Add the Postmark MCP server to Claude Code

Config last verified Jun 1, 2026

The exact config to run Postmark in Claude Code — paste it in, restart, and the tools load.

Prerequisites

Claude Code installed.
POSTMARK_SERVER_TOKEN — Your Postmark server API token.
DEFAULT_SENDER_EMAIL — Default verified sender email address.
DEFAULT_MESSAGE_STREAM — Postmark message stream to send through (e.g., 'outbound').

Setup

1. Open `~/.claude.json`

2. Add this configuration

Add to ~/.claude.json

~/.claude.json

json

{
  "mcpServers": {
    "postmark": {
      "command": "node",
      "args": [
        "/path/to/postmark-mcp/index.js"
      ],
      "env": {
        "POSTMARK_SERVER_TOKEN": "<POSTMARK_SERVER_TOKEN>",
        "DEFAULT_SENDER_EMAIL": "<DEFAULT_SENDER_EMAIL>",
        "DEFAULT_MESSAGE_STREAM": "<DEFAULT_MESSAGE_STREAM>"
      }
    }
  }
}

Or via CLI

bash

claude mcp add postmark -- node /path/to/postmark-mcp/index.js

3. Restart Claude Code and confirm the Postmark tools load.

Gotchas

Claude Code stores MCP servers under an "mcpServers" object in ~/.claude.json. It also reads a project-scoped .mcp.json and supports adding servers from the command line with "claude mcp add". Each entry must declare either a "type" or a "command"; Claude Code refuses an entry that has neither. Remote servers connect natively over Streamable HTTP with OAuth.

← Back to the Postmark MCP server