Crypto Zombies

Learn to build smart contracts on the MultiversX blockchain through the Crypto Zombies course. This guide accompanies the MultiversX YouTube tutorials: Part 1 and Part 2.

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Why MultiversX?

MultiversX offers a robust blockchain platform with unparalleled performance and developer-friendly tools. Here's why you should consider it:

Performance

• Throughput: 15,000 transactions per second (TPS) with $0.001 transaction cost.
• Scalability: Adaptive State Sharding allows scaling beyond 100,000 TPS as the network grows.
• Efficiency: Achieved 263,000 TPS on testnet.

Developer Ecosystem

• IDE and Framework: MultiversX IDE, Rust-based framework, and debugging tools.
• Royalties: Developers earn 30% of the gas paid for smart contract execution.
• WebAssembly (WASM) VM: Support for smart contracts written in any language that compiles to WASM.

Rust Framework

• Low-level, multi-paradigm language optimized for performance and safety.
• Enables high-efficiency, low-gas smart contracts.

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Getting Started

Installation

1. Install pipx

pipx is the recommended way to install the MultiversX CLI (mxpy).

Ubuntu & Windows WSL

sudo apt update
sudo apt install pipx
pipx ensurepath

macOS

brew install pipx
pipx ensurepath

Confirm installation:

pipx --version

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2. Install mxpy

The MultiversX CLI (mxpy) is a versatile tool for interacting with the blockchain and managing smart contracts.

Install mxpy:

pipx install multiversx-sdk-cli --force

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3. Install Rust

Rust is essential for compiling smart contracts.

Ubuntu & Windows WSL

sudo apt install build-essential pkg-config libssl-dev

macOS

xcode-select --install

Install Rust using mxpy:

mxpy deps install rust --overwrite

Verify installation:

mxpy --version
rustup show

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Creating a New Smart Contract Project

To create an empty smart contract project:

sc-meta new --template empty --name crypto-zombies

Verify the project setup:

cargo check

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Building the Smart Contract

Compile the smart contract source code into WebAssembly (WASM) bytecode:

sc-meta all build

This generates an output directory containing:

output/
├── crypto-zombies.abi.json
├── crypto-zombies.imports.json
├── crypto-zombies.mxsc.json
└── crypto-zombies.wasm

Key Outputs:

• crypto-zombies.wasm: The WASM bytecode to deploy to the blockchain.
• crypto-zombies.abi.json: The Application Binary Interface (ABI) defines how to interact with the smart contract.

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Deploying the Smart Contract

To deploy the compiled contract:

mxpy --verbose contract deploy \
  --recall-nonce \
  --bytecode="./output/crypto-zombies.wasm" \
  --keyfile="../<your-wallet-keyfile>.json" \
  --gas-limit=100000000 \
  --proxy="https://devnet-gateway.multiversx.com" \
  --chain="D" \
  --send

Replace <your-wallet-keyfile>.json with your wallet file name. The command will ask for your password twice.

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