Token Ecosystem

Required Memo on Transfer

A Token-2022 extension that requires all incoming transfers to include a memo instruction (via the Memo Program) in the same transaction. If no memo is present, the transfer fails. Used for compliance-driven tokens where transaction metadata must be recorded on-chain.

IDmemo-required

Plain meaning

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A Token-2022 extension that requires all incoming transfers to include a memo instruction (via the Memo Program) in the same transaction. If no memo is present, the transfer fails. Used for compliance-driven tokens where transaction metadata must be recorded on-chain.

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SPL assets, token standards, metadata, and NFT primitives.

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Required Memo on Transfer (memo-required)
Category: Token Ecosystem
Definition: A Token-2022 extension that requires all incoming transfers to include a memo instruction (via the Memo Program) in the same transaction. If no memo is present, the transfer fails. Used for compliance-driven tokens where transaction metadata must be recorded on-chain.
Related: Token-2022 (Token Extensions), Memo Program
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Branch

Token-2022 (Token Extensions)

The next-generation token program (TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb) that extends SPL Token with configurable extensions. Extensions include transfer fees, confidential transfers, transfer hooks, permanent delegate, non-transferable tokens, interest-bearing tokens, metadata, and more. Token-2022 is backwards-compatible with SPL Token for basic operations.

Branch

Memo Program

An SPL program (MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr) that validates a UTF-8 string and records it in the transaction log. Memos attach human-readable notes to transactions—used for exchange deposit identification, compliance metadata, and transaction tagging. The memo must be signed by at least one account.

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Token Ecosystem

Token-2022 (Token Extensions)

The next-generation token program (TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb) that extends SPL Token with configurable extensions. Extensions include transfer fees, confidential transfers, transfer hooks, permanent delegate, non-transferable tokens, interest-bearing tokens, metadata, and more. Token-2022 is backwards-compatible with SPL Token for basic operations.

Token Ecosystem

Memo Program

An SPL program (MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr) that validates a UTF-8 string and records it in the transaction log. Memos attach human-readable notes to transactions—used for exchange deposit identification, compliance metadata, and transaction tagging. The memo must be signed by at least one account.

Token Ecosystem

Royalty Enforcement

Mechanisms that ensure NFT creators receive their specified royalty percentage on secondary sales. After marketplaces began allowing royalty-optional trading in 2022-2023, Metaplex introduced programmable NFTs (pNFTs) with on-chain transfer rules that enforce royalty payments. Alternative approaches include economic incentives (rewarding royalty-paying holders) and social pressure. Royalty enforcement remains a debated topic in the NFT ecosystem.

Token Ecosystem

Programmable NFT (pNFT)

A Metaplex NFT type (pNFT) that enforces creator-defined rules on transfers using an on-chain authorization rules engine. pNFTs always require the token record (state PDA) and must go through the Metaplex program for transfers, enabling royalty enforcement. Transfer rules are defined in a RuleSet account that can allow/deny based on program IDs, collections, or custom logic.

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Token Ecosystemmemo-program

Memo Program

An SPL program (MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr) that validates a UTF-8 string and records it in the transaction log. Memos attach human-readable notes to transactions—used for exchange deposit identification, compliance metadata, and transaction tagging. The memo must be signed by at least one account.

Token Ecosystemtransfer-fee

Transfer Fee Extension

A Token-2022 extension that automatically withholds a percentage of every transfer as a fee. The fee (basis points + max fee) is configured on the mint by the transfer fee authority. Withheld fees accumulate in recipient token accounts and can be harvested by the withdraw authority. Enables on-chain royalties for fungible tokens.

Token Ecosystemtransfer-hook

Transfer Hook

A Token-2022 extension that invokes a custom program on every token transfer. The hook program receives the transfer details and can enforce additional logic (royalties, compliance checks, transfer restrictions). The hook program address is set on the mint. Hooks execute via CPI and must conform to the Transfer Hook Interface.

Related terms

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Token Ecosystemtoken-2022

Token-2022 (Token Extensions)

The next-generation token program (TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb) that extends SPL Token with configurable extensions. Extensions include transfer fees, confidential transfers, transfer hooks, permanent delegate, non-transferable tokens, interest-bearing tokens, metadata, and more. Token-2022 is backwards-compatible with SPL Token for basic operations.

Token Ecosystemmemo-program

Memo Program

An SPL program (MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr) that validates a UTF-8 string and records it in the transaction log. Memos attach human-readable notes to transactions—used for exchange deposit identification, compliance metadata, and transaction tagging. The memo must be signed by at least one account.

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Token Ecosystem

SPL Token Program

The original Solana Program Library token program (TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA) that implements fungible and non-fungible token operations. It manages mints (token definitions) and token accounts (balances). Core instructions include InitializeMint, MintTo, Transfer, Burn, Approve (delegation), and Revoke. All SPL tokens on mainnet before Token-2022 use this program.

Token Ecosystem

Solana Program Library (SPL)

Solana Program Library—a collection of on-chain programs and client libraries maintained by Solana Labs. Key SPL programs include Token, Token-2022, Associated Token Account, Memo, Name Service, Stake Pool, and Account Compression. SPL programs are deployed to well-known addresses and serve as the standard building blocks for Solana applications.

Token Ecosystem

Token-2022 (Token Extensions)

The next-generation token program (TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb) that extends SPL Token with configurable extensions. Extensions include transfer fees, confidential transfers, transfer hooks, permanent delegate, non-transferable tokens, interest-bearing tokens, metadata, and more. Token-2022 is backwards-compatible with SPL Token for basic operations.

Token Ecosystem

Mint

An on-chain account defining a token type. A mint specifies: supply (total minted), decimals (0 for NFTs, 6 for USDC, 9 for most tokens), mint authority (who can mint), and optional freeze authority. Each unique token (USDC, JitoSOL, etc.) has exactly one mint account. Mint address serves as the token's unique identifier.