Client Integration Guides

Connect the Mailofly MCP server to your AI editor with a single click or a quick configuration snippet. Mailofly MCP supports two transports:

Transport	Best for	Requires
Hosted URL (SSE)	Claude.ai, Smithery, web-based clients	Nothing — just a URL
Stdio (npx)	Cursor, Claude Desktop, Windsurf, Zed, VS Code	Node.js 18+

One-Click & Quick Add

Add to Cursor Add to Antigravity Add to Claude

Hosted URL (SSE) — Zero Install

For clients that accept an MCP server URL instead of a command, use the Mailofly hosted endpoint:

https://mcp.mailofly.com/sse

Pass your API key as a query parameter:

https://mcp.mailofly.com/sse?key=mf_live_your_api_key_here

The hosted server auto-suspends when idle and wakes instantly on connection. It runs across Singapore and London via Fly.io for low-latency access worldwide.

Claude.ai

Open claude.ai and go to Settings → Integrations.
Click Add Integration → Add custom integration.

Set the MCP Server URL to:

https://mcp.mailofly.com/sse?key=mf_live_your_api_key_here

Click Add. Mailofly tools appear automatically in your Claude.ai chats.

Smithery

Search for Mailofly on smithery.ai or configure directly with:

https://mcp.mailofly.com/sse?key=mf_live_your_api_key_here

Any SSE-Compatible Client

Any client that supports the MCP SSE transport can connect using the URL above. If your client requires separate SSE and POST endpoints:

Endpoint	URL
SSE (handshake)	`https://mcp.mailofly.com/sse?key=YOUR_KEY`
Messages (POST)	`https://mcp.mailofly.com/messages`

Include the Authorization: Bearer YOUR_API_KEY header on POST /messages requests.

Stdio (npx) — Local Editors

Select your environment below to view tailored installation options and configuration snippets:

Method A: One-Click Deep Link

Click the button below to trigger Cursor’s automated MCP installation dialog:

Method B: Project Configuration (Recommended)

Create or edit .cursor/mcp.json in your repository root:

{
  "mcpServers": {
    "mailofly": {
      "command": "npx",
      "args": ["-y", "@mailofly/mcp"],
      "env": {
        "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
      }
    }
  }
}

Method C: Global GUI Setup

Open Cursor Settings (Cmd + , on macOS or Ctrl + , on Windows).
Navigate to Features > MCP.
Click + Add New MCP Server.
Fill in:
- Name: mailofly
- Type: command
- Command: npx -y @mailofly/mcp
Add environment variable MAILOFLY_API_KEY.
Click Save.

Method A: Configuration File (Recommended)

Add the mailofly server to your global user configuration (~/.gemini/config/mcp_config.json on macOS/Linux, or %USERPROFILE%\.gemini\config\mcp_config.json on Windows):

{
  "mcpServers": {
    "mailofly": {
      "command": "npx",
      "args": ["-y", "@mailofly/mcp"],
      "env": {
        "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
      }
    }
  }
}

You can also define it at the project level in .gemini/antigravity-ide/mcp_config.json.

Method B: Antigravity CLI

If you have the Antigravity CLI (agy) installed in your PATH:

agy mcp add mailofly -- npx -y @mailofly/mcp

Antigravity autonomous agents automatically detect Mailofly tools during execution loops, allowing agents to check sending quotas, review delivery logs, or trigger test emails autonomously.

Method A: Claude Code (CLI)

If you use Claude Code in your terminal, add Mailofly with a single command:

claude mcp add mailofly -- npx -y @mailofly/mcp

Method B: Claude Desktop Configuration

Locate your claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

Add mailofly to the mcpServers object:

{
  "mcpServers": {
    "mailofly": {
      "command": "npx",
      "args": ["-y", "@mailofly/mcp"],
      "env": {
        "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
      }
    }
  }
}

Restart Claude Desktop after saving. You will see a hammer icon 🔨 in the chat box showing that Mailofly tools are active.

Cascade MCP Configuration

Open Windsurf Settings (Cmd + , or Ctrl + ,).
Navigate to Advanced Settings > Cascade > Model Context Protocol (MCP), or edit ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "mailofly": {
      "command": "npx",
      "args": ["-y", "@mailofly/mcp"],
      "env": {
        "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
      }
    }
  }
}

Extension Configuration

In VS Code with Cline or Roo Code installed:Open cline_mcp_settings.json (accessible by clicking the MCP icon in the extension sidebar) and add:

{
  "mcpServers": {
    "mailofly": {
      "command": "npx",
      "args": ["-y", "@mailofly/mcp"],
      "env": {
        "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
      }
    }
  }
}

Zed Assistant Configuration

Open your Zed settings (~/.config/zed/settings.json) and configure the experimental MCP transport:

{
  "experimental": {
    "model_context_protocol": {
      "servers": {
        "mailofly": {
          "command": "npx",
          "args": ["-y", "@mailofly/mcp"],
          "env": {
            "MAILOFLY_API_KEY": "mf_live_your_api_key_here"
          }
        }
      }
    }
  }
}

Verifying Your Connection

Once configured in any client, start a new chat with your AI assistant and enter:

"Check my Mailofly email sending quota and list verified domains."

Your assistant will immediately invoke mailofly_get_usage and mailofly_list_domains, returning live status data from your account!

Get started

Learn

MCP Server

Integrations

Resources

Client Integration Guides

Client Integration Guides

One-Click & Quick Add

Hosted URL (SSE) — Zero Install

Claude.ai

Smithery

Any SSE-Compatible Client

Stdio (npx) — Local Editors

Method A: One-Click Deep Link

Method B: Project Configuration (Recommended)

Method C: Global GUI Setup

Method A: Configuration File (Recommended)

Method B: Antigravity CLI

Method A: Claude Code (CLI)

Method B: Claude Desktop Configuration

Cascade MCP Configuration

Extension Configuration

Zed Assistant Configuration

Verifying Your Connection

​Client Integration Guides

​One-Click & Quick Add

​Hosted URL (SSE) — Zero Install

​Claude.ai

​Smithery

​Any SSE-Compatible Client

​Stdio (npx) — Local Editors

​Method A: One-Click Deep Link

​Method B: Project Configuration (Recommended)

​Method C: Global GUI Setup

​Method A: Configuration File (Recommended)

​Method B: Antigravity CLI

​Method A: Claude Code (CLI)

​Method B: Claude Desktop Configuration

​Cascade MCP Configuration

​Extension Configuration

​Zed Assistant Configuration

​Verifying Your Connection

Client Integration Guides

One-Click & Quick Add

Hosted URL (SSE) — Zero Install

Claude.ai

Smithery

Any SSE-Compatible Client

Stdio (npx) — Local Editors

Method A: One-Click Deep Link

Method B: Project Configuration (Recommended)

Method C: Global GUI Setup

Method A: Configuration File (Recommended)

Method B: Antigravity CLI

Method A: Claude Code (CLI)

Method B: Claude Desktop Configuration

Cascade MCP Configuration

Extension Configuration

Zed Assistant Configuration

Verifying Your Connection