@decentchat/protocol

Transport-agnostic protocol SDK for serverless, E2E-encrypted, CRDT-based P2P messaging. This is the core library behind DecentChat.

No servers required. Peers connect directly, encrypt everything end-to-end, and sync state using CRDTs and vector clocks. The protocol layer has no opinion about how peers find each other or how bytes move between them -- that's the transport's job.

What's in the box

• Identity -- BIP39 seed phrases, deterministic HD key derivation (P-256), device linking, recovery URIs
• Crypto -- ECDH + AES-GCM-256 encryption, ECDSA signatures, Double Ratchet (Signal-style forward secrecy), pre-key bundles
• CRDT + sync -- Vector clocks, message CRDTs, Negentropy set reconciliation for efficient sync
• Workspaces -- Multi-workspace management, channels, DMs, member directories, roles and permissions
• Messages -- Persistent message store (IndexedDB), offline queue with replay, custody tracking, delivery receipts
• Media -- Chunked file transfer, thumbnails, waveform generation, blob storage abstraction
• Invites -- Signed invite URIs with workspace/server metadata
• Security -- Rate limiting, message guards, peer authentication, handshake verification

Install

npm install @decentchat/protocol

The only runtime dependency is @noble/curves for elliptic curve crypto.

Quick start

import { SeedPhraseManager, IdentityManager, WorkspaceManager, PersistentStore } from '@decentchat/protocol';

// Generate a new identity from a 12-word seed phrase
const { mnemonic, keys } = await SeedPhraseManager.generate();

// Or restore from an existing phrase
const restored = await SeedPhraseManager.fromMnemonic('your twelve words ...');

The SDK is transport-agnostic. To actually connect peers, pair it with a transport implementation like @decentchat/transport-webrtc.

Build

npm run build    # compiles to dist/ via tsc
npm test         # runs the test suite (bun)

Both compiled JS (dist/) and raw TypeScript (src/) are included in the npm package. Bun users get direct .ts imports via the "bun" export condition.

Repository

This package lives in the decent-protocol/ directory of the DecentChat monorepo.

License

MIT