Meet flash-tunnel

One command turns a local server into a shareable public preview. flash-tunnel detects your project, starts its server, connects it through Cloudflare Tunnel, and cleans up after you exit.

Use it to review a work in progress with a teammate, open a local app on a phone, or give a client a link to a demo without deploying a build first.

Early preview

flash-tunnel is currently in the 0.0.x stage. APIs and behavior may change. These docs describe the implementation in the project repository.

Two ways to share

	Quick mode	Named mode
Public address	Random *.trycloudflare.com URL	A hostname on your Cloudflare domain
Cloudflare account / token	Not required	Required
DNS management	No DNS record in your account	Creates and removes a CNAME record
Best for	Temporary demos, collaboration	Recognizable preview URLs
Start	npx flash-tunnel --mode quick	npx flash-tunnel --zone example.com

The default mode is named. Pass --mode quick explicitly when you want a token-free temporary URL. Quick URLs change between sessions.

What happens when you run it?

1. Detect the framework, package manager, startup script, and port.
2. Start the local server, serve a static directory, or attach to an existing URL.
3. Start a Cloudflare Tunnel; named mode also creates the tunnel and DNS record through the API.
4. Wait for the public URL to respond, then print the link.
5. On exit, stop the processes and remove session-owned cloud resources.

A detached watchdog and startup sweep help recover sessions after an interrupted exit. See cleanup and recovery for their limits and retry commands.

What you need

• Node.js 22.14 or newer.
• The cloudflared executable, available on your PATH or configured explicitly.
• A local project, a built static directory, or an already running HTTP server.
• For named mode: a Cloudflare account, an active domain, and an API token.

Start here

Create your first preview, connect your own domain, or look up a flag in the CLI reference.