nft contract

src/NFTIndexer.sol

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.13;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
+
+contract Indexer is ERC721URIStorage, Ownable {
+    address public holder;
+
+    uint256 private _tokenId;
+
+    constructor() ERC721("OpenFlow", "OF") Ownable(msg.sender) {}
+
+    function mint(string memory _uri) public onlyOwner {
+        __mint(_uri);
+    }
+
+    function mintBatch(string[] memory _uris) public onlyOwner {
+        for (uint256 i = 0; i < _uris.length; i++) {
+            __mint(_uris[i]);
+        }
+    }
+
+    function __mint(string memory _uri) private {
+        uint256 newtokenId = _tokenId++;
+
+        _setTokenURI(newtokenId, _uri);
+        _mint(holder, newtokenId);
+    }
+}