SendGrid MCP Server

A Python MCP (Model Context Protocol) server that lets an AI assistant send email and manage contacts through SendGrid's Web API v3.

Tools

Tool	Description
send_email	Send plain/HTML email to one or more recipients
get_template_info	Inspect a dynamic template's structure
send_template_email	Send via a dynamic template with substitution data
add_contact	Add/update a marketing contact (processed asynchronously by SendGrid)
search_contacts	Search contacts with a bounded SGQL query
get_contact_lists	List the named marketing contact lists
authenticate_domain	Start Domain Authentication for a new sending domain, returns DNS records to add
list_domain_authentications	List domains and their validation status
validate_domain_authentication	Re-check DNS after records are added
delete_domain_authentication	Remove a domain authentication

Setup

1. Create a virtual environment and install dependencies:

   python -m venv venv
   source venv/bin/activate   # Windows: venv\Scripts\activate
   pip install -r requirements.txt
   

2. Copy .env.example to .env and fill in your SendGrid API key (Settings > API Keys in the SendGrid dashboard) and default sender:

   cp .env.example .env
   

3. Verify your sender email under Settings > Sender Authentication in SendGrid before sending -- unverified senders will be rejected.

4. (Optional) Create a dynamic template under Email API > Dynamic Templates and set DEFAULT_TEMPLATE_ID in .env.

Running

python main.py

This runs the server over stdio, the transport MCP clients like Claude Desktop expect for a local subprocess.

Verifying it works

python smoke_test.py

Lists the registered tools and makes one live call against your SendGrid account. For interactive schema/tool inspection:

npx @modelcontextprotocol/inspector python main.py

Connecting to Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "sendgrid-mcp": {
      "command": "python",
      "args": ["/path/to/twilio-sendgrid-mcp/main.py"],
      "cwd": "/path/to/twilio-sendgrid-mcp",
      "env": {
        "SENDGRID_API_KEY": "SG.your-actual-api-key-here"
      }
    }
  }
}

Restart Claude Desktop afterward. If a tool call fails, check ~/Library/Logs/Claude/mcp*.log (macOS) for the server's stderr output.