# Advanced Permissions reference

> Advanced Permissions (ERC-7715) reference.

# Advanced Permissions reference

When [executing on a MetaMask user's behalf](../../guides/advanced-permissions/execute-on-metamask-users-behalf.md), you can request the following permission types for ERC-20 token and native token transfers.
Learn [how to use Advanced Permissions types](../../guides/advanced-permissions/use-permissions/erc20-token.md).

## ERC-20 token permissions

### ERC-20 allowance permission

Ensures a fixed ERC-20 token allowance.
Transfers are allowed until the total transferred amount reaches the allowance amount.

#### Parameters

| Name              | Type      | Required | Description                                                            |
| ----------------- | --------- | -------- | ---------------------------------------------------------------------- |
| `tokenAddress`    | `Address` | Yes      | The ERC-20 token contract address.                                     |
| `allowanceAmount` | `bigint`  | Yes      | The maximum total amount of tokens that can be transferred.            |
| `startTime`       | `number`  | No       | The start timestamp in seconds. The default is the current time.       |
| `justification`   | `string`  | No       | A human-readable explanation of why the permission is being requested. |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'erc20-token-allowance',
  data: {
    tokenAddress: '0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238',
    allowanceAmount: parseUnits('50', 6),
    startTime: currentTime,
    justification: 'Permission to transfer up to 50 USDC in total',
  },
  isAdjustmentAllowed: true,
}
```

### ERC-20 periodic permission

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.                                |
| `startTime`      | `number`  | No       | The start timestamp in seconds. The default is the current time.       |
| `justification`  | `string`  | No       | A human-readable explanation of why the permission is being requested. |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'erc20-token-periodic',
  data: {
    tokenAddress: '0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238',
    periodAmount: parseUnits('10', 6),
    periodDuration: 86400,
    justification: 'Permission to transfer 10 USDC every day',
  },
  isAdjustmentAllowed: true,
}
```

### ERC-20 stream permission

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`  | No       | The initial amount that can be transferred at start time. The default is `0`. |
| `maxAmount`       | `bigint`  | No       | The maximum total amount that can be unlocked. The default is no limit.       |
| `amountPerSecond` | `bigint`  | Yes      | The rate at which tokens accrue per second.                                   |
| `startTime`       | `number`  | No       | The start timestamp in seconds. The default is the current time.              |
| `justification`   | `string`  | No       | A human-readable explanation of why the permission is being requested.        |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'erc20-token-stream',
  data: {
    tokenAddress: '0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238',
    amountPerSecond: parseUnits('0.1', 6),
    initialAmount: parseUnits('1', 6),
    maxAmount: parseUnits('2', 6),
    startTime: currentTime,
    justification: 'Permission to use 0.1 USDC per second',
  },
  isAdjustmentAllowed: true,
}
```

## Native token permissions

### Native token allowance permission

Ensures a fixed native token allowance.
Transfers are allowed until the total transferred amount reaches the allowance amount.

#### Parameters

| Name              | Type     | Required | Description                                                            |
| ----------------- | -------- | -------- | ---------------------------------------------------------------------- |
| `allowanceAmount` | `bigint` | Yes      | The maximum total amount of tokens that can be transferred.            |
| `startTime`       | `number` | No       | The start timestamp in seconds. The default is the current time.       |
| `justification`   | `string` | No       | A human-readable explanation of why the permission is being requested. |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'native-token-allowance',
  data: {
    allowanceAmount: parseEther('0.05'),
    startTime: currentTime,
    justification: 'Permission to transfer up to 0.05 ETH in total',
  },
  isAdjustmentAllowed: true,
}
```

### Native token periodic permission

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.                                |
| `startTime`      | `number` | No       | The start timestamp in seconds. The default is the current time.       |
| `justification`  | `string` | No       | A human-readable explanation of why the permission is being requested. |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'native-token-periodic',
  data: {
    periodAmount: parseEther('0.001'),
    periodDuration: 86400,
    startTime: currentTime,
    justification: 'Permission to use 0.001 ETH every day',
  },
  isAdjustmentAllowed: true,
}
```

### Native token stream permission

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` | No       | The initial amount that can be transferred at start time. The default is `0`. |
| `maxAmount`       | `bigint` | No       | The maximum total amount that can be unlocked. The default is no limit.       |
| `amountPerSecond` | `bigint` | Yes      | The rate at which tokens accrue per second.                                   |
| `startTime`       | `number` | No       | The start timestamp in seconds. The default is the current time.              |
| `justification`   | `string` | No       | A human-readable explanation of why the permission is being requested.        |

#### Example

```typescript

const currentTime = Math.floor(Date.now() / 1000)
const expiry = currentTime + 604800

const permission = {
  type: 'native-token-stream',
  data: {
    amountPerSecond: parseEther('0.0001'),
    initialAmount: parseEther('0.1'),
    maxAmount: parseEther('1'),
    startTime: currentTime,
    justification: 'Permission to use 0.0001 ETH per second',
  },
  isAdjustmentAllowed: true,
}
```