> For the complete documentation index, see [llms.txt](https://docs.davinci.wtf/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.davinci.wtf/get-to-know-erc404/version-2-contract-enhancements.md).

# Version 2 Contract Enhancements

ERC404 has already undergone its first major upgrade citing significant enhancements. 

The ERC404 protocol version 2.0-beta introduces significant updates to improve functionality and efficiency. Notably, it adopts a FIFO queue for ERC-721 token IDs, enhancing predictability and reusability, aligning with typical NFT collection behaviors. Full ERC-20 token transfers now also move associated ERC-721 tokens directly, streamlining asset management. The update brings clearer event emissions, dedicated functions for balance and supply queries, optional fixed supply cap, simplified transfer logic, and a more user-friendly minting function. Additionally, it incorporates EIP-2612 for permit approvals and EIP-165 support, alongside optimizations for gas savings.