@tabnav/mcp-local-bridge

A local MCP server with one job: expose a site running on your own machine (e.g. localhost:3000) through a public HTTPS URL, via a Cloudflare Quick Tunnel — no Cloudflare account needed — so it can be scanned by Tabnav's tabnav-accessibility MCP server before you deploy it.

It doesn't talk to Tabnav's backend and doesn't need your API key. It only opens/closes tunnels; your AI agent chains the two servers together itself.

Install

Nothing to install ahead of time — npx fetches and runs the published package on demand:

npx -y @tabnav/mcp-local-bridge

You won't normally run that yourself; your MCP client runs it for you via the config below. It's shown here just so you can sanity-check it works (it starts an MCP server on stdio and waits — Ctrl+C to stop).

Setup

Add both servers to your MCP client's config (example shown for the JSON config format used by Claude Desktop and similar clients):

{
  "mcpServers": {
    "tabnav-accessibility": {
      "url": "https://api.tabnav.com/mcp/scanning",
      "headers": { "Authorization": "Bearer <your-tabnav-api-key>" }
    },
    "tabnav-local-bridge": {
      "command": "npx",
      "args": ["-y", "@tabnav/mcp-local-bridge"]
    }
  }
}

Requires Node.js to already be installed (npx ships with it). The first run downloads a small cloudflared binary for your platform automatically — no separate install step.

Usage

Once both servers are configured, just ask your agent in plain language, e.g. "scan my local site on port 3000 before I deploy it." It will:

1. Call expose_local_site on tabnav-local-bridge to get a public URL.
2. Call start_site_mapping / start_monitor_scan on tabnav-accessibility with that URL, exactly as it would for any other domain.
3. Optionally call stop_tunnel once scanning is done.

Tools

• expose_local_site({ port, host? }) → { publicUrl, port, host }. host defaults to localhost; set it to reach another device on your LAN (e.g. 192.168.1.223). Re-calling with the same port+host while its tunnel is still open returns the same URL.
• stop_tunnel({ port, host? }) → { port, host, stopped }. host must match what was passed to expose_local_site, if anything. Any tunnels still open when the bridge process exits are torn down automatically.

Security note

While a tunnel is open, anyone with the URL can reach your local site — the URL is unguessable but not authenticated. Don't leave one running against a build with real user data, and prefer stop_tunnel over letting it sit idle.