VaultChat — E2EE Messaging Relay

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Overview

VaultChat is a self-hosted, end-to-end encrypted messaging relay.
The server is opaque — it never reads, stores, or processes any plaintext.
All encryption happens client-side using AES-256-GCM, ECDH P-256 and ECDSA P-256.

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Features

Algorithm	Usage
AES-256-GCM	Message & file encryption
ECDH P-256	Key agreement (pairwise & sealed)
ECDSA P-256	Identity signatures
HKDF-SHA-256	Key derivation

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Feature	Description
Direct Messages	1-to-1 encrypted conversations
Group Chats	Multi-member with shared group key
File Sharing	Encrypted file upload & download (20 MB max)
GIF Picker	Integrated search via Gifukai & Openverse
Emoji Picker	Full emoji panel with categories
GIF Favorites	Save and reuse favorite GIFs

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Feature	Description
Zero-Knowledge	Server never sees plaintext data
Signed Requests	Every API call is identity-signed
Rate Limiting	Sliding-window per-route limits
CSP + Helmet	Strict Content Security Policy
HSTS	Enforced in production
ID Validation	Strict format checks on all identifiers

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Feature	Description
WebSocket	Instant message delivery
Polling Backup	Light 12s fallback polling
Notifications	Browser push notifications

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Feature	Description
Bilingual	French & English (live switch)
Responsive	Desktop & mobile layout
Dark Theme	Modern dark UI
Custom Dialogs	No native browser alerts
Password Manager	Auto-fill compatible login
Session Resume	Instant reload without flash

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How It Works

Client generates identity keys (ECDSA + ECDH)
        ↓
Vault encrypted with login key (AES-256-GCM)
        ↓
Sealed envelopes sent through opaque relay
        ↓
Recipient decrypts with their private key
        ↓
Server only stores encrypted blobs + indexes

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Requirements

Requirement	Details
Node.js	>= 18.0.0
PM2	Recommended for production
SQLite	Via Prisma (auto-managed)
Browser	Modern browser with Web Crypto API

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Setup

1. Clone the repository
2. Edit config.json (project name, logo, credits)
3. npm install
4. npm start

Install

git clone https://github.com/Kurama250/VaultChat.git
cd VaultChat
npm install

Start with PM2

npm install -g pm2

pm2 start server/index.js --name vaultchat
pm2 save
pm2 startup

PM2 commands

pm2 status              # Check process status
pm2 logs vaultchat      # Live logs
pm2 restart vaultchat   # Restart after config change
pm2 stop vaultchat      # Stop the relay
pm2 delete vaultchat    # Remove from PM2

config.json

{
  "name": "Chat.kurama.info",
  "logo": "/img/kurama.png",
  "url": "https://chat.kurama.info",
  "credits": {
    "author": "Kurama",
    "github": "https://github.com/Kurama250/"
  }
}

Change the project name and logo here — the entire UI updates automatically.

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Scripts

Command	Description
npm start	Push DB schema & start server
npm run dev	Dev mode with auto-reload
pm2 start server/index.js --name vaultchat	Production with PM2

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Project Structure

VaultChat/
├── config.json
├── package.json
├── prisma/
│   └── schema.prisma
├── server/
│   ├── index.js
│   ├── core/
│   │   ├── db.js
│   │   ├── paths.js
│   │   ├── config.js
│   │   └── verify.js
│   ├── middleware/
│   │   ├── auth.js
│   │   └── security.js
│   ├── data/
│   │   └── store.js
│   ├── services/
│   │   ├── avatar.js
│   │   ├── profile.js
│   │   └── gifs.js
│   └── routes/
│       ├── http.js
│       └── ws.js
├── client/
│   ├── index.html
│   ├── styles.css
│   └── js/
│       ├── app.js
│       ├── boot-early.js
│       ├── core/
│       │   ├── state.js
│       │   ├── util.js
│       │   ├── vault.js
│       │   ├── api.js
│       │   ├── crypto.js
│       │   ├── idb.js
│       │   ├── i18n.js
│       │   ├── profile.js
│       │   └── media.js
│       ├── chat/
│       │   ├── session.js
│       │   ├── protocol.js
│       │   ├── conversations.js
│       │   ├── contacts.js
│       │   └── messages.js
│       └── ui/
│           ├── render.js
│           ├── modals.js
│           ├── dialog.js
│           ├── lang.js
│           ├── picker.js
│           ├── emoji-data.js
│           └── gif-favs.js
└── data/
    ├── index.db
    ├── vaults/
    ├── envelopes/
    └── files/

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Startup Preview

  ╔════════════════════════════════════════════╗
  ║      Chat.kurama.info relay               ║
  ╠════════════════════════════════════════════╣
  ║  Status     Running                        ║
  ║  Address    http://127.0.0.1:8787          ║
  ║  Crypto     E2EE · AES-256-GCM            ║
  ║  Mode       Opaque relay (zero-knowledge)  ║
  ║  Author     Kurama                         ║
  ║  GitHub     https://github.com/Kurama250/  ║
  ╚════════════════════════════════════════════╝

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Support

If you like this project don't hesitate to give it a star ⭐ !

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Developer

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VaultChat — Self-hosted end-to-end encrypted messaging with an opaque relay