The gap limit is a compatibility contract, not a scanner setting
An HD wallet scanner quits twenty unused addresses after the last one that received money. An address handed out past that window still belongs to your key, your own indexer will watch it happily, and no standard wallet will ever reach it. That makes the gap limit a constraint on what you are allowed to issue, not a parameter you tune on your own side of the system. An address that is yours and…
The gap limit is not a customizable setting for scanners, but rather a compatibility contract that defines what addresses can be issued. An unused address after the gap limit belongs to the keyholder and can still be visited, but standard wallets will not reach it. When deriving an address from an extended public key, the process is purely mathematical with no regard to whether others can find it.
The address is still valid and can receive funds, but discovery relies on convention rather than mathematical proofs. A conforming wallet will scan sequentially from the last index with a deposit, pausing once it encounters a series of unused addresses. The BIP44 standard sets this gap limit at twenty unused addresses. After the last index with funds, a scanner will stop at index 500, which will never be visited.
This gap limit is not something the user can adjust, as it is a wallet user experience detail. However, it is crucial when restoring an account from a mnemonic or during an incident where funds are lost. The indexer is not responsible for finding these unfindable addresses, and the responsibility lies with the software that handles the issuance of addresses.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
