cindertunnel is a small native agent you run once and keep running. Pair with a friend one time — each side generates a key, the agent derives the same shared secret between you — and from then on you can tunnel a local server to them with no port forwarding, send files directly, and send encrypted chat messages, one-to-one or in small group rooms. No account beyond pairing itself, and no cloud relay sitting in the middle holding your traffic once a connection is made.
P2P Contacts — pair with a friend once, automatically or with a typed shared secret; every other feature below reuses that same paired relationship.
P2P Play — the original tunnel: one side hosts a local server, the other gets a new local port that bridges straight to it over a WebRTC DataChannel, opened via cinder-mediated signaling.
P2P Share — send a file straight to a friend, peer to peer, with no size uploaded to any server in between.
AES Relay Chat — end-to-end encrypted messages with a friend, or a small group room with several — delivered even when you're not both online at the same moment, since this one leg uses a relay-held encrypted mailbox rather than a live peer connection.
Both sides run the same small native binary. Play/Share open a direct WebRTC DataChannel between you, mediated only for the initial signaling handshake. Chat/Rooms instead write and poll a short-lived, encrypted mailbox on cinder's own relay — the relay only ever sees ciphertext and never holds a key, so it can't read anything either. Unlike everything else in this family, cindertunnel has no server-side presence of its own beyond that relay role — it's a tool you run, not a site you visit.
P2P Contacts, Share, and Chat/Rooms are free to use for anyone who installs the agent. The only thing that ever needs a key is hosting a Play tunnel: a one-year host-mode key, a single purchase — no account, no subscription, no recurring charge. Anyone joining your tunnel, or any of your friends, connects for free, no key needed on their end at all.
Power users (Linux/macOS): install or update with one command:
curl -fsSL https://cinderapps.org/cindertunnel/install.sh | bash
It verifies the download's checksum before installing, and is safe to re-run any time to pick up a newer version — or read the script first.
Windows: open PowerShell and run:
iwr -useb https://cinderapps.org/cindertunnel/install.ps1 | iex
Lets you pick an install folder (or just take the default), offers to start at login, and the running agent shows up as a system-tray icon — click it any time to reopen the web admin UI, or read the script first.
Not code-signed on any platform; your OS may warn you the first time, expected for now. Each download's checksum is computed server-side, from the file actually on disk — verify with sha256sum -c against the SHA256SUMS file in the same directory.