We scan your code for leaked secrets, then open the tunnel. Built for humans and the agents shipping with them.
AI coding tools put a public URL within reach in minutes — and the safety step got skipped. There's no layer between localhost and the internet that knows what's in your code.
The model takes the easy path and inlines an OpenAI key directly in App.tsx.
ngrok, a Cloudflare tunnel, a quick deploy — pick your flavor. None of them read your source.
Public URLs get crawled within minutes. Rotate-and-hope becomes the weekend plan.
One command. No config. No Docker. No vercel.json. It scans first, then opens the tunnel — and refuses to start if something critical is exposed.
flieger sits on top of Cloudflare's proven tunneling infrastructure. What's new is the gate — the thing that runs before the URL goes public.
--json for AI agentsDeterministic rules for the three ways vibe-coded apps get pwned most often. Every "my app leaked" thread on X starts with one of these.
Scans your source for OpenAI, Anthropic, Stripe, GitHub, Google, Slack, AWS keys. Flags plaintext hits so you can rotate before someone runs up your bill overnight.
Checks that .env is in .gitignore — and that it wasn't committed earlier in your history. If it was, flieger tells you exactly how to rotate and scrub.
Detects cors(), origin: '*', and friends — configs that let any site on the web call your API from a logged-in user's browser.
Tell it "ship this." It runs flieger share --json, reads the URL from a structured response, and paste-backs — with any security findings already triaged. Non-interactive. Exit codes that mean something.
Done. Live at my-recipe-app.flieger.app.
I also fixed one issue — your .env wasn't in .gitignore, so your Supabase service role key would have hit the next commit.
Tunnel stays up until you close this terminal.
The cost of a leak isn't theoretical — and the rate at which code is produced has jumped an order of magnitude. The safety layer has to keep up.
Scrapers hit new public subdomains in minutes, and rate limits don't save you on a fresh account.
Open CORS, missing auth, wide-open admin routes — "it's just a demo" is the exact time these ship.
Human review is no longer the last gate — so the gate has to be the tunnel itself.
Free covers the CLI and all three safety checks. Paid tiers add a stable subdomain and a deeper scan engine.
flieger share--json output*.trycloudflare.com URL*.flieger.app subdomainsyour-appflieger check --ci fails GitHub Actions on new leaksall plans · cancel anytime · EU VAT included
Can't find yours? Use the form below — you'll actually get a reply.
You can. ngrok and cloudflared give you a tunnel; they don't check your code for leaks before opening it. flieger's point is the safety pass that runs first — and the fact that it's one command instead of six flags.
No. All scans run locally. The tunnel forwards HTTP traffic between Cloudflare's edge and your dev server — flieger never reads, logs, or transmits your files. Open source: the published package is exactly what runs.
No tool will. flieger catches the three biggest, most-common ways vibe-coded apps leak — the ones on every postmortem thread. Deeper scans (RLS, rate-limit, cookie flags) are on the Pro roadmap. For the rest, you still need a human review — flieger just makes sure the obvious stuff never ships.
Yes. Free tunnels go through Cloudflare's Quick Tunnels, which are free for reasonable use. We don't charge for the free tier because there's nothing to charge for — no servers, bandwidth, or storage on our side.
The URL stops. Pro gives you a stable slug — your URL stays my-app.flieger.app across restarts — but the tunnel still needs your laptop running. Persistent 24/7 tunnels are on the roadmap.
Yes. The tunnel is language-agnostic. flieger auto-detects Next.js, Vite, SvelteKit, Nuxt, and Express; for anything else, pass --port 3000 (or whatever port your server is on).
Run flieger share --json in any agent environment — Claude Code, Cursor, Cline, Aider. You get a single JSON object with the URL, tier, and safety report. The tunnel keeps running until the agent kills it. A native MCP server is coming; for now stdout JSON is the contract.
Self-serve in your Lemon Squeezy customer portal — link is in your receipt. Cancel anytime; you keep Pro through the billing period. No calls, no emails, no dark patterns.
Bug reports, feature requests, "can you make it detect X" — drop a line. I read everything and usually reply within a day.