Delegation scopes

When creating a delegation, you can configure the following scopes to define the delegation's initial authority. Learn how to use delegation scopes.

Spending limit scopes

ERC-20 periodic scope

Ensures a per-period limit for ERC-20 token transfers. At the start of each new period, the allowance resets.

Parameters

Name	Type	Required	Description
tokenAddress	Address	Yes	The ERC-20 token contract address as a hex string.
periodAmount	bigint	Yes	The maximum amount of tokens that can be transferred per period.
periodDuration	number	Yes	The duration of each period in seconds.
startDate	number	Yes	The timestamp when the first period begins in seconds.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "erc20PeriodTransfer",
    tokenAddress: "0xb4aE654Aca577781Ca1c5DE8FbE60c2F423f37da",
    periodAmount: 1000000000000000000n,
    periodDuration: 86400,
    startDate: 1743763600,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

ERC-20 streaming scope

Ensures a linear streaming transfer limit for ERC-20 tokens. Token transfers are blocked until the defined start timestamp. At the start, a specified initial amount is released, after which tokens accrue linearly at the configured rate, up to the maximum allowed amount.

Parameters

Name	Type	Required	Description
tokenAddress	Address	Yes	The ERC-20 token contract address.
initialAmount	bigint	Yes	The initial amount that can be transferred at start time.
maxAmount	bigint	Yes	The maximum total amount that can be unlocked.
amountPerSecond	bigint	Yes	The rate at which tokens accrue per second.
startTime	number	Yes	The start timestamp in seconds.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "erc20Streaming",
    tokenAddress: "0xc11F3a8E5C7D16b75c9E2F60d26f5321C6Af5E92",
    amountPerSecond: 100n,
    initialAmount: 1000000n,
    maxAmount: 10000000n,
    startTime: 1703980800,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

ERC-20 transfer scope

Ensures that ERC-20 token transfers are limited to a predefined maximum amount. This scope is useful for setting simple, fixed transfer limits without any time-based or streaming conditions.

Parameters

Name	Type	Required	Description
tokenAddress	Address	Yes	The ERC-20 token contract address.
maxAmount	bigint	Yes	The maximum amount of tokens that can be transferred by delegate.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "erc20TransferAmount",
    tokenAddress: "0xc11F3a8E5C7D16b75c9E2F60d26f5321C6Af5E92",
    maxAmount: 10000n,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

ERC-721 scope

Limits the delegation to ERC-721 token (NFT) transfers only.

Parameters

Name	Type	Required	Description
tokenAddress	Address	Yes	The ERC-721 token contract address.
tokenId	bigint	Yes	The ID of the ERC-721 token that can be transferred by delegate.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "erc721Transfer",
    tokenAddress: "0x3fF528De37cd95b67845C1c55303e7685c72F319",
    tokenId: 1n,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

Native token periodic scope

Ensures a per-period limit for native token transfers. At the start of each new period, the allowance resets.

Parameters

Name	Type	Required	Description
periodAmount	bigint	Yes	The maximum amount of tokens that can be transferred per period.
periodDuration	number	Yes	The duration of each period in seconds.
startDate	number	Yes	The timestamp when the first period begins in seconds.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "nativeTokenPeriodTransfer",
    periodAmount: 1000000000000000000n,
    periodDuration: 86400,
    startDate: 1743763600,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

Native token streaming scope

Ensures a linear streaming transfer limit for native tokens. Token transfers are blocked until the defined start timestamp. At the start, a specified initial amount is released, after which tokens accrue linearly at the configured rate, up to the maximum allowed amount.

Parameters

Name	Type	Required	Description
initialAmount	bigint	Yes	The initial amount that can be transferred at start time.
maxAmount	bigint	Yes	The maximum total amount that can be unlocked.
amountPerSecond	bigint	Yes	The rate at which tokens accrue per second.
startTime	number	Yes	The start timestamp in seconds.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "nativeTokenStreaming",
    amountPerSecond: 100n,
    initialAmount: 1000000n,
    maxAmount: 10000000n,
    startTime: 1703980800,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

Native token transfer scope

Ensures that native token transfers are limited to a predefined maximum amount. This scope is useful for setting simple, fixed transfer limits without any time based or streaming conditions.

Parameters

Name	Type	Required	Description
maxAmount	bigint	Yes	The maximum amount of tokens that can be transferred by delegate.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "nativeTokenTransferAmount",
    // 0.001 ETH in wei format.
    maxAmount: 1000000000000000n,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

Function call scope

Defines the specific methods, contract addresses, and calldata that are allowed for the delegation.

Parameters

Name	Type	Required	Description
targets	Address[]	Yes	The list of addresses that the delegate is allowed to call.
selectors	MethodSelector[]	Yes	The list of method selectors that the delegate is allowed to call. The selector value can be 4-byte hex string, ABI function signature, or ABI function object.
allowedCalldata	AllowedCalldataBuilderConfig[]	No	The list of calldata that the delegate is allowed to call.
exactCalldata	ExactCalldataBuilderConfig	No	The calldata that the delegate is allowed to call.

Example

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

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const delegation = createDelegation({
  scope: {
    type: "functionCall",
    targets: ["0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238"], // USDC address on Sepolia.
    selectors: ["approve(address, uint256)"]
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});

Ownership transfer scope

Restricts a delegation to ownership transfer calls only.

Parameters

Name	Type	Required	Description
contractAddress	Address	Yes	The target contract address for which ownership transfers are allowed.

Example

import { createDelegation, getDelegatorEnvironment } from "@metamask/delegation-toolkit";
import { sepolia } from "viem/chains";

const contractAddress = "0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238"

const delegation = createDelegation({
  scope: {
    type: "ownershipTransfer",
    contractAddress,
  },
  // Address that is granting the delegation
  from: "0x7E48cA6b7fe6F3d57fdd0448B03b839958416fC1",
  // Address to which the delegation is being granted
  to: "0x2B2dBd1D5fbeB77C4613B66e9F35dBfE12cB0488",
  // Alternatively you can use environment property of MetaMask smart account.
  environment: getDelegatorEnvironment(sepolia.id);
});