> For the complete documentation index, see [llms.txt](https://docs.streamnft.tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.streamnft.tech/for-developers/on-chain-reference.md).

# On-Chain Reference

If your project uses on-chain calls for `token owner`, replace them with streamNFT contract calls using the streamNFT ABI

<details>

<summary>StreamNFT ABI for NFT State calls</summary>

```json
[
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "ownerOf",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "tokenAddress",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "tokenId",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "user",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "tokenAddress",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "user",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  }
]
```

</details>

1. For ERC721 token, you need to update on-chain call with <br>

   ```javascript
   (ERC721) ownerOf(tokenId) -> (streamNFT) ownerOf(tokenAddress,tokenId)
   (ERC721) balanceOf(user) -> (streamNFT) balanceOf(tokenAddress,user)
   ```
2. For ERC1155 token, you need to update on-chain call with&#x20;

   ```javascript
   (ERC1155) balanceOf(tokenId,user) -> (streamNFT) balanceOf(tokenAddress,tokenId,user)
   ```