SPL Token lock/unlock

Question

I need help with locking and unlocking SPL tokens. Does Solana or Metaplex provide any functionality for this, or do we need to work on a Rust program to achieve this?

Answer 1

Token 2022 has a couple extensions you might consider: https://spl.solana.com/token-2022/extensions

You could set a transfer fee of 100% which effectively locks the tokens.

You could set NonTransferable.

Or probably the best option is to add a Transfer Hook that checks with a very simple program to see if the token is locked or unlocked.

Answer 2

Yep. But it depends with what you want to achieve.

Here is a simple instruction to lock an NonFungible token using umi

import { lockV1 } from '@metaplex-foundation/mpl-token-metadata'

await lockV1(umi, {
  mint,
  authority,
  tokenStandard: TokenStandard.NonFungible,
}).sendAndConfirm(umi)

and unlock

import { unlockV1 } from '@metaplex-foundation/mpl-token-metadata'

await unlockV1(umi, {
  mint,
  authority,
  tokenStandard: TokenStandard.NonFungible,
}).sendAndConfirm(umi)

To note is that the number of accounts you interact with will change with different standard. For example, the pNFT standard introduces two a new way to lock asset with the Metadata delegate authority, where you transfer authority over the metadata account to a new authority.

Check out this section of the Metaplex docs https://developers.metaplex.com/token-metadata/delegates