Customer.io MCP Server

MCP server for Customer.io email delivery diagnosis. Provides tools for customer lookup, message history, suppression checks, and delivery diagnosis via the Customer.io App API.

Local Testing with Claude Code

1. Build the server:

cd apps/customerio-mcp
npm install && npm run build

2. Create .mcp.json in this directory (gitignored):

{
  "mcpServers": {
    "customerio-local": {
      "command": "node",
      "args": ["<absolute-path-to>/apps/customerio-mcp/dist/index.js"],
      "env": {
        "CUSTOMERIO_APP_KEY": "<your-cio-app-api-key>"
      }
    }
  }
}

3. Start a new Claude Code session from this directory. The MCP server will start automatically.

4. Test with queries like:

   • "Look up [email protected] in Customer.io"
   • "Check suppression status for [email protected]"
   • "Diagnose email delivery for [email protected]"

Environment Variables

| Variable | Required | Description | |----------|----------|-------------| | CUSTOMERIO_APP_KEY | Yes | Customer.io App API key (Bearer token) | | CUSTOMERIO_BEARER_TOKEN | No | Fallback alias for CUSTOMERIO_APP_KEY |

Tools

| Tool | Description | |------|-------------| | customerio_lookup_customer | Find customer by email, return profile and attributes | | customerio_get_messages | Get message history with optional date/template filters | | customerio_get_activities | Get activity log (deliveries, bounces, opens, clicks) | | customerio_check_suppression | Check if email is on bounce/unsubscribe/complaint lists | | customerio_remove_suppression | Remove a suppression (two-step confirmation required) | | customerio_diagnose_delivery | One-shot diagnosis: profile + messages + suppression status |