Transaction Request

class TransactionRequest

Each TransactionRequest contract represents one transaction that has been scheduled for future execution. This contract is not intended to be used directly as the RequestFactory contract can be used to create new TransactionRequest contracts with full control over all of the parameters.


//pragma solidity 0.4.1;

contract TransactionRequestInterface {
     *  Primary actions
    function execute() public returns (bool);
    function cancel() public returns (bool);
    function claim() public returns (bool);

     *  Data accessors
    function requestData() constant returns (address[6],
    function callData() constant returns (bytes);

     *  Pull mechanisms for payments.
    function refundClaimDeposit() public returns (bool);
    function sendDonation() public returns (bool);
    function sendPayment() public returns (bool);
    function sendOwnerEther() public returns (bool);


TransactionRequest.Cancelled(uint rewardPayment, uint measuredGasConsumption)

When a request is cancelled, the Cancelled event will be logged. The rewardPayment is the amount that was paid to the party that cancelled the request. This will always be 0 when the owner of the request cancels the request.


When a request is claimed this event is logged.

TransactionRequest.Aborted(uint8 reason);

When an attempt is made to execute a request but one of the pre-execution checks fails, this event is logged. The reason is an error code which maps to the following errors.

  • 0 => WasCancelled
  • 1 => AlreadyCalled
  • 2 => BeforeCallWindow
  • 3 => AfterCallWindow
  • 4 => ReservedForClaimer
  • 5 => StackTooDeep
  • 6 => InsufficientGas
TransactionRequest.Executed(uint payment, uint donation, uint measuredGasConsumption)

When a request is successfully executed this event is logged. The payment is the total payment amount that was awarded for execution. The donation is the amount that was awarded to the donationBenefactor. The measuredGasConsumption is the amount of gas that was reimbursed which should always be slightly greater than the actual gas consumption.

Data Model

The data for the transaction request is split into 5 main sections.

  • Transaction Data: Information specific to the execution of the transaction.
  • Payment Data: Information related to the payment and donation associated with this request.
  • Claim Data: Information about the claim status for this request.
  • Schedule Data: Information about when this request should be executed.
  • Meta Data: Information about the result of the request as well as which address owns this request and which address created this request.

Retrieving Data

The data for a request can be retrieved using two methods.


This function returns the serialized request data (excluding the callData) in a compact format spread across four arrays. The data is returned alphabetical, first by type, and then by section, then by field.

The return value of this function is four arrays.

  • address[6] addressValues
  • bool[3] boolValues
  • uint256[15] uintValues
  • uint8[1] uint8Values

These arrays then map to the following data fields on the request.

  • Addresses (address)
    • addressValues[0] => claimData.claimedBy
    • addressValues[1] => meta.createdBy
    • addressValues[2] => meta.owner
    • addressValues[3] => paymentData.donationBenefactor
    • addressValues[4] => paymentData.paymentBenefactor
    • addressValues[5] => txnData.toAddress
  • Booleans (bool)
    • boolValues[0] => meta.isCancelled
    • boolValues[1] => meta.wasCalled
    • boolValues[2] => meta.wasSuccessful
  • Unsigned 256 bit Integers (uint aka uint256)
    • uintValues[0]  => claimData.claimDeposit
    • uintValues[1]  => paymentData.anchorGasPrice
    • uintValues[2]  => paymentData.donation
    • uintValues[3]  => paymentData.donationOwed
    • uintValues[4]  => paymentData.payment
    • uintValues[5]  => paymentData.paymentOwed
    • uintValues[6]  => schedule.claimWindowSize
    • uintValues[7]  => schedule.freezePeriod
    • uintValues[8]  => schedule.reservedWindowSize
    • uintValues[9]  => schedule.temporalUnit)
    • uintValues[10] => schedule.windowStart
    • uintValues[11] => schedule.windowSize
    • uintValues[12] => txnData.callGas
    • uintValues[13] => txnData.callValue
    • uintValues[14] => txnData.requiredStackDepth
  • Unsigned 8 bit Integers (uint8)
    • uint8Values[0] => claimData.paymentModifier

Returns the bytes value of the callData from the request’s transaction data.

Transaction Data

This portion of the request data deals specifically with the transaction that has been requested to be sent at a future block or time. It has the following fields.

address toAddress

The address that the transaction will be sent to.

bytes callData

The bytes that will be sent as the data section of the transaction.

uint callValue

The amount of ether, in wei, that will be sent with the transaction.

uint callGas

The amount of gas that will be sent with the transaction.

uint requiredStackDepth

The number of stack frames required by this transaction.

Payment Data

Information surrounding the payment and donation for this request.

uint anchorGasPrice

The gas price that was used during creation of this request. This is used to incentivise the use of an adequately low gas price during execution.

See Gas Multiplier for more information on how this is used.

uint payment

The amount of ether in wei that will be paid to the account that executes this transaction at the scheduled time.

address paymentBenefactor

The address that the payment will be sent to. This is set during execution.

uint paymentOwed

The amount of ether in wei that is owed to the paymentBenefactor. In most situations this will be zero at the end of execution, however, in the event that sending the payment fails the payment amount will be stored here and retrievable via the sendPayment() function.

uint donation

The amount of ether, in wei, that will be sent to the donationBenefactor upon execution.

address donationBenefactor

The address that the donation will be sent to.

uint donationOwed

The amount of ether in wei that is owed to the donationBenefactor. In most situations this will be zero at the end of execution, however, in the event that sending the donation fails the donation amount will be stored here and retrievable via the sendDonation() function.

Claim Data

Information surrounding the claiming of this request. See Claiming for more information.

address claimedBy

The address that has claimed this request. If unclaimed this value will be set to the zero address 0x0000000000000000000000000000000000000000

uint claimDeposit

The amount of ether, in wei, that has been put down as a deposit towards claiming. This amount is included in the payment that is sent during request execution.

uint8 paymentModifier

A number constrained between 0 and 100 (inclusive) which will be applied to the payment for this request. This value is determined based on the time or block that the request is claimed.

Schedule Data

Information related to the window of time during which this request is scheduled to be executed.

uint temporalUnit

Determines if this request is scheduled based on block numbers or timestamps.

  • Set to 1 for block based scheduling.
  • Set to 2 for timestamp based scheduling.

All other values are interpreted as being blocks or timestamps depending on what this value is set as.

uint windowStart

The block number or timestamp on which this request may first be executed.

uint windowSize

The number of blocks or seconds after the windowStart during which the request may still be executed. This period of time is referred to as the execution window. This period is inclusive of it’s endpoints meaning that the request may be executed on the block or timestamp windowStart + windowSize.

uint freezePeriod

The number of blocks or seconds prior to the windowStart during which no activity may occur.

uint reservedWindowSize

The number of blocks or seconds during the first portion of the the execution window during which the request may only be executed by the address that address that claimed the call. If the call is not claimed, then this window of time is treated no differently.

uint claimWindowSize

The number of blocks prior to the freezePeriod during which the call may be claimed.

Meta Data

Information about ownership, creation, and the result of the transaction request.

address owner

The address that scheduled this transaction request.

address createdBy

The address that created this transaction request. This value is set by the RequestFactory meaning that if the request is known by the request factory then this value can be trusted to be the address that created the contract. When using either the BlockScheduler or TimestampScheduler this address will be set to the respective scheduler contract..

bool isCancelled

Whether or not this request has been cancelled.

bool wasCalled

Whether or not this request was executed.

bool wasSuccessful

Whether or not the execution of this request returned true or false. In most cases this can be an indicator that an execption was thrown if set to false but there are also certain cases due to quirks in the EVM where this value may be true even though the call technically failed.


The TransactionRequest contract has three primary actions that can be performed.

  • Cancellation: Cancels the request.
  • Claiming: Reserves exclusive execution rights during a portion of the execution window.
  • Execution: Sends the requested transaction.



Cancellation can occur if either of the two are true.

  • The current block or time is before the freeze period and the request has not been claimed.
  • The current block or time is after the execution window and the request was not executed.

When cancelling prior to the execution window, only the owner of the call may trigger cancellation.

When cancelling after the execution window, anyone may trigger cancellation. To ensure that funds are not forever left to rot in these contracts, there is an incentive layer for this function to be called by others whenever a request fails to be executed. When cancellation is executed by someone other than the owner of the contract, 1% of what would have been paid to someone for execution is paid to the account that triggers cancellation.



Claiming may occur during the claimWindowSize number of blocks or seconds prior to the freeze period. For example, if a request was configured as follows:

  • windowStart: block #500
  • freezePeriod: 10 blocks
  • claimWindowSize: 100 blocks

In this case, the call would first be claimable at block 390. The last block in which it could be claimed would be block 489.

See the Claiming section of the documentation for details about the claiming process.



Execution may happen beginning at the block or timestamp denoted by the windowStart value all the way through and including the block or timestamp denoted by windowStart + windowSize.

See the Execution section of the documentation for details about the execution process.

Retrieval of Ether

All payments are automatically returned as part of normal request execution and cancellation. Since it is possible for these payments to fail, there are backup methods that can be called individually to retrieve these different payment or deposit values.

All of these functions may be called by anyone.

Returning the Claim Deposit


This method will return the claim deposit if either of the following conditions are met.

  • The request was cancelled.
  • The execution window has passed.

Retrieving the Payment


This function will send the paymentOwed value to the paymentBenefactor. This is only callable after the execution window has passed.

Retrieving the Donation


This function will send the donationOwed value to the donationBenefactor. This is only callable after the execution window has passed.

Return any extra Ether

This function will send any exta ether in the contract that is not owed as a donation or payment and that is not part of the claim deposit back to the owner of the request. This is only callable if one of the following conditions is met.

  • The request was cancelled.
  • The execution window has passed.