Mint Authority

Every SPL token has a mint account. That account stores the token’s total supply, its decimals, and two optional authorities: a mint authority and a freeze authority. The mint authority is the only account that can run the MintTo instruction, which creates new units and raises the supply.

Setting the mint authority to none with the SetAuthority instruction is permanent. Nobody can mint again, so the supply is fixed. Creators do this to show they cannot print more tokens. A token whose mint authority is still set can be diluted at any moment by whoever holds that key, and holders have no way to stop it.

To check it, read the mint account and decode it. The account is 82 bytes long. The mint authority is the first field: a four-byte option tag followed by a 32-byte public key. If the tag is zero, the authority is none. Wallets and explorers show the same field, and the Token-2022 program stores it in the same place.

A revoked mint authority is a good sign, not a guarantee. A token can still be unsafe through its liquidity, how concentrated its holders are, or its freeze authority. Token-2022 mints can also carry extra authorities, such as a permanent delegate or a transfer-fee authority, that matter just as much.

You read it from getAccountInfo on a mint address, from the token-creation events a launchpad stream emits, and from the safety filters in trading bots. A sniper bot’s block_mint_authority rule is this check: it skips any launch whose mint authority is still set.

Our token-creation stream surfaces new mints as they appear, so a bot can read the mint authority at the moment a token launches. The sniper bots we build turn the check into a rule you can switch on.