Ethereum NFT 数据是目前 Web3 最常使用的数据，所以我使用 Ethereum NFT 来举例。

1. Ethereum NFT 使用 EIP-721 标准，它的数据格式非常“灵活”，比如一个 NFT 的图片可能根据发布者不同的喜好使用 image image_url 或 animation_url 等各种不统一的字段，甚至根本不是一个图片，还可能是视频、3D 模型等，这给前端展示带来了很多麻烦。

2. 获取一个地址拥有的全部 Ethereum NFT 也非常麻烦，由于 Ethereum 的设计，想要获取它需要读取这个地址的全部交易记录，而且 Ethereum 不止主网，还有 Polygon、BSC、Arbitrum、fantom、Gnosis 等各种侧链，这对前端是一个不可能的工作，目前各种各样的数据索引服务可以部分解决这个问题，但这些服务返回的数据格式各不相同、功能各有优劣、各支持了不同的链，应该如何选择呢？

针对第一个问题，Unidata 设计了一系列友好和统一的数据格式，分为 Profiles、Links、Assets、Notes 四个部分。Ethereum NFT 属于 Assets 的格式。通过 Unidata 返回的固定的数据格式，前端不再需要做麻烦的适配混乱的数据格式的工作。

另外值得一提的是不止 Ethereum NFT，Unidata 目前还支持了 Solana NFT，Ethereum NFT 和 Solana NFT 的数据格式也是统一的，Unidata 还将继续支持更多的 Assets 来源，他们的格式也都会是统一的。

解决完第一个问题，第二个问题也就很容易解决了。Unidata 的做法是把各个服务返回的数据统一成相同的格式并做聚合。比如 OpenSea 服务支持了主网，Alchemy 服务支持了 Polygon，Moralis 服务支持了 BSC、Arbitrum、fantom，POAP 服务支持了 Gnosis 链的 POAP NFT。通过 Unidata 一行代码就可以同时使用这些服务同时获取到主网、Polygon、BSC、Arbitrum、fantom、POAP 的所有 NFT 了。可以在这里看在线演示。

除了 Assets，Unidata 还有 Profiles、Links、Notes 三个部分。

Assets 目前支持了 Ethereum NFT（Mainnet、Polygon、BSC、Arbitrum、Fantom、Gnosis、POAP）、Solana NFT、Alchemy、Solscan、Moralis、OpenSea。

Notes 目前支持了 Mirror Entry、Ethereum NFT Activity（Mainnet、Polygon、BSC、Arbitrum、Fantom、Gnosis、POAP）、RSS3。

Profiles 目前支持了 ENS、Crossbell、Infura。

Links 目前支持了 CyberConnect。

还有很多正在不断添加中，可以在文档看目前支持的所有服务和数据源。

链接：

Docs: https://unidata.app/

GitHub: https://github.com/NaturalSelectionLabs/Unidata

Discord: https://discord.com/invite/ggrfhdS9Fe

Twitter: https://twitter.com/Unidata_

Ethereum NFT data is by far the most commonly used data in Web3, so I will use Ethereum NFT as an example.

1. Ethereum NFT uses the EIP-721 standard and its data format is very "flexible". For example, an NFT image may use various inconsistent fields such as image image_url or animation_url depending on the publisher's preference, or it may not even be an image at all, but a video, a 3D model, etc., which causes a lot of problems for its front-end presentation.

2. Getting all the Ethereum NFTs owned by a given address is also very problematic, as Ethereum is designed in such a way that you would need to read all the transaction records of that address to get all its Ethereum NFTs. This is an impossible task for the front-end, but can be partially solved by the various data indexing services currently available. However the data returned by these services are in different formats, each having its own advantages and disadvantages, and each supporting different chains. So how should we choose which one to use?

To address the first issue, Unidata has designed a series of user-friendly and uniform data specifications, divided into four sections - Profiles, Links, Assets and Notes. Ethereum NFT falls under the Assets specification. With a fixed data format returned by Unidata, the front-end no longer has to do the troublesome work of adapting a confusing data format.

It is also worth noting that Unidata currently supports Solana NFT in addition to Ethereum NFT, and that the data specifications for Ethereum NFT and Solana NFT are unified. Unidata will continue to support more Assets sources, all of which will also have unified specifications.

Once the first issue was solved, the second is easy: Unidata's approach is to unify and aggregate the data returned by the various services into the same format. For example, the OpenSea service supports the mainnet, the Alchemy service supports Polygon, the Moralis service supports BSC, Arbitrum and fantom, and the POAP service supports POAP NFT for the Gnosis chain. With a single line of code from Unidata, you can use these services to get all the NFTs for mainnet, Polygon, BSC, Arbitrum, fantom and POAP at the same time. An online demo can be seen here.

In addition to Assets, Unidata has Profiles, Links and Notes sections.

Assets currently supports Ethereum NFT(mainnet, Polygon, BSC, Arbitrum, Fantom, Gnosis, POAP), Solana NFT, Alchemy, Solscan, Moralis, OpenSea.

Notes currently supports Mirror Entry, Ethereum NFT Activity(mainnet, Polygon, BSC, Arbitrum, Fantom, Gnosis, POAP), RSS3.

Profiles currently supports ENS, Crossbell, Infura.

Links currently supports CyberConnect.

Many more are being added and you can see all the services and data sources currently supported in the documentation.

Links:

Docs: https://unidata.app/

GitHub: https://github.com/NaturalSelectionLabs/Unidata

Discord: https://discord.com/invite/ggrfhdS9Fe

Twitter: https://twitter.com/Unidata_