Always connects
When a direct WebRTC path is blocked, Dendri falls back through STUN, then TURN, then an encrypted TLS relay. The connection just happens.
Realtime for your app, on your server.
Presence, cursors, chat, video, and live document sync over peer-to-peer WebRTC. One small SDK, any framework, self-hosted and free.
app.ts
// npm install @afterrealism/dendri-client
import { createDendriStore }
from "@afterrealism/dendri-client";
const room = createDendriStore({
url: "wss://signal.example.com", // yours
});
room.join("design-review");
room.broadcast({ cursor: { x, y } });
// every peer sees it, instantlyWhy Dendri
Ship it in an afternoon
One createDendriStore() call gives you rooms, presence, and messaging, with drop-in bindings for React, Vue, and Svelte.
No message tax
After the handshake, data flows directly between peers. Nobody meters your messages, because nobody carries them.
Self-host first
The server is open source (AGPL-3.0) and yours to run — free forever, no vendor lock-in, no metering.
The hard parts, handled.
Reconnection, NAT traversal, encryption, and document sync are built in, not homework.
End-to-end encrypted relay
On the last tier, payloads are sealed with ECDH and AES-GCM before they touch the server. It relays bytes it cannot read.
Rooms & presence
Star-topology rooms with host migration and typed presence for every peer.
Video & audio
Media calls ride the same room primitives as data.
Yjs document sync
A first-class CRDT provider for collaborative editing.
Auto-reconnect
Exponential backoff, offline queueing, seamless resume.
See it live, peer to peer.
Eleven demos, every one deployed against the production stack. Open one in two tabs, watch them sync, then read the source.
Three steps to live.
No backend to write, no protocol to learn. The store is the whole API surface for most apps.
-
Install
Add the framework-neutral client to your app.
npm install @afterrealism/dendri-client -
Connect
Point it at your server. That's the whole config.
createDendriStore({ url }) -
Build
Join a room and broadcast. Peers update live.
room.join("lobby")
Built for peer-to-peer work.
Production-grade P2P signaling: the layer between a weekend library and a full video platform.
Collaborative apps
Cursors, presence, and Yjs document sync for whiteboards, editors, and design tools. Rooms and presence are first-class, not an add-on.
Collaborative editing guide →Multiplayer games
Host authority, deterministic host migration, and typed RPC between peers. Close the host tab and the game keeps running.
View the game source →Private file transfer
Files move directly between browsers. When the relay tier kicks in, payloads stay sealed end to end; the server cannot read them.
View the file-transfer source →Coming from PeerJS
The API will feel familiar: connect(), call(), the same events. You gain reconnection that keeps your ID, transport fallback, and a maintained server.
Read the migration guide →Where Dendri fits.
An honest map of the landscape. Sometimes another tool is the right call.
| Dendri | PeerJS | Liveblocks / PartyKit | LiveKit / Daily | |
|---|---|---|---|---|
| Model | Self-host-first P2P signaling | Library + best-effort free cloud | Hosted collaboration SaaS | Managed video platform (SFU) |
| Rooms & presence | Built in | None | Built in | Built in |
| Connection fallback | P2P, STUN, TURN, encrypted relay | None | Server-relayed by design | SFU-routed by design |
| Pricing model | Free and open source | Free | Usage-based | Per participant-minute |
| Sweet spot | Data rooms up to 50 peers; video calls 2-6 | Demos and prototypes | Hosted collab apps | Large video conferences |
Building 10+ person video conferences? That is SFU territory: LiveKit or Daily will serve you better.
Free. Open source. Yours.
There is no paid tier and nothing to buy. The server is AGPL-3.0, the SDKs are Apache-2.0, and every feature runs in the open-source binary you deploy — no gates, no metering, no lock-in.
Questions, answered.
Is the SDK license safe for commercial apps?
Yes. The client SDKs (@afterrealism/dendri-client, @afterrealism/dendri-y) are Apache-2.0: embed them in anything, closed source included. AGPL-3.0 covers only the signaling server: run it freely, and if you modify it and offer it as a network service, publish those modifications. Your application code never inherits AGPL.
Do I have to run my own server?
Yes — that's the whole idea. The open-source server is free, AGPL-licensed, and runs anywhere from a $5 VPS to Kubernetes. The SDK ships no default endpoint: every app points at a URL you configure, so there is no hidden dependency on anyone's infrastructure.
What happens on hostile networks?
Connections fall back through STUN, TURN, and an end-to-end encrypted TLS relay. Signaling itself falls back from WebSocket to SSE to long-polling. If the browser can reach the web, Dendri connects.
Can the server read my data?
On the P2P tiers it never sees payloads. On the relay tier, payloads are sealed in the browser with ECDH and AES-GCM before they leave; the server relays bytes it cannot decrypt.
How many peers can share a room?
Rooms are star-topology: the host fans out to everyone else. Data rooms hold up to 50 peers by default (configurable with --max_room_size); for video calls plan for 2 to 6 peers. Beyond that you want an SFU platform, not P2P.
Do I need to set up TURN?
Only for the strictest networks. The server mints short-lived TURN credentials when started with --turn-secret (enable fetchTurnCredentials in the client); the self-hosting guide covers running coturn alongside it.
Self-host realtime today.
Run the open-source server on your own infrastructure — free forever, AGPL-licensed, no vendor lock-in, nothing to buy.