Xmit

Remote MCP server for the Transmit email platform, deployed on Cloudflare Workers with OAuth 2.1 authentication.

Paste a URL into your MCP client. No install, no build, no binary.

Connect

Add to your MCP client config:

{
  "mcpServers": {
    "transmit": {
      "url": "https://mcp.xmit.sh/mcp"
    }
  }
}

The first time you connect, a browser window opens. Enter your Transmit API key (pm_live_*) to authorize. Tokens refresh automatically.

Tools (18)

Category	Tools
Email	send_email
Contacts	add_contact
Senders	list_senders, get_sender
Templates	list_templates, get_template, create_template, update_template, delete_template
Campaigns	list_campaigns, get_campaign, create_campaign, update_campaign, delete_campaign, duplicate_campaign
Lists	get_lists
Suppressions	list_suppressions, check_suppression

Prompts (2)

• create-campaign - Step-by-step campaign creation workflow
• create-template - Step-by-step template creation workflow

Development

pnpm install
pnpm dev

Starts a local dev server at http://localhost:8787. Visit / for the landing page, /mcp for the MCP endpoint.

Deploy

# Create KV namespace for OAuth tokens
wrangler kv namespace create OAUTH_KV

# Update wrangler.toml with the namespace ID, then:
pnpm deploy

Architecture

MCP Client -> mcp.xmit.sh (CF Worker, OAuth) -> api.xmit.sh (Transmit API)

• OAuthProvider from @cloudflare/workers-oauth-provider handles OAuth 2.1 (PKCE, client registration, token lifecycle)
• createMcpHandler from agents SDK handles MCP Streamable HTTP transport
• All tool calls proxy to api.xmit.sh using the user's API key stored in the OAuth grant

License

MIT