mcp-notify

mcp-notify is a minimal MCP server that sends Slack messages using a single tool called send_message. It supports two authentication modes: bot token mode (xoxb) and user-token mode (xoxc + cookie). In bot-token mode, messages are sent as the Slack app with appropriate branding; in user-token mode, each message includes a :robot_face: context block to indicate AI-assisted origin. The server uses Block Kit with a plain-text fallback and stores channel/user data in a SQLite cache to improve performance and enable concurrent access across multiple MCP instances.

Prerequisites:

• Node.js and npm installed
• Access to publish/run MCP servers (Claude Code configuration or your MCP client)

Installation steps:

1. Install the MCP server via npx in your environment (no global install required):

# Bot token (recommended for Slack apps)
npx -y @pilat/mcp-notify

or configure via Claude Code using the example config below (Bot token):

{
  "mcpServers": {
    "mcp-notify": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@pilat/mcp-notify"],
      "env": {
        "SLACK_MCP_BOT_TOKEN": "xoxb-..."
      }
    }
  }
}

2. If you prefer the user-token mode, supply the user token and cookie token in the environment:

SLACK_MCP_XOXC_TOKEN=xoxc-...
SLACK_MCP_XOXD_TOKEN=xoxd-...
npx -y @pilat/mcp-notify

3. If using the MCP via a YAML/JSON config (Claude Code), ensure the configuration is saved to your MCP config file (e.g., ~/.claude.json or .mcp.json):

{
  "mcpServers": {
    "mcp-notify": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@pilat/mcp-notify"],
      "env": {
        "SLACK_MCP_BOT_TOKEN": "xoxb-...",
        "SLACK_MCP_XOXC_TOKEN": "xoxc-...",
        "SLACK_MCP_XOXD_TOKEN": "xoxd-..."
      }
    }
  }
}

Tips and caveats:

• Do not set both bot token and user token environment variables simultaneously; the server expects one mode of authentication at a time.
• The data directory can be customized with SLACK_MCP_DATA_DIR; ensure the path is writable by the MCP process.
• The server uses a lightweight SQLite cache (WAL mode) to improve performance and enable concurrent access; monitor disk usage if you run many instances.
• For user-token mode, ensure you secure the xoxc token and the cookie value (d= token) as described in the README; exposure could allow misuse.
• If you need to update configuration, restart the MCP server to pick up new environment variables or token changes.
• This MCP focuses on a single send_message tool; if you need advanced features like reading channels or reacting, consider the full-featured Slack MCP server linked in the README.