[Feature]: MAX_URI_LENGTH to allow completely on-chain metadata.

[akutruff]

Which package is this feature request for?

token-metadata

Feature

Right now the token metadata length is limited to 200 characters. There are many use cases where a the json metadata could be a data URI that's stored entirely on-chain with the image field of the meta also being set to a data uri that contains a fully encoded and simple SVG. The ETH world has already started allowing this and it greatly decreases the burden of creating dynamic on-chain NFTS.

A very simple use case - a game wants to be able to allow a user to mint an in-game item that has a unique name and a unique image for that NFT. Right now, the game must store the metadata on a separate server or on arweave a-priori.

Phantom already supports SVG's encocded as data uri's, but the metaplex uri length is too limiting to store the actual json

Standard Change?

No

Ideal solution or implementation

On-chain program allows a much more permissive url length. Naive and ideal solution - The url length constants in the program are simply removed.

Alternative solutions or implementations

If there are storage size concerns for wallet-fetching, then you could also add a metadata_account field that is used instead of a json url. That way, a wallet can fetch the program accounts, and then start loading metadata by url as they currently do. For on-chain metadata, the wallet will instead load those the metadata_accounts accounts. There's trade-offs either way.

Other context

A blog post describing historical approaches to storing on-chain metadata and SVG's in the ETH world.