Balance/history now render as soon as tx downloads finish instead of
blocking on every historical Merkle proof, critical for mobile where
proof-checking can take much longer than the download itself. Proofs
continue to be checked in the background and each tx's Verified flag
catches up progressively; header ranges are now fetched in batches
(blockchain.block.headers) instead of one call per header to keep this
fast over high-latency links.
Coin selection (UtxoSpendability.IsSpendable) refuses to spend a UTXO
until its Merkle proof is actually checked, regardless of confirmation
count, so a server that fabricates a confirmed balance can get it
displayed early but never spent before the forgery is caught. The disk
cache only ever persists the fully-verified end state of a sync.
UI surfaces the new PendingVerificationSats/SpendableSats split with a
"verifying..." badge, and the sync save now runs off the UI thread to
avoid freezing on slower hardware.
ChainProfiles.Mainnet.Checkpoints was an empty array with a "populate
before release" TODO, and even BlockHeaderInfo.MatchesCheckpoint()/
IsValidChild() — the methods meant to enforce it — were never called
anywhere in WalletSynchronizer. So on this LWMA chain, where PoW can't
be recomputed client-side (SkipPowValidation), a malicious or
eclipsing server could hand back any internally-consistent 80-byte
header for a Merkle proof: nothing tied it to the real Palladium
chain.
Populated Mainnet.Checkpoints with 24 real [height, hash, bits]
checkpoints (every 20,000 blocks + one near tip), pulled via RPC from
a fully-synced palladiumd. Testnet/Regtest are left empty (no node
available to verify against, and WalletSynchronizer already treats a
missing checkpoint as a no-op, so this is safe, just unanchored).
Added WalletSynchronizer.AnchorToCheckpointAsync: for every header
used in a Merkle proof, downloads the intervening headers back to the
nearest checkpoint at or below that height and verifies an unbroken
prev-hash chain terminating in the checkpoint's exact hash, finally
wiring up the previously-dead MatchesCheckpoint/IsValidChild. Verified
ranges are memoized in-memory per sync session to avoid re-walking.
Updated SECURITY.md and USERGUIDE.md to describe what is actually
enforced now (previously the guide deliberately avoided promising
checkpoint anchoring, since the array was empty).
Extract confirmation-threshold logic into UtxoSpendability (shared by
TransactionFactory and WalletSynchronizer) and use it to compute
ImmatureSats, so coinbase/under-confirmed amounts are shown separately
from spendable balance in the GUI and CLI instead of being lumped into
"confirmed".
Coinbase outputs require COINBASE_MATURITY + 1 = 121 confirmations before
they can be spent. The consensus rule (palladiumcore tx_verify.cpp) is
nSpendHeight - nHeight >= 120; the +1 adds one block of safety margin,
matching the Qt wallet (wallet.cpp: COINBASE_MATURITY+1). Regular UTXOs
require MinConfirmations (6 on mainnet, 1 on testnet/regtest — wallet
policy, no consensus rule).
Changes:
- ChainProfile: add CoinbaseMaturity and MinConfirmations fields
- ChainProfiles: mainnet CoinbaseMaturity=120 / MinConfirmations=6;
testnet/regtest inherit 120, override MinConfirmations=1
- PalladiumNetworks: align NBitcoin Consensus.CoinbaseMaturity to 120
- CachedUtxo: add IsCoinbase flag (ElectrumX listunspent does not expose
this; derived from Transaction.IsCoinBase on the raw tx)
- WalletSynchronizer: set IsCoinbase during local UTXO reconstruction
- TransactionFactory.Build: add tipHeight param; filter by threshold;
error reports reason (immature coinbase with X/121 counter, under-
confirmed regulars with best-seen count, mempool amounts)
- All Build() call sites updated (App, Donate, CLI)
- Two new tests: coinbase maturity boundary (119→220 tip) and mainnet
min-conf boundary (5→6 confirmations)
Translate every Italian /// XML doc comment, <!-- --> XAML comment, and
// inline comment to English across all source files (Core, App, tests).
Add the language policy to CLAUDE.md (conversation Italian; all code
and docs English). Update one test assertion that checked an Italian
exception message that was also translated.
Speed up wallet synchronization, especially re-syncs of large wallets:
- Incremental address discovery: known indices from the previous sync
(NextReceiveIndex/NextChangeIndex) are fetched in a single parallel
burst instead of sequential gap-limit rounds, cutting round-trips from
O(used/gapLimit) to ~O(1). Receive and change chains scan in parallel.
- Merge tx download and Merkle verification into one parallel phase
(no barrier between them); the per-call semaphore is dropped in favor
of the transport-level in-flight gate.
- Persist verified block headers (SyncCache.BlockHeaders, height -> hex):
immutable once stored, so blockchain.block.header round-trips for
already-verified proofs are eliminated on later syncs.
- RetryOnBusyAsync with exponential backoff around server calls, treating
-101/-102 and "server busy"/"excessive resource usage" as transient.
Wire the new PreloadCaches/ExportCaches signatures through the desktop
view model and the CLI sync command.
Three interrelated fixes for sync reliability on large wallets:
1. Prevent -101 "excessive resource usage":
ScanChainAsync uses GetHistoryAsync for discovery instead of
SubscribeScripthashAsync. Subscriptions are limited to the gap window
only (≤ 2×gapLimit addresses), so the session subscription count stays
constant regardless of wallet history size — eliminating -101 on
wallets with 1000+ historical addresses.
2. Persist and resume tx cache across sessions and disconnects:
WalletSynchronizer gains ExportCaches() and PreloadCaches(). On every
successful sync (and on partial failure) the downloaded raw tx hex and
verified Merkle heights are written to SyncCache.RawTxHex/VerifiedAt
in the wallet file. On reconnect or app restart the new synchronizer
is pre-populated from disk so only new transactions are downloaded.
_synchronizer is always nulled on reconnect (new client = new instance)
while caches survive via the wallet file.
3. Auto-connect with multi-server fallback and retry:
ConnectAndSync iterates BuildServerCandidates() (current server first,
then all KnownServers in order) and stops at the first that responds.
_autoReconnect and _syncFailed are set in OpenLoaded() so the keepalive
timer (20 s) retries automatically on any failure — connection error,
-101 mid-download, or timeout. PersistPartialTxCache() saves whatever
was downloaded so each retry resumes from its checkpoint.
WalletSynchronizer now pipelines JSON-RPC requests (address subscribes,
histories, tx downloads and Merkle proofs run in parallel batches) and
keeps per-connection caches of downloaded transactions and verified
proofs, so notification-triggered resyncs only cost the delta.
The app connects automatically when a wallet opens, keeps one
synchronizer per connection, and queues notifications that arrive
during a sync instead of dropping them: incoming transactions now show
up within seconds.
davide