Ethereum’s first chain letter: cracked byte-for-byte, 10 years later

On August 7, 2015 — the first day of Ethereum mainnet — someone deployed a 764-byte chain letter contract. Entry fee: 0.1 ETH. It had 100+ transactions.

Nobody knew who wrote it. No source code. No Etherscan verification.

We cracked it byte-for-byte this week. Compiler: soljson v0.1.1 with optimizer ON. The source follows the same MyScheme pattern as other Frontier-era chain letters — send ETH in, get paid out when the next person joins.

Proof and source: https://github.com/cartoonitunes/chainlettersmall-verification

What's interesting is that someone was already deploying these schemes on day 1. The Ethereum mainnet launched August 7, 2015 and the chain letter was deployed the same day (block 304).

We've been working through the unverified Frontier-era contract backlog systematically. Most of these contracts still have ETH locked inside. None of them have verified source code on Etherscan — the compilers are too old for the platform to support.

More documented on ethereumhistory.com