| File | Who it's for | |
|---|---|---|
| Windows | Relay-Setup-x64.exe | Windows 10/11. Installs for you alone — no admin prompt. |
| Windows 32-bit | Relay-Setup-x86.exe | Only if you know you need it. |
| Android | Relay-android-arm64-v8a.apk | Android 8.0+. Almost every phone since 2017. |
| Android (any device) | Relay-android-universal.apk | Bigger, works everywhere. Use this if the one above says "app not compatible". |
| Checksums | SHA256SUMS.txt | sha256sum -c SHA256SUMS.txt |
Windows warns on first run because the installer isn't code-signed yet — More info → Run anyway. If Android says "App not installed", this page covers every cause I've seen.
On your phone
- Turn on your hotspot — or put the phone and the PC on the same Wi-Fi.
- Open Relay and tap Start Sharing.
- The screen shows a QR code and a two-digit number.
On your PC
- Open Relay. It lists the phones sharing right now, each with the code it is showing — click yours. Or click Scan QR and hold the phone up to your webcam, or Enter the 2-digit code and type those two digits.
- Approve the request that appears on your phone.
That's it — your browser, your apps, everything goes through the phone. Press Disconnect when you're done and Windows goes back exactly as it was.
Fast Mode or Full Mode?
Fast Mode is the default and needs no permissions. It carries TCP — browsing, video, downloads, most apps.
Full Mode carries TCP and UDP, so games and some video calls work too. It uses WireGuard, and Windows asks for permission once when you connect, because creating a network adapter needs it. Only that one small tunnel process gets the permission — never the whole app.
Switch modes on the phone before you tap Start Sharing.
If something goes wrong
Relay tries to tell you what actually happened instead of showing "connection failed". Every error has a name and a next step — the full list is in docs/errors.md.
Both apps keep a local log you can read and share (Advanced → Logs). Nothing is ever uploaded on its own.
I kept ending up in the same place: laptop with no internet, phone with plenty. Windows hotspot refuses to start. USB tethering needs a driver. Third-party apps want a subscription, an account, and permission to see everything.
The connection was always right there. The problem was never the network — it was the setup.
So Relay has no accounts, no servers, no telemetry, no subscription. Your traffic goes phone → PC over your own Wi-Fi and touches nothing of mine. Scan a code and it works, and when it doesn't, it tells you why.
Fast Mode's transport is a SOCKS5 proxy with no password. That's a deliberate trade — Windows can't supply proxy credentials system-wide, and requiring them would break the "no configuration" promise that is the whole point.
So instead: your phone asks you before any computer is allowed through. The two-digit code just picks your phone out of the ones nearby; the approval is what keeps strangers out. Full Mode doesn't ask, because there the PC proves itself with a key that existed only inside your QR code.
Safe on your own hotspot. On shared or public Wi-Fi, prefer Full Mode. The full threat model is in SECURITY.md — including what Relay does not protect you from.
Every commit installs the real app on real Android images (API 30–36), drives it through its own UI, and pushes real bytes through the real proxy. The Windows client's own code runs against a live phone over adb. The real installer is installed, launched and uninstalled, with the system proxy checked at every stage. Full Mode's tunnel is brought up on a real WinTun adapter and a real WireGuard handshake is verified across it.
Then the published APK is installed on Android 11 through 16 — because a release nobody can install is not a release.
What hardware still has to prove is written down in docs/testing.md, not hidden.
| ⚡ Fast Mode (SOCKS5, TCP) | ✅ Shipping |
| 🚀 Full Mode (WireGuard, TCP + UDP) | ✅ Shipping — both platforms |
| 🔄 Auto-reconnect, actionable errors, EN + FA | ✅ Shipping |
| ✍️ Signed Windows installer | 🔨 Planned |
| 🍎 macOS client | 💭 Later |
Detail in docs/roadmap.md · CHANGELOG
Full-Stack Developer × Product Builder × Problem Solver
📍 Iran
I'm Mahdi. I don't build demos — I build the thing I needed, then keep working on it until it's good enough to hand to someone else.
Relay is exactly that. It began as my own frustration with a laptop that had no internet and a phone that did. Now it runs a device lab on every commit, ships on two platforms, and tells you the truth about what it can't do yet. That last part is the standard I hold my work to — I'd rather write down a limitation than let you discover it.
If Relay is useful to you, a ⭐ genuinely helps. If it breaks, tell me — I read everything.
🚀 Startup Legend — my community, where I share what I'm building, what broke, and what I learned fixing it.
Two apps and one shared contract. Android is Kotlin + Compose; Windows is .NET 8 + WinUI 3; Full Mode's tunnel is Go (wg/), used by both ends.
There is no local build required — CI is the build system (ADR-0004). Push and the pipeline builds, tests on real devices, and can cut a release.
android/ Kotlin + Compose windows/ .NET 8 + WinUI 3
wg/ WireGuard endpoint (Go) shared/ the cross-platform contract
docs/ architecture, ADRs, testing, errors
Start with docs/architecture.md and the ADRs — every significant decision is written down with the reasoning that produced it. CONTRIBUTING.md has the rest.