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Zeus Node Lifecycle Campaign

This is an executable, decision-gated investigation campaign for Zeus's hardest live problem (maintainer-confirmed, 2026-07-06): races in starting, stopping, deleting, and switching embedded nodes (embedded LND and LDK Node), including Tokio-thread crashes and Wallet.tsx fetchData re-entrancy. Everything below was verified by reading the code at master c5fd094fb (v13.1.3-alpha) unless explicitly labeled HYPOTHESIS.

When to use / When NOT to use

Use this skill when you are reproducing, diagnosing, or fixing node start/stop/delete/switch races, or reviewing any PR that touches views/Wallet/Wallet.tsx connection flow, SettingsStore lifecycle flags, utils/LndMobileUtils.ts, utils/LdkNodeUtils.ts, or the native node modules.

Do NOT use this skill for:

NeedGo to sibling skill
General symptom→triage for other bugszeus-debugging-playbook
How to capture logs / measure (general tooling)zeus-diagnostics-and-tooling
Past incident narratives beyond lifecyclezeus-failure-archaeology
Backend capability matrix, adding an RPCzeus-backends-and-capabilities
Formal race-analysis method (generic recipes)zeus-proof-and-analysis-toolkit
PR/commit/review rules, the non-negotiableszeus-change-control
Running the app / connecting nodes at allzeus-run-and-operate
Settings blob, migrations, keychainzeus-storage-and-migrations
What counts as test evidence, jest trapszeus-validation-and-qa

Jargon (one line each, both domains)

  • Embedded LND: a full LND Lightning node compiled to a mobile library (gomobile) running inside the Zeus app process; Zeus implementation string 'embedded-lnd'.
  • LDK Node: a Rust Lightning node (ldk-node crate, ZeusLN fork) embedded via uniffi FFI bindings; implementation string 'ldk-node'.
  • Tokio: the Rust async runtime ldk-node uses. If the last reference to the Node object is dropped from one of Tokio's own worker threads, the runtime is destroyed from inside itself → Rust panic → native crash (SIGABRT), killing the whole app.
  • uniffi: Mozilla's Rust↔Kotlin/Swift binding generator; the checked-in ldk_node.kt / LDKNode.swift are its output.
  • gomobile / Messenger IPC: embedded LND is a Go library; on Android it runs behind LndMobileService.java, a bound Android Service the RN module talks to via Messenger message passing (Blixt-derived code, TODO(hsjoberg) debt).
  • Foreground service: an Android service with a persistent notification, allowed to keep running in background; used for "persistent mode".
  • Focus event: react-navigation fires 'focus' every time a screen becomes active — including returning from another screen. Wallet.tsx re-runs its connect logic on focus.
  • AppState: React Native's app-level state (active/background/inactive); Wallet also re-runs connect logic on active.
  • MobX observable: mutable store field that re-renders observers; the lifecycle flags below are plain observables with no atomicity guarantees.
  • Neutrino: LND's light-client chain backend (connects to Bitcoin P2P peers). Esplora/RGS/VSS: LDK Node's chain API server / rapid gossip sync server / remote channel-state storage (vss.zeusln.com).
  • fetchData: the ~800-line method in views/Wallet/Wallet.tsx that resets stores, starts/attaches to the node for the active backend, and loads wallet data. It IS the boot sequence (not App.tsx).

The lifecycle state machine as it actually exists (verified 2026-07-06)

There is no single owner. Lifecycle state is smeared across four layers:

LayerFileOwns
Orchestrationviews/Wallet/Wallet.tsxhandleFocus / handleAppStateChange / handleOpenURL → getSettingsAndNavigate() → fetchData(); the _navigating instance flag; a 60s slow-startup alert timer
Flagsstores/SettingsStore.tsconnecting (init true), fetchLock, embeddedLndStarted, walletJustCreated, triggerSettingsRefresh, posWasEnabled, ldkNodeSyncing; setConnectingStatus(); updateNodeProperties() (swaps implementation, dirs, creds on every settings write)
JS node controlutils/LndMobileUtils.ts (initializeLnd, startLnd, stopLnd, waitForRpcReady, createLndWallet, deleteLndWallet) and utils/LdkNodeUtils.ts (startLdkNodeWallet, stopLdkNode, waitForLdkNodeReady, createLdkNodeWallet, deleteLdkNodeWallet)retry loops, sleeps, error classification (utils/LndMobileErrors.ts)
NativeAndroid android/app/src/main/java/com/zeus/LndMobileService.java (+ LndMobile.java, LndMobileScheduledSyncWorker.java), android/app/src/main/java/app/zeusln/zeus/LdkNodeModule.kt; iOS ios/LndMobile/, ios/LdkNodeMobile/LdkNodeModule.swiftthe actual daemon/Node object, lndStarted boolean, nodeLock/takeNode()
Mutation entry pointsviews/Settings/Wallets.tsx (switch), views/Settings/WalletConfiguration.tsx (create/edit/delete), utils/WalletCreationUtils.ts (Quick Start), views/Settings/SeedRecovery.tsxwrite settings.nodes/selectedNode via updateSettings, then setConnectingStatus(true) + popTo('Wallet')

The guards, in evaluation order

  1. _navigating (Wallet.tsx instance field) — guards getSettingsAndNavigate re-entry from the focus event and AppState active. Added in c71a04ce9 (2026-04-07) because the focus event fires twice on startup and both raced into fetchData → duplicate buildNode, second build times out holding VSS resources. Bypassed by three call sites that invoke getSettingsAndNavigate() directly: pull-to-refresh (LayerBalances onRefresh), the error-screen Restart button (iOS branch), and handleOpenURL for zeusln://share.
  2. fetchLock (SettingsStore observable) — checked/set at fetchData entry (if (fetchLock) return; SettingsStore.fetchLock = true;). Cleared in exactly two places: the happy-path end of fetchData, and setConnectingStatus(true). Every early-return error path leaves fetchLock === true — by design: the app then shows the error screen, and recovery requires setConnectingStatus(true) (Restart button, wallet switch, transient-retry loop), which clears the lock. Consequence: any code path that errors out and then expects a plain focus event to reconnect will hang silently.
  3. connecting — initialized true, so the first fetchData after cold start runs the full connect branch (stop→init→start + reset of ~12 stores). Set false at the end of a successful connect or on fatal errors; set true by every wallet-switch/create/restart path. When false, fetchData becomes a light data refresh (embedded-lnd still calls waitForRpcReady() + full data fetch on every focus).
  4. walletJustCreated — set by createLndWallet / LDK create paths; makes fetchData skip the stop→init→start cycle because the node is already running from wallet creation. Consumed (set false) on first use.
  5. embeddedLndStarted — whether stopLnd() is called before re-init (if (!recovery && SettingsStore.embeddedLndStarted) await stopLnd();). Set true in startLnd (only when a wallet password is present), false in stopLnd and several views.
  6. Native guards — LDK: nodeLock (Kotlin synchronized) / takeNode() (Swift) makes stop/build swap the node reference atomically; LND Android: a single lndStarted boolean inside LndMobileService; the Go daemon itself rejects double starts with "lnd already started".

setConnectingStatus(true) side effects (SettingsStore.ts)

Resets error/errorMsg/lndFolderMissing, calls BackendUtils.clearCachedCalls() (flushes the request dedup cache — see zeus-backends-and-capabilities), and clears fetchLock. This is the universal "reconnect" lever; treat any call to it as a lifecycle transition.

Per-backend connect branch inside fetchData (only when connecting)

  • ldk-node: stopLdkNode() (unless walletJustCreated) → startLdkNodeWallet (initializeNode FFI + node.start() retried up to 5×500ms on "Node not initialized" + syncWallets) → later branch waitForLdkNodeReady() (polls status() every 500ms up to 60s, tolerating "Node not initialized" and not-running — added by b54e8f138, 2026-05-17; the companion buildNode-race fix 8fc9698a0, same day, added the walletJustCreated skip).
  • embedded-lnd: stopLnd() (if started) → initializeLnd (writes lnd.conf, binds service) → optional express graph sync → startLnd (retry ladder incl. force-stop on LND_ALREADY_RUNNING, wallet unlock on WALLET_LOCKED) → waitForRpcReady() (polls getInfo 500ms up to 30s). Transient RPC errors route through retryOnTransientError (max 5 retries, 2s base exponential backoff; it toggles connecting false→true, which is also what re-clears fetchLock).
  • Remote backends (lndhub login, LNC connect(), NWC connectNWC(), REST default) have no native lifecycle but share the same flags.

Native stop/delete rules (the Tokio contract)

From LdkNodeModule.kt (stop, buildNode) and LdkNodeModule.swift (same methods), established by d416052cd + 0e2b89164 (both 2026-03-10):

  1. Take the node reference out of the module under nodeLock/takeNode() first, so no other call can reach a stopping node.
  2. Call node.stop() on a dedicated non-Tokio thread (raw Thread on Android, GCD global queue on iOS) — never on a Tokio callback thread.
  3. Resolve the JS promise only after stop() returns — callers may delete wallet files or build a new node the moment stop() resolves.
  4. Keep the reference alive 2 more seconds after resolving (Thread.sleep(2000) + hashCode() on Android, withExtendedLifetime on iOS) so internal Tokio tasks drop their Arc refs before ours — otherwise the "Runtime dropped on worker thread" panic.
  5. buildNode applies the same stop-and-hold to any existing node before building, and clears the JS-visible node reference up front — which is why any FFI call during a rebuild window rejects with "Node not initialized" (JS must tolerate it: LDK_NODE_NOT_INITIALIZED handling in utils/LdkNodeUtils.ts).

Embedded LND has no equivalent contract; stopLnd() in utils/LndMobileUtils.ts approximates one (status check → stopDaemon → killLnd → poll status up to 10×500ms).

Known race windows (the target list)

Each window is verified by code read at c5fd094fb. Runtime confirmation status noted.

#WindowStatus
W1Double focus → duplicate getSettingsAndNavigateFIXED by _navigating (c71a04ce9); residual: the three bypass call sites rely only on fetchLock, which does NOT stop a second getSettingsAndNavigate from re-running the pre-fetchData navigation logic concurrently
W2JS call into LDK during buildNode rebuild → "Node not initialized" rejectionTolerated in waitForLdkNodeReady (b54e8f138) and the pre-existing start retries; unguarded for every other store that calls the backend during the window (e.g. polling stores)
W3Cross-implementation switch leaves the previous node running: fetchData's ldk-node branch calls only stopLdkNode(), the embedded-lnd branch only stopLnd(). Switching embedded-lnd → ldk-node (or reverse) stops NEITHER the old node; views/Settings/Wallets.tsx onWalletPress only calls setPersistentMode(false) (dismisses the Android notification, does not stop the node) and BackendUtils.disconnect() for LNCConfirmed by code read; runtime impact (two chain-syncing nodes, memory/battery, port/db contention) needs Phase 3 measurement
W4Delete-active-wallet flow: WalletConfiguration.deleteNodeConfig stops node → updateSettings({ justDeletedWallet: active }) → deletes files → navigates to Wallets; selecting the next wallet runs handleJustDeletedWallet which does setConnectingStatus(true) then sleep(2000) — a bare time-based wait standing in for "old node fully gone"Open; the sleep is a fenced symptom-patch pattern (below)
W5JS reload with live daemon: LND runs in the app process (android/app/src/main/AndroidManifest.xml declares LndMobileService with no android:process attribute), so a JS-only restart (RNRestart, dev-menu reload, JS crash) leaves the Go daemon running → next start hits LND_ALREADY_RUNNING → force-stop ladder in startLndWithRetry with 2–4s cleanup sleepsHandled but fragile; see W6
W6LndMobileTools.killLnd() scans running processes for packageName + ":zeusLndMobile", but no such process is ever created (no android:process in the manifest) — so killLnd can never find/kill anything and resolves false. Recovery therefore rests entirely on the Go stopDaemon call. Also killLndProcess() uses getCurrentActivity() which is null when no Activity is attached (background) → NPE riskCode-read finding; runtime confirmation = log killLnd result in Phase 4. Blixt heritage: Blixt runs the service in a separate process, Zeus does not
W7LndMobileScheduledSyncWorker.java (background sync) binds the same LndMobileService and — per its own FIXME at ~line 310 — calls thread.run() instead of thread.start(), executing the "thread" body synchronously on the worker's calling thread with handlers on the main looper. A scheduled sync racing a foreground app start can send MSG_START_LND against an already-started daemon (the worker's own comment: "Make sure we don't attempt to start lnd twice... better fix would be MSG_CHECKSTATUS")Open, acknowledged debt (TODO(hsjoberg))
W8LndMobileService.onUnbind: when the last client unbinds it calls stopLnd(null, -1) + stopSelf() — but the RN module (LndMobile.java) binds once in initialize() and its unbindLndMobileService is flagged in lndmobile/LndMobile.d.ts as "function looks broken" and is never called from TS (verified: zero TS call sites). So service lifetime ≈ process lifetime; unbind-triggered stop is effectively dead code in the app (only the sync worker unbinds)Confirmed by code read
W9Background/foreground storm: AppState active triggers getSettingsAndNavigate (guarded by _navigating), inactive resets NostrWalletConnectStore; iOS fires inactive on mere app-switcher/notification-shade interactionsGuarded but untested under storm; Phase 0 E4
W10LDK delete-then-create same dir: stop() resolves before the 2s native Arc-hold expires; deleteLdkNodeWallet then RNFS.unlinks the storage dir while background Tokio cleanup may still touch itHYPOTHESIS — the 2s hold was added for the ref-drop panic, not for file-handle safety; needs Phase 5 experiment

Phase 0 — Baseline: reproduce and measure

Goal: a numeric crash/hang rate per scenario BEFORE any fix, so any fix can be judged. Do not skip; the maintainer's revert-first culture means an unmeasured "fix" is unlandable.

Prerequisites

  • Dev builds on BOTH platforms (see zeus-run-and-operate; yarn android / yarn ios, Metro via yarn start).
  • Two test wallets on one device: one embedded-lnd (Mainnet or Testnet) and one ldk-node. Create via IntroSplash Quick Start + Settings → Wallets → Add.
  • Log capture:
# Android — native lifecycle tags + crashes (works on debug and release):
adb logcat -v time | grep -E "ReactNativeJS|LdkNodeModule|LndMobileService|LndMobile|AndroidRuntime|FATAL|Fatal signal"

# Android — crash buffer only (count crashes across trials):
adb logcat -b crash -v time

# Android JS console in DEBUG builds goes to the Metro terminal, not logcat.
# In RELEASE builds console.log appears under the ReactNativeJS logcat tag.

# LDK Node's own Rust log (debug builds; substitute the wallet's uuid dir):
adb shell run-as app.zeusln.zeus sh -c 'ls files/ldk-node/'
adb shell run-as app.zeusln.zeus sh -c 'tail -f files/ldk-node/<uuid>/ldk_node.log'

# Embedded LND's log: in-app Settings → Embedded node → LND Logs, or (debug):
adb shell run-as app.zeusln.zeus sh -c 'tail -f files/<lndDir>/logs/bitcoin/mainnet/lnd.log'

# iOS — native NSLog (simulator; process name is "zeus"):
xcrun simctl spawn booted log stream --predicate 'process == "zeus"' --style compact
# iOS JS console: Metro terminal.

Log milestones (the vocabulary of every experiment)

All verified present in source:

MilestoneExact string (grep-able)Source
Focus fired, connect starting[Wallet] handleFocus: triggering getSettingsAndNavigateWallet.tsx
Re-entry suppressedskipping — getSettingsAndNavigate already in flightWallet.tsx (focus + AppState variants)
LDK teardown[LDK startup] stopping previous instance / [LDK startup] stoppedWallet.tsx
LDK build+start[LDK startup] calling startLdkNodeWallet / LDK Node: Started successfully / LDK Node: Sync completeWallet.tsx / LdkNodeUtils.ts
LDK ready-wait[LDK startup] waiting for node to be readyWallet.tsx
LDK native timingLdkNodeModule: [timing] FFI buildWithDualStore starting/completedLdkNodeModule.kt/.swift
LND readyRPC ready - Node pubkey:LndMobileUtils.ts waitForRpcReady
LND statesCurrent LND state: (NON_EXISTING/LOCKED/UNLOCKED/RPC_ACTIVE/SERVER_ACTIVE)LndMobileUtils.ts
LND double-start recoveryLND already started - force stop (Go thinks running)LndMobileUtils.ts
Connect finished[Wallet] connect time: Wallet.tsx
LDK race symptomNode not initializednative modules / LdkNodeUtils.ts
Transient-retry loopTransient ... - retry N/5 in XmsLndMobileErrors.ts

E1 — Cold start, each backend (control; 5 trials each)

Kill the app (swipe from recents), relaunch, wait for balance screen.

  • Expect: one triggering line, typically followed by one skipping line (the startup focus event fires twice — see c71a04ce9), the backend's start milestones once each, exactly one connect time: line.
  • If you see two triggering lines with no skipping → the _navigating guard regressed or a bypass path fired → branch to Phase 2.
  • If connect time: never appears and the spinner persists → note which milestone was last; fetchLock is likely stranded (Phase 2's flag table tells you which return path).

E2 — Rapid wallet switch, embedded-lnd ↔ ldk-node (20 cycles)

Settings → Wallets → tap the other wallet; as soon as the Wallet screen shows anything (don't wait for full sync), switch back. Record: crashes (logcat -b crash), stuck-spinner incidents, and whether the OLD node keeps running.

  • Old-node liveness probe (W3): after switching embedded→ldk, keep tail -f on the old wallet's lnd.log — if new log lines keep appearing (neutrino banner/filter activity), the LND daemon is still running alongside LDK. Expected per code read: it is. Symmetrically, ldk_node.log continues after switching ldk→embedded.
  • Expect per switch: triggering → store resets → old-backend stop milestone only if switching within the same implementation → new-backend start milestones → connect time:.
  • If crash with Fatal signal 6 (SIGABRT) mentioning tokio/runtime → LDK ref released on a Tokio thread; capture the full tombstone; this is the d416052cd class — branch to Phase 5.
  • If Node not initialized surfaces in the UI (error screen) rather than being retried → an unguarded call site hit W2 — branch to Phase 2 call-site census.
  • If a switch hangs with no triggering line at all → focus fired while _navigating was stuck true (a getSettingsAndNavigate that never resolved) — capture the last milestone.

E3 — Delete active wallet mid-operation (5 trials each backend)

While the node is mid-sync (do this within ~30s of connect), Settings → Wallets → gear icon → Delete wallet → confirm; then immediately select the remaining wallet.

  • Expect: stop milestone, justDeletedWallet flow (2s pause in Wallets.handleJustDeletedWallet before reconnect), new wallet connects.
  • If crash on the delete itself (LDK) → W10 or a d416052cd regression — branch to Phase 5.
  • If "wallet not found"/LND_FOLDER_MISSING alert on the NEXT connect → stale lndDir/ldkNodeDir read from a not-yet-propagated settings write — record selectedNode at each step (Phase 1 instrumentation).

E4 — Background/foreground storm (20 cycles)

Rapidly background/foreground the app (Android: home + reopen; iOS: app switcher). Then once more with ≥30s in background.

  • Expect: skipping lines for suppressed re-entries; at most one connect flow per foregrounding; NWC store reset lines on iOS inactive are normal.
  • If store data visibly resets (balance flashes to 0) on every foreground → connecting got stuck true, making every fetchData run the full reset branch.

E5 — JS reload with live daemon (Android, 10 trials)

With embedded-lnd running: dev-menu Reload (debug) or trigger the in-app restart. The process survives, so the Go daemon does too.

  • Expect: LND already started - force stop (Go thinks running) → stop ladder → successful restart within ~10s (includes the 4s ANDROID_PROCESS_CLEANUP_DELAY_MS).
  • If it loops on LND still running (attempt N) - force stop until LND_START_FAILED → the stop ladder can't actually kill the daemon (consistent with W6: killLnd is a no-op on this manifest) → Phase 4.

Baseline record: for each experiment, crashes / trials, hangs / trials, and the last milestone before each failure. This table is the campaign's ground truth.


Phase 1 — Instrument the flags (temporary)

Add TEMPORARY logging so every flag transition is attributable. Instrumentation must not ship: strip it before any PR, or land it only behind an explicit maintainer-approved debug gate — unconditional console noise in the connect path will be rejected in review (zeus-change-control; there is no developer-mode toggle to hide behind, see zeus-config-and-flags).

Instrumentation points (grep anchors, all verified):

WhereAnchorLog
stores/SettingsStore.ts setConnectingStatuspublic setConnectingStatus = (status = false)old→new value + new Error().stack (caller attribution — MobX gives you none)
views/Wallet/Wallet.tsx fetchData entryif (fetchLock) return;log BOTH the rejected entries (currently silent) and the acquisitions, with implementation, connecting, walletJustCreated
views/Wallet/Wallet.tsx fetchData exitSettingsStore.fetchLock = false;matched release log; any acquisition without a release = a stranded lock
utils/LndMobileUtils.ts stopLnd/startLndfunction headsentry/exit + embeddedLndStarted value
utils/LdkNodeUtils.ts stopLdkNode/startLdkNodeWalletfunction headsentry/exit timestamps (measures overlap with builds)
views/Settings/Wallets.tsx onWalletPressconst onWalletPressold/new selectedNode, old/new implementation

Re-run E1–E5 with instrumentation. Decision gate: produce a timeline for every Phase 0 failure showing which flag was in the wrong state. If any failure shows two node-start sequences interleaved (start A begins, start B begins before A's ready milestone), the serialization defect is confirmed and Phase 2 is mandatory.

Phase 2 — Entry-path and lock-outcome census (desk analysis + targeted tests)

Enumerate every path into getSettingsAndNavigate/fetchData and every exit's flag outcome. Starting set (verified at c5fd094fb — re-derive, don't trust):

grep -n "getSettingsAndNavigate\|_navigating" views/Wallet/Wallet.tsx
grep -rn "setConnectingStatus(true)" --include="*.ts" --include="*.tsx" . | grep -v node_modules

Entry paths: focus (guarded), AppState active (guarded), componentDidMount→handleFocus, pull-to-refresh (UNguarded), error-screen Restart (UNguarded, iOS), zeusln://share URL (UNguarded), transient-retry recursion (retryOnTransientError → getSettingsAndNavigate(undefined, count+1)).

For each return/throw inside fetchData, record: fetchLock left true? connecting left true? Is there a UI affordance that will call setConnectingStatus(true) to recover? Build the full table (there are ~12 early returns).

Decision gate:

  • If every observed Phase 0 hang maps to a "lock stranded + no recovery affordance" row → solution (b) below fixes the hangs; scope it to those rows.
  • If hangs occur even with clean flag states → the defect is deeper (native), go to Phase 4/5 first.

Phase 3 — Cross-implementation teardown (W3)

Experiment: E2's old-node liveness probe, plus resource measurement:

# Memory of the app process while both nodes run vs one:
adb shell dumpsys meminfo app.zeusln.zeus | head -30

Also test: switch embedded→ldk, wait 5 min, switch back — does the returning stopLnd()+startLnd() find a healthy daemon or a wedged one?

Decision gate: if the old node demonstrably keeps syncing after a switch (expected), classify severity: (i) resource-only → fold the fix into solution (a)/(c); (ii) causes E2 crashes or db contention → promote solution (c) to first.

Phase 4 — Android native service model (W5–W8)

  1. Log killLnd's return value during E5. Expected per code read: always false (no :zeusLndMobile process exists to kill). If confirmed, the "force stop" ladder is stopDaemon-only, and the manifest/no-process finding should be written into the fix design.
  2. Audit LndMobileScheduledSyncWorker interaction: enable persistent mode / scheduled sync, background the app, watch for a worker-initiated MSG_START_LND colliding with a foreground start.
  3. Decide (with maintainer, this is Blixt-heritage territory): separate process like Blixt (android:process), or keep in-process and delete the dead killLnd scan + fix the thread.run() FIXME.

Decision gate: only proceed to native changes if Phase 0/1 shows failures that JS-level serialization cannot prevent (e.g. daemon survives all stop attempts). Native service changes require full re-test of: background receive, persistent mode notification, scheduled sync, graceful-stop notification action.

Phase 5 — LDK stop/delete timing (W2, W10)

  1. Census every JS call site that can reach the LDK FFI while buildNode/stop is in flight (grep -rn "LdkNode\." stores/ backends/ utils/ --include="*.ts"); classify each as tolerant (retries on Node not initialized) or crash/error-surfacing.
  2. W10 experiment: script delete-then-recreate of an ldk-node wallet as fast as the UI allows, 10 cycles, watching ldk_node.log and the crash buffer. If unlink-during-cleanup errors appear, the fix is to move the delete into native (delete after the Arc-hold) or extend the JS wait — with a real completion signal, NOT a longer sleep.

Decision gate: any crash here re-opens the d416052cd/0e2b89164 contract — fix in the native module (both platforms symmetrically; the Kotlin and Swift implementations are deliberate mirrors), never by adding JS-side sleeps.


Solution menu — ranked, with obligations

Ranking reflects maintainer culture: minimal diffs first, big designs only with prior sign-off. Every option below is funds-adjacent (a node torn down mid-payment can strand an HTLC or force-close exposure), so all inherit: no drive-by refactors in payment paths, manual 2-platform testing by the author, revert-first if release testing regresses (zeus-change-control).

1. fetchData lock-hygiene + serialization audit (smallest, do first)

Make lock acquire/release provably paired: single exit point (try/finally) for fetchLock; extend the _navigating guard (or fold it into one SettingsStore-owned in-flight promise) to cover the three bypass call sites.

  • Theory obligations: the Phase 2 table with every entry path × every exit → flags outcome; prove the error-screen Restart and transient-retry recovery still work (they depend on setConnectingStatus(true) clearing the lock — don't break that contract silently).
  • Blast radius: Wallet.tsx + SettingsStore only. No storage change, no migration.
  • Gates: standard PR gates + E1/E2/E4 re-run showing hang rate → 0.

2. Cross-implementation teardown fix (W3)

Before starting backend B, stop whichever embedded node type is actually running — e.g. track "last started native node" (type + dir) in SettingsStore and stop it in fetchData's connect branch regardless of the NEW implementation, or stop-old in onWalletPress before updateSettings.

  • Theory obligations: prove stopLnd() is safe when LND isn't running (it is — status-check path returns early) and stopLdkNode() likewise (native stop resolves ok on null node); measure added switch latency; prove the delete flow (which stops nodes itself) doesn't double-stop into an error state.
  • Blast radius: Wallet.tsx or Wallets.tsx + SettingsStore. No storage change (the tracking flag must stay a non-persisted observable — persisting it would trigger the storage gate, zeus-storage-and-migrations).
  • Gates: E2 with liveness probe showing old node actually stops; both platforms.

3. LDK stop/delete hardening (W2, W10)

Give delete a real completion signal (native-side delete after Arc-hold, or a stopAndAwaitCleanup FFI method); make non-tolerant FFI call sites tolerant or gate them on a ready flag.

  • Theory obligations: preserve the four-step Tokio contract verbatim; enumerate all FFI call sites (Phase 5 census) and prove each is either serialized-after-ready or retry-tolerant.
  • Blast radius: LdkNodeModule.kt + LdkNodeModule.swift (must change in lockstep) + utils/LdkNodeUtils.ts. Native binary/bindings untouched (pure module-layer change) — if the ldk-node fork itself must change, that's a fetch-libraries-versions.json bump with its own process (zeus-build-and-env).
  • Gates: E3 ×20 both platforms, crash buffer clean.

4. Single lifecycle state machine (the end state — design sign-off REQUIRED first)

One owner (e.g. a NodeLifecycleStore / manager) with explicit states — STOPPED, STARTING, RUNNING, STOPPING, DELETING, SWITCHING — through which ALL start/stop/delete/switch flows pass; Wallet.tsx becomes a consumer, not an owner.

  • Theory obligations (non-negotiable before code): (i) full state/transition enumeration with the illegal transitions listed; (ii) proof of no orphaned native handle — every start has exactly one matching stop on every path including error paths and app-kill (invariant: at most one native node per implementation, and after the W3 fix, at most one total); (iii) mapping of ALL existing flags (connecting, fetchLock, embeddedLndStarted, walletJustCreated, _navigating) onto machine states, with a staged migration so each PR stays reviewable; (iv) re-entrancy story: transitions are serialized on one async queue, concurrent requests coalesce or queue, never interleave.
  • Blast radius: Wallet.tsx, SettingsStore, Wallets/WalletConfiguration/SeedRecovery/WalletCreationUtils, both utils files. This is exactly the shape of refactor that produced fdad118ed — land it as a series of minimal PRs, each independently revertible.
  • Gates: maintainer design ACK before implementation; full Phase 0 suite as regression harness; both platforms per PR.

5. Android native service overhaul (W6–W8)

Fix/delete dead killLnd, resolve the thread.run() FIXME, decide the process model, fix or remove the broken unbindLndMobileService.

  • Theory obligations: document Blixt-divergence (separate process vs in-process) and its tradeoffs (a separate process makes kill reliable but changes IPC failure modes and memory accounting); prove scheduled-sync and persistent-mode still work.
  • Blast radius: highest — background receive, notifications, WorkManager. Android-only, which violates the "both platforms behave the same" instinct — extra review scrutiny.
  • Gates: only after Phase 4's decision gate says JS-level fixes are insufficient; maintainer sign-off; full background-services manual test matrix.

Fenced wrong paths (do not repeat; hashes verified in this repo)

  • UNSAFE-lifecycle shortcut: fdad118ed (2025-10-24) refactored Wallet's React lifecycle methods and caused infinite loading, fixed only three weeks later by 93227029e. Fence: no mechanical lifecycle refactors of Wallet.tsx; behavior-preserving proof + full Phase 0 suite or don't touch it.
  • Releasing LDK refs on the Tokio thread / resolving stop early: crash class fixed by d416052cd + 0e2b89164 (2026-03-10). Fence: the four-step native contract above is load-bearing; any "simplification" that drops the dedicated thread, the blocking resolve, or the 2s hold re-introduces a hard native crash.
  • Treating the buildNode window as fatal: before b54e8f138 (2026-05-17), startup had no ready-wait, so "Node not initialized" from post-start FFI calls could surface as a fatal error (the node.start() retry itself predates that commit). Fence: during rebuild windows, retry-with-classification (specific error strings, bounded retries) — but do NOT blanket-retry all FFI errors; only the two sentinels in utils/LdkNodeUtils.ts.
  • Sleeps as synchronization: the codebase already carries load-bearing sleeps (sleep(2000) in Wallets.handleJustDeletedWallet, ANDROID_PROCESS_CLEANUP_DELAY_MS = 4000, the 2s Arc-holds, STATE_SUBSCRIPTION_SETTLE_MS). Fence: adding another timeout to make a race "go away" is symptom-patching; every new wait must be a real completion signal (status poll, event, promise) or it will be NACKed. Existing sleeps may only be removed by a change that replaces them with an owned signal.
  • Forward-fixing under release pressure: regressions found in release testing get reverted same-day, never patched forward (maintainer rule; see zeus-change-control and the same-day-revert record in zeus-failure-archaeology). Fence: if your lifecycle change regresses anything in manual testing, the move is revert, then re-derive.
  • Unattributed duplicate-work "fixes": c71a04ce9 shows the right shape — the commit body names the exact double-fire mechanism (focus fires twice with initialLoad=true) before adding the guard. Fence: no guard/lock may be added without a written statement of which concrete interleaving it prevents.

Validation & promotion protocol

A lifecycle fix is promotable when ALL of the following hold:

  1. Scripted counts, both platforms (Android device/emulator AND iOS device/simulator — maintainer's manual 2-platform rule, CI builds nothing mobile):
    • E2 wallet-switch: 0 crashes and 0 stuck-spinners in 30 cycles per platform.
    • E3 delete/create: 0 crashes in 10 cycles per backend.
    • E4 bg/fg storm: 0 duplicate connects, 0 hangs in 20 cycles.
    • E5 JS-reload recovery: reconnect succeeds 10/10 (Android).
  2. Log-assertion checklist on captured logs: exactly one triggering per user action (plus skipping lines); one connect time: per connect; zero UI-surfaced Node not initialized; zero Fatal signal in adb logcat -b crash; after a cross-implementation switch, the old node's log file goes quiet (post W3 fix).
  3. No stranded flags: with Phase 1 instrumentation applied locally, every fetchLock acquisition has a matching release in every experiment (then strip the instrumentation).
  4. yarn verify green (Test, Lint, Prettier, Typescript Check — see zeus-validation-and-qa). Note stores/views have zero jest coverage; your manual evidence IS the test.
  5. PR structure (zeus-change-control): minimal diff; no drive-by refactors (especially none in payment paths); PR template intact with the backend testing matrix filled (embedded-lnd + ldk-node at minimum, plus one remote backend to prove the shared flags still work); commit message names the interleaving fixed and cites the relevant hashes; screenshots/recordings of the connect flow if UI-visible.
  6. Change-control routing: storage untouched (no new persisted keys — else zeus-storage-and-migrations gates apply); new dependencies need prior maintainer discussion; native ldk-node/lnd binary bumps go through fetch-libraries-versions.json (zeus-build-and-env).

Provenance and maintenance

Facts verified 2026-07-06 against master c5fd094fb (v13.1.3-alpha) by direct code read; commit hashes verified with git log. The maintainer priority statement dates from 2026-07-06. Runtime numbers (crash rates) are deliberately absent — Phase 0 produces them.

One-line re-verification commands (run from repo root):

git log -1 --format="%h %s"                                          # still c5fd094fb?
grep -n "_navigating" views/Wallet/Wallet.tsx                        # re-entry guard still present
grep -n "if (fetchLock) return" views/Wallet/Wallet.tsx              # lock acquire site
grep -n "remove fetchLock on reconnect" stores/SettingsStore.ts      # lock cleared in setConnectingStatus(true)
grep -n "connecting = true" stores/SettingsStore.ts                  # connecting initialized true
grep -n "walletJustCreated" views/Wallet/Wallet.tsx | head -3        # skip-start flag still consumed
grep -n "stopLdkNode()" views/Wallet/Wallet.tsx                      # ldk branch stops only ldk (W3)
grep -rn "stopLnd" views/Wallet/Wallet.tsx | head -3                 # lnd branch stops only lnd (W3)
grep -n "thread.run()" android/app/src/main/java/com/zeus/LndMobileScheduledSyncWorker.java   # W7 FIXME
grep -n "zeusLndMobile" android/app/src/main/java/com/zeus/LndMobileTools.java                # W6 dead scan
grep -n "android:process" android/app/src/main/AndroidManifest.xml   # expect NO output (in-process LND)
grep -n "looks broken" lndmobile/LndMobile.d.ts                      # W8 unbind still flagged broken
grep -n "Thread.sleep(2000)" android/app/src/main/java/app/zeusln/zeus/LdkNodeModule.kt       # 2s Arc-hold
grep -n "withExtendedLifetime" ios/LdkNodeMobile/LdkNodeModule.swift # iOS mirror of the hold
grep -n "LDK_NODE_NOT_INITIALIZED" utils/LdkNodeUtils.ts             # tolerated sentinel
grep -n "MAX_TRANSIENT_RPC_RETRIES\|TRANSIENT_RPC_RETRY_BASE_MS" utils/LndMobileErrors.ts     # 5 / 2000ms
grep -n "sleep(2000)" views/Settings/Wallets.tsx                     # delete-flow sleep still load-bearing
git log -1 --format="%h %ad %s" --date=short c71a04ce9 d416052cd 0e2b89164 b54e8f138 8fc9698a0 fdad118ed 93227029e

If any of these greps come back empty or changed, the corresponding claim above is stale — re-read the file before acting on it.