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Use the function call scope

The function call scope defines the specific methods, contract addresses, and calldata that are allowed for the delegation. For example, Alice delegates to Bob the ability to call the approve function on the USDC contract, with the approval amount set to 0.

Internally, this scope uses the allowedTargets and allowedMethods caveat enforcers, and optionally uses the allowedCalldata or exactCalldata caveat enforcers when those parameters are specified.

Prerequisites​

Function call scope​

This scope requires targets and selectors as mandatory parameters for the configuration. You can specify the allowed methods in selectors and the permitted contract addresses in targets.

The following example sets the delegation scope to allow the delegate to call the approve function on the USDC token contract.

import { createDelegation } from "@metamask/delegation-toolkit";

// USDC address on Sepolia.
const USDC_ADDRESS = "0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238"

const delegation = createDelegation({
  scope: {
    type: "functionCall",
    targets: [USDC_ADDRESS],
    selectors: ["approve(address, uint256)"]
  },
  to: delegateAccount,
  from: delegatorAccount,
  environment: delegatorAccount.environment,
});

Next steps​

See how to further refine the authority of a delegation using caveat enforcers.

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