Multiply7: The First Ethereum Tutorial Contract, Verified (August 10, 2015)

Three days after Ethereum mainnet launched in July 2015, someone deployed a contract that multiplied any number by 7.

That's it. One function. Ten lines of Solidity.

solidity
contract Multiply7 {
function multiply(uint input) constant returns (uint) {
return input * 7;
}
}


It's the canonical example from the original Solidity documentation – the "Hello World" of smart contracts. And someone deployed it to mainnet on August 10, 2015, block 63,886.

We just verified it using compiler archaeology: exact bytecode match with soljson v0.1.1 (the first public Solidity release), optimizer off. The deployer's address (0xc70ba22f) also deployed 10 other contracts in the same period – CoinFlip gambling variants, early token experiments, a Greeter. A developer working through every tutorial they could find in Ethereum's first week.

The contract is long since dormant. 126 bytes of bytecode, 49,243 gas to deploy. But it's verifiably there, permanently, on the canonical chain.

Verification repo: https://github.com/cartoonitunes/multiply7-verification
EthereumHistory page: https://www.ethereumhistory.com/contract/0xfcb20ae9a3fa95af55803b8cdab4b0643fb96d3f

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