> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peaq.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Ensure Transfer Fee Allowance

## `vault.ensureTransferFeeAllowance(EnsureTransferFeeAllowance)`

Ensure an ERC20 allowance is set to pay the vault transfer fee for a given token transfer. If the allowance is insufficient, it submits an approval transaction.

### EnsureTransferFeeAllowance Type Parameters

| Parameter               | Type     | Required | Description                                                         |
| ----------------------- | -------- | -------- | ------------------------------------------------------------------- |
| **allowanceSigner**     | `Signer` | Required | Signer that pays the transfer fee. Must be connected to a provider. |
| **vault**               | `string` | Required | Vault address that computes the transfer fee.                       |
| **token**               | `string` | Required | Security token address being transferred.                           |
| **erc20**               | `string` | Required | ERC20 token address used to pay the fee.                            |
| **transferAmountHuman** | `string` | Required | Transfer amount in human-readable units (e.g., `"2"`).              |

### Returns

| Field          | Type                                                                                 | Description                                                       |
| -------------- | ------------------------------------------------------------------------------------ | ----------------------------------------------------------------- |
| **status**     | `already_sufficient` or `approved`                                                   | Whether an approval was sent.                                     |
| **vault**      | `string`                                                                             | Vault address.                                                    |
| **feeToken**   | `string`                                                                             | ERC20 token address used for fees.                                |
| **transfer**   | `{ token: string; amountHuman: string; amountUnits: bigint; tokenDecimals: number }` | Transfer amount details.                                          |
| **fee**        | `{ requiredAllowance: bigint; allowanceBefore: bigint; allowanceAfter: bigint }`     | Fee allowance details.                                            |
| **approvedBy** | `string`                                                                             | Address that submitted the approval (or current allowance owner). |
| **receipt**    | `TransactionReceipt`                                                                 | Only present when `status` is `'approved'`.                       |

### Usage

#### TypeScript

```TypeScript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
import 'dotenv/config';
import { RWA, Chain, type SDKInit } from "@peaq-network/rwa";
import { JsonRpcProvider, Wallet } from "ethers";

async function main() {
  // 0. Create RWA instance and get provider
  const provider = new JsonRpcProvider(process.env.HTTPS_BASE_URL);
  const init: SDKInit = { chainId: Chain.AGUNG, provider: provider };
  const rwa_sdk = new RWA(init);

  // 1. Allowance signer (pays transfer fee)
  const alice = new Wallet(process.env.ALICE_PRIVATE_KEY!, provider);

  // 2. Ensure transfer fee allowance
  const result = await rwa_sdk.vault.ensureTransferFeeAllowance({
    allowanceSigner: alice,
    vault: "0x907229D0A25A5Bb16F0ff3D890f38Eb4Ad52Ea1a",
    token: "0x2a6aA5ef4e236aeE4247EAA7B926cd843a95bFc8",
    erc20: rwa_sdk.getAddresses().erc20.peaq,
    transferAmountHuman: "2"
  });
  console.log("Result", result);
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});
```

#### JavaScript

```js theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
import 'dotenv/config';
import { RWA, Chain } from "@peaq-network/rwa";
import { JsonRpcProvider, Wallet } from "ethers";

async function main() {
  // 0. Create RWA instance and get provider
  const provider = new JsonRpcProvider(process.env.HTTPS_BASE_URL);
  const rwa_sdk = new RWA({ chainId: Chain.AGUNG, provider });

  // 1. Allowance signer (pays transfer fee)
  const alice = new Wallet(process.env.ALICE_PRIVATE_KEY, provider);

  // 2. Ensure transfer fee allowance
  const result = await rwa_sdk.vault.ensureTransferFeeAllowance({
    allowanceSigner: alice,
    vault: "0x907229D0A25A5Bb16F0ff3D890f38Eb4Ad52Ea1a",
    token: "0x2a6aA5ef4e236aeE4247EAA7B926cd843a95bFc8",
    erc20: rwa_sdk.getAddresses().erc20.peaq,
    transferAmountHuman: "2"
  });
  console.log("Result", result);
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});
```

### Example outputs

```
Result {
  status: 'approved',
  vault: '0x907229D0A25A5Bb16F0ff3D890f38Eb4Ad52Ea1a',
  feeToken: '0x...',
  transfer: {
    token: '0x2a6aA5ef4e236aeE4247EAA7B926cd843a95bFc8',
    amountHuman: '2',
    amountUnits: 2000000000000000000n,
    tokenDecimals: 18
  },
  fee: {
    requiredAllowance: 1000000000000000000n,
    allowanceBefore: 0n,
    allowanceAfter: 1000000000000000000n
  },
  approvedBy: '0x16cd4D21537eD8F33bE08271A9FA6DCC426709b2',
  receipt: ContractTransactionReceipt {
    ...
  }
}
```