@afterrealism/dendri-y

Minimal Yjs provider on top of a Dendri P2P room. Bridges a Y.Doc (and optionally an Awareness instance) over Dendri's reserved __yjs topic.

Install

npm install @afterrealism/dendri-client @afterrealism/dendri-y yjs y-protocols

@afterrealism/dendri-client, yjs, and y-protocols are peer dependencies — bring your own to avoid dual instances breaking CRDT identity.

Usage

import { createDendriStore } from "@afterrealism/dendri-client";
import { DendriYjsProvider } from "@afterrealism/dendri-y";
import * as Y from "yjs";
import { Awareness } from "y-protocols/awareness";

const room = createDendriStore({
	host: "signal.example.com",
	port: 443,
	secure: true,
	path: "/",
});

const doc = new Y.Doc();
const awareness = new Awareness(doc);
const provider = new DendriYjsProvider({ room, doc, awareness });

room.join("my-room");

// ...later, during app cleanup
provider.destroy();
room.destroy();
doc.destroy();

The provider only depends on a small DendriRoomLike surface, so React, Vue, Svelte, and vanilla apps can use it with their normal UI reactivity.

Wire Format

Reserved topic: __yjs. Each frame is a single header byte followed by raw Yjs bytes:

| Byte | Type | Payload | | ---- | ----------- | ------------------------------------------- | | 0 | SyncStep1 | Y.encodeStateVector(doc) | | 1 | SyncStep2 | Y.encodeStateAsUpdate(doc, remoteVector) | | 2 | Update | Incremental update from doc.on('update') | | 3 | Awareness | encodeAwarenessUpdate(awareness, ids) |

On peer-join the new peer sends SyncStep1, the remote responds with SyncStep2, and both sides stream Update frames thereafter. Yjs updates are idempotent and commutative, so no delivery guarantees beyond Dendri's defaults are required.

Requires

• Dendri client >= 2.3.7 (for room.broadcastBinary())
• yjs ^13.6.0
• y-protocols ^1.0.0

License

Apache-2.0