The Alarm service operates under a scheduler pays model, which means that the scheduler of a call is responsible for paying up front for all costs associated with execution. These funds are held within the call contract until execution or cancellation.

Call Payment and Donation

When a call is scheduled, the scheduler can either provide values for the payment and donation, or leave them off in favor of using the default values.

The account which executes the scheduled call is reimbursed 100% of the gas cost + payment for their service.

The donation is sent to the creator of the Alarm service.

Default Payment Value

The default used for the payment value for each scheduled call is ultimately decided by the open market.

  • If calls are being claimed early in the claim window the value will decrease.
  • If calls are being claimed late in the claim window the value will increase


This algorithm is a work in progress. If you have ideas on ways to improve this feel free to reach out to me.

Gas Costs

  • Scheduling a function call takes approximately 1.1 million gas.
  • Execution adds approximately 100,000 gas of overhead.

The Gas Price Scalar multiplier

Both the payment and the donation are multiplied by the GasPriceScalar.

GasPriceScalar is a multiplier that ranges from 0 - 2 which is based on the difference between the gas priced used for call execution and the gas price used during call scheduling. This number incentivises the call executor to use as low a gas price as possible.

This multiplier is computed with the following formula.

  • IF gasPrice > anchorGasPrice

anchorGasPrice / gasPrice

  • IF gasPrice <= anchorGasPrice

anchorGasPrice / (2 * anchorGasPrice - gasPrice)


  • anchorGasPrice is the tx.gasprice used when the call was scheduled.
  • gasPrice is the tx.gasprice used to execute the call.

At the time of call execution, the anchorGasPrice has already been set, so the only value that is variable is the gasPrice which is set by the account executing the transaction. Since the scheduler is the one who ends up paying for the actual gas cost, this multiplier is designed to incentivize the caller using the lowest gas price that can be expected to be reliably picked up and promptly executed by miners.

Here are the values this formula produces for a baseGasPrice of 20 and a gasPrice ranging from 10 - 40;

gasPrice multiplier
15 1.20
16 1.17
17 1.13
18 1.09
19 1.05
20 1.00
21 0.95
22 0.91
23 0.87
24 0.83
25 0.80
26 0.77
27 0.74
28 0.71
29 0.69
30 0.67
31 0.65
32 0.63
33 0.61
34 0.59
35 0.57
36 0.56
37 0.54
38 0.53
39 0.51
40 0.50

You can see from this table that as the gasPrice for the executing transaction increases, the total payout for executing the call decreases. This provides a strong incentive for the entity executing the transaction to use a reasonably low value.

Alternatively, if the gasPrice is set too low (potentially attempting to maximize payout) and the call is not picked up by miners in a reasonable amount of time, then the entity executing the call will not get paid at all. This provides a strong incentive to provide a value high enough to ensure the transaction will be executed.