screenshot of Composition in Quinacridone Magenta CNFT by chiarascuro on

CNFT creators: How to tell if your asset’s policy is valid, and what to do if it’s not

It’s recently come to my attention — because I went down one of my rabbit holes — that some CNFTs are being minted with “unknown” policies. This happened with one that I recently minted.

Since I didn’t get to view or edit the policy prior to the minting process, I didn’t know if it locked, or when, or any of its other attributes. So I looked up the asset on and and immediately noticed something wasn’t right when I saw the policy icon.

The policy icon on your asset’s page should look something like this. And here I’m going to show off my NFTrinity, which was minted on Tokhun. (Never noticed a policy issue with any NFT I’ve minted there, by the way.)

screenshot of Confrontation CNFT by NFTrinity on

The lock symbol indicates whether the policy is locked or unlocked. That’s something you should know about the policy whether you’re a creator or collector, and shows you.

But what if there’s a question mark instead of a lock symbol, like in this NFT I minted a few days ago.

screenshot of Composition in Quinacridone Magenta CNFT by chiarascuro on

When I clicked on it, I got a screenful of stress — an error message warning me that the policy is unknown and I need to paste a script into a text box. unknown policy warning

I asked the platform’s developer and he told me how to find the script and paste it into the box. (Apparently I was expected to already know I needed to do that, and also how to do it.)

how to find the policy script of your CNFT

1. Look up the policy ID in Cardanoscan

Just paste the policy ID into that search box. The next screen will show you transaction information, and below that you see this section with three tabs.

Go to the middle tab that says TokenMint.

screenshot of asset information on Cardanoscan

2. Click on the policy ID to go to the policy details page

The policy details page contains policy details at the top. To the left, there’s an icon that looks like a scroll.

screenshot of Cardanoscan policy details page

Click on this scroll, and you’ll get a popup with a script in it like this.

screenshot of popup screen containing code on Cardanoscan

3. Copy the script to your clipboard

You’ll have to manually highlight it, because if you type ctrl-A, you’ll highlight everything on that screen and also the screen behind it.

Double-check the highlighted area to make sure you’re not leaving out a line or character. If you do, the code won’t be recognized whether the policy is valid or not.

4. Paste the script into text box

Again, check that you grabbed all the code.

screenshot of invalid policy script on

And it looks like my asset’s minting policy is invalid, and since I didn’t get to edit the policy during minting, there’s nothing I could have done about it.

But this is a problem. I’m told by that just because it doesn’t recognize a policy doesn’t mean it’s not valid. The minting platform was responsible for providing me with the script and instructions for how to upload it to

In this case, that wasn’t done.

So as soon as I work out how to do it, I’ll write another blog post and tell you how to do it, too.

curating best practices

This space is relatively new. On Cardano, it’s a circus. Most creators and collectors are trustworthy people with good intentions. But even people with the best intentions sometimes make mistakes.

And there are always those looking for vulnerabilities to exploit. That’s why we must be as transparent as possible and learn best practices to uphold integrity in this space.

Going forward, I’ll be looking for that question mark and using this process to double-check the validity of every policy, regardless of where I created it.

I strongly urge every CNFT creator to do the same. Collectors, too. But, as the folks doing the actual creating and minting, we’re responsible for doing everything we can to deliver exactly what we promise.

And if a minting platform doesn’t do what they’re supposed to, walk away.

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