I would like to propose an open standard for VRChat avatars called an Avatar Bill of Materials (ABOM).

Today, many VRChat avatars are assembled from multiple assets: a base avatar, clothing, hairstyles, accessories, shaders, animations, tools, and other components purchased from different marketplaces or created by different authors.

However, once these assets are imported into Unity and combined into a finished avatar, there is usually no standardized way to preserve information about where each component came from, whether it was obtained legitimately, which version is being used, or what license applies to it.

This creates problems for both users and creators.

Users may forget where an asset was purchased, lose track of dependencies, or have difficulty determining whether a particular use is permitted by the original license. Creators, meanwhile, have limited ways to distinguish legitimate users from unauthorized redistribution or extracted copies.

I propose that VRChat, ideally in cooperation with major avatar marketplaces and tools such as BOOTH/pixiv, VRoid, Jinxxy, Gumroad, and others, develop an open ABOM specification.

An ABOM could record information such as:

The proof-of-purchase system should protect user privacy. It should not expose personal information, order numbers, or account names publicly. Ideally, marketplaces could issue signed or anonymous verification tokens that confirm only that an asset was legitimately obtained.

The ABOM should not be DRM, and it should not be mandatory for uploading an avatar.

Avatars without an ABOM should remain fully uploadable and usable. The purpose of ABOM should be to provide optional provenance and license metadata, not to create a requirement for participation in VRChat.

Individual components should also be allowed to omit or hide provenance information when appropriate. For example, a user may have:

In such cases, an ABOM entry could simply mark the component as private, self-created, unverified, or not disclosed, without preventing the avatar from being uploaded.

This distinction is important: ABOM should make legitimate provenance easier to prove when users want to provide it, but it should not force creators to disclose the full contents or origin of their avatars.

The ABOM should also not be used to lock files, prevent modification, or restrict normal avatar creation workflows. It should instead provide standardized provenance and ownership metadata that can survive workflows such as:

VRoid → Unity → VRChat

or

Purchased base avatar → Unity customization → VRChat

The system could also support machine-readable license information. For example, licenses based on VN3 could potentially be checked by Unity tools, allowing creators to receive warnings when a planned use may conflict with the declared license terms.

Such checks should be advisory rather than legal judgments. A tool might report:

This would be especially useful when multiple assets with different licenses are combined into one avatar.

An ABOM could also make long-term avatar maintenance much easier. Years later, a user could identify which asset version was used, where it came from, whether an update exists, and which dependencies are required.

This could benefit several parts of the VRChat ecosystem at once:

Ideally, this would be developed as an open, interoperable specification rather than a VRChat-only proprietary format, so that marketplaces, avatar creation tools, Unity packages, and other social VR platforms could support the same metadata.

VRChat avatars are increasingly complex creative works assembled from many different components. Treating them more like software packages with optional, privacy-respecting provenance and dependency metadata could make the ecosystem safer, easier to maintain, and more sustainable for both creators and users.