Skip to main content

ETM_ATTRIBUTES_v1.0.0

ETM Attributes Extension​

AuthorsZack Pantely, Kavan Sikand
Contributors
Discussions Tohttps://github.com/ETM-Standard/etm-standard.github.io/discussions/4
TypeETM Extension
Extension NameETM_ATTRIBUTES_v1.0.0
Created2022-06-06

Table of contents​

Summary​

This extension is a formalization of a de-facto standard in the Non-Fungible Token (NFT) community. It draws heavy inspiration from OpenSea's Attributes Standard, and allows it to be used in conjunction with other extensions to ETM.

Abstract​

This extension exists only to formalize, name, and freeze the attributes standard provided by OpenSea. In formalizing this standard, we seek to remove all ambiguity about the form and intended interpretation of items in the attributes array. In naming this standard, we seek to allow its form to be identified by a metadata consumer or possibly replaced with a future standard. In freezing this standard, we seek to let consumers be sure about how to interpret the attributes array for all time, even if OpenSea were to later update their standard.

Motivation​

In the future, it is likely that more functionality and flexibility will be desired when assigning attributes to an NFT. Adopting this standard now means that all metadata creators and consumers will have the ability to migrate seamlessly to a new standard at a later time while still supporting NFTs that were made following an older standard. If such adoption does not take place, the longer-term solution may be to add a new top-level key such as "attributes2" in order to make breaking changes to the standard -- a fate which should make us cringe in disgust and dismay.

Specification​

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.

Top-Level Metadata:​

This specification adds the attributes key to the top level of ETM metadata JSON.

{
  "metadata_standard": "ETM_v1.0.0",
  "extensions": [ "ETM_ATTRIBUTES_v1.0.0" ],
  "attributes": []
}

In the above metadata, the attributes array is left empty in order to show the minimum valid implementation of this extension. For a non-trivial example, refer to the Metadata Examples section.

Extended Top-Level Data Types:​

The top-level keys of the metadata MUST include all required fields in the below table in addition to fields required by the metadata standard to which this extension is applied.

Field NameData TypeInclusion
attributesAttribute[]REQUIRED

The attributes key provides an array of Attribute data types, defined below.

Attribute Data Type:​

The Attribute data type is a JSON object which defines all attribute data. The fields for this data type are defined in the table below.

Field NameData TypeInclusion
display_typestringOPTIONAL
trait_typestringRECOMMENDED
valuestring | number | booleanREQUIRED

The optional display_type key allows creators to define how an attribute should be displayed. This extension does not specify a set of valid entries for the display_type and instead leaves that definition to a subsequent extension.

The trait_type key allows creators to set the name of the trait this attribute represents.

The value key allows creators to set the value of an attribute. The value of this field can be any valid JSON value type and must be handled appropriately by metadata consumers.

Metadata Examples​

Supporting OpenSea's Standard​

The following is an example of this extension being used as a wrapper for OpenSea's standard.

{
  "metadata_standard": "ETM_v1.0.0",
  "extensions": [ "ETM_ATTRIBUTES_v1.0.0" ],
  "attributes": [
    {
      "trait_type": "Base", 
      "value": "Starfish"
    }, 
    {
      "trait_type": "Eyes", 
      "value": "Big"
    }, 
    {
      "trait_type": "Mouth", 
      "value": "Surprised"
    }, 
    {
      "trait_type": "Level", 
      "value": 5
    }, 
    {
      "trait_type": "Stamina", 
      "value": 1.4
    }, 
    {
      "trait_type": "Personality", 
      "value": "Sad"
    }, 
    {
      "display_type": "boost_number", 
      "trait_type": "Aqua Power", 
      "value": 40
    }, 
    {
      "display_type": "boost_percentage", 
      "trait_type": "Stamina Increase", 
      "value": 10
    }, 
    {
      "display_type": "number", 
      "trait_type": "Generation", 
      "value": 2
    }
  ]
}

Backwards Compatibility​

This extension to the metadata standard is backwards compatible with existing metadata suggestions proposed in ERC-721 and ERC-1155, as well as ETM.

Security Considerations​

Because this standard is merely a metadata extension and does not interface with the underlying contract, there are no additional security considerations.

Copyright and related rights waived via CC0.