Memos and history

History is local

for tx in wallet.transactions(since=0):          # newest first
    print(tx.txid, tx.status, tx.net_value, tx.fee, tx.confirmations)
    for out in tx.outputs:
        print(" ", out.direction, out.pool, out.value, out.address)

tx = wallet.transaction("ab12...")                # or None

Both read the local database only: listing history sends nothing to the server. Memos the wallet sent are included. Output reprs hide memo contents; read out.memo (text) or out.memo_bytes when you need them.

tx.memo_pending is true when a received note's memo is not known yet, and tx.pool_crossing_value shows any amount the transaction published by crossing pools.

Received memos are opt-in

Compact blocks carry only the first 52 bytes of each note ciphertext, so a received memo needs the full transaction, requested by txid. A server that sees one txid fetched soon after it was mined learns that a light wallet received in it. So nothing fetches memos unless you call:

report = await wallet.fetch_memos(decoys=7, max_delay=10.0)
report.fetched, report.waiting, report.unavailable

When you do:

1. Only what is needed. Only transactions holding a received shielded note whose memo is unknown. Not the funding transactions of transparent inputs.
2. Never alone. Each real txid is fetched with decoys others (1 to 31, default 7): non-coinbase transactions with shielded outputs within 100 blocks, taken from compact blocks the wallet already downloaded.
3. No rank tell. The decoys are a window of consecutive candidates, offset so the real transaction's rank is uniform. A unit test checks this over 5,000 draws.
4. Wait rather than go out bare. A payment without enough candidates stays waiting.
5. Separate circuit, random time. Each batch uses its own Tor circuit after a random delay of up to max_delay seconds, in shuffled order.

Without Tor, to a remote server, it raises PrivacyError.