🛹 Token Extensions

tl; dr

The Transfer Hook extension and Transfer Hook Interface allow users to create Mint Accounts that execute custom instruction logic on every token transfer.
To achieve this, developers must build a program that implements the Transfer Hook Interface and initialize a Mint Account with an enabled Transfer Hook extension.
For every token transfer involving tokens from the Mint Account, the Token Extensions program invokes a Cross-Program Instruction (CPI) to execute an instruction on the Transfer Hook program.

Creating a Token with Token Extensions

You can use the Solana Tool Suite (see chapter 4) to create tokens with a CLI:

spl-token --program-id TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb create-token <extension flags>

These are the flags to add to create tokens with each type of extension:
- Mint Close Authority: --enable-close
- Transfer Fees :--transfer-fee <basis points> <max fee>
- Non-Transferable: `--enable-non-transferable``
- Interest-Bearing: --interest-rate <rate>
- Permanent Delegate: --enable-permanent-delegate
- Transfer Hook: --transfer-hook <programID>
- Metadata: --enable-metadata
- Metadata Pointer: --metadata-address <accountId>
- Confidential Transfers: --enable-confidential-transfers auto

Demo

Demo 10: Token Extensions for Membership NFT

Resources