⚡ Stylus SDK - Mulai dari Nol

📅 Townhall Session 2 - 29 Januari 2026 (Part 2)

Belajar membuat smart contract pertama dengan Rust dan Stylus SDK. Mulai dari yang paling sederhana!

🎯 Apa yang Akan Dibuat

Dalam tutorial ini, kita akan membuat Counter Contract - smart contract paling sederhana untuk memahami Stylus SDK.

Counter Contract ini bisa:

✅ Menyimpan angka counter
✅ Menambah counter (+1)
✅ Membaca nilai counter
✅ Reset counter ke 0

Mengapa mulai dari Counter?

Mudah dipahami (hanya 1 variabel)
Tidak perlu logic kompleks
Perfect untuk belajar storage, methods, dan deployment
Sama seperti "Hello World" tapi lebih berguna!

✅ Prerequisites

Sebelum memulai, pastikan sudah terinstall:

Tool	Minimum Version	Stable/Working	Check Command
Rust	1.81.0	1.88.0-1.93.0	`rustc --version`
Cargo	1.81.0	1.88.0-1.93.0	`cargo --version`
cargo-stylus	0.5.0	0.6.3	`cargo stylus --version`

Versi Penting

Rust 1.81+ diperlukan untuk compile Stylus contracts
cargo-stylus 0.5.0+ diperlukan untuk contract verification di Arbiscan
cargo-stylus 0.6.3 adalah versi terbaru (29 Januari 2026)

Versi SDK yang Stable

Per Januari 2026, gunakan stylus-sdk 0.9.0 (bukan 0.10.0) untuk stability:

stylus-sdk = "=0.9.0" ✅ STABLE & PROVEN WORKING
stylus-sdk = "0.10.0" ⚠️ Ada known issues dengan cargo-stylus

Dokumentasi ini menggunakan 0.9.0 untuk ensure workshop berjalan lancar!

Install Rust (jika belum):

# Install rustup (Rust installer)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Setup environment
source "$HOME/.cargo/env"

# Verifikasi
rustc --version  # Should be 1.81.0 or higher

🚀 1. Setup Stylus Project

1.1. Install cargo-stylus

Pertama, install tool Stylus CLI:

# Install cargo-stylus versi terbaru
cargo install cargo-stylus

# Verifikasi instalasi
cargo stylus --version
# Output: cargo-stylus 0.6.3 (atau lebih baru)

Berhasil!

Jika muncul versi cargo-stylus, Anda siap melanjutkan!

Update cargo-stylus

Jika sudah install sebelumnya, update ke versi terbaru:

cargo install cargo-stylus --force

1.2. Buat Project Baru

Buat project Stylus dari template resmi:

# Buat project baru bernama "my-counter"
cargo stylus new my-counter

# Masuk ke folder project
cd my-counter

# Struktur folder:
# my-counter/
# ├── Cargo.toml      # Konfigurasi project & dependencies
# ├── src/
# │   └── lib.rs      # Smart contract kita
# └── .gitignore

Penjelasan:

cargo stylus new - membuat project Stylus baru dengan template
my-counter - nama project (bisa diganti sesuai keinginan)
Cargo.toml - seperti package.json untuk Rust
src/lib.rs - file utama smart contract

Verifikasi Cargo.toml:

Buka Cargo.toml dan pastikan strukturnya lengkap seperti ini:

[package]
name = "my-counter"
version = "0.1.0"
edition = "2021"

[dependencies]
alloy-primitives = "=0.8.20"  # EXACT version untuk stability
alloy-sol-types = "=0.8.20"   # EXACT version untuk stability
stylus-sdk = "=0.9.0"         # STABLE version (Jan 2026)
hex = { version = "0.4", default-features = false }
ruint = "=1.15.0"             # Lock untuk avoid conflicts

[dev-dependencies]
tokio = { version = "1", features = ["full"], default-features = false }
ethers = "2"

[features]
export-abi = ["stylus-sdk/export-abi"]
default = ["mini-alloc"]
mini-alloc = []

[lib]
crate-type = ["lib", "cdylib"]

[profile.release]
codegen-units = 1
opt-level = 3
lto = true
panic = "abort"
strip = true

Versi yang Proven Working!

Template di atas menggunakan exact versions (=) untuk mencegah dependency conflicts. Setup ini sudah tested dan guaranteed working per Januari 2026!

Common Error

Jika Anda hanya punya section [dependencies] tanpa [package], Anda akan mendapat error:

error: this virtual manifest specifies a `dependencies` section, which is not allowed

Solusi: Pastikan ada section [package] di atas [dependencies]!

stylus-sdk v0.10.0

Versi 0.10.0 (rilis 12 Januari 2026) memperkenalkan:

stylus-tools untuk programmatic deployment
contract-client-gen feature flag untuk library contracts
Improved workspace support dengan Stylus.toml

1.3. Verifikasi Project Bisa Di-compile

Test apakah project bisa di-compile:

# Compile project
cargo build --release --target wasm32-unknown-unknown

# Jika berhasil, akan muncul:
# Compiling my-counter v0.1.0
# Finished release [optimized] target(s) in X.XXs

Target WASM

wasm32-unknown-unknown adalah target compile untuk WebAssembly. Stylus menggunakan WASM untuk menjalankan smart contract Rust!

📝 2. Membuat Counter Contract

Sekarang kita akan menulis Counter Contract step-by-step.

2.1. Hapus Template Default

Buka file src/lib.rs dan hapus semua isinya. Kita akan menulis dari nol untuk memahami setiap baris!

2.2. Import Dependencies

Tambahkan import yang diperlukan:

// lib.rs
#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]
#![cfg_attr(not(any(test, feature = "export-abi")), no_std)]
extern crate alloc;

// Import untuk ABI export
use alloc::vec;
use alloc::vec::Vec;

// Import dari Stylus SDK
use stylus_sdk::prelude::*;
use stylus_sdk::storage::StorageU256;
use stylus_sdk::alloy_primitives::U256;

Penjelasan:

#![cfg_attr(..., no_main)] - disable main function untuk WASM
#![cfg_attr(..., no_std)] - no standard library (untuk WASM optimization)
extern crate alloc - untuk alokasi memory (wajib di WASM)
use alloc::vec - import Vec untuk ABI export compatibility
use stylus_sdk::prelude::* - import semua yang sering dipakai
StorageU256 - tipe storage untuk angka (seperti uint256 di Solidity)
U256 - tipe data untuk angka besar (256-bit)

StorageU256 vs U256

StorageU256 - untuk menyimpan data ON-CHAIN (permanent)
U256 - untuk variable temporary (seperti parameter function)

2.3. Definisi Storage

Buat struct untuk menyimpan state contract:

// Definisi storage contract
#[storage]
#[entrypoint]
pub struct Counter {
    count: StorageU256,  // Variabel untuk menyimpan counter
}

Penjelasan:

#[storage] - attribute yang menandai ini adalah storage contract
#[entrypoint] - menandai ini adalah contract utama yang bisa dipanggil
pub struct Counter - nama contract kita (seperti contract Counter di Solidity)
count: StorageU256 - variabel state untuk menyimpan nilai counter

Analogi Solidity:

contract Counter {
    uint256 public count;  // Sama seperti ini di Solidity!
}

2.4. Implementasi Methods

Sekarang tambahkan fungsi-fungsi untuk interact dengan counter:

#[public]
impl Counter {
    // Fungsi untuk increment counter (+1)
    pub fn increment(&mut self) {
        let current = self.count.get();           // Baca nilai sekarang
        let new_value = current + U256::from(1);  // Tambah 1
        self.count.set(new_value);                // Simpan nilai baru
    }

    // Fungsi untuk membaca nilai counter
    pub fn get_count(&self) -> U256 {
        self.count.get()  // Return nilai counter
    }

    // Fungsi untuk reset counter ke 0
    pub fn reset(&mut self) {
        self.count.set(U256::from(0));  // Set ke 0
    }
}

Penjelasan setiap fungsi:

1. increment() - Menambah counter

&mut self - mutable reference (bisa ubah data)
self.count.get() - membaca nilai counter dari storage
U256::from(1) - convert angka 1 menjadi U256
self.count.set(new_value) - menyimpan nilai baru ke storage

2. get_count() - Membaca nilai

&self - immutable reference (hanya baca, tidak ubah)
-> U256 - function return nilai bertipe U256
Gratis dipanggil (tidak butuh gas!)

3. reset() - Reset ke 0

&mut self - perlu mutate data
U256::from(0) - convert 0 menjadi U256

View vs Non-View

Fungsi dengan &self (get_count) - GRATIS, hanya baca data
Fungsi dengan &mut self (increment, reset) - BUTUH GAS, mengubah state

2.5. Code Lengkap

Berikut adalah code lengkap src/lib.rs:

// src/lib.rs
#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]
#![cfg_attr(not(any(test, feature = "export-abi")), no_std)]
extern crate alloc;

use alloc::vec;
use alloc::vec::Vec;
use stylus_sdk::prelude::*;
use stylus_sdk::storage::StorageU256;
use stylus_sdk::alloy_primitives::U256;

// Storage contract
#[storage]
#[entrypoint]
pub struct Counter {
    count: StorageU256,
}

// Public methods
#[public]
impl Counter {
    /// Increment counter by 1
    pub fn increment(&mut self) {
        let current = self.count.get();
        let new_value = current + U256::from(1);
        self.count.set(new_value);
    }

    /// Get current counter value
    pub fn get_count(&self) -> U256 {
        self.count.get()
    }

    /// Reset counter to 0
    pub fn reset(&mut self) {
        self.count.set(U256::from(0));
    }
}

File tambahan: src/main.rs

Untuk support ABI export, buat file src/main.rs:

// src/main.rs
#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]

#[cfg(not(any(test, feature = "export-abi")))]
#[no_mangle]
pub extern "C" fn main() {}

#[cfg(feature = "export-abi")]
fn main() {
    my_counter::print_from_args();
}

Struktur Project

Project Stylus membutuhkan 2 file:

src/lib.rs - Contract logic utama
src/main.rs - Entry point untuk ABI export (auto-generated oleh macros)

File main.rs ini hanya diperlukan untuk cargo stylus export-abi, tidak affect deployment contract!

🔨 3. Compile dan Check Contract

3.1. Compile ke WASM

Compile contract menjadi WebAssembly:

# Compile dengan optimization
cargo build --release --target wasm32-unknown-unknown

# Jika berhasil:
# Compiling stylus-sdk v0.9.0
# Compiling my-counter v0.1.0
# Finished release [optimized] target(s) in 15.2s

File WASM akan ada di:

target/wasm32-unknown-unknown/release/my_counter.wasm

3.2. Check Contract Valid

Verifikasi bahwa contract valid untuk Stylus:

# Check apakah contract bisa di-deploy
cargo stylus check

# Output jika berhasil:
#    Compiling stylus-sdk v0.9.0
#    Compiling my-counter v0.1.0
#     Finished `release` profile [optimized] target(s) in 51.29s
# contract size: 4.8 KB (4807 bytes)

Validasi Berhasil!

Jika muncul contract size: X KB, artinya contract kita berhasil di-compile menjadi WASM dan siap di-deploy!

Error "Connection refused"

Jika muncul error:

error: no error payload found in response: Transport(Custom(reqwest::Error ...
Connection refused ...

Ini NORMAL dan bisa diabaikan! Error ini muncul karena cargo stylus check mencoba connect ke local node (localhost:8547) yang tidak running. Yang penting adalah:

✅ Compilation berhasil
✅ Contract size muncul (e.g., 4.8 KB)

Contract Anda VALID dan siap deploy ke testnet!

3.3. Export ABI

Generate ABI untuk interaksi dari frontend:

# Generate ABI JSON (save to file)
cargo stylus export-abi > abi.json

# Atau lihat langsung di terminal
cargo stylus export-abi

Membutuhkan src/main.rs

Command export-abi membutuhkan file src/main.rs yang sudah kita buat di step 2.5. Jika Anda mendapat error "a bin target must be available", pastikan file src/main.rs ada!

Output ABI (Solidity-compatible):

// SPDX-License-Identifier: MIT-OR-APACHE-2.0
pragma solidity ^0.8.23;

interface ICounter {
    function increment() external;

    function getCount() external view returns (uint256);

    function reset() external;
}

Penjelasan ABI:

increment() - function untuk tambah counter (butuh gas)
getCount() - function view untuk baca counter (gratis!)
reset() - function untuk reset counter (butuh gas)

Apa itu ABI?

ABI (Application Binary Interface) adalah "manual instruction" yang menjelaskan cara interact dengan smart contract. Frontend perlu ABI untuk panggil function contract!

Stylus menggenerate ABI dalam format Solidity interface, sehingga compatible dengan tools Ethereum ecosystem seperti ethers.js, web3.js, dll.

🚀 4. Deploy ke Arbitrum Sepolia

4.1. Setup Arbitrum Sepolia

Sebelum deploy, pastikan sudah:

1. Punya wallet dengan private key

2. Punya Sepolia ETH untuk gas

Claim dari Google Cloud Faucet
Atau Alchemy Faucet

3. Bridge ETH ke Arbitrum Sepolia

Buka Arbitrum Bridge Sepolia
Connect wallet
Bridge minimal 0.01 ETH ke Arbitrum Sepolia

PENTING!

Pastikan bridge ke Arbitrum Sepolia (testnet), BUKAN Arbitrum One (mainnet)!

4.2. Set Environment Variables

Buat file .env untuk menyimpan private key:

# Buat file .env di root project
touch .env

# Edit .env dan tambahkan:
PRIVATE_KEY=your_private_key_here_without_0x_prefix

Cara mendapatkan private key dari MetaMask:

Buka MetaMask
Klik titik 3 → Account Details
Klik "Export Private Key"
Masukkan password MetaMask
Copy private key (tanpa "0x")

Keamanan Private Key!

JANGAN commit file .env ke Git!
Pastikan .env ada di .gitignore
Gunakan wallet testnet, JANGAN wallet dengan ETH asli!

4.3. Deploy Contract

Deploy contract ke Arbitrum Sepolia:

# Deploy dengan cargo stylus
cargo stylus deploy \
  --private-key-path=.env \
  --endpoint=https://sepolia-rollup.arbitrum.io/rpc

# Process deployment (tunggu 30-60 detik):
# Reading WASM file...
# Deploying contract to Arbitrum Sepolia...
# Transaction sent: 0x1234...
# Waiting for confirmation...
# Contract deployed at: 0xabcd1234...

RPC Endpoint

https://sepolia-rollup.arbitrum.io/rpc adalah RPC endpoint untuk Arbitrum Sepolia testnet. Ini GRATIS digunakan!

4.4. Simpan Contract Address

Setelah deploy berhasil, SIMPAN contract address!

Contoh:

Contract deployed at: 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb

Anda akan butuh address ini untuk interact dengan contract!

4.5. (Optional) Cache Contract untuk Gas Optimization

Setelah deployment berhasil, Anda akan melihat rekomendasi untuk cache contract:

# Cache contract di ArbOS
cargo stylus cache bid YOUR_CONTRACT_ADDRESS 0

# Contoh:
cargo stylus cache bid 0x95597662d6306b6591f33b966a1a6d2843638288 0

Mengapa perlu caching?

✅ Cheaper calls - Contract calls menjadi lebih murah
✅ Faster execution - Contract execution lebih cepat
✅ Better UX - User experience lebih baik karena lower gas fees

Contract Caching

Caching adalah optional tapi sangat direkomendasikan untuk production contracts. Cache menyimpan compiled WASM di ArbOS cache untuk akses yang lebih efisien.

Baca lebih lanjut: Stylus Contract Caching

4.6. Verify Contract di Arbiscan

Contract verification membuat source code Anda visible & verifiable di Arbiscan. Ini penting untuk:

✅ Transparency - User bisa lihat source code
✅ Trust - User tahu contract aman
✅ Interaction - Arbiscan bisa generate UI untuk interact

Ada 3 metode verification:

API V2 - Modern, reliable (RECOMMENDED)
Command Line - Local verification
Web Interface - Currently broken di Sepolia (API V1 deprecated)

Method 1: API V2 Verification (RECOMMENDED) ⭐

Prerequisites:

Item	Value	Link
Arbiscan API Key	Get free key	arbiscan.io/myapikey
GitHub Repository	Public repo	Push code to GitHub (root directory!)
Chain ID	`421614`	Arbitrum Sepolia

Step 1: Get API Key

Visit https://arbiscan.io/myapikey
Login/Register (gratis!)
Click "Add" → Create new API key
Copy API key Anda

Step 2: Push Code to GitHub

# Di directory project Anda
git init
git add .
git commit -m "Add Stylus Counter Contract"

# Create repo di GitHub, lalu:
git remote add origin https://github.com/YOUR_USERNAME/my-counter.git
git push -u origin main

Important!

Contract HARUS di root directory repo, tidak bisa di subdirectory!

✅ Correct:

my-counter/        ← Root
├── Cargo.toml
└── src/lib.rs

❌ Wrong:

repo/
└── contracts/
    └── my-counter/   ← Subdirectory tidak supported!

Step 3: Verify via API

# Replace values with yours:
API_KEY="YOUR_API_KEY"
CONTRACT="0x95597662d6306b6591f33b966a1a6d2843638288"
GITHUB_REPO="https://github.com/YOUR_USERNAME/my-counter"

curl -X POST "https://api.arbiscan.io/api" \
  -d "chainid=421614" \
  -d "module=contract" \
  -d "action=verifysourcecode" \
  -d "apikey=$API_KEY" \
  -d "codeformat=stylus" \
  -d "sourceCode=$GITHUB_REPO" \
  -d "contractaddress=$CONTRACT" \
  -d "contractname=my_counter" \
  -d "compilerversion=stylus:0.6.3" \
  -d "licenseType=3"

Expected Response:

{
  "status": "1",
  "message": "OK",
  "result": "a7lpxkm9kpcpicx7daftmjifrfhiuhf5vqqnawhkfhzfrcpnxj"
}

Step 4: Check Status

# Use GUID from previous response
GUID="a7lpxkm9kpcpicx7daftmjifrfhiuhf5vqqnawhkfhzfrcpnxj"

curl "https://api.arbiscan.io/api?module=contract&action=checkverifystatus&guid=$GUID&apikey=$API_KEY"

Success Response:

{
  "status": "1",
  "message": "OK",
  "result": "Pass - Verified"
}

License Types:

Code	License
`1`	No License (None)
`2`	The Unlicense (Unlicense)
`3`	MIT License (MIT)
`4`	GNU GPLv2 (GNU GPLv2)
`5`	GNU GPLv3 (GNU GPLv3)
`6`	Apache 2.0 (Apache-2.0)

Automated Script

Saya sudah buat script verify-contract.sh di project directory Anda yang automate semua steps ini!

# Edit API_KEY di script, lalu run:
chmod +x verify-contract.sh
./verify-contract.sh

Script ini akan:

✅ Submit verification request
✅ Get GUID untuk tracking
✅ Auto-check status setelah 10 seconds
✅ Show verification result

Method 2: Command Line Verification

Local verification untuk prove reproducibility:

cargo stylus verify \
  --deployment-tx YOUR_DEPLOYMENT_TX_HASH \
  --endpoint https://sepolia-rollup.arbitrum.io/rpc \
  --no-verify

Expected Output:

✅ Verification successful
📊 Contract size: 4.8 KB
🔒 Metadata hash: d5d1e2b15036069b7c500c378ca15809d61e4e1d4354dce29b9990e7ea9a663a

Method 3: Web Interface (Currently Broken)

Deprecated API V1

Web verification di Arbiscan Sepolia currently broken dengan error:

Error: You are using a deprecated V1 endpoint

Status per Januari 2026:

❌ Arbiscan Sepolia - Broken (API V1)
✅ Arbiscan One (Mainnet) - Working (API V2)

Gunakan Method 1 (API V2) atau Method 2 (CLI) sebagai gantinya.

Cek Status Verification

Buka contract di Arbiscan Sepolia:

https://sepolia.arbiscan.io/address/YOUR_CONTRACT_ADDRESS

Klik tab "Contract"
Lihat status:
- ✅ "Contract Source Code Verified" - Sudah verified!
- ❌ "Are you the contract creator?" - Belum verified

Manual Verification (Jika Belum Verified)

Step 1: Buka Verification Page

Option A - Direct:

https://sepolia.arbiscan.io/verifyContract

Option B - From contract page:

Tab "Contract" → Click "Verify and Publish"

Step 2: Fill Details

Field	Value
Contract Address	`YOUR_CONTRACT_ADDRESS`
Compiler Type	Stylus (Rust)
Compiler Version	v0.6.3
License	MIT atau Apache-2.0

Step 3: Upload Source Code

Option A - Copy-Paste:

Upload src/lib.rs dan Cargo.toml
Paste lengkap dengan dependencies

Option B - Fetch from Git (Recommended):

Push project ke GitHub (di root directory!)
Pilih "Fetch from Git"
Enter repository URL

Project Structure

Jika menggunakan "Fetch from Git", pastikan:

❌ Contract BUKAN di subdirectory
✅ Contract di ROOT repository
✅ Include Cargo.toml, Cargo.lock, src/lib.rs

Step 4: Verify

Click "Verify and Publish"
Wait 10-30 seconds
Refresh page

Expected Result:

✅ Contract Source Code Verified (Exact Match)

4.7. Verification Troubleshooting

Error: "Contract source code not found"

✅ Pastikan GitHub repo PUBLIC (bukan private)
✅ Pastikan contract di ROOT directory repo
✅ Pastikan Cargo.toml dan src/lib.rs accessible

Error: "Compilation failed"

✅ Check compiler version match: stylus:0.6.3
✅ Check contract name match (gunakan _ bukan -)
✅ Pastikan dependencies di Cargo.toml correct

Error: "Bytecode does not match"

✅ Pastikan source code di GitHub = source code deployed
✅ Pastikan tidak ada uncommitted changes
✅ Check Cargo.lock committed ke repo

Status: "Pending in queue"

⏳ Tunggu 30-60 seconds
⏳ Check status lagi dengan checkverifystatus endpoint
⏳ Normal untuk verification memakan waktu

4.8. View Verified Contract

Setelah verification, cek contract di Arbiscan Sepolia:

Buka https://sepolia.arbiscan.io/address/YOUR_CONTRACT_ADDRESS
Tab "Contract" akan menampilkan:
- ✅ Green checkmark "Contract Source Code Verified"
- ✅ Source code (Rust) yang bisa dibaca
- ✅ ABI interface
- ✅ Read Contract tab - View functions (gratis!)
- ✅ Write Contract tab - State-changing functions

Verification Benefits

Setelah verified, user bisa:

📖 Read source code langsung di browser
🔍 Verify contract logic aman
🎮 Interact via Arbiscan UI (no need cast!)
📊 See all contract methods & events
🔗 Share verifiable contract dengan community

Expected Deployment Output:

$ cargo stylus deploy --private-key-path=.env --endpoint=https://sepolia-rollup.arbitrum.io/rpc

Building project with Cargo.toml version: 0.1.0
    Finished `release` profile [optimized] target(s) in 1.30s
contract size: 4.8 KB (4831 bytes)
wasm data fee: 0.000067 ETH
deployed code at address: 0x95597662d6306b6591f33b966a1a6d2843638288
deployment tx hash: 0xbe550788c54bbf9f1784062fc2369251e5235d1b43588016ff386752d742b44c
successfully activated contract

Deployment Berhasil!

Jika muncul "successfully activated contract" dengan contract address, deployment Anda berhasil! 🎉

Simpan contract address untuk interact nanti!

🎮 5. Interact dengan Contract

5.1. Menggunakan Cast (Foundry)

Install Foundry jika belum punya:

# Install Foundry
curl -L https://foundry.paradigm.xyz | bash
foundryup

Baca nilai counter (view function - gratis!):

# Panggil getCount
cast call YOUR_CONTRACT_ADDRESS \
  "getCount()(uint256)" \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

# Contoh dengan contract yang sudah deployed:
cast call 0x95597662d6306b6591f33b966a1a6d2843638288 \
  "getCount()(uint256)" \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

# Output:
# 0x0000000000000000000000000000000000000000000000000000000000000000
# (dalam hex = 0 dalam decimal)

Convert Hex ke Decimal

Gunakan cast --to-base untuk convert:

cast --to-base 0x0000000000000000000000000000000000000000000000000000000000000001 10
# Output: 1

Increment counter (butuh gas):

# Panggil increment (butuh private key untuk sign transaksi)
cast send YOUR_CONTRACT_ADDRESS \
  "increment()" \
  --private-key YOUR_PRIVATE_KEY \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

# Output:
# Transaction hash: 0x...
# Block: 12345
# Gas used: 45000

Baca counter lagi (seharusnya 1):

cast call YOUR_CONTRACT_ADDRESS \
  "getCount()(uint256)" \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

# Output:
# 0x0000000000000000000000000000000000000000000000000000000000000001
# (1 dalam decimal!)

Reset counter:

cast send YOUR_CONTRACT_ADDRESS \
  "reset()" \
  --private-key YOUR_PRIVATE_KEY \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

5.2. Menggunakan ethers.js

Buat file JavaScript untuk interact:

// interact.js
const { ethers } = require('ethers');

// Setup
const PRIVATE_KEY = 'your_private_key';
const CONTRACT_ADDRESS = 'your_contract_address';
const RPC_URL = 'https://sepolia-rollup.arbitrum.io/rpc';

// ABI - hanya function yang kita butuhkan
const ABI = [
  "function getCount() view returns (uint256)",
  "function increment()",
  "function reset()"
];

async function main() {
  // Connect ke Arbitrum Sepolia
  const provider = new ethers.JsonRpcProvider(RPC_URL);
  const wallet = new ethers.Wallet(PRIVATE_KEY, provider);
  const contract = new ethers.Contract(CONTRACT_ADDRESS, ABI, wallet);

  // Baca counter
  const count = await contract.getCount();
  console.log('Current count:', count.toString());

  // Increment
  console.log('Incrementing...');
  const tx = await contract.increment();
  await tx.wait();
  console.log('Incremented!');

  // Baca lagi
  const newCount = await contract.getCount();
  console.log('New count:', newCount.toString());
}

main();

Jalankan:

node interact.js

🐛 6. Troubleshooting

6.1. Error: "this virtual manifest specifies a `dependencies` section"

Penyebab: Cargo.toml tidak lengkap, hanya ada [dependencies] tanpa [package].

Solusi: Pastikan Cargo.toml memiliki struktur lengkap:

[package]           # ← WAJIB ada ini!
name = "my-counter"
version = "0.1.0"
edition = "2021"

[dependencies]
stylus-sdk = "0.10.0"
alloy-primitives = "1.0.1"
alloy-sol-types = "1.0.1"

[lib]
crate-type = ["cdylib"]

6.2. Error: "insufficient funds for gas"

Penyebab: Wallet tidak punya cukup ETH di Arbitrum Sepolia.

Solusi:

Bridge lebih banyak ETH ke Arbitrum Sepolia
Claim dari faucet lagi
Cek balance: cast balance YOUR_ADDRESS --rpc-url https://sepolia-rollup.arbitrum.io/rpc

6.3. Error: "WASM validation failed"

Penyebab: Contract tidak valid atau terlalu besar.

Solusi:

Pastikan compile dengan --release:

cargo build --release --target wasm32-unknown-unknown

Check contract: cargo stylus check

6.4. Error: "nonce too high"

Penyebab: Nonce transaksi tidak sinkron.

Solusi: Reset account di MetaMask:

Settings → Advanced
Clear activity tab data

6.5. Error: "evaluation of ... failed" atau "BYTES must be equal"

Penyebab: Dependency version conflict, biasanya dengan ruint package.

Error message:

error[E0080]: evaluation of `alloy_primitives::ruint::bytes::<impl ...>` failed
BYTES must be equal to Self::BYTES

Solusi: Lock ruint ke versi 1.15.0:

[dependencies]
alloy-primitives = "=0.8.20"
alloy-sol-types = "=0.8.20"
stylus-sdk = "=0.9.0"
ruint = "=1.15.0"  # ← IMPORTANT!

Lalu update:

cargo update
cargo clean
cargo stylus check

6.6. Error: "build did not generate wasm file"

Penyebab: Ada src/main.rs yang conflict dengan library setup.

Solusi: Hapus file src/main.rs jika ada:

rm src/main.rs
cargo clean
cargo stylus check

Stylus contracts hanya butuh src/lib.rs, tidak butuh main.rs!

6.7. Contract deployed tapi tidak bisa dipanggil

Penyebab: Mungkin lupa #[public] di impl block.

Solusi: Pastikan ada #[public] sebelum impl Counter:

#[public]  // ← WAJIB ada ini!
impl Counter {
    // ...
}

6.8. Warning: "unexpected cfg condition value: contract-client-gen"

Penyebab: Warning harmless dari internal stylus-sdk macros.

Pesan warning:

warning: unexpected `cfg` condition value: `contract-client-gen`
  --> src/lib.rs:10:1
   |
10 | #[storage]
   | ^^^^^^^^^^

Solusi: Warning ini AMAN dan bisa diabaikan. Tidak mempengaruhi functionality contract. Ini adalah internal feature flag dari stylus-sdk yang muncul di compile time tapi tidak affect runtime behavior.

6.9. Arbiscan Error: "deprecated V1 endpoint"

Penyebab: Arbiscan Sepolia masih menggunakan deprecated API V1 untuk Stylus verification.

Error message:

Error: You are using a deprecated V1 endpoint,
switch to Etherscan API V2 using https://docs.etherscan.io/v2-migration

Ini BUKAN kesalahan Anda! Ini adalah bug dari Arbiscan Sepolia yang belum migrate ke API V2.

Solusi - Command Line Verification:

Gunakan cargo stylus verify untuk verify contract secara lokal:

# Verify contract deployment
cargo stylus verify \
  --deployment-tx YOUR_DEPLOYMENT_TX_HASH \
  --endpoint https://sepolia-rollup.arbitrum.io/rpc \
  --no-verify

# Expected output:
# Verification successful
# project metadata hash: d5d1e2b15036069b7c500c378ca15809d61e4e1d4354dce29b9990e7ea9a663a

Deployment TX Hash bisa dilihat dari output cargo stylus deploy:

deployment tx hash: 0xbe550788c54bbf9f1784062fc2369251e5235d1b43588016ff386752d742b44c

Apa arti "Verification successful"?

✅ Deployed contract cocok 100% dengan source code lokal
✅ Contract reproducible dan bisa diverifikasi
✅ Deployment authentic tanpa tampering

Status Arbiscan Verification

Per Januari 2026:

❌ Arbiscan Sepolia - Broken (API V1 deprecated)
✅ Arbiscan One (Mainnet) - Working (API V2)
✅ Command Line Verification - Always works

Untuk testnet, gunakan command line verification. Untuk mainnet production, web verification di Arbiscan One sudah working.

📊 7. Perbandingan Rust vs Solidity

Mari bandingkan Counter Contract di Rust (Stylus) vs Solidity:

Rust (Stylus):

#[storage]
pub struct Counter {
    count: StorageU256,
}

#[public]
impl Counter {
    pub fn increment(&mut self) {
        let current = self.count.get();
        self.count.set(current + U256::from(1));
    }
}

Solidity:

contract Counter {
    uint256 public count;

    function increment() public {
        count++;
    }
}

Perbedaan:

Aspek	Rust (Stylus)	Solidity
Syntax	Lebih verbose	Lebih ringkas
Type Safety	Sangat ketat (compile-time)	Kurang ketat
Gas Cost	10x lebih murah untuk logic kompleks	Standard
Performance	10-100x lebih cepat	Standard
Learning Curve	Lebih tinggi	Lebih rendah
Memory Safety	Guaranteed by compiler	Manual checks

Kapan pakai Stylus:

✅ Logic kompleks (game, ML, crypto)
✅ Butuh performance tinggi
✅ Butuh gas optimization maksimal

Kapan pakai Solidity:

✅ Contract sederhana (token, NFT)
✅ Tim sudah familiar Solidity
✅ Banyak library existing

🎓 Checklist Pembelajaran

Pastikan Anda memahami:

🔍 Quick Reference: Verification Methods

Comparison Table

Method	Status	Use Case	Complexity	Public Visibility
API V2	✅ Working	Production verification	⭐⭐ Medium	✅ Yes (Arbiscan)
Command Line	✅ Working	Local verification	⭐ Easy	❌ No (local only)
Web Interface	❌ Broken	N/A (deprecated)	⭐⭐⭐ Easy	Would be ✅

When to Use Each Method

API V2 (Recommended for Production):

✅ Want contract visible on Arbiscan
✅ Need public verification
✅ Have GitHub public repo
✅ Want users to interact via Arbiscan UI

Command Line (Good for Testing):

✅ Want to prove reproducibility
✅ Local verification only
✅ Don't need Arbiscan visibility
✅ Quick verification check

Web Interface:

❌ Currently broken (API V1 deprecated)
⏳ Wait for Arbiscan Sepolia update

API V2 Quick Command

# One-liner verification (replace values!)
curl -X POST "https://api.arbiscan.io/api" \
  -d "chainid=421614" \
  -d "module=contract" \
  -d "action=verifysourcecode" \
  -d "apikey=YOUR_API_KEY" \
  -d "codeformat=stylus" \
  -d "sourceCode=https://github.com/YOUR_USERNAME/YOUR_REPO" \
  -d "contractaddress=YOUR_CONTRACT_ADDRESS" \
  -d "contractname=YOUR_CONTRACT_NAME" \
  -d "compilerversion=stylus:0.6.3" \
  -d "licenseType=3"

CLI Quick Command

# One-liner local verification
cargo stylus verify \
  --deployment-tx YOUR_TX_HASH \
  --endpoint https://sepolia-rollup.arbitrum.io/rpc \
  --no-verify

📦 Quick Reference: Project Template

Cargo.toml

Simpan template ini untuk semua project Stylus Anda:

[package]
name = "your-project-name"    # Ganti dengan nama project
version = "0.1.0"
edition = "2021"

[dependencies]
alloy-primitives = "=0.8.20"  # ✅ EXACT version (proven working)
alloy-sol-types = "=0.8.20"   # ✅ EXACT version (proven working)
stylus-sdk = "=0.9.0"         # ✅ STABLE version (Jan 2026)
hex = { version = "0.4", default-features = false }
ruint = "=1.15.0"             # ✅ Lock version to avoid conflicts

[dev-dependencies]
tokio = { version = "1", features = ["full"], default-features = false }
ethers = "2"

[features]
export-abi = ["stylus-sdk/export-abi"]
default = ["mini-alloc"]
mini-alloc = []

[lib]
crate-type = ["lib", "cdylib"] # ✅ Required for WASM

[profile.release]
codegen-units = 1              # Optimize for size
opt-level = 3                  # Optimization level
lto = true                     # Link-time optimization
panic = "abort"                # Reduce binary size
strip = true                   # Strip symbols

Catatan Penting:

✅ GUNAKAN exact versions (=) untuk stability
✅ GUNAKAN stylus-sdk 0.9.0 (stable), bukan 0.10.0 (ada known issues)
❌ JANGAN lupakan section [package]
❌ JANGAN lupakan section [lib] dengan crate-type = ["lib", "cdylib"]
✅ SELALU lock ruint = "=1.15.0" untuk avoid version conflicts

src/lib.rs (Template Minimal)

#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]
#![cfg_attr(not(any(test, feature = "export-abi")), no_std)]
extern crate alloc;

use alloc::vec;
use alloc::vec::Vec;
use stylus_sdk::prelude::*;
use stylus_sdk::storage::StorageU256;
use stylus_sdk::alloy_primitives::U256;

#[storage]
#[entrypoint]
pub struct YourContract {
    // Storage variables here
}

#[public]
impl YourContract {
    // Public functions here
}

src/main.rs (Required untuk ABI Export)

#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]

#[cfg(not(any(test, feature = "export-abi")))]
#[no_mangle]
pub extern "C" fn main() {}

#[cfg(feature = "export-abi")]
fn main() {
    your_project_name::print_from_args();
}

Project Name

Ganti your_project_name dengan nama project Anda di Cargo.toml (field name).

Contoh: Jika name = "my-counter", maka gunakan my_counter::print_from_args() (ganti - dengan _)

📝 Assignment

🎯 Tugas: Deploy Counter Sendiri

Requirements:

Setup Stylus project bernama my-first-counter

Template Cargo.toml

Gunakan template lengkap ini untuk Cargo.toml:

[package]
name = "my-first-counter"
version = "0.1.0"
edition = "2021"

[dependencies]
alloy-primitives = "=0.8.20"
alloy-sol-types = "=0.8.20"
stylus-sdk = "=0.9.0"
hex = { version = "0.4", default-features = false }
ruint = "=1.15.0"

[dev-dependencies]
tokio = { version = "1", features = ["full"], default-features = false }
ethers = "2"

[features]
export-abi = ["stylus-sdk/export-abi"]
default = ["mini-alloc"]
mini-alloc = []

[lib]
crate-type = ["lib", "cdylib"]

[profile.release]
codegen-units = 1
opt-level = 3
lto = true
panic = "abort"
strip = true

Buat Counter contract dengan 4 fungsi:
- increment() - tambah 1
- decrement() - kurang 1 (jangan sampai underflow!)
- get_count() - baca nilai
- add(amount: U256) - tambah sejumlah amount
Deploy ke Arbitrum Sepolia
Interact minimal 5 kali (increment, add, decrement, dll)
Screenshot transaksi di Arbiscan

Deliverables:

Link GitHub repository dengan code
Contract address di Sepolia
Screenshot Arbiscan dengan minimal 5 transaksi
Submit ke HackQuest platform

Deadline: 3 Februari 2026, 23:59 WIB

🔗 Resources & Links

Official Documentation (Updated 2026)

Arbitrum Stylus Docs - Getting started guide
Stylus Quickstart - Official quickstart
Stylus Rust SDK Guide - Advanced features
Using Stylus CLI - CLI reference

GitHub Repositories

cargo-stylus - Latest releases & changelog
stylus-sdk-rs - SDK source code
awesome-stylus - Curated examples

Package Registries

cargo-stylus on crates.io - Latest version info
stylus-sdk on crates.io - SDK versions

⏭️ Next Steps

Setelah menguasai Counter Contract, lanjut ke:

Storage Patterns - StorageMap, StorageVec, nested storage
Events & Logging - Emit events dari Rust
ERC-20 Token - Build token standard dengan Rust
External Calls - Panggil Solidity contract dari Rust

🎉 Selamat! Anda sudah berhasil membuat, deploy, dan interact dengan Stylus smart contract pertama! Next step adalah buat contract yang lebih kompleks. 💪

📊 Deployment Success Example

Berikut adalah contoh successful deployment dari workshop participant:

Contract Details:

Contract Address: 0x95597662d6306b6591f33b966a1a6d2843638288
Network: Arbitrum Sepolia Testnet
Contract Size: 4.8 KB (4831 bytes)
Deployment Cost: ~0.000067 ETH
Status: ✅ Successfully Activated

Verification:

# View on Arbiscan
https://sepolia.arbiscan.io/address/0x95597662d6306b6591f33b966a1a6d2843638288

# Interact via cast
cast call 0x95597662d6306b6591f33b966a1a6d2843638288 \
  "getCount()(uint256)" \
  --rpc-url https://sepolia-rollup.arbitrum.io/rpc

Workshop Achievement

Contract ini adalah hasil dari workshop Townhall Session 2 (29 Januari 2026). Semua peserta workshop berhasil deploy Counter Contract mereka ke Arbitrum Sepolia! 🚀

Keep Building! 🦀⚡

📅 Townhall Session 2 - 29 Januari 2026 (Part 2)

🎯 Apa yang Akan Dibuat​

✅ Prerequisites​

🚀 1. Setup Stylus Project​

1.1. Install cargo-stylus​

1.2. Buat Project Baru​

1.3. Verifikasi Project Bisa Di-compile​

📝 2. Membuat Counter Contract​

2.1. Hapus Template Default​

2.2. Import Dependencies​

2.3. Definisi Storage​

2.4. Implementasi Methods​

2.5. Code Lengkap​

🔨 3. Compile dan Check Contract​

3.1. Compile ke WASM​

3.2. Check Contract Valid​

3.3. Export ABI​

🚀 4. Deploy ke Arbitrum Sepolia​

4.1. Setup Arbitrum Sepolia​

4.2. Set Environment Variables​

4.3. Deploy Contract​

4.4. Simpan Contract Address​

4.5. (Optional) Cache Contract untuk Gas Optimization​

4.6. Verify Contract di Arbiscan​

Method 1: API V2 Verification (RECOMMENDED) ⭐​

Method 2: Command Line Verification​

Method 3: Web Interface (Currently Broken)​

Cek Status Verification​

Manual Verification (Jika Belum Verified)​

4.7. Verification Troubleshooting​

4.8. View Verified Contract​

🎮 5. Interact dengan Contract​

5.1. Menggunakan Cast (Foundry)​

5.2. Menggunakan ethers.js​

🐛 6. Troubleshooting​

6.1. Error: "this virtual manifest specifies a dependencies section"​

6.2. Error: "insufficient funds for gas"​

6.3. Error: "WASM validation failed"​

6.4. Error: "nonce too high"​

6.5. Error: "evaluation of ... failed" atau "BYTES must be equal"​

6.6. Error: "build did not generate wasm file"​

6.7. Contract deployed tapi tidak bisa dipanggil​

6.8. Warning: "unexpected cfg condition value: contract-client-gen"​

6.9. Arbiscan Error: "deprecated V1 endpoint"​

📊 7. Perbandingan Rust vs Solidity​

🎓 Checklist Pembelajaran​

🔍 Quick Reference: Verification Methods​

Comparison Table​

When to Use Each Method​

API V2 Quick Command​

CLI Quick Command​

📦 Quick Reference: Project Template​

Cargo.toml​

src/lib.rs (Template Minimal)​

src/main.rs (Required untuk ABI Export)​

📝 Assignment​

🎯 Tugas: Deploy Counter Sendiri

🔗 Resources & Links​

Official Documentation (Updated 2026)​

GitHub Repositories​

Package Registries​

⏭️ Next Steps​

📊 Deployment Success Example​

🎯 Apa yang Akan Dibuat

✅ Prerequisites

🚀 1. Setup Stylus Project

1.1. Install cargo-stylus

1.2. Buat Project Baru

1.3. Verifikasi Project Bisa Di-compile

📝 2. Membuat Counter Contract

2.1. Hapus Template Default

2.2. Import Dependencies

2.3. Definisi Storage

2.4. Implementasi Methods

2.5. Code Lengkap

🔨 3. Compile dan Check Contract

3.1. Compile ke WASM

3.2. Check Contract Valid

3.3. Export ABI

🚀 4. Deploy ke Arbitrum Sepolia

4.1. Setup Arbitrum Sepolia

4.2. Set Environment Variables

4.3. Deploy Contract

4.4. Simpan Contract Address

4.5. (Optional) Cache Contract untuk Gas Optimization

4.6. Verify Contract di Arbiscan

Method 1: API V2 Verification (RECOMMENDED) ⭐

Method 2: Command Line Verification

Method 3: Web Interface (Currently Broken)

Cek Status Verification

Manual Verification (Jika Belum Verified)

4.7. Verification Troubleshooting

4.8. View Verified Contract

🎮 5. Interact dengan Contract

5.1. Menggunakan Cast (Foundry)

5.2. Menggunakan ethers.js

🐛 6. Troubleshooting

6.1. Error: "this virtual manifest specifies a `dependencies` section"

6.2. Error: "insufficient funds for gas"

6.3. Error: "WASM validation failed"

6.4. Error: "nonce too high"

6.5. Error: "evaluation of ... failed" atau "BYTES must be equal"

6.6. Error: "build did not generate wasm file"

6.7. Contract deployed tapi tidak bisa dipanggil

6.8. Warning: "unexpected cfg condition value: contract-client-gen"

6.9. Arbiscan Error: "deprecated V1 endpoint"

📊 7. Perbandingan Rust vs Solidity

🎓 Checklist Pembelajaran

🔍 Quick Reference: Verification Methods

Comparison Table

When to Use Each Method

API V2 Quick Command

CLI Quick Command

📦 Quick Reference: Project Template

Cargo.toml

src/lib.rs (Template Minimal)

src/main.rs (Required untuk ABI Export)

📝 Assignment

🔗 Resources & Links

Official Documentation (Updated 2026)

GitHub Repositories

Package Registries

⏭️ Next Steps

📊 Deployment Success Example