Alarm

The Ethereum Alarm Clock (contract name: Alarm) was deployed at block 429,088 (October 23, 2015) by Piper Merriam, whose Ethereum address 0xd3cda913deb6f67967b99d67acdfa1712c293601 is hard-coded into the protocol's documentation as the default donation benefactor. The contract introduced a primitive but functional scheduler for the Ethereum Virtual Machine: by paying a small deposit, any account or contract could register a future block height at which a target function should be called. A network of "callers"—independent keepers—would monitor pending calls and execute them in exchange for a bounty drawn from the deposit.

The contract's source code, compiled with Solidity v0.1.6, shipped with a complete suite of utility libraries authored by Merriam himself: StringLib (integer-to-string conversion), a custom AccountingLib, and a SchedulerLib—together comprising more than 90,000 bytes of verified Solidity source. This made it one of the largest and most modular Solidity codebases deployed on Ethereum mainnet in the Frontier era, and an early demonstration that real application logic could live entirely on-chain.

The Ethereum Alarm Clock addressed a fundamental limitation of smart contracts: they cannot initiate actions autonomously. Without an external trigger, a contract can only respond to incoming transactions. Merriam's solution prefigured the modern "keeper" and "gelato" automation ecosystems that would emerge years later. The v0.7 deployment at block 429,088 was a mature iteration of the service; the project's GitHub shows active development from at least August 2015.

The project continued through multiple versions. Later iterations of Ethereum Alarm Clock (EAC) would influence Chainlink Automation, Gelato Network, and other scheduling protocols. The donationBenefactor constant in v1.0's documentation still points to Merriam's address, a direct link between the 2015 Frontier-era deployment and the modern codebase.