Byzantium Era

ERC20 token built on OpenZeppelin v1.3.0 with owner-restricted burn function. Deployed during the 2017-2018 ICO era.

CryptoCats pre-launch test contract (Nov 2017). The first version to introduce cat names and the allInitialOwnersAssigned() initialization pattern.

Proxy wallet that forwards received ETH to a configured bank address. Owner can sweep ETH and ERC-20 token balances to that same destination.

The first NFT game to achieve mainstream adoption, introducing on-chain collectibles, breeding mechanics, and ERC-721 ownership at global scale.

Exchange deposit wallet (UserWallet). Owner-only ETH collection and ERC-20 token sweeping with Deposit event logging.

Minimal delegatecall proxy. Forwards all calls to a hardcoded implementation address using DELEGATECALL, preserving the caller's storage context.

Exchange deposit wallet with ETH and ERC20 sweep functions. One of the most widely deployed bytecodes on Ethereum.

Token sweeper contract. Collects ERC20 balances from deposit addresses by calling sweep(tokenAddress) and forwarding tokens to a master wallet.

Token relay contract. Forwards ERC20 token transfers via transferToken(token, recipient, amount) on behalf of a configured owner.

ETH forwarder with configurable destination. Forwards incoming Ether to a parent address set at deployment, with an owner-only flush() method.

Minimal ETH forwarder. Hardcodes a destination address at deployment and unconditionally forwards all incoming Ether to it.

On-chain JPEG of a tabby cat: a 128x128 JFIF baseline image returned as a hex-text string by a single read() function. January 2018.

An ERC-20 token called FartCoin (FART) deployed in January 2018.

Exchange deposit wallet that collects ERC20 tokens via collect(tokenAddress, recipient, amount) and ETH via a payable fallback function.

Token distributor contract. Transfers ERC20 tokens from the contract to recipients via sendCoin(recipient, amount, tokenAddress).

User withdrawal account. Holds ETH and ERC20 tokens on behalf of a user and allows owner-authorized withdrawals to a registered user address.

February 2018 hot-potato collectible game on Ethereum. Five tokens: Red, Blue, Lime, Yellow, Orange — each storing R/G/B values on-chain.

The original EIP-918 mineable token, Bitcoin's proof-of-work on Ethereum

First deploy of CryptHall Of Fame by colmea.eth, abandoned 8 minutes later. No tokens were ever created on this instance. The canonical contract is at 0xb041de4

Feb 2018 personal NFT scrapbook by Belgian dev colmea.eth — 12 heroes (5 named: De Sprimont family, friend Hadrien, dog Noukie, Kylo Ren, belle panthère) on a C

ETH forwarder with administrative controls. Forwards incoming Ether to a parent address and supports flushTokens(ERC20) and a kill() self-destruct.

First 0xBitcoin clone, deployed 10 days after 0xBTC. Permanently bricked after 12 mints by a reward dust term and a recursive era-cap bug.

ERC-721 collectible card game of historical figures. mineCard() costs 0.001 ETH and randomly assigns a figure via block.timestamp randomness.

BitGo WalletSimple multisig wallet. Requires two-of-three key signatures for sendMultiSig ETH transfers and sendMultiSigToken ERC20 transfers.