> 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/ERC721Portal.sol
    title: ERC721Portal contract
---

The **ERC721Portal** allows anyone to perform transfers of
ERC-721 tokens to a dApp while informing the off-chain machine.

## `depositERC721Token()`

```solidity
function depositERC721Token(contract IERC721 _token, address _dapp, uint256 _tokenId, bytes _baseLayerData, bytes _execLayerData) external
```

Transfer an ERC-721 token to a dApp and add an input to
the dApp's input box to signal such operation.

The caller must change the approved address for the ERC-721 token
to the portal address beforehand, by calling the `approve` function in the
token contract.

#### Parameters

| Name            | Type             | Description                                              |
| --------------- | ---------------- | -------------------------------------------------------- |
| \_token         | contract IERC721 | The ERC-721 token contract                               |
| \_dapp          | address          | The address of the dApp                                  |
| \_tokenId       | uint256          | The identifier of the token being transferred            |
| \_baseLayerData | bytes            | Additional data to be interpreted by the base layer      |
| \_execLayerData | bytes            | Additional data to be interpreted by the execution layer |