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Arcjet - MCP Server

Provides Arcjet context to AI agents via MCP, enabling access to teams, sites, and processed request data.

Installation

Add the following to your MCP client configuration file.

Configuration

{
  "mcpServers": {
    "arcjet-mcp": {
      "command": "node",
      "args": [
        "/PATH/TO/mcp/index.js"
      ],
      "env": {
        "ARCJET_API_KEY": "YOUR_KEY_HERE"
      }
    }
  }
}

Arcjet MCP Server provides AI agents with contextual information about processed requests to enable security-focused tooling in your apps. It exposes a simple, local server you can connect to from MCP clients to supply Arcjet context and retrieve enriched insights.

How to use

You connect to the Arcjet MCP server from your MCP client to retrieve contextual data about processed requests. Start by ensuring you have a running Arcjet session key to authorize the MCP server. Use the following local server configuration to enable the Arcjet MCP endpoint in your client tools.

In your MCP client, enable the Arcjet MCP server and provide the API key you obtained from Arcjet in your environment configuration. The Arcjet MCP server runs as a local process and communicates with your client to supply teams and sites information and other contextual data.

How to install

Prerequisites you need before installation:

- Node.js and npm installed on your machine

- A working Arcjet account to obtain a session key for the API key

Install and build steps you will run locally to prepare the MCP server integration:

# 1) Install dependencies for the MCP integration tooling
npm install

# 2) Build the MCP integration bundle
npm run build

Configuration and wiring

Configure the MCP client to connect to the Arcjet MCP server by creating or updating the mcp.json configuration. This file defines how the Arcjet MCP server is started and what environment variable it requires.

{
  "mcpServers": {
    "arcjet": {
      "command": "node",
      "args": ["/PATH/TO/mcp/index.js"],
      "env": {
        "ARCJET_API_KEY": "YOUR_KEY_HERE"
      }
    }
  }
}

Start and run tips

Placeholders in the config indicate where you point to the local MCP runtime script. Replace "/PATH/TO/mcp/index.js" with the absolute path to the index.js file produced by your build. For example, if you clone the project to your Downloads folder for a user named totoro, you might use "/Users/totoro/Downloads/mcp/index.js".

Ensure the arcjet MCP server shows as enabled in your MCP client settings and restart the server if needed to pick up changes.

Security and key management

Arcjet API keys are managed as a session key currently. You must obtain a session ID from your Arcjet account by logging in through your browser, then retrieve the value of the session cookie and place it in your mcp.json under ARCJET_API_KEY. This key authorizes the MCP server to access Arcjet context.

Get help

If you need help, join our support channels via Discord or contact the Arcjet team for assistance.