AddrIndex implements a transaction by address index. That is to say, it supports querying all transactions that reference a given address because they are either crediting or debiting the address. The returned transactions are ordered according to their order of appearance in the blockchain. In other words, first by block height and then by offset inside the block.

In addition, support is provided for a memory-only index of unconfirmed transactions such as those which are kept in the memory pool before inclusion in a block.