WebZjs Zcash Snap

🔐 Overview

WebZjs Zcash Snap is a MetaMask Snap that brings Zcash functionality directly into the MetaMask browser extension. WebZjs is the first JavaScript SDK for Zcash, enabling seamless integration of Zcash privacy features for web users.

📘 Project Description

Snap uses a Rust library WebZjs compiled to WebAssembly (Wasm). It is meant to be used in conjunction with WebZjs web-wallet.

🛠 Prerequisites

WebZjs

• Node.js
• Yarn
• MetaMask Browser Extension (MetaMask Flask for development purposes) Install MM Flask

🔨 Development

The snap manifest (snap.manifest.json) controls which origins can communicate with the snap via allowedOrigins. A script (scripts/generate-manifest.js) handles switching between dev and production origins automatically — you should not need to edit the manifest by hand.

Build Scripts

• yarn dev / yarn start - Adds http://localhost:3000 to allowedOrigins, then watches for changes
• yarn build - Strips any localhost origins from allowedOrigins and runs a production build

Development Steps

1. Install dependencies with yarn install
2. For local development: yarn dev (automatically adds localhost to allowed origins)
3. For production: yarn build (automatically removes localhost from allowed origins)
4. Host snap on localhost http://localhost:8080 with yarn serve

CI: Allowed Origins Check

Two CI workflows (check-snap-manifest.yml and check-snap-allowed-origins.yml) verify that snap.manifest.json on main only contains the production origin ["https://webzjs.chainsafe.dev"]. If localhost is present, the check will fail.

Do not commit snap.manifest.json after running yarn dev — it will contain http://localhost:3000. Run yarn build or yarn manifest:prod first to reset it before committing.