sham3js

No data? No problem! Generate massive amounts of fake web3 data for testing and development.

import { sham } from 'sham3js';

sham.seed(42); // Deterministic output

sham.address.wallet();          // '0x742d35Cc6634C0532925a3b844Bc9e7595f2bD28'
sham.nft.metadata();            // Full ERC-721 metadata JSON
sham.dex.candles(100);          // 100 realistic OHLCV candles
sham.dao.proposal();            // DAO governance proposal
sham.scenario.nftDrop(10000);   // Full 10k PFP collection

Why sham3js?

Building web3 apps means constantly needing test data: wallet addresses, NFT metadata, transaction histories, price feeds, DAO votes, airdrop lists... Currently you either hand-craft JSON fixtures or write throwaway scripts every time.

sham3js gives you one library that generates all of it — realistic, typed, deterministic, and chain-aware.

Features

🎯 10 specialized modules — addresses, tokens, NFTs, transactions, blocks, DEX data, DAO governance, DeFi, contracts, signatures
🎬 Scenario generators — pre-built complex test setups (NFT drops, DAO elections, trading simulations)
🌐 Multi-chain — EVM (Ethereum, Polygon, Arbitrum, Base, Optimism, Avalanche, BSC) + Solana
🎲 Seedable PRNG — deterministic output for reproducible tests
📊 Realistic distributions — power-law token holdings, Geometric Brownian Motion price data, weighted vote distributions
📦 Zero dependencies — pure TypeScript, ~60KB bundled
🔧 TypeScript-first — full type exports for every generated structure
🖥️ CLI included — generate data from the command line

Install

npm install sham3js
# or
yarn add sham3js
# or
pnpm add sham3js

Quick Start

import { sham } from 'sham3js';

// Or create your own instance
import { Sham3 } from 'sham3js';
const sham = new Sham3({ seed: 42, chain: 'solana' });

API Reference

`sham.address` — Wallet & Contract Addresses

sham.address.wallet()       // '0x742d35Cc6634C0532925a3b844Bc9e7595f2bD28'
sham.address.contract()     // '0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984'
sham.address.ens()          // 'degenwhale.eth'
sham.address.solana()       // '7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU'
sham.address.zero()         // '0x0000000000000000000000000000000000000000'
sham.address.dead()         // '0x000000000000000000000000000000000000dEaD'
sham.address.any()          // Chain-appropriate address
sham.address.wallets(100)   // 100 unique addresses

`sham.token` — ERC-20 / SPL Tokens

sham.token.erc20()
// {
//   name: 'Flux Protocol',
//   symbol: 'FLUX',
//   decimals: 18,
//   totalSupply: '1000000000000000000000000',
//   address: '0xa3f...'
// }

sham.token.symbol()         // 'PRISM'
sham.token.name()           // 'Nexus Finance'
sham.token.stablecoin()     // 'USDC'
sham.token.price()          // 2847.53
sham.token.balance()        // { token, balance, balanceFormatted, valueUsd }
sham.token.pair()           // { token0, token1 }
sham.token.marketCap()      // 54200000000

`sham.nft` — NFT Metadata & Collections

sham.nft.metadata()
// {
//   name: 'Cosmic Apes #4217',
//   description: 'A unique Cosmic Apes NFT...',
//   image: 'ipfs://Qm.../4217.png',
//   external_url: 'https://cosmicapes.xyz/token/4217',
//   attributes: [
//     { trait_type: 'Background', value: 'Aquamarine' },
//     { trait_type: 'Eyes', value: 'Laser' },
//     { trait_type: 'Hat', value: 'Crown' },
//   ]
// }

sham.nft.trait()                   // { trait_type: 'Eyes', value: 'Laser' }
sham.nft.traits(6)                 // Array of 6 traits
sham.nft.collectionName()          // 'Mystic Dragons'
sham.nft.ipfsCid()                 // 'Qm8a2f...'
sham.nft.imageUrl(42)              // 'ipfs://Qm.../42.png'
sham.nft.collection(10000)         // Full 10k collection with metadata
sham.nft.royalty()                 // { receiver, bps: 500, percentage: '5.0%' }

`sham.transaction` — Transactions & Receipts

sham.transaction.hash()            // '0x8a2f3b...' (or Solana signature)
sham.transaction.evm()             // Full EVM transaction object
sham.transaction.receipt()         // Receipt with logs
sham.transaction.solana()          // Solana transaction with instructions
sham.transaction.gasPrice()        // '25000000000' (25 gwei)
sham.transaction.gasUsed('swap')   // 185432
sham.transaction.calldata()        // '0xa9059cbb...'
sham.transaction.log()             // EVM event log

`sham.block` — Block Headers

sham.block.number()                // 19482610
sham.block.evm()                   // Full EVM block header
sham.block.solana()                // Solana block with slot and rewards

`sham.dex` — DEX & Trading Data

// Realistic price candles using Geometric Brownian Motion
sham.dex.candles(500, {
  startPrice: 2000,
  interval: '1h',
  volatility: 0.04,
})
// Returns 500 OHLCV candles with realistic price movement

sham.dex.swap()                    // Swap event with amounts, prices, gas
sham.dex.orderBook({ midPrice: 2000 })  // Full order book with bids/asks
sham.dex.pool()                    // Liquidity pool (TVL, APR, reserves)
sham.dex.tradeHistory(100)         // 100 swap events for a pair
sham.dex.pair()                    // 'ETH/USDC'
sham.dex.name()                    // 'Uniswap'

`sham.dao` — DAO Governance

sham.dao.proposal()
// {
//   id: 42,
//   title: 'Deploy Protocol on Base',
//   status: 'active',
//   forVotes: '12500000000000000000000000',
//   againstVotes: '3200000000000000000000000',
//   ...
// }

sham.dao.vote()                    // Vote with weight, support, reason
sham.dao.delegate()                // Delegate profile with voting stats
sham.dao.config()                  // DAO configuration (quorum, thresholds)
sham.dao.election(5, 1000)         // 5 proposals, 1000 voters, full results

`sham.defi` — DeFi Protocols

sham.defi.lendingPosition()        // Supply/borrow with APY, health factor
sham.defi.stakingPosition()        // Staking with rewards and lock period
sham.defi.vault()                  // Yield vault (TVL, APY breakdown)
sham.defi.airdrop(1000)            // 1000 claims with Merkle proofs
sham.defi.vestingSchedule()        // Token vesting with cliff and schedule

`sham.contract` — Smart Contracts

sham.contract.abi()                // Random ABI (functions + events)
sham.contract.erc20Abi()           // Standard ERC-20 ABI
sham.contract.erc721Abi()          // Standard ERC-721 ABI
sham.contract.info()               // Contract deployment info
sham.contract.bytecode(1024)       // Fake bytecode
sham.contract.selector()           // '0xa9059cbb' (4-byte selector)

`sham.signature` — Signatures & Signed Data

sham.signature.raw()               // 65-byte ECDSA signature
sham.signature.personal()          // Signed message with v, r, s
sham.signature.eip712('permit')    // EIP-712 Permit typed data
sham.signature.eip712('order')     // EIP-712 Exchange Order
sham.signature.eip712('vote')      // EIP-712 Governance Ballot

`sham.scenario` — Complex Scenarios

Pre-built generators for common testing setups:

// Full NFT drop — collection + 10k items with metadata
const drop = sham.scenario.nftDrop(10000);

// DAO election — proposals + voters + delegates + config
const election = sham.scenario.daoElection(3, 500);

// DEX trading — candles + trades + pool + order book
const trading = sham.scenario.dexTrading(1000);

// Wallet portfolio — tokens + NFTs + native balance
const portfolio = sham.scenario.walletPortfolio();

// Token airdrop — claims with Merkle proofs
const airdrop = sham.scenario.airdrop(5000);

// Full block — block header + transactions + receipts
const block = sham.scenario.fullBlock(200);

`sham.helpers` — Utilities

// Generate multiple of anything
sham.helpers.multiple(() => sham.address.wallet(), { count: 100 });

// Template strings
sham.helpers.fake('Wallet: {{address.wallet()}}');

Multi-Chain Support

sham.setChain('ethereum');  // Default
sham.setChain('polygon');
sham.setChain('arbitrum');
sham.setChain('optimism');
sham.setChain('base');
sham.setChain('avalanche');
sham.setChain('bsc');
sham.setChain('solana');

// Chain affects address formats, tx structures, and more
sham.setChain('solana');
sham.address.any();         // Base58 Solana address
sham.nft.metadata();        // Includes Metaplex `properties` field

sham.setChain('ethereum');
sham.address.any();         // EIP-55 checksummed address
sham.nft.metadata();        // Standard ERC-721 metadata

Deterministic Output

const a = new Sham3({ seed: 42 });
const b = new Sham3({ seed: 42 });

a.address.wallet() === b.address.wallet(); // true — always

CLI

# Generate 10 wallet addresses
npx sham3 address.wallet -n 10

# Generate NFT metadata for Solana
npx sham3 nft.metadata --chain solana

# Generate 100 OHLCV candles with seed
npx sham3 dex.candles -n 100 --seed 42

# Generate and save to file
npx sham3 scenario.nftDrop -n 1000 -o ./nfts.json

# DAO election data
npx sham3 dao.election

Use Cases

Scenario	How
NFT storefront testing	`sham.nft.collection(10000)` → JSON metadata for 10k NFTs
DAO governance testing	`sham.scenario.daoElection(5, 10000)` → proposals + voters
DEX trading bot testing	`sham.dex.candles(1000)` → realistic OHLCV price data
Airdrop testing	`sham.defi.airdrop(50000)` → claims with Merkle proofs
Wallet UI development	`sham.scenario.walletPortfolio()` → complete wallet state
Subgraph development	`sham.transaction.evm()` + `sham.transaction.log()` → event data
Smart contract testing	`sham.address.wallets(100)` → test accounts
Price feed mocking	`sham.dex.candles(500, { startPrice: 2000, volatility: 0.05 })`

Project Structure

sham3js/
├── src/
│   ├── index.ts              # Entry point & exports
│   ├── sham3.ts              # Main Sham3 class
│   ├── cli.ts                # CLI tool
│   ├── core/
│   │   ├── prng.ts           # Seeded PRNG (Mulberry32)
│   │   ├── keccak.ts         # Keccak-256 (pure JS)
│   │   ├── chains.ts         # Chain configurations
│   │   └── base-module.ts    # Base class for modules
│   ├── data/
│   │   └── pools.ts          # Static data pools
│   ├── modules/
│   │   ├── address.ts        # Wallet/contract addresses
│   │   ├── token.ts          # ERC-20 / SPL tokens
│   │   ├── nft.ts            # NFT metadata & collections
│   │   ├── transaction.ts    # Transactions & receipts
│   │   ├── block.ts          # Block headers
│   │   ├── dex.ts            # DEX trading data
│   │   ├── dao.ts            # DAO governance
│   │   ├── defi.ts           # DeFi protocols
│   │   ├── contract.ts       # Smart contracts & ABIs
│   │   └── signature.ts      # Signatures & EIP-712
│   └── scenarios/
│       └── index.ts          # Pre-built complex scenarios
├── tests/
│   └── sham3.test.ts         # Test suite (61 tests)
├── package.json
├── tsconfig.json
├── tsup.config.ts
└── vitest.config.ts

Contributing

PRs welcome! Areas that could use help:

More chain support (Cosmos, Aptos, Sui, TON)
More realistic data pools (real token names, real collection styles)
Subgraph entity generation
Hardhat/Foundry plugin
Browser bundle

License

MIT

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Repository files navigation

sham3js

Why sham3js?

Features

Install

Quick Start

API Reference

`sham.address` — Wallet & Contract Addresses

`sham.token` — ERC-20 / SPL Tokens

`sham.nft` — NFT Metadata & Collections

`sham.transaction` — Transactions & Receipts

`sham.block` — Block Headers

`sham.dex` — DEX & Trading Data

`sham.dao` — DAO Governance

`sham.defi` — DeFi Protocols

`sham.contract` — Smart Contracts

`sham.signature` — Signatures & Signed Data

`sham.scenario` — Complex Scenarios

`sham.helpers` — Utilities

Multi-Chain Support

Deterministic Output

CLI

Use Cases

Project Structure

Contributing

License

About

Uh oh!

Releases

Packages

Uh oh!

Contributors

Uh oh!

Languages

Name		Name	Last commit message	Last commit date
Latest commit History 3 Commits
src		src
tests		tests
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json
tsup.config.ts		tsup.config.ts
vitest.config.ts		vitest.config.ts

Folders and files

Latest commit

History

Repository files navigation

sham3js

Why sham3js?

Features

Install

Quick Start

API Reference

sham.address — Wallet & Contract Addresses

sham.token — ERC-20 / SPL Tokens

sham.nft — NFT Metadata & Collections

sham.transaction — Transactions & Receipts

sham.block — Block Headers

sham.dex — DEX & Trading Data

sham.dao — DAO Governance

sham.defi — DeFi Protocols

sham.contract — Smart Contracts

sham.signature — Signatures & Signed Data

sham.scenario — Complex Scenarios

sham.helpers — Utilities

Multi-Chain Support

Deterministic Output

CLI

Use Cases

Project Structure

Contributing

License

About

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Uh oh!

Contributors

Uh oh!

Languages

`sham.address` — Wallet & Contract Addresses

`sham.token` — ERC-20 / SPL Tokens

`sham.nft` — NFT Metadata & Collections

`sham.transaction` — Transactions & Receipts

`sham.block` — Block Headers

`sham.dex` — DEX & Trading Data

`sham.dao` — DAO Governance

`sham.defi` — DeFi Protocols

`sham.contract` — Smart Contracts

`sham.signature` — Signatures & Signed Data

`sham.scenario` — Complex Scenarios

`sham.helpers` — Utilities

Packages