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A few MCP clients — ChatGPT, Claude.ai web, n8n — only accept remote MCP HTTPS URLs, not local stdio. The Kataven MCP server is stdio-only today, so you need a tunnel that exposes the local server publicly. This page is the recipe.
Direct stdio clients (Claude Desktop, Cursor, Windsurf, Zed, VS Code, JetBrains, Warp, Goose, Raycast) don’t need a tunnel — they spawn kataven-mcp as a local subprocess. Skip this page and go to your client’s setup guide.

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What you need

  • The kataven-mcp binary installed (pip install kataven-mcp). Full install: Install →.
  • An sk_live_ API key minted at hub.kataven.ai/settings → API Keys.
  • A tunneling tool. We’ll use ngrok below; alternatives in Stable URLs.
  • supergateway — a small npm package that bridges stdio MCP servers to SSE.

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The 30-second recipe

Your remote MCP URL is https://abc123.ngrok.app/sse — paste this into your AI client’s MCP config: That’s it. The AI client makes HTTPS requests to the ngrok URL, ngrok proxies to your local supergateway, supergateway pipes through to the stdio kataven-mcp subprocess.

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Stable URLs

Free ngrok URLs change every session and idle out. For day-to-day use, three better options:

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Option A — pinned ngrok subdomain (paid)

URL stays the same across restarts. Requires an ngrok paid plan.

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Option B — Cloudflare Tunnel (free, stable)

Quick mode gives a stable URL per machine without a Cloudflare account. For a permanent named tunnel, follow Cloudflare’s tunnel docs — this is the option we use internally.

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Option C — Tailscale Funnel

If you’re already running Tailscale on the machine:
Stable Tailscale-issued HTTPS URL, only your tailnet members can reach it (more private than ngrok).

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Running supergateway as a service

For a tunnel that survives reboots / terminal closes, daemonize supergateway. macOS launchd example:
Pair with a Cloudflare Named Tunnel (also daemonized via cloudflared service install) for a fully background setup.

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Security tradeoffs

  • Anyone with the public URL can call kataven-mcp during the session, gated only by the KATAVEN_API_KEY baked into the supergateway environment. The AI vendor (OpenAI, Anthropic, n8n) sees the URL but not the API key.
  • Random ngrok URLs are obscurity, not security. A determined attacker scanning subdomains could find them, though ephemeral free URLs make this impractical for short sessions. For team / production use, use a Cloudflare Named Tunnel with Cloudflare Access in front of it (free SSO gate) — see Cloudflare’s docs.
  • Shut the tunnel down when you’re not using it. kill the supergateway and ngrok processes when the session ends, or lean on KeepAlive: false in launchd.
Full risk model: Security.

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What’s next: hosted remote MCP

We’re working on a hosted Kataven MCP endpoint at mcp.kataven.ai — once shipped, you’ll skip the tunnel entirely and paste a Kataven-managed URL into ChatGPT / Claude.ai web / n8n directly. This page will update with the new pattern when it ships.

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See also