SPLSimple mint, transfer and burn — no attached behaviour
Token-2022Optional extensions enabled per mint
Watch forTransfer fee, transfer hook, permanent delegate
FBT Swap
What you should know
The original SPL token program is deliberately simple: mint, transfer, burn. Token-2022 adds optional extensions that attach behaviour to a token at the program level.
Those extensions are legitimate and useful. They also mean that for a Token-2022 mint, a transfer may not do what a transfer normally does.
What the extensions can add
A transfer fee deducted on every movement. A transfer hook that calls arbitrary external logic on each transfer. Confidential transfers that hide amounts. Non-transferable tokens. Permanent delegate authority. Interest-bearing balances that update by formula.
Each is opt-in per mint and is visible in the mint's configuration on-chain.
Why this matters for swapping
A transfer fee means the amount arriving is less than the amount sent, so a quote based on the sent amount overstates the result. A transfer hook can make a transfer fail under conditions the sender cannot see.
A permanent delegate means an authority can move tokens from any holder. That is a legitimate compliance feature for some issuers and a complete loss of control for a holder who did not know.
Checking a mint before you buy
The mint account shows which extensions are enabled. Explorers surface this, and so do several Solana token tools. Look specifically for transfer fee, transfer hook and permanent delegate.
A token with a permanent delegate is not a token you hold unconditionally, and that should be a conscious decision rather than a discovery.
How interfaces handle it
Aggregators generally support Token-2022 mints and account for transfer fees in routing where they can detect them. Hooks are harder, because the external logic can behave differently at execution time.
FBT Swap routes Solana swaps through public aggregators and shows the quote and fee before signing. For any token you selected by mint address, checking the extensions yourself is the reliable step.
At a glance
At a glance
01
SPL
Simple mint, transfer and burn — no attached behaviour
02
Token-2022
Optional extensions enabled per mint
03
Watch for
Transfer fee, transfer hook, permanent delegate
04
Where to check
The mint configuration on an explorer or token tool
FAQ
Frequently asked questions
Clear answers before you decide.
Is Token-2022 less safe than SPL?+
The program itself is audited and widely used. The risk comes from what a specific mint enables — a permanent delegate or a hostile hook changes your position materially, and neither is visible from the symbol.
Why did I receive less than I swapped for?+
Most likely a transfer fee extension on that mint. The fee is taken by the token program on every movement and is configured by the mint authority.
Can a transfer hook steal my tokens?+
A hook runs logic on transfer and can cause it to fail or enforce conditions. Combined with a permanent delegate, an issuer can have substantial control, which is why those two extensions deserve a direct check.
Risk notice
Crypto assets are volatile and on-chain transactions cannot be reversed. You can lose money, including all of it. Nothing here is financial advice.
