  },
  "description": "Email and calendar tools via Nylas CLI",
  "timeout": 30000
}

Once registered, your Manus agent has access to tools like nylas_send_email, nylas_list_emails,nylas_create_event, and nylas_check_availability. See the command reference for the full list.

Send email through the Nylas MCP server

After registering the Nylas CLI as an MCP server, you can send email either through natural language prompts to your Manus agent or by calling the MCP tool directly. The agent automatically selects the nylas_send_email tool when you ask it to send a message. For direct invocation, use the manus-mcp-cli call command.

# Send email via manus-mcp-cli tool call
manus-mcp-cli call nylas nylas_send_email '{
  "to": "recipient@example.com",
  "subject": "Weekly report",
  "body": "Hi team, here is the weekly status update.",
  "reply_to": "me@example.com"
}'

For HTML email with attachments:

# Send HTML email with an attachment
manus-mcp-cli call nylas nylas_send_email '{
  "to": "client@example.com",
  "subject": "Project proposal",
  "body": "<h1>Proposal</h1><p>Please find the proposal attached.</p>",
  "content_type": "text/html",
  "attach": ["/tmp/proposal.pdf"]
}'

You can also ask Manus in natural language: “Send an email to alice@example.com with the meeting notes from today.” Manus will compose the message and call the MCP tool. It will ask for confirmation before sending unless you include --yes in the tool configuration.

Configure Gmail for Nylas in Manus

In the Manus sandbox, Gmail access comes from the grants already connected to your Nylas application. Configure the CLI once with your API key, verify that a Gmail-connected grant appears in nylas auth list, and the MCP server uses that connected mailbox automatically.

# Configure your API key once in Manus
nylas auth config --api-key YOUR_NYLAS_API_KEY

# Verify that a Gmail-connected grant is available
nylas auth list

# The MCP server auto-detects your Gmail grant
manus-mcp-cli call nylas nylas_list_emails '{
  "limit": 5,
  "folders": ["INBOX"]
}'

Configure Yahoo Mail for Nylas in Manus

Yahoo Mail works the same way as Gmail in Manus: connect the Yahoo account to your Nylas application in the dashboard, configure the CLI with the same API key inside the sandbox, and let the MCP server use the connected grant automatically.

# Configure your API key once in Manus
nylas auth config --api-key YOUR_NYLAS_API_KEY

# Verify that a Yahoo-connected grant is available
nylas auth list

# Read Yahoo inbox through manus-mcp-cli
manus-mcp-cli call nylas nylas_list_emails '{
  "limit": 10,
  "query": "from:support@yahoo.com"
}'

Configure Exchange and Microsoft 365 for Nylas in Manus

Microsoft 365 and Exchange access also come from the grants already connected to your Nylas application. In the Manus sandbox, use the API key for that application, then verify the relevant Microsoft-connected grant is available before calling the MCP tools.

# Configure your API key once in Manus
nylas auth config --api-key YOUR_NYLAS_API_KEY

# Verify that a Microsoft-connected grant is available
nylas auth list

# Search Exchange mailbox through manus-mcp-cli
manus-mcp-cli call nylas nylas_list_emails '{
  "query": "subject:quarterly review",
  "limit": 20
}'

# Create a calendar event
manus-mcp-cli call nylas nylas_create_event '{
  "title": "Sprint planning",
  "start": "2026-03-17T10:00:00",
  "end": "2026-03-17T11:00:00",
  "participants": ["team@company.com"]
}'

Should you add a Manus Skill alongside the Nylas MCP server?

Beyond MCP servers, manus-mcp-cli can register Skills, which are instruction packages that teach your Manus agent specific workflows. Skills complement MCP by providing procedural knowledge. While MCP gives the agent tools, Skills tell the agent when and how to use those tools for a specific task.

# Register a Nylas email skill
manus-mcp-cli register skill --path /path/to/nylas-email-skill/

# The skill directory should contain SKILL.md:
# nylas-email-skill/
#   SKILL.md         <- Instructions and metadata
#   scripts/
#     setup.sh       <- Install and auth Nylas CLI
#     send-email.sh  <- Email sending wrapper
#   references/
#     tools.md       <- Available MCP tools

For a complete walkthrough of creating a Manus Skill for email and calendar, see the Manus AI Skills guide.

Example Nylas MCP server configurations for Manus

Server configurations are JSON objects that follow the MCP specification. Here are the most common Nylas-specific patterns: a default server, a region-specific server, and a grant-pinned server for multi-account routing.

{
  "servers": [
    {
      "name": "nylas",
      "command": "nylas",
      "args": ["mcp", "serve"],
      "env": {
        "PATH": "/usr/local/bin:/usr/bin:/bin:$HOME/.nylas/bin"
      },
      "description": "Email and calendar tools",
      "timeout": 30000
    },
    {
      "name": "nylas-eu",
      "command": "nylas",
      "args": ["mcp", "serve", "--region", "eu"],
      "env": {
        "PATH": "/usr/local/bin:/usr/bin:/bin:$HOME/.nylas/bin"
      },
      "description": "Email and calendar tools (EU region)",
      "timeout": 30000
    }
  ]
}

For multi-account setups where you need to route to specific grants:

{
  "name": "nylas-work",
  "command": "nylas",
  "args": ["mcp", "serve", "--grant", "work@company.com"],
  "env": {
    "PATH": "/usr/local/bin:/usr/bin:/bin:$HOME/.nylas/bin"
  },
  "description": "Work email and calendar"
}

Nylas MCP vs Manus Skills vs direct Nylas CLI

There are three ways to give your Manus agent email and calendar access. Each has trade-offs. The right choice depends on whether you want structured tool access, procedural automation, or maximum flexibility. Here is a side-by-side comparison.

For most Manus users, the recommended approach is MCP via manus-mcp-cli for tool access, combined with a Skill for any multi-step workflows you repeat often. See the Skills guide and the MCP guide for the full setup of each approach.

Troubleshooting Nylas MCP setup in Manus

Here are the most common problems when setting up manus-mcp-cli with the Nylas CLI, and how to fix them.

Server not found after registration

The most common cause is a PATH issue. The Nylas CLI binary needs to be on the PATH that manus-mcp-cli uses when spawning the server process. Include the full PATH in your server configuration.

# Check if nylas is on the PATH
which nylas

# If not found, add it
export PATH="$PATH:$HOME/.nylas/bin"

# Re-register with explicit PATH in env
manus-mcp-cli register server --config '{
  "name": "nylas",
  "command": "/home/user/.nylas/bin/nylas",
  "args": ["mcp", "serve"],
  "env": {
    "PATH": "/usr/local/bin:/usr/bin:/bin:/home/user/.nylas/bin"
  }
}'

No authenticated grants found

The MCP server requires at least one connected grant on the Nylas application behind your API key. Run nylas auth config --api-key YOUR_NYLAS_API_KEY, then verify with nylas auth list.

# Check existing grants
nylas auth list

# If empty, configure your Nylas API key
nylas auth config --api-key YOUR_NYLAS_API_KEY

# Then test the MCP server manually
echo '{"jsonrpc":"2.0","method":"initialize","id":1,"params":{"capabilities":{}}}' | nylas mcp serve

Tool calls timing out

Increase the timeout in your server configuration. The default may be too low for operations that involve large mailboxes or slow network connections. Set it to 30000ms (30 seconds) or higher.

Wrong email account used

If you have multiple authenticated grants, the MCP server picks the first one by default. Specify the grant explicitly in the server args to route to a specific account.

# Register with a specific grant
manus-mcp-cli register server --config '{
  "name": "nylas-personal",
  "command": "nylas",
  "args": ["mcp", "serve", "--grant", "personal@gmail.com"],
  "env": {}
}'

Next steps

• Create a Manus Skill for Email and Calendar for reusable multi-step workflows
• Give AI Agents Email Access via MCP for local setup with Claude Desktop, Cursor, or VS Code
• Automate Email with Manus AI: Beginner Guide if you are new to Manus
• Command Reference for the complete list of CLI commands and MCP tools