EthereumAlarmClock

This contract was deployed at block 273762 on September 22, 2015, by the address 0xd3CdA913deB6f67967B99D67aCDFa1712C293601, identified as belonging to Piper Merriam (pipermerriam). Merriam confirmed the September 22, 2015 launch date in a 2018 Medium post describing the service's history. The contract received seven transactions, with an initial burst of activity in the days immediately following deployment.

The Ethereum Alarm Clock addressed a fundamental limitation of the Ethereum protocol: smart contracts cannot schedule their own future execution. In Ethereum's design, a contract runs only when triggered by a transaction from an external account. The Alarm Clock provided a workaround by allowing users to schedule a function call at a specified target block number. Third-party executors would send the triggering transaction at the appropriate time, receiving a payment as compensation along with reimbursement for gas costs.

Merriam described working intensively on the service over the year following the initial launch, fixing attack vectors and refining the game-theoretic incentives for executors. A rewritten set of contracts was being prepared in September 2016 when the Ethereum network's gas-price denial-of-service attacks disrupted development. The service was later revived in partnership with ChronoLogic, which contributed development resources to reboot and modernize the contracts.

This initial deployment represents the prototype that established the scheduling model. Subsequent versions by the same deployer, including a cluster of five contracts deployed on December 23, 2015, iterated on the design over the following months.