For this example let’s say you’re terrible with remembering birthdays 😬 so you want to set up automatic on-chain reminders. Let’s write a smart contract that will emit an event to remind you:
BirthdayReminder.sol
// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.26;

contract BirthdayReminder {

    event HappyBirthday(string name, uint8 month, uint8 day);

    function remind(string calldata name, uint8 month, uint8 day) external {
        emit HappyBirthday(name, month, day);
    }
}
Now, let’s say you want to remind yourself about your friend Alice’s birthday. Simply construct an Instruction that uses the Call Action to call your BirthdayReminder contract one week before Alice’s birthday every year. Let’s break this down:
  • set Instruction.action to the address of the Call Action
  • set Instruction.arguments to encoded calldata specifying:
    • set Schedule.startAt to a Unix timestamp that’s about one week before Alice’s next birthday
    • set Schedule.interval to one year in seconds
    • the address of your BirthdayReminder contract
    • the function selector for remind
    • the encoded arguments name = "Alice", month = 1, and day = 1
These steps might look intimidating, but never fear, the Otim App will walk you through this process and abstract away these low-level details. Now, activate this Instruction and you’ll never forget Alice’s birthday again!