What is it?

Alarm is a service that operates on the Ethereum world computer.

Within the network there are two types of accounts.

  • Contracts: Controlled by a piece of code that has been deployed to the Ethereum network.
  • Private Key: Accounts that are controlled by a private key which is used to sign transaction.

The only difference between the capabilities of these two types of accounts is that only Private Key based accounts can initiate the execution of code which is done by sending a signed transaction into the Ethereum network.

A common requirement for software systems is execution of code at a specified time in the future. An example of one such mechanism is the crontab on unix based systems.

The Alarm service serves a similar purpose for Contracts on Ethereum. Since contracts are unable to initiate transactions themselves, the Alarm service sets up a marketplace that allows the operator of a private key based account to claim a reward in exchange for initiating the required transaction.