Arcjet — Claude Code MCP server: security and setup
Connect an AI coding assistant to Arcjet to inspect requests, analyze traffic, and manage remote security rules.
claude mcp add --transport http mcp https://api.arcjet.com/mcpWhat Arcjet does
Once connected, the assistant can list Arcjet teams and sites, create a site, and retrieve its ARCJET_KEY. It can inspect request details, explain allow or deny decisions, check quota usage, and analyze traffic for unusual patterns. That gives you a way to investigate what happened to a request without leaving the assistant.
The server can assess the effect of DRY_RUN rules before promotion, and create, replace, promote, or delete remote rules. It connects over HTTP at https://api.arcjet.com/mcp and uses OAuth. In Claude Code, add it with claude mcp add --transport http arcjet https://api.arcjet.com/mcp; the first connection opens a browser sign-in. OAuth is required to access the Arcjet account.
What it helps with
- trace why an Arcjet request was denied
- filter a site's requests by outcome
- compare traffic with the previous period to spot anomalies
- check dry-run rule impact before switching to LIVE
- manage remote Arcjet rules without changing code
Example prompts for the agent
- Explain why this Arcjet request was denied and show the rules that ran.
- Analyze this site's traffic against the previous period and flag unusual patterns.
- Check the impact of the DRY_RUN rules before promoting them to LIVE.
How to install Arcjet
Platform CLI: remote server
claude mcp add --transport http mcp https://api.arcjet.com/mcpPlatform CLI: remote server
codex mcp add arcjet --url https://api.arcjet.com/mcpConfig file
{
"mcpServers": {
"arcjet": {
"url": "https://api.arcjet.com/mcp"
}
}
}Config file
{
"servers": {
"arcjet": {
"type": "http",
"url": "https://api.arcjet.com/mcp"
}
}
}Platform CLI: remote server
gemini mcp add -t http arcjet https://api.arcjet.com/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Arcjet
How do I install Arcjet in Claude Code?
Run claude mcp add --transport http arcjet https://api.arcjet.com/mcp. On the first connection, Claude Code opens a browser for OAuth sign-in.
What does Arcjet do?
It connects an AI assistant to Arcjet tools for inspecting requests, explaining security decisions, analyzing traffic, and managing remote rules.
Which clients support the Arcjet MCP server?
The listed clients include Claude Code, Codex, Cursor, GitHub Copilot, Windsurf, Cline, Zed, and Gemini CLI. The connection uses OAuth.
