> For the complete documentation index, see [llms.txt](https://docs.cartesi.io/llms.txt)

---
resources:
  - url: https://github.com/cartesi/rollups-contracts/blob/v1.4.0/onchain/rollups/contracts/portals/ERC20Portal.sol
    title: ERC20Portal contract
---

The **ERC20Portal** allows anyone to perform transfers of
ERC-20 tokens to a dApp while informing the off-chain machine.

## `depositERC20Tokens()`

```solidity
function depositERC20Tokens(contract IERC20 _token, address _dapp, uint256 _amount, bytes _execLayerData) external
```

Transfer ERC-20 tokens to a dApp and add an input to
the dApp's input box to signal such operation.

The caller must allow the portal to withdraw at least `_amount` tokens
from their account beforehand, by calling the `approve` function in the
token contract.

#### Parameters

| Name            | Type            | Description                                              |
| --------------- | --------------- | -------------------------------------------------------- |
| \_token         | contract IERC20 | The ERC-20 token contract                                |
| \_dapp          | address         | The address of the dApp                                  |
| \_amount        | uint256         | The amount of tokens to be transferred                   |
| \_execLayerData | bytes           | Additional data to be interpreted by the execution layer |