Safe_ExecTransaction_OnReturnValue

Safe_ExecTransaction_OnReturnValue is an advanced integration mandate that executes a transaction on a Gnosis Safe, dynamically constructing the call data using the return value of a previous action.

Overview

This mandate allows for complex, multi-step workflows where the output of one action (e.g., a deployed contract address or a calculated value) becomes a parameter in a subsequent Safe transaction. It “sandwiches” the dynamic return data between static byte arrays to form the complete function call.

It assumes that the Powers contract is an owner of the target Safe, allowing it to authorize transactions directly.

Configuration

When adopting a Safe_ExecTransaction_OnReturnValue instance, the following parameters are required:

1. TargetContract (address): The destination address for the internal Safe transaction.
2. FunctionSelector (bytes4): The function selector of the call to be made.
3. paramsBefore (bytes): Static bytes to append before the dynamic return data.
4. Params (string[]): The description of input parameters required by the parent mandate.
5. parentMandateId (uint16): The ID of the parent mandate that generates the dynamic data.
6. paramsAfter (bytes): Static bytes to append after the dynamic return data.

Usage

Proposing an Action

When calling the mandate, the inputs provided must match the inputs expected by the parent parentMandateId. These inputs are used to re-compute the parent’s Action ID to look up its result.

Execution Flow

1. Data Retrieval

   • Computes the parentActionId using the provided calldata.
   • Retrieves the returnData from the executed parent action.

2. Transaction Construction

   • Assembles the full transaction data: FunctionSelector + paramsBefore + returnData + paramsAfter.
   • Constructs a signature (v=1) authorizing the transaction as the Powers contract (owner).

3. Safe Execution

   • Identifies the Safe Treasury address.
   • Generates a call to Safe.execTransaction.
   • The Safe executes the internal call to TargetContract with the assembled data.

Technical Specifications

Functions

initializeMandate

function initializeMandate(...) public override

• Initializes the mandate configuration.
• Sets the input parameter descriptions.

handleRequest

function handleRequest(...) public view override returns (...)

• Retrieves dynamic data.
• Constructs the composite call data.
• Generates the Safe transaction.

Current Deployments

Chain ID	Chain Name	Address