CAIP-22: Asset Reference for the ERC721 Asset Namespace

Author	Antoine Herzog, Pedro Gomes, Joel Thorstensson
Discussions-To	https://github.com/ChainAgnostic/CAIPs/pull/19
Status	Superseded
Type	Standard
Created	2020-06-23
Updated	2020-06-23
Requires	19
Superseded By	https://github.com/ChainAgnostic/namespaces/tree/main/eip155/caip19.md

Simple Summary
Abstract
Motivation
Specification
- ERC721 Asset Namespace
Rationale
Backwards Compatibility
Test Cases
Copyright

Simple Summary

This document is about the details of the ERC721 asset namespace and reference for CAIP-19.

Abstract

In CAIP-19 a general asset identification scheme is defined. This is the implementation of CAIP-19 for ERC721 (referencing NFT tokens).

Motivation

See CAIP-19.

Specification

ERC721 Asset Namespace

The asset namespace is called “erc721” as in ERC721. It reference erc721 tokens (NFT) in the eip155 namespace (cf. CAIP3).

Asset Reference Definition

The Asset Reference format is the smart contract address of the erc721 token in the current chain_id.

Token ID Definition

The Token Id format is the NFT Identifier of the erc721 specification in the current chain_id.

Rationale

The smart contract address strives for uniqueness for any erc721 tokens in the chain_id scope.

Backwards Compatibility

Not applicable

Test Cases

This is a list of manually composed examples

# CryptoKitties Collectible
eip155:1/erc721:0x06012c8cf97BEaD5deAe237070F9587f8E7A266d

# CryptoKitties Collectible ID
eip155:1/erc721:0x06012c8cf97BEaD5deAe237070F9587f8E7A266d/771769

Copyright

Citation

Please cite this document as:

Antoine Herzog, Pedro Gomes, Joel Thorstensson, "CAIP-22: Asset Reference for the ERC721 Asset Namespace," Chain Agnostic Improvement Proposals, no. 22, June 2020. [Online serial]. Available: https://github.com/ChainAgnostic/CAIPs/blob/master/CAIPs/caip-22.md