multi: passive Esplora polling for lwwallet

darepod/config.go

@@ -73,7 +73,13 @@ const (
 
 	// DefaultEsploraPollInterval is the default interval at which the
 	// lwwallet polls the Esplora API for new blocks and transactions.
-	DefaultEsploraPollInterval = 5 * time.Second
+	// Mainnet blocks land roughly every 10 minutes, so a 30 s cadence
+	// stays comfortably within one block's worth of latency while
+	// keeping the request volume well under the public mempool.space
+	// rate limits. Tests / regtest environments that mine blocks on
+	// demand should override this to a sub-second value via the
+	// `wallet.pollinterval` config knob.
+	DefaultEsploraPollInterval = 30 * time.Second
 
 	// DefaultRecoveryWindow is the default address look-ahead window
 	// used during lwwallet recovery.

darepod/server.go

@@ -1198,6 +1198,18 @@ func (s *Server) startLwwallet(ctx context.Context,
 	s.lwWallet = fn.Some(w)
 	s.refreshProofKeyBackend()
 
+	// Wire up the chain backend reference if it was deferred at
+	// startup because the wallet was not yet available. The wallet's
+	// chain backend was already started inside w.Start() above
+	// (lwwallet.Wallet.Start calls chainBackend.Start as part of its
+	// startup sequence). Calling Start a second time here would
+	// subscribe to the shared TipPoller again and spawn a duplicate
+	// handleTipEvents goroutine, which would double block-epoch
+	// notifications and confirmation/spend re-checks.
+	if s.chainBackend == nil {
+		s.chainBackend = w.ChainBackend()
+	}
+
 	// Refresh the RPC clients once the wallet is available so the
 	// indexer client picks up the wallet-backed identity key and signer
 	// before any deferred wallet-dependent actors start.
@@ -1607,23 +1619,25 @@ func (s *Server) initChainBackend(ctx context.Context) error {
 
 	case WalletTypeLwwallet:
 		// If the lwwallet is already started (auto-unlock
-		// succeeded), use its chain backend. Otherwise, we
-		// need a standalone Esplora chain backend that can
-		// serve the chain source actor before the wallet is
-		// ready.
+		// succeeded), use its chain backend. Otherwise defer
+		// chain backend creation to startLwwallet so that the
+		// wallet's TipPoller, EsploraClient, and ChainBackend
+		// are all owned by the wallet — running a standalone
+		// EsploraClient + TipPoller here in the interactive-
+		// unlock path would silently double the Esplora call
+		// rate and pin s.chainBackend to an orphan that the
+		// wallet never replaces.
 		if s.lwWallet.IsSome() {
 			w := s.lwWallet.UnsafeFromSome()
 			s.chainBackend = w.ChainBackend()
 			alreadyStarted = true
 		} else {
-			s.chainBackend = lwwallet.NewChainBackend(
-				lwwallet.NewEsploraClient(
-					s.cfg.Wallet.EsploraURL,
-					s.subLogger(lwwallet.Subsystem),
-				),
-				s.cfg.Wallet.PollInterval,
-				s.subLogger(lwwallet.Subsystem),
-			)
+			// Defer chain backend start to startLwwallet.
+			// Skip the Start() call below; mirrors the
+			// btcwallet path. The chain source actor
+			// registration in Run is also deferred via
+			// the same chainBackend == nil check.
+			return nil
 		}
 
 	case WalletTypeBtcwallet:

go.mod

@@ -25,6 +25,7 @@ require (
 	github.com/lightninglabs/lndclient v0.21.0-rc1
 	github.com/lightninglabs/loop v0.33.0-beta
 	github.com/lightninglabs/neutrino v0.16.2
+	github.com/lightninglabs/neutrino/cache v1.1.3
 	github.com/lightninglabs/taproot-assets v0.7.0
 	github.com/lightninglabs/taproot-assets/taprpc v1.0.11
 	github.com/lightningnetwork/lnd v0.21.0-beta.rc1
@@ -39,6 +40,7 @@ require (
 	github.com/stretchr/testify v1.11.1
 	golang.org/x/crypto v0.47.0
 	golang.org/x/exp v0.0.0-20251113190631-e25ba8c21ef6
+	golang.org/x/sync v0.19.0
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20251202230838-ff82c1b0f217
 	google.golang.org/grpc v1.79.3
 	google.golang.org/protobuf v1.36.11
@@ -124,7 +126,6 @@ require (
 	github.com/klauspost/compress v1.17.9 // indirect
 	github.com/lightninglabs/gozmq v0.0.0-20191113021534-d20a764486bf // indirect
 	github.com/lightninglabs/lightning-node-connect/hashmailrpc v1.0.4-0.20250610182311-2f1d46ef18b7 // indirect
-	github.com/lightninglabs/neutrino/cache v1.1.3 // indirect
 	github.com/lightningnetwork/lightning-onion v1.3.0 // indirect
 	github.com/lightningnetwork/lnd/actor v0.0.6 // indirect
 	github.com/lightningnetwork/lnd/cert v1.2.2 // indirect
@@ -202,7 +203,6 @@ require (
 	golang.org/x/mod v0.32.0 // indirect
 	golang.org/x/net v0.49.0 // indirect
 	golang.org/x/oauth2 v0.34.0 // indirect
-	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.40.0 // indirect
 	golang.org/x/term v0.39.0 // indirect
 	golang.org/x/text v0.33.0 // indirect