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

# Patching

> Extending existing NFTs and accounts

A patch is a 721 that "extends" another NFT (721, 1155) or an account. A patch is soulbound to the patched target and by default cannot point to anything else.

Patchwork Patches are mostly regular Patchwork 721s and can have Patchwork metadata. They can also be fragments but with soulbound ownership rules.

Patchwork has 3 types of patches: 721, 1155 and Account.

## 721 Patch

721 patches target an ERC-721 contract by targeting the address and tokenId.

```solidity theme={null}
patchworkProtocol.patch(address owner, address originalAddress, uint originalTokenId, address patchAddress)
```

721 Patch contracts must implement the `IPatchworkPatch` interface and can be generated with the feature `patch` in a PDK contract configuration

## 1155 Patch

1155 patches target an ERC-1155 contract by targeting the address, tokenId and account address. By using a `0x0` address for the account, you can target the entirety of an 1155's tokenId.

```solidity theme={null}
patchworkProtocol.patch1155(address to, address originalAddress, uint originalTokenId, address originalAccount, address patchAddress)
```

1155 Patch contracts must implement the `IPatchwork1155Patch` interface and can be generated with the feature `1155patch` in a PDK contract configuration

## Account Patch

An account patch targets a plain address.

```solidity theme={null}
patchworkProtocol.patchAccount(address owner, address originalAddress, address patchAddress)
```

Account Patch contracts must implement the `IPatchworkAccountPatch` interface and can be generated with the feature `accountpatch` in a PDK contract configuration