Shade

End-to-end encryption library implementing the Signal Protocol (X3DH + Double Ratchet) for TypeScript/Bun. Drop into any project — frontend, backend, mobile — to get forward secrecy, post-compromise recovery, and self-healing security.

What you get

• X3DH initial key agreement (works asynchronously via prekey bundles)
• Double Ratchet for per-message forward secrecy and post-compromise security
• Self-authenticated prekey server (Hono, Docker-ready) with rate limiting, metrics, health checks
• Persistent storage backends: SQLite (zero-config) and PostgreSQL (Drizzle)
• Identity rotation with grace period for old sessions
• Safety numbers (Signal-style fingerprints) for out-of-band verification
• Constant-time comparisons and memory zeroization for hardened operation
• Binary wire format that's significantly smaller than JSON
• Crash-safe — sessions survive container restarts, power outages, SIGKILL

Quick start

# In your project
bun add @shade/core @shade/crypto-web @shade/storage-sqlite

import { ShadeSessionManager } from '@shade/core';
import { SubtleCryptoProvider } from '@shade/crypto-web';
import { SQLiteStorage } from '@shade/storage-sqlite';

const crypto = new SubtleCryptoProvider();
const storage = new SQLiteStorage('/data/shade-client.db');

const manager = new ShadeSessionManager(crypto, storage);
await manager.initialize();

// Establish a session with a peer (after fetching their bundle)
await manager.initSessionFromBundle('bob', bobBundle);

// Encrypt
const envelope = await manager.encrypt('bob', 'Hello, encrypted world!');

// Decrypt
const plaintext = await manager.decrypt('alice', incomingEnvelope);

Architecture

                     Shade Prekey Server (Hono)
                              │
              POST /v1/keys/register (signed)
              GET  /v1/keys/bundle/:address
              POST /v1/keys/replenish (signed)
              DELETE /v1/keys/:address (signed)
                              │
        ┌─────────────────────┴─────────────────────┐
        │                                           │
    [Client A]                                  [Client B]
    ShadeSessionManager                         ShadeSessionManager
        │                                           │
        ├──── X3DH ────────────────────────────────►│
        │                                           │
        │◄──── Double Ratchet messages ────────────►│
        │                                           │
    SQLiteStorage / PostgresStorage             SQLiteStorage / PostgresStorage

Packages

Package	Purpose
@shade/core	Protocol logic (X3DH, Double Ratchet, session manager, errors)
@shade/crypto-web	SubtleCrypto + @noble/curves provider, in-memory storage
@shade/storage-sqlite	Persistent SQLite storage (zero-config, bun:sqlite)
@shade/storage-postgres	PostgreSQL storage with Drizzle for shared databases
@shade/server	Prekey server (Hono routes, auth, rate limit, health, metrics)
@shade/transport	HTTP + WebSocket transport wrappers with auto-encryption
@shade/proto	Compact binary wire format (smaller than JSON)

Security properties

Property	Description
Forward secrecy	Compromising a key cannot decrypt past messages
Post-compromise security	Self-heals after key compromise on next DH ratchet
Authentication	Ed25519 identity signatures on prekey server writes
Replay protection	±5 minute timestamp window on signed requests
Constant-time comparisons	Timing attacks on identity keys are blocked
Memory zeroization	Key material is zeroed after use (best-effort in JS)
Identity verification	Safety numbers (60 digits) for out-of-band comparison
Identity rotation	7-day grace period for old sessions during rotation

Documentation

• SECURITY.md — Reporting vulnerabilities, security policy
• THREAT-MODEL.md — Honest threat model and assumptions
• examples/ — Runnable example applications
• MIGRATION.md — How to replace existing crypto with Shade

Deployment

For containerized deployment (Docker/Dokploy):

services:
  shade-prekey:
    image: shade-prekey-server:latest
    ports:
      - "3900:3900"
    volumes:
      - shade-data:/data
    environment:
      - SHADE_PREKEY_DB_PATH=/data/shade-prekeys.db
volumes:
  shade-data:

The SQLite database persists to a Docker volume so all keys and prekey bundles survive restarts.

License

MIT