user5264: Given a policy with a list of non-fungible tokens,

Could a smart contract update the metadata of all NFTs in the collection, under certain conditions?
If not, could this be done "manually" by a node?

On a side note, does my question make any sense or am I missing a fundamental aspect on how the whole protocol works?

user5085: So one way you could do it is by minting NFTs that have a URL in their metadata that links to your server hosting the corresponding metadata - not IPFS.
Then you can easily change the metadata independently of what's on-chain.
It is not very decentralized, since if you're server goes down the NFT's corresponding metadata is not accessible but it gives you the ability to update them without having to create another transaction.
Alternatively, you can use a so called time-lock based minting policies which allows you to change or update tokens up to a certain deadline.
That way you could burn and re-mint a given NFT in the future to update its metadata. But again, trust is required since you basically are in control of the NFTs at all times.

user4627: If the policy allows you to mint and burn those same tokens (or NFTs) again, you can update the linked metadata for those NFTs by creating a new minting transaction with the updated metadata and then burning those newly minted tokens.
According to CIP-25 the "valid" metadata for an NFT is that of the latest minting transaction, so just by creating and deleting an exact copy of an NFT you will have "updated" its metadata, since metadata is always connected to transactions, and not to the token itself.
https://cips.cardano.org/cips/cip25/#updatemetadatalinkforaspecifictoken

5264: <p>Given a policy with a list of non-fungible tokens,</p>
<ul>
<li>Could a smart contract update the metadata of all NFTs in the collection, under certain conditions?</li>
<li>If not, could this be done &quot;manually&quot; by a node?</li>
</ul>
<p>On a side note, does my question make any sense or am I missing a fundamental aspect on how the whole protocol works?</p>
 5085: <p>So one way you could do it is by minting NFTs that have a URL in their metadata that links to your server hosting the corresponding metadata - not IPFS.
Then you can easily change the metadata independently of what's on-chain.</p>
<p>It is not very decentralized, since if you're server goes down the NFT's corresponding metadata is not accessible but it gives you the ability to update them without having to create another transaction.</p>
<p>Alternatively, you can use a so called time-lock based minting policies which allows you to change or update tokens up to a certain deadline.
That way you could burn and re-mint a given NFT in the future to update its metadata. But again, trust is required since you basically are in control of the NFTs at all times.</p>
 4627: <p>If the policy allows you to mint and burn those same tokens (or NFTs) again, you can update the linked metadata for those NFTs by creating a new minting transaction with the updated metadata and then burning those newly minted tokens.</p>
<p>According to CIP-25 the &quot;valid&quot; metadata for an NFT is that of the latest minting transaction, so just by creating and deleting an exact copy of an NFT you will have &quot;updated&quot; its metadata, since metadata is always connected to transactions, and not to the token itself.</p>
<p><a href="https://cips.cardano.org/cips/cip25/#updatemetadatalinkforaspecifictoken" rel="nofollow noreferrer">https://cips.cardano.org/cips/cip25/#updatemetadatalinkforaspecifictoken</a></p>
