Crocodile

Peer-to-peer, end-to-end encrypted voice, video and text chat. Hang out like on Discord or TeamSpeak (spaces, text channels, voice rooms, friends, DMs, calls, screen sharing) with the privacy of Signal: your voice, video and messages go only between the people in the conversation. Servers never see them.

• Always E2E, always P2P. Voice frames and messages are encrypted on your device with ratcheting keys and post-quantum (ML-KEM) key exchange. For groups, the member with the best connection hosts a tiny relay that forwards ciphertext it cannot read, and a runner-up stands by to take over.
• Video calls and screen sharing. Turn your camera on in a call or a voice room, or share a screen or a window, sharp for text and slides or smooth for motion. People see cameras right away and choose which screens to watch, full screen or in a pop-out window. Encrypted end to end like voice.
• No passwords, no accounts to lose. Your account is a key pair; you get a recovery key once. Pick a name and you're in. Add your other computers by typing a short code.
• Works on strict networks too. If a direct connection is impossible you can opt in to relaying your (still encrypted) traffic through a volunteer server, only while a direct connection is impossible.
• Messages wait for offline friends. Your device keeps them until you're both online; optionally a server holds them sealed for up to a week.
• Files of any size, straight to your people. Pictures, videos and other files go directly from one member's device to another's, encrypted, never through a server, and resume if the connection drops. Anyone who has a file can pass it on, so it stays available after the sender goes offline.
• Community-run coordination. Volunteer coordination servers introduce peers, elect hosts and replicate signed public metadata among themselves. Your app picks the fastest one automatically and keeps a backup.
• Anyone can contribute a server. Tick "Host a coordination server" in the app, or run it with Docker.

Install

# macOS and Linux
curl -fsSL https://raw.githubusercontent.com/pwalda/crocodile/main/scripts/install.sh | sh

# Windows (PowerShell)
irm https://raw.githubusercontent.com/pwalda/crocodile/main/scripts/install.ps1 | iex

Or download the installer for your system from Releases (.exe, .dmg, .AppImage / .deb / .rpm). There is nothing to configure. Until the builds are code-signed, browser downloads show a one-time warning; see docs/DISTRIBUTION.md.

Mobile apps are on the roadmap.

Say hi in the Lounge, our public space for questions, feedback and trying out a call: with the app installed, open croc://join/ph4j2sg3g3pqhtmibl2pcrrzx5rs7bq77pac5in4yeurokm557vq or paste the code ph4j2sg3g3pqhtmibl2pcrrzx5rs7bq77pac5in4yeurokm557vq under + Space → Join a space.

Command line

crocodile sends and receives files from a terminal, for servers and scripts, straight to and from the people you'd send them to in the app:

npm install -g crocodile-cli
# or: curl -fsSL https://raw.githubusercontent.com/pwalda/crocodile/main/scripts/install.sh | sh -s -- --cli
crocodile link                    # use your account (or: crocodile init <name>)
crocodile send backup.tar.gz --to alice#1234
crocodile get --from bob#5678

See apps/cli.

How it works

directory ──► list of coordination servers ──► your app picks the fastest
coordination servers (mesh) ── signed metadata, presence, signalling, host election
peers ── WebRTC to the elected host's relay, carrying E2E-encrypted frames

Read ARCHITECTURE.md for the full design, docs/QA.md for testing and releases, and docs/SECURITY.md for the threat model.

Repository layout

Path	Contents
apps/desktop	Electron app (React + Tailwind UI) and packaging
apps/directory	Directory service
packages/coordinator	Coordination server (library + crocodile-coordinator CLI + Dockerfile)
packages/relay	Host relay (SFU run by the elected host peer)
packages/client-core	Platform-neutral client logic, E2E layer, voice engine
packages/crypto	Identities, signed records, sealed boxes, sender keys
packages/protocol	Wire formats and schemas
tests	Integration tests: server mesh, clients, real-browser WebRTC, Electron smoke test

Development

Requirements: Node.js 22+, pnpm 10 (corepack enable).

pnpm install
pnpm check                     # typecheck, lint, format and all tests (what CI runs)
pnpm qa:env                    # local directory + 3 coordination servers
pnpm qa:app alice bob          # app instances with separate profiles

# Run a local directory and coordination server, then the desktop app against them
pnpm dev:directory             # :7400  (set CROC_DIR_ALLOW_PRIVATE=1 for LAN URLs)
pnpm dev:coordinator -- --directory http://127.0.0.1:7400 --public-url http://127.0.0.1:7443
CROC_DIRECTORIES_OVERRIDE=http://127.0.0.1:7400 pnpm dev:desktop

Useful extras:

以上為 README 的開頭部分。其餘內容請閱讀原文。 檢視完整 README ↗