SCASH Web Wallet – Backend (Nest.js)

Backend service for the SCASH Web Wallet, built with Nest.js and Prisma (MySQL 5.7).

This project exists because of my passion for the SCASH community. The goal is to provide reliable, open tooling that makes SCASH easier to build on and safer to use. This backend focuses on block data caching, price fetching, and RPC relay (proxy) services to keep the web/extension wallet fast, scalable, and developer-friendly.

What this service does

• RPC Relay / Proxy
  Centralizes wallet RPC traffic to protect nodes from overload, add retries/rate-limit, and enable load balancing.
• Block/UTXO Data Caching
  Caches frequently used chain data (e.g., fee rates, UTXOs, tx lookups) to reduce node pressure and speed up responses.
• Price Fetching
  Pulls market prices (e.g., SCASH vs. BTC/USDT) and exposes them via simple endpoints for the UI.

Note: This service never handles mnemonics or private keys. Signing happens in the frontend only.

SCASHD Node Configuration

This backend requires access to a SCASH full node (scashd) via RPC.
By default, the service expects a locally running node on port 8342.

1) Configure RPC credentials

Edit the file:

src/scash/scash.service.ts

and update the following fields to match your local node setup:

public SCASH_RPC_URL: string = 'http://127.0.0.1:8342' // SCASH node RPC URL
public RPC_USER: string = 'scashd'                      // RPC username
public RPC_PASS: string = 'XXX233'                      // RPC password

2) Configure your scashd.conf

Make sure your SCASH node has RPC enabled. Example config (~/.scash/scashd.conf):

rpcuser=scashd
rpcpassword=XXX233
rpcport=8342
rpcallowip=127.0.0.1
server=1
daemon=1
listen=1
txindex=1

⚠️ Important: txindex=1 must be enabled so the backend can retrieve transactions by txid from the full node. Without it, only mempool transactions will be available.

3) Restart scashd

After updating scashd.conf, restart your node:

scashd -daemon

Verify the node is running:

scash-cli getblockchaininfo

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Tech Stack

• Nest.js – modular, testable Node.js framework
• Prisma ORM – type-safe DB access (MySQL 5.7)
• Node.js – recommended LTS
• Caching – in-memory or external cache (optional, depending on your deployment)

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Installation & Setup

1) Install Node.js (LTS)

Linux/macOS (via nvm):

# Install nvm
curl -fsSL https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
# Restart shell, then:
nvm install --lts
node -v

Windows: Use the official Node.js LTS installer from nodejs.org or install nvm-windows.

2) Enable Yarn (recommended)

If your Node version includes Corepack:

corepack enable
corepack prepare yarn@stable --activate
yarn -v

Or install globally:

npm i -g yarn

3) Clone the repository

git clone https://github.com/Forlingham/scash_web_wallet_server_nest.js.git
cd scash_web_wallet_server_nest.js

4) Configure environment variables

EDIT .env

# MySQL 5.7 connection
DATABASE_URL="mysql://root:root@localhost:3306/scash_web_wallet"

Ensure your MySQL user has permissions to create tables and run migrations.

5) Install dependencies

yarn install

6) Apply Prisma schema (use migration deploy)

For consumers of this repo, do not use migrate dev. Apply the committed migrations:

# Generate Prisma client
npx prisma generate

# Apply existing migrations to your database
npx prisma migrate deploy

# (Optional) Inspect DB
npx prisma studio

7) Run the service

Development:

npm run dev

The server starts on http://localhost:7020 by default.

Production (example):

npm run build
npm run start

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Security Model

• No private keys in backend – The server never receives mnemonics or private keys.
• Frontend-only signing – Transactions are built and signed in the UI, then sent here only for broadcasting or enrichment.
• RPC isolation – This service shields your nodes with caching/rate limiting (implementation-dependent) and centralizes network access.

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Development Scripts

Common scripts (your package.json may already include these):

# Development
npm run dev

# Build & run
npm run build
npm run start

# Prisma helpers
npx prisma generate
npx prisma migrate deploy
npx prisma studio

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Support the Author

If this project helps you or your community, consider supporting continued development:

BTC bc1qnvdrxs23t6ejuxjs6mswx7cez2rn80wrwjd0u8

BNB 0xD4dB57B007Ad386C2fC4d7DD146f5977c039Fefc

USDT (BEP-20) 0xD4dB57B007Ad386C2fC4d7DD146f5977c039Fefc

SCASH scash1qy48v7frkutlthqq7uqs8lk5fam24tghjdxqtf5

Stars, issues, and PRs are also very welcome. Thank you for supporting the SCASH ecosystem! 🙏

📢 Links

• 🌐 Wallet Website (Web version): https://wallet.scash.network/
• 📦 GitHub (Web Wallet): https://github.com/Forlingham/scash_web_wallet_next.js
• 🐦 Twitter: https://x.com/Hysanalde