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token-extensions

Skill111 starsChanged 11 days agoMITView on GitHub

Token-2022 (Token Extensions) on Solana. Pick, combine and create mint and account extensions with the spl-token CLI, @solana/kit or Anchor, and integrate extension mints. Use for transfer fees, hooks, metadata, groups, pausable, permanent delegate, soulbound, interest-bearing, scaled UI or confidential tokens.

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SKILL.md

Token Extensions (Token-2022)

Program TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb. Checked on 2026-09-30 against the mainnet program (spl-token-2022 v11.0.0, per its verified build), spl-token-2022-interface 3.1.2, spl-token-cli 5.6.1, @solana-program/token-2022 0.19.0 on @solana/kit 8, and anchor-lang / anchor-spl 1.2.0. Newer releases may rename things; check before relying on a name from memory.

Links into the kit's ext/ directory, here and in the references, need its full install; in a plugin install, read the same paths in solana-foundation/solana-dev-skill.

Pick the extensions

Fixed-size mint extensions can only be set before InitializeMint, so pick them up front. TokenMetadata, TokenGroup and TokenGroupMember can be initialized later, but only if their pointer was set at creation. Venues accept different sets; Orca's rules are in programs.

Extension (mint)Use it forAuthorityToken accounts getRead
TransferFeeConfigA fee withheld on every transferfee config, withdraw withheldTransferFeeAmountfees
TransferHookYour program runs on every transferhook authority (sets the program id)TransferHookAccounttransfer-hooks
MetadataPointer + TokenMetadataName, symbol, URI and fields stored on the mintpointer authority, metadata update authoritymetadata-groups
GroupPointer + TokenGroupA collection parent mintpointer authority, group update authoritymetadata-groups
GroupMemberPointer + TokenGroupMemberA mint inside a collectionpointer authority; group update authority co-signsmetadata-groups
PermanentDelegateIssuer can transfer or burn from any accountpermanent delegateissuer-controls
DefaultAccountStateNew accounts start frozen (KYC gating)freeze authorityissuer-controls
PausableStop transfers, mints and burnspause authorityPausableAccountissuer-controls
PermissionedBurnBurning needs an extra authoritypermissioned-burn authorityissuer-controls
NonTransferableSoulbound: holders can't transfernoneNonTransferableAccount, ImmutableOwnerissuer-controls
MintCloseAuthorityClose the mint once supply is 0close authorityissuer-controls
InterestBearingConfigDisplayed amount accrues interestrate authoritydisplay-amounts
ScaledUiAmountDisplayed amount = raw × multipliermultiplier authoritydisplay-amounts
ConfidentialTransferMint (+ ConfidentialTransferFeeConfig, ConfidentialMintBurn)Encrypted balances and amountsconfidential authority, auditor keyConfidentialTransferAccount, opt-in per accountconfidential

Holder-side account extensions (ImmutableOwner, MemoTransfer, CpiGuard), account sizing and Reallocate: account-extensions. Accepting any Token-2022 mint in a program, and CPIs from Anchor: programs.

Combinations

CombinationResult
ConfidentialTransferFeeConfig without both TransferFeeConfig and ConfidentialTransferMintRejected at InitializeMint: InvalidExtensionCombination
TransferFeeConfig + ConfidentialTransferMint without ConfidentialTransferFeeConfigRejected: InvalidExtensionCombination
ConfidentialMintBurn without ConfidentialTransferMintRejected: InvalidExtensionCombination
NonTransferable + ConfidentialTransferMint without ConfidentialMintBurnRejected: InvalidExtensionCombination
InterestBearingConfig + ScaledUiAmountRejected: InvalidExtensionCombination
DefaultAccountState Frozen without a freeze authorityRejected: MintCannotFreeze
NonTransferable + TransferFeeConfig or TransferHookAccepted, but pointless: every transfer fails with NonTransferable
NonTransferable + PermanentDelegateThe delegate can burn but not transfer
TransferHook + ConfidentialTransferMintConfidential transfers call the hook with amount = u64::MAX
Pausable, while pausedTransferChecked, MintTo and burns fail with MintPaused

Tooling gaps: anchor-spl 1.2.0 has no helpers for ScaledUiAmount, PermissionedBurn or the confidential extensions (it builds on spl-token-2022-interface 2.x, which has no PermissionedBurn), and spl-token-cli 5.6.1 can't initialize ConfidentialMintBurn.

spl-token-cli 5.6.1 can't act for a multisig extension authority. set-interest-rate, set-transfer-fee, set-transfer-hook, initialize-metadata, update-metadata, initialize-group, update-group-max-size, initialize-member and update-confidential-transfer-settings reject --multisig-signer. pause, resume and update-ui-amount-multiplier accept it but ignore it and send an under-signed transaction. Build those instructions with Kit or Rust instead.

Confidential transfers need the ZK ElGamal Proof program enabled on the cluster (on mainnet since epoch 982, and on devnet), a per-account opt-in (Reallocate, then ConfigureAccount with a proof), and an owner who applies pending balances. Decisions and what is out of date in the linked Rust walkthrough: confidential.

Create a mint

One transaction, in this order:

  1. Create the account, owned by Token-2022, with space for the fixed-size extensions only: ExtensionType::try_calculate_account_len::<Mint>(&types) (Rust), getMintLen(types) (web3.js 1.x), or Kit's getMintSize over the list without TokenMetadata, TokenGroup and TokenGroupMember (it counts whatever it is given), with rent from getMintSize over the full list. InitializeMint rejects any other length (InvalidAccountData) and a mint below the rent-exempt minimum (NotRentExempt).
  2. Each extension's initialize instruction. On an initialized mint these fail with AlreadyInUse, so fixed-size extensions can't be added later.
  3. InitializeMint2 (or InitializeMint).
  4. TokenMetadata, TokenGroup and TokenGroupMember. They grow the mint but move no lamports, so fund the mint for its final size in step 1 (Kit's createMint does), or transfer the difference to the mint before the initialize, in an earlier instruction of the same transaction (the CLI does) or in your program before the CPI.

Kit: the plugin's createMint does the sizing, funding and ordering. It doesn't initialize TokenGroupMember, doesn't write additionalMetadata (it only pays rent for it), and skips TokenMetadata when updateAuthority is null (metadata-groups). client is a Kit 8 client with an RPC, a payer and transaction planning and sending (Kit plugins).

import { generateKeyPairSigner } from '@solana/kit';
import { extension, token2022Program } from '@solana-program/token-2022';

const token = client.use(token2022Program());
const mint = await generateKeyPairSigner();
const authority = client.payer.address;
await token.token2022.instructions
  .createMint({
    newMint: mint,
    decimals: 6,
    mintAuthority: client.payer,
    extensions: [
      extension('MetadataPointer', { authority, metadataAddress: mint.address }),
      extension('TokenMetadata', {
        updateAuthority: authority, mint: mint.address,
        name: 'Example', symbol: 'EXM', uri: 'https://example.com/exm.json',
        additionalMetadata: new Map(),
      }),
    ],
  })
  .sendTransaction();

Without the plugin, compose the same steps (space from the filtered list, rent from the full one, as createMint does) with getMintSize, getPreInitializeInstructionsForMintExtensions, getInitializeMintInstruction and getPostInitializeInstructionsForMintExtensions, or call getCreateMintInstructionPlan(client, input).

CLI: spl-token --program-2022 create-token --decimals 6 --enable-metadata then spl-token initialize-metadata <MINT> Example EXM https://example.com/exm.json. After creation the CLI infers the program from the account's owner, so later commands don't need --program-2022, except with --sign-only, where it can't look the account up and defaults to classic Token.

Anchor 1.2.0: init on an InterfaceAccount<'info, Mint> accepts extensions::metadata_pointer::{authority, metadata_address}, extensions::group_pointer::{authority, group_address}, extensions::group_member_pointer::{authority, member_address}, extensions::transfer_hook::{authority, program_id}, extensions::close_authority::authority, extensions::permanent_delegate::delegate and extensions::pausable::authority. The same constraints on an existing mint check the extension's values. TokenMetadata, TokenGroup and TokenGroupMember are CPIs after init (metadata-groups); the other extensions need a manual create-and-initialize sequence (programs).

Token accounts and transfers

  • Associated token accounts derive from the token program id. Pass the Token-2022 id (findAssociatedTokenPda({ owner, mint, tokenProgram }), getAssociatedTokenAddressSync(mint, owner, false, TOKEN_2022_PROGRAM_ID)), or you get the address of an account that doesn't exist. web3.js's createAssociatedTokenAccountIdempotentInstructionWithDerivation derives with the classic program id even when you pass Token-2022; derive the address yourself.
  • Token accounts need the extensions their mint requires (table above). Associated token accounts and Anchor's init get them. For an account you create yourself, Kit's getTokenSize counts only the extensions you pass it: account-extensions.
  • Transfer with TransferChecked. Plain Transfer fails with MintRequiredForTransfer when the source account has TransferFeeAmount, TransferHookAccount or PausableAccount, because the program needs the mint to charge the fee, call the hook or check the pause.
  • With a fee, the recipient gets amount - fee: credit the balance delta, not the argument. The fee stays withheld in the recipient's account until anyone harvests it to the mint or the withdraw authority withdraws it; an account holding withheld fees can't close (fees).
  • With a hook, the hook program's ExtraAccountMetaList PDA (seeds ["extra-account-metas", mint]) must exist before the first transfer, and every transfer appends the hook program, that PDA and the extra accounts it lists (Kit: getTransferCheckedWithTransferHookInstructionAsync).
  • A TransferChecked to the same account moves nothing, charges no fee and skips the hook. Confidential transfers have no such shortcut and call the hook.
  • In a program, anchor_spl::token_interface::transfer_checked passes only the four base accounts, so it can't move a hook mint: transfer-hooks.
  • Destinations with MemoTransfer enabled need a memo instruction right before the transfer. Owners with CpiGuard enabled can't sign transfers inside a CPI.

Reading an unknown mint

  • Kit: fetchMint(rpc, address) then mint.data.extensions, an Option of an array tagged by __kind. web3.js 1.x: getExtensionTypes(mint.tlvData) on the result of getMint(connection, address, undefined, TOKEN_2022_PROGRAM_ID). Rust: StateWithExtensions::<Mint>::unpack(&data)? then get_extension_types() or get_extension::<T>(); Anchor: anchor_spl::token_interface::get_mint_extension_data::<T>(&account_info).
  • Match on each tool's own names. Kit's __kind is ScaledUiAmountConfig, PausableConfig and ConfidentialTransferFee where Rust says ScaledUiAmount, Pausable and ConfidentialTransferFeeConfig; web3.js uses ScaledUiAmountConfig and PausableConfig. Under anchor-spl 1.2.0 (interface 2.x), get_extension_types() fails with InvalidAccountData on a PermissionedBurn mint, while get_extension::<T>() still works.
  • Allow-list the extensions you support. PermanentDelegate, TransferHook, Pausable, DefaultAccountState, NonTransferable and TransferFeeConfig each change what your program or UI can rely on; the attack side is in security.md, Token-2022 section.
  • Show balances with the mint's UI conversion when InterestBearingConfig or ScaledUiAmount is present: display-amounts.

Related

  • kit/programs/token-2022.md: the Kit client basics. Its "Extension Initialization Order" puts every extension before the mint initialize; TokenMetadata, TokenGroup and TokenGroupMember go after it, as in Create a mint. confidential-transfers.md: the Rust confidential flow; confidential lists what in it is out of date. testing.md: LiteSVM and Mollusk.
  • NFTs and collections: the skills hub also routes to the Metaplex skill (install first: bash .claude/bin/skills.sh add metaplex).
  • Official guides: https://solana.com/docs/tokens/extensions

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