Resend MCP Server
Streamable HTTP MCP server for email and newsletter management via Resend.
Author: overment
[!WARNING]
This server gives an AI agent access to your email sending capabilities. Language models can make mistakes, misinterpret instructions, or send unintended emails. Always:
- MAKE SURE that the client you use with this MCP requires you to REVIEW and CONFIRM the action before use.
- Test with a small segment first
- Broadcasts are always scheduled (minimum 5 minutes ahead) so you can cancel if needed (default is 5 minutes)
- Set
RESEND_DEFAULT_FROM to a verified sender address
Motivation
Traditional email APIs require knowing exact IDs, segment structures, and API quirks. This server is designed so AI agents can:
- Send newsletters — broadcast to segments with proper formatting
- Manage subscribers — add, update, remove contacts in bulk
- Use human identifiers — segment names and emails, not UUIDs
- Handle formatting — automatic multipart emails (HTML + plain text)
- Track campaigns — view delivery status, cancel scheduled sends
The result: an agent that can reliably manage your newsletter without you touching the Resend dashboard.
Features
- ✅ Contacts — Add, update, remove, search contacts (bulk-capable, up to 100 per call)
- ✅ Segments — Create, list, delete segments and manage membership
- ✅ Send — Individual emails or broadcast to segments
- ✅ Campaigns — View history, check delivery status, cancel scheduled
- ✅ Templates — List available templates with variables
- ✅ Subscriptions — Topic opt-in/opt-out management
- ✅ Multipart Emails — Auto-generates HTML + plain text for best deliverability
- ✅ Dual Runtime — Node.js/Bun or Cloudflare Workers
Design Principles
- LLM-friendly: Task-oriented tools, not 1:1 API mirrors
- Bulk-first: Contact operations accept arrays by default
- Human identifiers: Use emails and segment names, not UUIDs
- Multipart by default: Plain text auto-generates HTML for proper rendering
- Clear feedback: Results include summaries and next-step suggestions
Server Instructions (What the Model Sees)
Use these tools to manage email contacts, segments, and send emails via Resend.
WORKFLOW:
1. find_contacts or segments(list) → discover existing data
2. upsert_contacts → add/update subscribers
3. send → individual email or broadcast to segment
4. campaigns(status) → track delivery
FORMATTING (for body):
- Use \n\n between paragraphs
- Use \n between list items
- Plain text is auto-converted to multipart (HTML + text) for proper rendering
IMPORTANT:
- Segment names are case-insensitive
- Templates must be published in Resend dashboard to use
- Broadcasts use segment name, not ID
Quick Start
Prerequisites
1. Install
cd resend-mcp
bun install
cp env.example .env
2. Configure
Get your Resend API key from resend.com/api-keys.
Edit .env:
PORT=3000
AUTH_ENABLED=true
AUTH_STRATEGY=bearer
# Generate with: openssl rand -hex 32
BEARER_TOKEN=your-random-auth-token
# Resend credentials
RESEND_API_KEY=re_your_resend_api_key
RESEND_DEFAULT_FROM=newsletter@yourdomain.com
3. Run
bun dev
# MCP: http://127.0.0.1:3000/mcp
4. Connect Client
Alice App:
- URL:
http://127.0.0.1:3000/mcp
- Type:
streamable-http
- Header:
Authorization: Bearer <your-BEARER_TOKEN>
Claude Desktop / Cursor:
{
"mcpServers": {
"resend": {
"command": "npx",
"args": ["mcp-remote", "http://localhost:3000/mcp", "--transport", "http-only"],
"env": { "NO_PROXY": "127.0.0.1,localhost" }
}
}
}
Tools
upsert_contacts
Add or update contacts in bulk. Creates if email doesn't exist, updates
... View full README on GitHub
