What is the AFA score?

Franck Dupont
OpenGem • GEM score
6 min readApr 11, 2021


⚠️ Hi! We just updated our scoring scheme and the AFA score’s fundamentals. You should read this article instead: “Why NFTs need to be graded?

We built the AFA score to evaluate the immutability level of an NFT and what the owner really gets from it.

👉 In short: this is a /100 score that measures how you can trust an NFT platform about the decentralization of the minted NFTs.

“Wait, wait. What is an NFT?”

We call NFTNon-Fungible Token — a token that can’t be interchanged with another unit of that same token. Unlike a fungible token that has the same value as another one, and can be interchanged (like bitcoins, ethers, etc.).

An NFT can be verified and authenticated by anyone because it’s on an open blockchain (like Ethereum). The thing is that we can attach something to the NFT: a picture, a video, a text, etc. So we got so many applications: video game items, digital arts, lottery tickets… A new world opens.

As we’re gonna describe here why we built the AFA score, if you want to know more about NFTs, I bring you to this article before coming back here 👋.

Let’s deep dive into the AFA scoring 🏊‍♂️

The deal is to know what you really own and how you own it. As we said, an NFT can attach assets: texts, pictures, videos, etc.
👉 The AFA score is based on specific questions around the token and the assets :

  • Do I own the token?
  • What is exactly stored in the token?
  • How are the assets stored in the token?
  • Do I own the assets?
  • Where are the assets hosted?
  • Can somebody alter or delete the assets?
  • Can I retrieve the assets even if the platform doesn’t exist anymore?

The answers are not obvious and are driven by technical blockchain limitations. Each NFT platform chose its own minting method. More or less decentralized… 👇

The assets storage 🌄

Most of the blockchains ask users for “gas fees” to write into it—a kind of contribution to remunerate the ones who run the chains. The more you want to write into it, the more you have to pay. Today, on Ethereum, a simple transaction costs ~$30, an NFT minting costs around $100…

As the ETH pumped a lot, storing data in an NFT (ERC-721) is expensive today. Storing 1 Mb costs ~$40k… Guess the price for 1 Gb 😅.

💡 Let’s say I want to sell my beautiful new illustration as an NFT on Ethereum. Here are different minting methods:

  1. Store the image in the token directly
    🥳 : the best way to make the image unalterable.
    😩 : the most expensive minting method (remember 1Mb = $40K…).
  2. Write an external link in the token that points to the image
    🥳 : cheaper minting method (~$20).
    😩 : the image is under the control of the host server’s owner.
  3. Upload it via a decentralized protocol and put the hash in the token
    🥳 : the image is unalterable, and the minting method is cheap.
    😩 : depending on the protocol, some conditions are required to maintain the image hosting.

Actually, the first minting method is the most decentralized. It deserves a +100/100 AFA score. Obviously, spending more than $10.000 to create my NFT is unthinkable. Or maybe my creation is worth it 😎.

You noticed that the 2nd method is very centralized. My illustration can be altered or deleted at any moment as it is on a server owned by the platform. That’s actually bad. In this case, my NFT is just a token in a blockchain that contains a link that can point to a 404 error at any moment.

The third method is very interesting. Because the image is hosted on several nodes of a decentralized network, like IPFS (the most used in the blockchain ecosystem), you can retrieve your asset, even if the NFT platform is offline. We will write an article about this procedure very soon.

The asset metadata 🖊

The AFA score pays a lot of attention to the method used to include the assets' metadata in the token. If I take my illustration example, I could have, as metadata: my name, the date of creation, the edition name, etc.

  1. Is it written directly in the token?
  2. Is it written in a file (JSON)?
  3. Where is the file hosted? Who has control of it?

Again, the methods are closed to those for asset storage. Some platforms use the token method. Others prefer to store the data on an external server.

👉 The most immutable method is to write this information in the token (so in the blockchain). And it doesn’t require so much gas fee, as we’re talking about text.

But some platforms are games like Sorare or Splinterlands. And when you get an item as NFT, sometimes it can have dynamic attributes: level, power, or skills depending on the game environment, for example. So the game editor may need to update these attributes. Do you see the point? Some metadata need to be inalterable by anyone, and others need to be alterable by the creator.

⚠️Some NFT platforms don’t make any distinction between these two kinds of attributes. They make everything alterable. Losing the benefit of blockchain immutability.

We want to offer a transparency of what you get, and what you don’t get.

Our mission 🌎

By generating a score based on all these criteria above, we can measure how you really own your NFT and who can alter its asset and metadata. We try to make it very clear and understandable on our website.

A concrete example

Let’s take a look at a score example with PancakeSwap NFTs. Yes, you can now own your bunny 🐰🥞. (GO CAKERS!)

We have here a 90/100 AFA score.

To be very understandable by the non-technical users, we chose to answer two main questions :

  • What is in my NFT?
  • If PancakeSwap dies, will I still have my NFT?

Actually, we think this is the first information that any NFT owner needs to know. Here we learn that the token contains metadata: id & name of the bunny, and an IPFS hash that points to a JSON.

👍 This is a good point. These metadata take advantage of the blockchain immutability.

In the JSON, we get the same metadata, the bunny description, and another IPFS hash that points to the bunny picture.

👍 This is a good point. The bunny picture takes advantage of the IPFS immutability.

To conclude, if the PancakeSwap website is offline :

  • we still get all the metadata token; as it’s in the blockchain,
  • we can retrieve the bunny picture from the IPFS protocol

We have here a good example of minting method to assure a data immutability.

What is the bad point?

PancakeSwap uses one smart contract to mint all the different types of bunnies. The practice is common.

👉 But if PancakeSwap had chosen to deploy a smart contract for each type of bunny, they would have been able to set up a max supply for each type of bunny in the corresponding contract. This practice would grow the value of the NFT. And a higher AFA score 😎. We can find this multi-contracts method at Nifty Gateway.

Please, reach us! ❤️

We’re not here to judge. We want more transparency for non-technical users to know exactly what they own.

🙌 The scoring is not perfect. We constantly improve the scoring method. For that, we need you to reach us if the analysis is not correct or if we miss something.

We are deeply in love with the NFT ecosystem and the blockchain. We love how the dapps are growing.

We want the NFTs democratization, and we believe the AFA score can really help reach this step.

So much love for all you guys 😻




Franck Dupont
OpenGem • GEM score