Piggy Banks

Accounts the program creates

Every account has an address derived from fixed seeds (a PDAPDA (program-derived address) An address computed from fixed words and other addresses. It has no private key, so only its program can sign for it.), so the page finds a Piggy Bank from the NFT alone and nobody can swap in a look-alike.

The Piggy Bank signs for its own token accounts, and only the program can make it sign. Before any redemption the program re-reads the NFT mint and the holder’s token account.

Who can do what

• ActionWho signsRules the program enforces
• CreateAnyone; pays the rent and the feeThe NFT has supply 1, 0 decimals and no way to mint more; the name is valid and free; the program is immutable. Creating gives no control.
• Deposit SOL or a coinAnyoneThe Piggy Bank exists and is not burned. Coins must pass the same token rules as NFTs, minus supply.
• RedeemThe NFT holder onlyThe signer’s token account holds exactly the NFT, with no delegate (an open listing or lock) and no outside close authority. Everything listed goes to the signer.
• Burn and redeemThe NFT holder onlySame holder checks, then an SPL burn of the NFT; token accounts are swept and closed and the signer is recorded as the burner.
• Sweep or close a burned bankThe burner onlyRedeem sweeps anything sent later; Close returns all the bank’s lamports, rent included, to the burner.
• Take anyone else’s depositNobodyNo creator, admin, VEYDUCT or upgrade path can move what is inside. Depositors cannot withdraw either.

A seller can redeem a Piggy Bank right before the NFT changes hands. If you buy an NFT for its Piggy Bank, check what is inside at the moment you buy, not an older listing.

Names

• 3 to 32 characters of letters, digits, spaces, hyphens and underscores; no leading, trailing or double spaces.
• Unique ignoring capital letters. The record’s address comes from the lowercase name, so “Moon Bank” and “moon bank” are the same name and only the first one can exist.
• Permanent. A name can never be changed and is never released, even after its Piggy Bank is burned and closed.
• Checked before you pay. Once the program is live the page reads the name record and tells you if a name is taken; the program refuses a taken name either way.

Redemption math, with a worked example

The Piggy Bank keeps exactly its rent-exempt minimum and pays out everything above it. Token balances go out in full.

1. SOL outSOL to holder = bank lamports − 1,503,680 (the 168-byte rent minimum)The bank account stays open, so it can be filled and redeemed again.
2. Tokens outeach listed token account → holder’s own account, full balanceUp to 6 coins per transaction. With “close”, the emptied accounts are closed and their rent goes to the holder too.
3. Something has to moverefused if no SOL above rent, no tokens and nothing to closeEach redemption bumps a counter; a plan made before someone else redeemed is refused.

Example

1. You create “Moonrise Bank”.0.01 SOL fee + 0.00150368 + 0.00089408 SOL rent + 0.000005 network fee = 0.01240276 SOL.
2. You deposit 0.5 SOL and 100,000 DEMO; a fan adds 0.25 SOL.The first DEMO deposit also pays 0.00151384 SOL for the bank’s Token-2022 account.
3. You send the NFT to Holder B.You can no longer redeem. Holder B redeems 0.75 SOL and 100,000 DEMO.
4. The NFT comes back; you deposit 0.2 SOL, then burn and redeem.You get 0.2 SOL, the DEMO account’s rent and your NFT account’s rent (0.00148844 SOL). Closing the burned bank returns its 0.00150368 SOL.

The Practice tab follows the same rules and the SDK’s own name check, so you will see these numbers.

Costs

VEYDUCT fee to create a Piggy BankPaid once, in the same transaction, to VEYDUCT’s fee wallet. Shown in the review.

0.01 SOL

Rent for the Piggy Bank168 bytes at mainnet rent of 5,080 lamports per byte plus 128 bytes per account. Returned only when a burned bank is closed.

0.00150368 SOL

Rent for the name record48 bytes. Never returned: the name stays taken.

0.00089408 SOL

First deposit of a coinThe Piggy Bank’s token account, paid by that depositor. Returned to the holder if a redemption closes it.

0.00151384 SOL (Token-2022) · 0.00148844 SOL (classic)

Network feePer transaction, one signature.

0.000005 SOL

Percentage feesDeposits, redemptions, burns and closes carry no VEYDUCT fee, and the program takes no cut.

None

Account rentRent SOL that Solana requires every account to hold, sized by its bytes. It comes back only when the account is closed. is a deposit, not a fee. If your wallet has no token account for a coin you redeem, the page creates it in the same transaction and shows that rent in the review.

Supported NFTs and coins

• NFTs: classic SPL and Token-2022 mints with supply 1 and 0 decimals, and no mint authority or only the Metaplex master-edition authority (which cannot mint more).
• Token-2022 extensions: only metadata and group extensions. Transfer fees, hooks, permanent delegates, mint close authority, non-transferable, default-frozen, confidential and pausable mints are refused.
• Coins you deposit: the same token rules, so Pump coins (Token-2022 with metadata only) and classic SPL coins work.
• Burn and redeem: an SPL burn, so not for programmable NFTs (pNFTs, whose token accounts stay frozen) or NFTs frozen by staking or a lock. Check NFT says so; plain Redeem still works for them.

Edge cases and what can go wrong

FAQ