FlClash/.agents/architecture.md

Architecture

Core Integration

The Go proxy core in core/ operates in two modes.

Android lib mode:

• gomobile bind builds core/mobile into an AAR: a native library per ABI, shipped as libclash.so, and the Java classes gobind generates in com.follow.clash.core.mobile. The :core Gradle module builds it and takes in its classes and libraries (see Android Core Build).
• The Android :core module owns the binding: Core.kt is the only caller of the generated Mobile class. Flutter crosses MethodChannels through lib/plugins/service.dart and Android's ServicePlugin rather than calling the Core directly: ${packageName}/service for lifecycle commands and Core events, ${packageName}/core for Core method calls.
• Flutter runs the UI isolate on Android's main thread (3.47 merges the two and ignores the opt-out in release), so main-thread work anywhere in the process, the Core's included, costs frames. Only sending to Dart needs that thread; a MethodChannel.Result may be answered from any thread. ${packageName}/core is handled on a serial background task queue and answered from the Core's goroutine, an event batch is encoded on the Core's thread and only sent on the main one, ForceGC (called from onLowMemory/onTrimMemory) collects on its own goroutine, and NetworkObserveModule refreshes DNS on its own looper.
• lib/core/lib.dart (CoreLib) implements the shared Core interface, gates method calls on its connection completer, initializes and synchronizes Android shared state, and closes the native service path exactly once.
• Because Core is in the application process on Android, application RSS already includes Core memory.

Desktop core mode:

• Go core runs as a separate process with CGO_ENABLED=0.
• rust_api's ipc module provides the native local-IPC primitives: a Unix domain socket on macOS/Linux and a named pipe on Windows, served by an IpcServer handle. Dart owns the transport state, RPC correlation, process ownership, and lifecycle convergence above those primitives.
• lib/core/service.dart (CoreService) is the composition root. It wires the IPC transport, launcher selection, lifecycle controller, RPC client, and crash-event bridge, and holds no lifecycle logic of its own.
• lib/core/desktop/transport.dart binds an IpcServer and turns its events into ready, connected, disconnected, and failed transport events plus a frame stream. A connection that ends on an I/O error is a disconnect carrying that error; failed means the server itself is gone and is terminal for that transport. A replaceable binding keeps RPC subscriptions stable when a failed or stale transport must be rebuilt.
• lib/core/desktop/rpc_client.dart owns request IDs and pending completers, waits up to 10 seconds for a connection, applies a three-minute default method timeout, unwraps CoreMethodResponse, and fails all pending calls when transport disconnects or closes.
• lib/core/desktop/lifecycle.dart serializes process intents and owns the authoritative desktop state machine.
• lib/core/desktop/launcher.dart abstracts direct child-process and privileged Helper ownership through idempotent process leases. lib/core/desktop/helper_client.dart is the typed local HTTP client for the privileged Helper.

lib/core/controller.dart (CoreController) selects the implementation based on platform. lib/core/interface.dart defines the shared CoreHandlerInterface.

Key Go core files:

• core/protocol.go: method names, event types, and the parameter and result shapes shared with Dart.
• core/method.go: MethodChannel-style method-call dispatch, the handler table, and response envelopes.
• core/lifecycle.go, config.go, proxy.go, delay.go, provider.go, geo.go, connection.go, log.go: the handler functions, one file per area. core/hooks.go wires mihomo's hooks to them.
• core/message.go: non-blocking state/priority/bulk event queues and bounded message batching.
• core/lib.go: the Android library API: TUN callbacks, the event listener, and the entry points core/mobile binds.
• core/mobile/: the package gomobile binds. gobind generates Java for its exported API, so it speaks only int32, bool, string, []byte and its own interfaces; a Go int would become a Java long.
• core/cmd/core/: the desktop entry point. core/ itself is the library package core, because gomobile cannot bind a main package.
• core/server.go: desktop socket/named-pipe client and framed message forwarding.

DNS, NTP and Sniffer Overrides

A URL or file profile brings its own sections; a custom profile brings none. The app's DNS page (PatchClashConfig.dns with dnsOverrideKeys) is written over the DNS of every URL and file profile, and offers only DnsOverrideKey.normalProfileKeys: keys that name nothing of a profile's own, because a subscription's groups and rule sets change with every update. A custom profile keeps all three sections in Profile.overrides, a ProfileOverrides stored as JSON in the profiles.overrides column, with every key available, and NTP and sniffer exist nowhere else. setupState resolves SetupState.overrides by profile type, intersecting the app-wide keys with the normal set, and _makeRealProfileTask merges whatever it is handed; there is no on/off toggle, a picked key is the override.

Each *OverrideKey names one Clash key, with parent.field paths for nested maps, and covers every yaml key of the matching mihomo raw struct; test/models/{dns,ntp,sniffer}_override_test.dart read core/Clash.Meta/config/config.go and fail when a core bump adds or drops one. overrideJson builds the fragment in model order and skips a key whose value is empty, so a key left without a value writes nothing: the core refuses an empty nameserver outright. mergeDnsOverride merges one level deep so a partial fallback filter keeps the profile's other filter keys; NTP spreads over the profile's flat ntp map. For a profile whose dns.enable is not true, the task first fills baselineDns for baselineDnsOverrideKeys (enable, enhanced-mode: fake-ip, nameserver), the one thing the core is never without: with DNS off, mihomo answers every TUN-hijacked query with an error. The baseline stays apart from the model defaults, which carry no preset of the app.

An added key starts from the spec's defaults through its OverrideField.reset, and those defaults are mihomo's: a key starts at the value mihomo parses without it, presets included, such as the nameservers, fake-IP range and filter, and NTP server of DefaultRawConfig. A key mihomo leaves unset, such as listen or a sniff protocol's ports, starts empty and writes nothing until the user fills it in, and so does the fallback filter's GeoIP code, whose value is left for the user to choose. mihomo sniffs a protocol listed without ports on that protocol's standard port, which the page shows as the default. The tests above pin the defaults against DefaultRawConfig. A spec that mixes in OverrideQuickEdit gets quick edit, which opens overrideYaml in an EditorPage and rebuilds the key set from the document through applyOverrideYaml, rejecting keys outside the section and values the model cannot hold.

mihomo upper-cases sniff protocol names and ignores the deprecated sniffing list once sniff holds anything, so mergeSnifferOverride drops the profile's entry for an overridden protocol in any case and first carries sniffing into sniff. A rule-set: key of a custom profile's DNS policy counts as a use of that rule provider, so _resolveInjectedProviders injects it like one a rule names. Safe mode forces write-to-system off on whatever ntp section reaches the core, because setting the system clock is a host change; loadConfig in the Go wrapper also drops it on Android, where the seccomp policy kills the process for settimeofday.

TUN is the exception to covering the raw struct. The network settings own only Tun.coreJson (enable, device, stack, and auto-route always on), spread last over the profile's section and patched again on every updateConfig, so TunOverrideKey offers only keys outside it that work in FlClash's TUN. Its keys exist app-wide (PatchClashConfig.tunOverride with tunOverrideKeys, listed in the network page's TUN section as OverrideEntry rows and added from its last row, as a custom group's options are) for every profile, and per custom profile, whose own keys ProfileOverrides.overAppTun lays over the app-wide ones. MTU, congestion control, strict route and the route lists are such keys on desktop, so a profile's own values apply unless picked; Android's TUN rows keep them in Tun, which its VPN service starts from, and a config saved before the move carries values changed from their defaults into picked keys. bypassPrivateRoute stays a network setting: the task appends the private ranges to whatever route-exclude-address results. dns-hijack is a key too: the task writes any:53 beneath the overrides, so a profile's own value never applies, a picked key replaces it, and the key starts at that value. A key sing-tun reads on some platforms only is listed only there (_isRead in lib/views/config/tun.dart): strict route on Linux and Windows, GSO and the interface, user ID and port filters on Linux. udp-timeout reaches only the gvisor and system stacks and congestion control only mips, which their descriptions say. Route address sets are left out: sing-tun applies them only through auto-redirect. test/models/tun_override_test.dart fails if a key comes to overlap Tun.coreJson. Android starts its VPN from core/tun without the section, so TUN is listed on desktop only. Being a part of the section, the page has no quick edit; see Quick Edit.

A custom profile's overview keeps rows for rules, providers and DNS, which every custom profile runs on, and puts the dialer proxies, NTP, sniffer and TUN behind a single "more" row, which opens a page listing them with their states. Both lists are the same grouped rows, glyph, title and state, ending in a chevron. Another rarely changed section joins the "more" list rather than taking a row of its own.

Every page is an OverrideView over an OverrideSpec from lib/views/config/override.dart. The spec supplies the section's keys, labels and fields; its OverrideTarget is where the model and keys live, PatchOverrideTarget for the app-wide DNS and ProfileOverrideTarget for a profile. Another overridable section is a spec, not a copy of a page.

A config from a release that still had the overrideDns toggle keeps, through Config.fromJson, the normal keys of an on toggle and none of an off one. That release had no custom profiles, so its app-wide NTP override is dropped.

Listener Exposure

_makeRealProfileTask in lib/common/task.dart writes mixed-port, allow-lan, and external-controller into every generated profile. With allow-lan off, mihomo's genAddr binds each listener to 127.0.0.1; the external controller is ExternalControllerStatus.close by default and never binds anywhere but loopback. The task also clears external-controller-tls, -unix and -pipe in every mode: the unix and pipe controllers answer without a secret, and the unix one unlinks whatever file sits at its path before opening it to everyone, so a profile may not choose them. Outside safe mode, profiles retain listeners, tunnels, ss-config, vmess-config, tuic-server, iptables, dns.listen and ntp.write-to-system. Extra inbounds can bypass the app's LAN and authentication settings, and a TUN listener can change routing independently of the app's TUN toggle. These network and clock effects are an accepted boundary; they are not treated as arbitrary filesystem modification. The task disables iptables when its inbound-interface contains a space, because mihomo interpolates it into commands and splits their arguments on spaces. Safe mode clears these extra inbounds and iptables, closes DNS listening and disables NTP system time writes even after local overrides. The editor omits disabled alternate controllers and keeps listener completion.

An open external controller always has a secret, because mihomo serves a controller with an empty one to every local user and, through CORS, to any page the user visits. PatchClashConfig.secret is that secret and it belongs to FlClash, as the address does: the task writes it over whatever the profile carries, and UpdateParams.secret hands the same value to a running Core, which restarts the controller when it changes. ensureControllerSecret keeps the pair consistent (an open controller gets a generated secret, a closed one drops it, so every opening rotates it) and runs where a config enters the app: the settings toggle, startup, and writeConfig for a restored backup. _effectivePatchConfig reports a controller without a secret as closed, and _makeRealProfileTask independently closes it without a secret or in safe mode, so a writer that skips ensureControllerSecret opens nothing. The settings page shows the secret in an editable row, which refuses an empty value.

The loopback listener takes local connections without authentication by default: mandatory credentials would lock out every external local consumer a proxy client exists for. The binding only guarantees traffic originates on the device; it does not isolate programs already running there, so on Android any app holding INTERNET can use the proxy and learn the outbound IP (#1934). The opt-in answer is the local authentication setting (NetworkProps.authentication), which spans four paths that must stay in sync: _makeRealProfileTask writes the credentials into authentication and force-clears skip-auth-prefixes so a profile cannot silently exempt loopback; UpdateParams.authentication applies the same list to a running core; FlClashHttpOverrides sends the credentials with the app's own proxied requests; and sharedState withholds the Android VPN system proxy declaration because ProxyInfo cannot carry credentials (TUN still captures that traffic). Desktop system proxy is deliberately not gated — dropping it would leak traffic direct, so the setting's description tells users to supply credentials manually instead.

Local Trust Boundary

The Windows Helper answers only a connection whose client process runs under the owner SID it was installed for; the Linux Helper only the owner uid. A setuid Core is executable by root:admin (macOS) or the installing user's primary group, so its boundary also includes every member of that group, not just the installing account. Profiles cannot choose a controller address, a secret or alternate controllers. Another account outside those permissions, a subscription, or a remote party reaching the privileged Core's control or filesystem APIs is a vulnerability.

A process running as the same account is not stopped. It can ask the Helper to start the Core against a socket or pipe it owns, or run a setuid Core against a port it listens on, and so become the host that drives a privileged Core: initClash chooses the home directory every path check anchors on, and getConfig, getProfileBase, getProfileOutbounds and a setupConfig or buildProfile base read any path. The Core connects to whatever address it is given and cannot tell that host from FlClash. An account check cannot distinguish it from a same-account process that can already read FlClash's memory and files. This remains a user-to-root or user-to-SYSTEM privilege escalation, not a complete security fix. An open external controller is inside the same boundary: its secret is stored under the account, and /upgrade stays mounted (it fetches fixed MetaCubeX release URLs, not caller-chosen code). mihomo's IsSafePath compares paths lexically, so a symlink inside the home directory escapes it; that fix belongs upstream, not in the submodule.

Closing the same-account case requires limiting what a hijacked Core can do. Keeping the main Core unprivileged and moving host changes into narrow platform helpers requires architectural work, but need not introduce repeated prompts or remove ordinary proxy functionality. Features that require additional privileges, such as identifying other users' processes, need platform-specific handling. Descriptor-based filesystem confinement can preserve ordinary managed paths; intentional external symlink targets need explicit allowed roots. These changes have not been implemented. Account authentication, a private socket directory or a symlink check at configuration time does not remove the privileged filesystem operations available to the host. Changes must not widen access to those operations.

Interface Name Modes

The same task also writes interface-name per PatchClashConfig.interfaceNameMode: clear (default) forces it empty so a subscription's value cannot survive into the generated profile, follow leaves whatever the profile YAML already has, and custom writes the user's interfaceName. mihomo ignores interface-name on Android whenever dialer.DefaultSocketHook is installed (core/lib.go installHooks, vendored dialer.go), so NetworkListView in lib/views/config/network.dart shows the mode picker and text field only on desktop.

Network Settings

Every Tun field is written over the profile's tun section and hot-applied through tunSchema, and the other keys of that section keep the profile's value; test/models/tun_test.dart keeps the model, RawTun and tunSchema in step. Beyond what FlClash always managed, Tun carries only the keys worth tuning: mtu, the mips stack's congestion-controller, and strict-route where sing-tun enforces it (Linux and Windows).

Routing is the same on every platform: route-address (empty routes everything), route-exclude-address, and NetworkProps.bypassPrivateRoute, which adds privateRouteAddress to the exclusions in Tun.getRealTun. Desktop hands both lists to sing-tun. VpnService can only add routes before Android 13, so Tun.vpnRouteAddress cuts the exclusions out of the routes with subtractCidrs and lists every family it routes; VpnService.addRoutes routes everything only for an empty list. A config saved with the old routeMode keeps its choice: bypassPrivate, which ignored the route list, loads with the flag on and the list cleared, and config with the flag off. Others were left out on purpose: no stack in the vendored sing-tun reads endpoint-independent-nat, the default mips stack ignores udp-timeout, and the rest are platform plumbing few users need. Android builds its TUN from the VpnService descriptor in core/tun/tun.go, so only MTU and the congestion controller reach it, through VpnOptions and the options argument of startTUN; the VpnService builder takes the same MTU.

The TUN fields start at mihomo's own defaults, and a saved zero MTU or empty congestion controller, which mihomo reads as those defaults, decodes to them. The outbound rows are plain settings written over every profile, and changing one re-applies the profile; keep-alive is forced off on Android, and only Linux honours routing-mark.

Lifecycle Ownership And Convergence

Shared Flutter Layer

CoreController.start(), restart(), stop(), and close() are the only shared lifecycle facade. close() is terminal; callers must not try to reuse a closed platform implementation.

CoreAction in lib/providers/actions/core.dart owns the user-facing Core status and setup sequence:

• startCore() publishes connecting, starts the platform Core, publishes connected, then initializes Core state. A startup error publishes disconnected and displays the error.
• restartCore() coalesces overlapping callers behind one worker. _requestedRestartRevision records newer requests. After the lifecycle restart, the worker reapplies running state or the profile, rereading isStartProvider on every pass, until it has consumed the latest revision, so the newest start intent wins.
• The provider is an orchestration and presentation layer, not a process owner. Platform lifecycle code remains responsible for determining whether a Core process/service is actually running.

Application exit is centralized in SystemAction and SystemExitCoordinator:

1. Optionally save config and clean up DNS, system proxy, and tray resources in parallel.
2. Close the desktop window.
3. Call terminal CoreController.close().
4. Exit the application exactly once.

The coordinator is idempotent, continues later cleanup steps after an earlier error, preserves the first error for the caller, and uses a three-second watchdog as an emergency application-exit path. Application.dispose() and CoreManager.onCrash() do not independently destroy Core; this avoids competing shutdown owners.

Applying Setting Changes

A changed setting is patched live through UpdateParams, re-applied with the profile, or, for the Android VPN, left to a restart the user confirms. setting-changes.md says which path each setting takes and how to choose one for a new setting.

Desktop Lifecycle

DesktopCoreLifecycle is a latest-desired-intent reconciler, not a queue that blindly executes every request:

• Public intents receive monotonically increasing revisions and target running, restarted, stopped, or closed.
• Observable phases are idle, starting, running, stopping, failed, and closed.
• A completed command reports applied, coalesced, or superseded, allowing callers and tests to distinguish a command that won from one satisfied or replaced by a newer compatible intent.
• Startup opens or replaces the IPC transport, resolves a launcher, generates a 128-bit lowercase hexadecimal session ID, launches Core, and waits for the matching connection. Windows additionally verifies that the named-pipe peer PID equals the process PID returned by the Helper lease.
• Each running session retains its process owner, lease, PID, session ID, and transport connection generation. Stop waits for both process-exit confirmation and the matching disconnect generation; a missing disconnect replaces the transport before later starts.
• An unconfirmed process exit is retained as an unconfirmed lease. New start/restart intents fail until ownership can be cleaned up, preventing two Core instances from being treated as the active session. Terminal close may continue on a best-effort basis because the application is exiting.
• An unexpected disconnect or transport failure while running is converted to DesktopCoreFailure, the owned process is cleaned up, and CoreService emits a Core crash event for the normal UI recovery path.

Direct launch is used on macOS, inside an AppImage, and as the Windows/Linux fallback when the privileged Helper is not ready. When the Helper is ready, it owns the Core child and Dart owns it through a session-scoped lease.

Android Service Lifecycle

Android deliberately keeps Flutter requests optimistic and the native layer authoritative:

• ServicePlugin.start() and stop() acknowledge immediately after submitting intent. They do not wait for service creation, VPN permission, binding, TUN establishment, or teardown.
• ServiceState owns the latest RunRequest and the shared configuration. Identity checks discard obsolete work. startPreparationLock serializes permission/setup preparation and transitionLock serializes actual service transitions.
• RunState is derived, never assigned by a step: ServiceStateMachine.publish computes it from the transition in flight, the latest intent, and ServiceController.runtime. A service that is up under a stop intent reads STOPPING, a start still waiting on a permission reads STOPPED, and STARTED needs both a running intent and a runtime. The tile and getRunTime both read this one value, so they cannot disagree with the service.
• ServiceController owns exactly one ManagedServiceBinding, selects VpnService or ProxyService from VpnOptions, binds with a five-second connection timeout, and invokes ManagedService.start()/stop() off the main thread. The binding and runtime (which service runs, and since when) are set and cleared together, by a stop, a failed start, or a lost connection and by nothing else. Flutter's shutdown only clears the Core event listener: Android keeps an established VpnService alive through its own connection, so a binding dropped on exit left a tunnel that was reported as running but that neither a stop nor a revoke could reach.
• The Core listens exactly while runtime is set: a successful start ends in Core.startListener() and every path that clears runtime calls Core.stopListener(). Both return at once when the Core is already there, which is the usual case, since startTUN/stopTun and Flutter's own startListener/stopListener got there first. They matter when nothing else does: a proxy-only run stopped from the tile used to keep the mixed port open with nothing reported as running. A start closes after itself the same way: Flutter's startListener and the native quickSetup both open the ports before any service exists, so a start that ends without a runtime, refused or cancelled, stops the empty service once more, without passing through STOPPING. Flutter may be gone by then and never see the stopped report.
• A start that does not bring the service up gives its intent back and takes down whatever it left running, unless a newer request has claimed the service. A failed start therefore always ends in STOPPED, whichever step refused it. The one start that mints no request is a repeat on a settled run of the same kind, which Flutter sends every time it reattaches: a request refused at a permission prompt there would stop a service that was running fine.
• Generic service creation/destruction is lifecycle evidence, not user intent. New commands must flow through ServiceState.requestStart()/requestStop() or the explicit system-action handlers instead of inferring intent from a callback.

Quick Settings, notification, revoke, and Always-on VPN paths converge on the same owner:

• With a Flutter engine attached, ServiceState.handleStartAction() forwards through TilePlugin to TileManager, because only Flutter can apply the current profile. Without Flutter, native code claims the intent, restores SharedState from preferences, runs quickSetup, checks VPN permission, and runs the start; claiming first is what makes a second action during the setup toggle that start off instead of racing a second setup against it.
• A stop never needs Flutter. handleStopAction() stops the service natively whether or not an engine is attached, so the tile, the notification action and a revoke work even when Flutter's own idea of the state is wrong.
• Whenever the run ends without Flutter having asked for it (a start that failed, a native stop, a revoke, a lost service), ServicePlugin sends stopped with the revision of the last start/stop command it received. Service in lib/plugins/service.dart drops a report older than its newest command, or one that arrives while its last command was a stop (on-demand suspension stops the service while isStartProvider stays true), and AndroidManager answers the rest with setRunning(false). The report is read on the platform thread, where the commands arrive, so the revision and the intent it carries describe the same instant.
• Android may create an Always-on VpnService through onStartCommand() without FlClash's bound-service path. The service sends the explicit, permission-protected VPN_START_REQUESTED broadcast to ServiceBroadcastReceiver, which routes it to ServiceState.handleStartAction() so Core/configuration and the normal binding are restored before TUN is treated as ready.
• VpnService.onRevoke() stops TUN/modules first, then sends VPN_REVOKED; the receiver only requests a stop while ServiceController.runtime is a VPN run.
• ServiceBroadcastReceiver uses goAsync() and an atomic one-shot completion. Normal completion or a nine-second watchdog calls PendingResult.finish() exactly once; the watchdog releases Android's broadcast lease and does not cancel or redefine the underlying lifecycle intent.

Core Protocol And Event Delivery

The shared protocol uses CoreMethodCall(id, method, arguments) and CoreMethodResponse(id, result, error) in both directions. The envelope is the only JSON serialization layer: keep arguments, results, and event data as structured JSON values rather than embedding pre-encoded JSON strings. Plain domain strings, such as country codes or provider contents, remain strings.

A response over 1 MiB goes to a file under <home>/responses/, and the envelope carries only its file (core/spill.go). Sent inline, Android copies it into the Java heap three times (the gomobile byte[], the codec and a direct buffer), and desktop IPC drops a frame above maxIPCFrameSize. lib/core/spill.dart reads a spilled file only from that directory, decodes it in an isolate and deletes it; initClash clears what an earlier run left.

A profile file's proxies, groups and rules never cross the bridge. getProfileBase returns the config without proxies, proxy-groups, sub-rules and rules, with their counts, the profile's MATCH rules and a sha256 digest. SetupAction.getProfile patches it as before and sends the result as SetupParams.base.overlay. core/profile_base.go puts the profile's bulk sections into the overlay, appends the profile's rules after the overlay's, writes config.yaml for the Android service and the controller's reload, and parses it. config.yaml is encoded a slice at a time, because on a profile of 100k proxies and 2M rules one Encode call doubles the peak heap. The preview reads the YAML buildProfile merges into the spill directory, and the extend page only the names and types getProfileOutbounds lists; a script extension still needs the whole config from getConfig.

Go event delivery is intentionally non-blocking:

• Loaded-provider, geo-update, and route-changed events use a state queue that never evicts; the rules for it are under Core API Safety in .agents/rules.md. Every other event except the bulk kinds, delay included, uses a 256-entry priority queue. Desktop process crashes are generated locally by CoreService from lifecycle failures rather than sent through the Go queue.
• High-volume log, request/connection, and DNS query events use a separate 256-entry bulk queue, so bulk floods cannot evict state.
• A full priority or bulk queue evicts only its own oldest event and retries the newest; DNS events never evict. Core work never blocks on event delivery.
• The batcher flushes at 32 messages or every 16 milliseconds. Priority events are preferred, but one bulk opportunity is guaranteed after eight priority messages to prevent starvation.
• sendMessage drops an event before it is queued when hasEventListener is false. That only happens on Android, after the Flutter engine detaches while the service keeps the Core running; request and DNS events would otherwise be encoded per connection and per query for nobody.

DNS query events come from the Clash.Meta fork's dns/patch.go and are raised where mihomo writes its [DNS] debug log, so the DNS page lists the same resolutions: one event per cache hit, and one per upstream exchange however many callers singleflight merged into it, carrying the upstream whose answer was used. Fake-IP and hosts answers never reach a resolver and are not recorded. Queries from apps arrive with the DNSContext that Service.ServeMsg created and report app; other initiators come from resolver.WithInitiator at the call site (rule matching, DIRECT, proxy server dialing), and unlabeled queries report other.

Dialer-loop events come from the fork's component/proxydialer/patch.go. mihomo follows a dialer-proxy that leads back to its own proxy until the stack overflows, so a dial that asks the same dialer-proxy for an address it is already dialing through it fails with ErrDialerLoop. core/hooks.go reports each looping name at most once every three seconds as a priority event, which the app shows as an error notice whether or not logs are captured. The custom profile pages flag only the loops FlClash can follow on its own, through a group's own list or an include-all-proxies that no filter, exclude filter or exclude type narrows; what filters and providers pick, including provider proxies that carry their own dialer-proxy, is left to this guard.

ProxyGroup.fromJson reads include-all as both include-all-proxies and include-all-providers, as the core does, so import and quick edit keep it. They take in only what the config declares, which is what some group of the profile names: its local proxies and the file or url profiles in a use. Setting one declares nothing more, so the app's other proxies and subscriptions stay out, and the core picks from the declared ones by the group's filters. Groups saved by v0.9.0 kept include-all-proxies in their stored definition, and it takes effect again.

Desktop RPC accepts both a single event object and batched event lists. Android and desktop listener dispatch isolate listener exceptions so one faulty observer does not prevent the remaining events/listeners from running.

User-Facing Core And Delay Feedback

CoreStatusButton in lib/views/dashboard/widgets/core_status_button.dart is the desktop dashboard's status/restart surface. It is shown only outside dashboard edit mode and only when coreLib == null:

• Provider state remains authoritative. The widget keeps a separate display-only status so a fast connecting -> connected transition still shows at least 600 milliseconds of progress instead of flashing.
• The hold arms only after an observed transition to connecting; mounting while already connecting does not invent a new delay. A real disconnected transition cancels the hold immediately so failure is never hidden, while a long-running connecting state remains visible after the timer expires.
• Taps during the display hold or while the provider is genuinely connecting are inert. Connected/disconnected taps show the appropriate confirmation and delegate restart to CoreAction; the widget never starts Core directly.

Proxy delay testing follows the same failure-safe UI rule. ProxiesAction._runDelayTests marks its keys in pendingDelayTestsProvider and releases them in finally, and a test the Core does not answer leaves the last measurement in place; the delay-test bullets under Core API Safety in .agents/rules.md give the reasons. A key stays queued until the TaskPool actually runs it, so node cards animate a loader for at most maxConcurrentDelayTests nodes and show a static glyph for the rest; a loader on every queued node made fast scrolling drop frames. A group's delay test button, the tab page's action and the list page's group header alike, spins while delayTestingGroupsProvider holds the group; delayTestPageGroup marks it, ignores a second request for the same group, and clears it in finally, so an RPC failure cannot leave the button spinning and remounting a header does not lose the state.

The dashboard's probe cards show a failure as still checking for five seconds after they see proxied turn true, through ProbeStartHold in lib/views/dashboard/probe_start_hold.dart: ServiceStatusCard holds the check on each tile, and CurrentOutboundCard holds the exit IP, whose refresh button stays inert meanwhile. SetupAction.setRunning flips the run time, and with it proxied, before the Core has brought its listeners up, so the probe launched on the spot often fails, and the config re-apply that follows every start probes again moments later; without the hold a card flashes a failure and then takes it back. The hold is local display state like the connecting hold above: the cache still records the failure, the hold arms only on an observed transition, a result that is not a failure shows at once, a stop cancels it, and a failure still standing when it ends is shown.

Route Consistency

A probe result on the dashboard — the exit IP, a node's exit IP, a service check — either describes the route in force or is being asked again. The full design is docs/plans/probe-route-consistency.md; the mechanism has three parts.

• The Core is the source of truth for the route. core/route.go keeps a structural epoch (advanced by a config apply, a mode or IPv6 switch, any proxy provider whose version changed, and any rule set that loaded new content, whether the user or its own interval updated it) and a picks map from each Selector, URLTest and Fallback group to what it resolves to right now, versioned on every change. handleChangeProxy re-reads the picks under selectMu and answers ChangeProxyResult{changed}, so the connection reset only runs when the pick moved. A health check moving a URLTest pick has no mihomo hook, so the picks are polled every second while the host watches (watchRoute(true)) and the listeners are up; the same poll notices a provider or rule set that updated in the background. Every probe answer carries the counters it started under; routeChanged publishes the state whenever it differs from the last read.
• routeTrackerProvider in lib/providers/route_state.dart merges that with the host's side: proxied (running and not suspended), a host epoch that a connectivity event moves, and synced, which is false until watchRoute has returned a snapshot and again after a Core disconnect. Nothing is fresh while unsynced, so a cache never judges answers against counters it made up. The tracker subscribes when the first target is watched and releases the Core when the last one goes; an answer newer than the state means an event was evicted, and the cache asks for a resync. It also releases the Core while the app is hidden and reads it again on return, keeping synced: the Core and its counters are the same ones, so the fresh snapshot invalidates only what moved. On Android the Core drops the watch itself when the event listener is cleared, because an engine that goes away never sends watchRoute(false).
• RoutedProbe in lib/providers/routed_probe.dart is the one cache both OutboundIpProbe and ServiceStatus mix in. A widget watches the target it shows and unwatches on the way out; only watched targets are probed, one request in flight per target. An answer is stamped with the Core's counters and the host state at launch, and RouteState.isFresh walks its chain against the picks, so a selection change only invalidates results that went through the changed group while an epoch change invalidates everything. A stale watched entry is asked again at once; an unwatched one is dropped. Nothing launches while the app is hidden: what falls due waits for it to be shown. Failures wait for retry, refresh, or the app resuming (markResumed), and a service check that timed out is a failure that still shows its status. refresh is the user's own request and runs for unwatched targets too: the service sheet reads the cache and never watches its rows, because one service check is one to four full HTTPS fetches where a delay test is a single empty request.

ipQuality(ip) in lib/providers/ip_quality.dart is keyed by the outbound IP found, so a route change reaches it as a new IP and an unchanged IP reuses the result. A lookup races its sources the way the IP check does and takes the first one that determines a type. A success is kept for the session with ref.keepAlive(); a failure is not cached, and Riverpod's automatic retry is off because a retry after an HTTP 429 spends the same per-outbound-IP quota again.

UI Layer

lib/ui/ holds the components and design tokens that know nothing of the app: shapes, surfaces, motion, colors, the scaffold, sheets, popups, lists and the glyphs under lib/ui/icons/. lib/widgets/ holds the components built from them that do: settings rows, subscription and profile pieces, anything that reads a provider or a model. widgets/widgets.dart re-exports ui/ui.dart, so app code imports either barrel.

test/lint/ui_layering_test.dart walks the imports of every file under lib/ui. Nothing they reach may leave lib/ui, except lib/common files whose own imports stay out of the app, never the common.dart barrel, and none may import Riverpod. A component that needs app state reads what the app provides above its navigator:

• ViewScope (lib/ui/view_scope.dart): the window size, whether the layout is mobile, and the window controls over a page. AppViewScope in lib/manager/theme_manager.dart fills it from viewSizeProvider, isMobileViewProvider and versionProvider. It is an InheritedModel, so a reader of one value does not rebuild when another changes; context.isMobileView reads it without listening.
• MeasureScope (lib/ui/measure.dart): the Measure that ThemeManager also assigns to globalState.measure.
• The MediaQuery text scaler that ThemeManager sets: the app text scale behind .ap(context), .mAp(context) and the ...Of(context) paddings in lib/ui/metrics.dart. Reading it there makes a widget sized by them rebuild when the scale changes; a global copy or a top-level final would keep the scale it was first read at.
• UiLocalizations (lib/ui/l10n.dart): the strings the components show themselves. AppUiLocalizations.delegate in lib/common/app_localizations.dart serves them from the ARB strings; a new one needs a getter on both.

A test that builds its own MaterialApp registers AppUiLocalizations.delegate and returns wrapAppScopes from test/helpers/test_app.dart in its builder, as TestApp does.

Icons

lib/ui/icons/ holds every icon the app shows. Nothing in lib/ uses the Material icon font, and test/lint/material_icons_test.dart fails on any Icons.* or AnimatedIcons.*, so every icon shares one stroke and can animate its shape. A Glyph is a list of shapes on a 24-unit grid, stroked at Glyph.strokeWidth with round caps and joins and superellipse corners; a curve the primitive shapes cannot draw is a GlyphPath, SVG path data traced along the stroke's center. Each shape has a role that decides its filled form, the way SF Symbols and Fluent pair an outlined icon with its filled variant:

• body fills;
• detail is cut out of the fill, and a solid detail such as a dot is cut as an area;
• line stays a stroke, for parts that belong to no body, like a handle or a link between nodes; it thickens from Glyph.strokeWidth toward 2.2 as the glyph fills, so a glyph of lines alone still carries weight in a filled button.

GlyphPainter paints any point between the two forms. Each body fills inward from its outline, reaching half its shorter side, which no point of the body lies beyond, as fill reaches 1. Details thin away over the first half and return as cutouts over the second, so a detail is never a stroke and a cutout at once. The glyph is painted opaque into one layer that carries the color's alpha: a translucent color, such as a disabled one, then stays even where strokes cross the fill, and a cutout clears only the glyph's own pixels. GlyphIcon shows a glyph at a fixed fill, taking its size, color, and fill from IconTheme unless it is given its own, as Icon does, and mirroring it in right-to-left text when Glyph.matchTextDirection is set. AnimatedGlyph drives a GlyphIcon from its filled flag and pops briefly when it fills. A glyph whose shape follows some other state, like the sidebar toggle that tracks the pane's width, is a builder in AppGlyphs such as AppGlyphs.sidebar(progress). A new glyph goes in AppGlyphs and in the list test/icons/glyph_painter_test.dart runs through its checks; it is named for what it means in the app, one glyph per meaning, with SF Symbols and Fluent as the reference for the metaphor. Tests find one with find.byGlyph from test/helpers/glyph_finders.dart.

Icons are outlined by default and filled inside a filled button: IconButton.filled and .filledTonal, and FilledButton in its tonal and icon forms draw their glyph with fill: 1, because an outline on a tinted container reads weaker than the container it sits in. A glyph with no body only thickens its lines and still takes fill: 1, so the rule holds if the glyph later gains one. test/lint/filled_button_glyphs_test.dart checks every GlyphIcon written inside such a button; an icon that reaches the button from elsewhere, as through a helper that picks the button variant, gets its fill by hand or from IconThemeData.fill. Everywhere else fill marks state only: the selected destination, a pinned window, a lit torch. The phone's floating navigation bar is the one exception: like an iOS tab bar it fills every destination and marks the selected one by colour alone.

Framework widgets that draw their own icon take it from the theme: the ActionIconThemeData in lib/application.dart supplies the back and close buttons, with AppGlyphs.backFor picking the platform's back glyph, and a DropdownMenu is given its chevrons. A framework widget added later that paints a Material icon needs the same treatment.

Empty states draw no image assets either. NullStatus in lib/ui/null_status.dart shows the glyph for its meaning filled on a Material 3 Expressive shape from material_new_shapes, with a few accent marks, and enters with one of three choreographies picked at random: the shape spins in, morphs out of a circle, or springs in while the accents orbit into place. The glyph takes onPrimaryContainer, not primary: the content scheme variant can leave primaryContainer as light as primary in dark mode.

CaptionIcon is the one icon that does not follow the glyph grid: the window caption buttons keep the one pixel, pixel-aligned stroke of Windows' 10-pixel caption glyphs on every platform.

App Bar Actions

CommonScaffold keeps at most three buttons in sight in its bar, the overflow menu button included. A page hands it what may fold as data: primaryAction, iconActions, menuItems, and searchActions while searching; custom widgets passed through actions never fold. Past three, two buttons stay beside the overflow menu: the search button (the clear button while searching) when there is one, then foldable actions, primary action first unless foldPrimaryAction puts the icon actions ahead of it; everything else goes into one overflow menu, primary action first, and a folded action that is loading shows as a disabled item. The bar reads as one button group of two beside a single button: the overflow menu button when something folds, otherwise the last action, so the proxies list shows a search and delay test group beside the menu. The bar holds primaryAction everywhere, a phone's home page above the fixed navigation bar included, and nothing in the app floats an action button: a secondary action such as selecting every app goes into menuItems. Saving or confirming, in a page, a side sheet or a form, is a check in confirmationAction, never among iconActions: it ends the bar and never folds, and only a form sheet moves it to its foot (Forms). Bar buttons are glyphs with tooltips, select all included; the one text button is the custom profile's Import, a filled button whose CommonPopupBox opens the import menu. Actions on a multi-selection, such as delete and select all, go into selectionActions instead: the bar keeps them in sight as one button group that takes a single slot beside the search or clear button, so they never fold. A sheet's close button leads its bar when the bar has actions, except beside a primary action: then the two end the bar as one button group, as the proxies sheet's delay test and close do.

Actions on what the page edits as a whole, such as renaming the custom profile or viewing its final config, go into titleMenuItems rather than the bar: the title shows a chevron and opens them, as an iOS document's title menu does. The menu opens from the title's start edge (PopupPlacement.overAnchorStart), since the bar's own menus, which open from their end edge, would cover the back button there.

A bar under a sheet drops its actions and keeps its title and back or close button. CommonScaffold fades the actions out with the entrance of a sheet laid over its page, or over the sheet it is a page of, so none on the layer below reads as an action of the sheet on top; sheetCoverOf in lib/ui/sheet_navigator.dart reads that entrance, which a sheet route hands down through SheetCoverRouteMixin, as SnapSheetRoute and ModalSideSheetRoute do.

Liquid Glass

ThemeProps.liquidGlass picks a LiquidGlassMode, none by default, and reaches widgets as LiquidGlassScope, on for standard and ultra with that LiquidGlassQuality, from ThemeManager. With it on, CommonScaffold passes glass to the bar's TonalButtonTheme, which puts a LiquidGlass pane behind each button through ButtonStyle.backgroundBuilder and one behind a TonalButtonGroup; the navigation dock's bar and lifted lens become panes as well, and so do a sheet's docked search, the cards of a CommonPopupMenu, and a CommonDialog. On the dashboard only the start button is a pane: its connected buttons and switches keep their fills, since each pane adds its area to a capture retaken whenever the dashboard redraws, which it does often. Each still swells on its own under ElasticPress, and a DashboardConnectedGroup paints the button pressed last over the neighbours it swells past. lib/ui/liquid_glass.dart holds the rest:

• A LiquidGlassHost over the app (lib/ui/liquid_glass_capture.dart, after g1455's atlas proxy) draws its panes without reading the backdrop. As the frame is composited, before its children, it redraws onto one small image what each pane under it would read: the layers painted before the pane, within its reach, shrunk as far as a sigma of the pane's frost still spans two of the image's pixels, twice where g1455 records its regular finish, and never past eight screen pixels to one, the coarsest g1455 measured, with that frost blurred in by the engine. A pane without frost, the dock's lens, keeps the screen's resolution, as g1455 keeps its clear finish. A pane with a haze takes a second slot in the same image, shrunk and blurred for its far wider hazeBlur, and mixes the two. Each pane paints the shader over its part of that image as an ordinary paint, one read a sample where its frost is even. No pane ends the frame's render pass or copies the surface, and the glass never trails the content by a frame. A pane outside any host draws only its tint and rim.
• ultra draws all of the glass below. standard leaves out what costs most for least: a haze becomes the whole frost, so the dock takes one shrunken slot in place of a sharp one at the screen's resolution, and its text no longer shows faintly through; a lens's rim parts no colors; the lifted lens's copy goes unwarped, tinted with the light its pane would add; and the dock casts no shadow, which is under 3/255. The host applies the style changes to every pane it draws, the dock the rest. A config saved with standard before ultra existed moves to ultra once (Migration.upgradeVersion 2), since that was its look. On the SwiftShader emulator, as raster time a frame over glass off, median of four alternating runs, the glass before the tiers, ultra and standard added 16.4, 13.5 and 9.5 ms scrolling, 52, 40 and 17 dragging the lens, 34, 26 and 18 scrolling under an open menu, 22, 13 and 11 opening it and 17, 9 and 5 closing it; scrolling took 18.8 render passes a frame in either tier against 23.6, and the lens 22 in ultra and 18 in standard against 30.
• A pane over one painted before it in the same root reads a second image, a level up, with the first drawn in as glass. Over means within 2.5 sigmas of its frost and as far as it bends, where a pane takes under 1% of what it reads, rather than the 3 sigmas and 2 dp its slot holds: the bar's buttons stand 8 dp apart, inside the slot of the overflow button, which went up a level and cost a second image every frame content moved under the bar. A pane's root is the host or its nearest ancestor that draws offscreen: as a backdrop filter would there, it sees only that ancestor's content, without the ancestor's own effect, and replaces what it covers. A LiquidGlassFade is no root: as Core Animation fades a layer, its panes still read what lies behind it and fade with the rest. A level keeps its image while what it drew, the same pictures under the same transforms, clips and effects, stays the same, so a still screen redraws its glass without a capture and content scrolling under glass captures once a frame. Within an image each band of slots that blur alike keeps its pixels the same way, copied from the last image rather than drawn and blurred again, and a slot without frost is a band of its own: dragging the lens redraws only its copy's slot, not the dock's haze or the buttons' frost. Not on Skia: an image there keeps what it was drawn from as long as it lives, so each capture copied from the last would hold every one before it, and memory grows by a capture a frame. The dark line along the rim darkens the blurred capture there rather than the sharp backdrop, a pixel or two wide.
• Measured on an Android emulator rendering in software (SwiftShader, 1080×2400 at density 420), as raster-thread time a frame counting the captures that FrameTiming's raster span leaves out, median of three runs, each capture against none in a run of its own: scrolling Tools takes 43 ms with none, 6 more with a sigma over one pixel of the capture and 11 over three; scrolling the dashboard 64, 9 and 19; switching to Proxies 34, 15 and 25; opening a menu 42, 9 and 13; closing it 41, 1 and 3; dragging the dock's lens 39, 38 and 42. One pixel adds about half what three do while content scrolls, and about as much while a page switches, where the capture's size is not what costs, or while the lens moves, which both capture at full resolution. Three was measured before a menu's capture was held to eight screen pixels to one, and two, which glass uses, has not been timed. Ultra, which read the backdrop under each pane, added 27 to 61 ms to the same frames and was dropped. A software renderer weighs passes and texture reads unlike a phone's GPU, so the figures rank the captures rather than price them; no phone has measured them. A still screen draws no frames.
• Rendered under flutter test --enable-impeller at density 3, against a capture with a sigma over three pixels, one pixel blurs text under the dark dock into blocks that set 16% of its pixels apart side by side (CIEDE2000 above 2), and two sets 0.5% apart. Reading a coarse capture through a bicubic filter barely helps: the blocks are in the capture.
• Where a pane's frost is uneven, as along a rim that softens, the shader reads what the capture does not hold as the engine's Gaussian, in device pixels, on a Vogel disc of 16 taps up to a sigma of 2 pixels, 32 up to 3.5 and 64 past it, so no taps lie further apart than 64 leave them at the widest; rendered at density 2.625 the lens moves by at most 12/255 on a few pixels from 64 taps throughout.
• Glass builds no pipelines ahead of use. A warm-up that rendered panes offscreen once the first frame landed was dropped: after an install, with no pipeline cache on disk, it compiled on the raster thread just as the app was first used, to spare the first menu and lens only a few pipelines.
• A pane is a rounded rectangle, each corner with its own radius, unless a clipper gives it a path, as the start button's cookie does. The shader reads that path as its reach from the pane's center in 64 directions, so it must meet every ray from the center once.
• Without Impeller's shader filters (Skia on the Intel macOS build, flutter test) a pane frosts from its capture: blur, saturation, brightness, tint, and a rim, with no refraction; the tint is not thickened there, as it is where a pane has no capture, since the capture holds the blur. flutter test --enable-impeller runs the shader, so toImage shows the real glass.
• A popup grows out of its anchor on a platter (CommonPopupRoute). On glass the platter is a LiquidGlassPane easing from the button's regular glass to the thicker menu glass, and the menu's cards stand bare while it shows, opening and returning, so one pane bends the backdrop at a time. The platter takes the menu glass's frost from the start and, as the cards do, paints with a hold over all it may sweep: the host captures that once and keeps it while the pane moves inside, its frost neither grows nor falls by a tenth, as a folding sub menu's glass does, and the page holds still, so a menu opening captures three times and closing twice rather than every frame. On the SwiftShader emulator that cut a menu's frames from 17 render passes to 12.4, against 11.1 without glass, but saved time only within noise: what glass still adds there, about half again a frame, is the shader over the growing platter. A held pane casts its shadow after itself, over its capture rather than in it, since a shadow moving with it would renew the capture. The anchor's snapshot is taken under LiquidGlass.withoutPanes: offscreen a pane has no backdrop and would come out a flat tint. A menu opened at a point fades out under the layer a LiquidGlassFade pushes, so its glass keeps reading the page as it goes.
• An alert on glass takes the alert glass, the menu glass frosted wider, under its AlertDialog's surface, which it finds as the dialog's Material lays it out, since a dialog takes only a color. Its route fades it under a LiquidGlassFade, so the glass keeps its full blur and fades with the text, as UIKit fades an alert and its glass on one layer. Its plain buttons and fields fill with glassFillOf, black or in dark mode white at 13%: iOS 27 shifts them from the glass under them by about 30/255, darker or lighter, a blend Flutter has no mode for, which 13% meets over the glass an alert shows on a page. Its route dims by alertScrim, iOS's fifth in light mode and near half in dark mode, not Material's third, so the glass reads the backdrop iOS's reads; under Material's a light alert came out grey. Measured against UIKit over the same page, the title sits 21 dp down, a message 6 dp under it and a field 16, the buttons 20 under either; plain button labels take the medium weight, and a light message takes onSurfaceVariant at 85%, as light as iOS's vibrant secondary label. UIKit sets a title with no message centred in the body weight, so an alert with fields (hasFields) does too, with room for a trailing control's width kept on both sides to hold the title on the alert's centre. A destructive action takes ColorScheme.destructive, iOS's systemRed: Material's error read dull in light mode and pink at tone 80 on dark glass.
• A press anywhere on an alert swells the whole alert, glass and content, as UIKit swells it, measured at 4 pt on its 320 width, and a drag past its edges stretches it about 3 pt; the button under the finger does not swell, it fades its fill to 40%, or a dark default button's to 50%, while a dark plain button keeps its fill. ElasticPress takes the swell and the pull in dp and finds the surface through panelOf, since an AlertDialog spans the screen around it.
• The menu and alert glass follow iOS 27's menus and alerts as the simulator showed them over solid, striped and split grounds, keeping the scheme's tint: in light mode the glass passes the backdrop at 45%, doubled in saturation and a tenth brighter, within 2/255 of iOS; in dark mode iOS keeps each colour's hue and chroma while it compresses white to mid grey and lifts black to 32/255, which the shader matches over solid grounds, within 4/255 and 11 at worst, by thickening the scheme's highest container over a light backdrop. The dark fit weighs black and dark grey most, the grounds a dark page puts behind it. That contrast reads the whole pane's backdrop, not each pixel, so over half black, half white the white half shows lighter than iOS's. It reads five points, each as four taps a frost sigma apart so that a glyph passing under one does not flicker the tint, but once under a haze or a frost of 8 dp or more, which blur a glyph past flickering. iOS frosts an alert at a sigma of about 13 dp and a menu at 10 to 13, with no sharp share like the dock's.
• The menu glass leaves its rim to a LiquidGlassRim, which alerts, menu cards and the platter as it lands draw around their panes: the line on the canvas outside the pane, and the highlight in the pane's shader, band by band and turn by turn as the fallback draws it in nine even-odd rings, within 12/255 of those. It is shaded unlike the bars' rim: as iOS 27 draws it around both, measured in the simulator, the dark line lies just outside the glass, darkest along the sides, and the highlight is light added to the glass, brightest at the middle of the top and bottom, about half as bright where a corner begins, a fifth where it ends and gone down the sides, fading over about 5 dp inward; a menu's line is lighter than an alert's. A glass menu and a glass alert cast iOS 27's shadow as measured over white, a deep one under a wide one, half again as dark in dark mode, where a solid menu keeps its softer one.
• The optics bend with a circular bevel whose width and depth shrink to fit a small pane, so the rim shows the content squeezed and mirrored. The materials are iOS 27's as codenameone/CodenameOne#5906 fitted them (pill for the dock, regular for buttons): the backdrop passes through as offset + scale * saturated backdrop, the tint at 1 - scale carrying the offset; a dark line takes the outermost pixels because UIKit draws it just outside the bounds, on the dock as faint all around as iOS draws it along the top and bottom, since the darker sides iOS draws read as brackets on a pale page; a highlight lights the top and bottom, fading over 1.3 dp and, as iOS 27's tab bar fades it around its rounded ends, with the square of the normal's upward part; the lifted lens keeps a narrower band. Buttons (regular, tinted) take the rim of iOS 27's glass and bar buttons, measured in the simulator: the line darkens toward the sides with the cube of the normal's sideways part, from nothing along a dark button's top and bottom, and the highlight fades over 1.2 dp with a sixth of it in a tail to 4.5 dp, dims round the ends far faster than the tab bar's, and is partly added as light, so it lifts a pale button as iOS does. The line and the highlight keep to the superellipse the pane is clipped to, which the shader traces after the engine's round_superellipse_param.cc: the circles the optics bend by lie up to half a dp outside it where a long side runs into its end, and a line on them breaks there. A test holds the traced curve to the engine's path. In dark mode the tint is the scheme's surfaceContainerHighest at iOS's alpha: iOS's mid grey lifts a dark page into a grey haze. The tint thickens over content much darker than it, or with a negative contrast much lighter.
• The pill's frost, line and shadow follow iOS 27's tab bar at rest, measured in the simulator over solid fills and a black and white split: 28% of the backdrop shows sharp and 72% through a blur of 15.6 dp, so a stripe under the bar spreads over its neighbours; iOS mixes the two brighter toward white, as if it blurred in linear light, which the engine's blur cannot. Dark mode draws no line, as iOS draws none along a dark bar's top and bottom. Glass bars cast 1.3% black blurred 3.8 dp and dropped 6.5 dp, shading only below and by 3/255 at most, in both modes; the solid dock keeps its wider shadow. The sharp part needs no blur pass of its own, so on the SwiftShader emulator the haze added half a render pass a frame scrolling Tools, about four on the dashboard, where it no longer shares the start button's blur, and no time beyond the noise of three alternating runs. Its colors are deliberately not iOS's: iOS's bar takes no contrast, its selection platter is a color matrix of the bar and its icons are vibrant, where the dock keeps the theme's.
• The dock and its lens follow UIKit's tab bar as codenameone/CodenameOne#5906 measured it frame by frame: 86 dp a destination, a resting lens 8 dp wider, a lift of 16 dp that magnifies what lies inside the lens by 16%, and springs taken from the capture; the lens's stretch and squash are a fit to its deformation tables. The lift stays up until it has risen fully and the lens has arrived, so a tap pops it all the way, and ElasticPress likewise finishes a tap's swell on the bar's press spring before it bounces back. The destinations stand on the lifted lens, as iOS draws them, so it bends only the bar; what lies inside it is copied, tinted and magnified, into an offscreen layer where a second clear pane warps it toward the rim on its own, as liquid_prism read UIKit's displacement inputs on iOS 27. The lens follows what iOS 27 shows of it over ramp and line backdrops in the simulator: it reads outward along its normal all around, by nothing at the rim and 4.3 dp a 5.5 dp bevel in, easing off toward its middle, so a band rings it with what lies right under its rim, drawn out; red and blue part by up to 6.5 dp along its top and bottom and about 3.9 dp around its ends, across the band's outer 7 dp. In dark mode both panes brighten what they show by a third, as iOS does, and the lens casts a soft shadow 8 dp down. A press lights the bar through LiquidGlass.glow: a wash over the whole pane, brightest at the finger, that spreads out as it fades. A pressed pane, as a glass button's or a TonalButtonGroup's is, hears the pointer on what it wraps and lights from the finger the same way.

Popup Motion

CommonPopupRoute follows WWDC25's account of iOS 26 menus: one that grows out of a control keeps the two continuous, so closing returns it into the control on the same platter, its content blurring out first. Apple documents only the opening; one opened at a point (a context menu) has no control to return into and shrinks toward the point to _dismissScale as it fades, as iOS context menus do.

A sub menu is a PopupMenuCard laid out once at full size. One spring (_unfold in lib/ui/popup.dart) moves its surface and clip from the item that opened it to its bounds, recedes the parent, and reveals the items, so a fold caught mid-unfold turns back with the speed it had. The parent's item hides under the sub menu's header, which draws it again, and the sub menu is removed only once it stands on that item.

A CommonPopupBox opens on its button's pointer down, as an iOS menu that is a button's primary action does, and the press carries on into the menu. _PopupPressRecognizer claims the pointer then, so the button's own tap and its tooltip's long press stand down. In a scroll view, as the settings rows are, it first waits kPressTimeout, as iOS scroll views hold back a touch, so a drag from the button scrolls and a quicker tap opens the popup on its release. The pointer's moves and release keep reaching the button, so the box hands them on (_CarriedPress) and lets go of the ElasticPress around it. The menu follows them only once they leave the slop, since it covers the button and a press let go where it went down would pick what now lies under it, and drives its own ElasticPress with them through ElasticPress.maybeOf. The box tells a disabled button by the onTap of its first InkResponse, and holds the popup's anchorShift, since it opens before the button's onPressed would run.

The menu stands in an ElasticPress of its own with pullPastEdges: it swells under a press and stretches only toward a finger that strays past it, so sliding over the items or scrolling leaves it in place. A press on a row belongs to the menu rather than the row's InkWell, which keeps only hover, focus, and keys: _RowPressRecognizer highlights the row under the finger as it slides, hit testing where the menu paints (ElasticPress.paintBoundsOf), with a selection click on each change, and picks the one it is let go on, or none off the rows. It claims the pointer only on release, so a menu long enough to scroll takes a drag first and drops the press. A press that rests for _dwellDuration on an item with a sub menu opens it, and one that rests on an open sub menu's header folds it back, each with a click as the highlight moves; the finger then stands on the header or on the item it folded into, and letting go there changes nothing. A tap that opens or folds a sub menu clicks no more than a tap on any item does, as iOS menus give selection feedback only to a sliding press.

Row Actions And Sort Mode

A list row or card carries no trailing more button. Its secondary actions go into a ContextMenuRegion, which opens them on a right click, a touch long press, the menu key or Shift+F10 of a focused row, and, under an enabled RemoteFocusAdapter (Android TV), a select key held past the long-press timeout; a short select there still presses the row, on key up rather than key down. A tap keeps the row's main action. A row whose tap does something other than open its page, as a profile card's tap selects the profile, may carry a trailing button to that page, as iOS's detail button does, built as a DetailButton so a desktop's compact density cannot pull it off the column the indicator and the handle share; a trailing button that repeats the row's own tap is never added. A row whose tap opens a page shows a DisclosureIndicator there instead, as a script or a rule-set proxy provider does. A provider opens its content on a tap, read-only unless it is a local text file the app owns, and keeps a second action on its trailing button: editing for a proxy provider backed by a text file, the options dialog for an app rule provider.

A long press can mean only one thing on a row. Where rows have no context menu, as in a plain list editor, the global or profile rules, the on-demand SSIDs or the custom proxies, a long press on the row drags it and there is no sort button. Where they have one, the list reorders only in a sort mode. When the list is the page, CommonScaffold owns the mode as it owns search and selection, and the page passes canSort for the toggle in its bar. Changes apply as they are made, so nothing confirms them: while the mode is on, the bar shows only its toggle, selected, and the back or close button fades in place rather than offer the same way out twice, as iOS hides its back button while editing; a system back still ends the mode. A list that is one section of its page, as the custom profile's proxy groups are, keeps its own SortModeScope around its rows and its toggle in its header and leaves the page bar alone, back button included; its header keeps adding while it sorts, and a system back ends its mode before it leaves the page. Each row sits in a SortableItem, which reads the scope: while it sorts DecorationListItem drops its tap and context menu, and SortableTrailing springs a SortHandle in from the row's trailing edge while the trailing it replaces shrinks away. The motion is painted, not built, and the row relayouts only while the two widths differ, since every row on screen animates at once. A page that only reorders, such as the profiles sort sheet or a group's members, shows its SortHandles without a mode. A handle drags on press, and with focus a select key lifts its row for the up and down keys to move through the enclosing SliverReorderableList's own onReorderItem, which is how a remote sorts.

Quick Edit

Quick edit, the compose button that opens what a page edits as text in an EditorPage, appears only where that text is the whole of it: a full list or section, such as a custom profile's rules, its proxies as share links, or its DNS, NTP and sniffer sections, or one isolated item, such as the definition of the proxy group or proxy a form edits. A page that edits only part of something other settings also write offers none, since its document would show a fragment and reject what it leaves out. The app-wide DNS page is that case, a few keys laid over the DNS of every URL and file profile, so only the profile's DNS spec mixes in OverrideQuickEdit. So is the custom profile's TUN page: it picks a few keys of a tun section the network settings own, so its spec does not mix in OverrideQuickEdit.

Where A Route Opens

On desktop each navigation destination has its own Navigator (_NavigationPage in lib/pages/home.dart); on mobile there is none, and everything goes on the root navigator, rootNavigatorKey in lib/ui/navigator.dart. A route takes the navigator of the context it opens from: BaseNavigator.push, showExtend, showSheet, showFormSheet and showSnapSheet all do, so a page or sheet opened from a destination stays beside the navigation rail, leaves the rail usable, and stays in that destination's stack when the user switches away and back. sheetNavigatorOf lifts a sheet out of a paged sheet's own SheetPagesNavigator, never past the destination.

The root navigator is only for what belongs to no single destination:

• dialogs, which dialogs in lib/common/dialog.dart hosts on the root unless it is given a context, and the notifier;
• a gate in front of the whole app, such as requestDisclaimerConsent;
• work that starts with no page behind it: a deep link, the tray, a hotkey, the update check.

Never reach for the root to open a page or sheet from a page, whether through rootNavigatorKey, globalState.navigatorKey, rootNavigator: true or useRootNavigator: true, and never push a page from the context of something on the root, such as a dialog: the page lands on the root too and covers the rail. The add profile sheet is the one exception. addProfileFormFile, addProfileFromLink and addProfilesFromLinks, which a deep link also reaches, close it with a root popUntil before switching to the profiles tab, so showAddProfilePage opens it on the root and takes the caller's context as origin; a page the sheet leads to opens from origin, as AddProfileView._toAddCustom does.

The mistake only shows in the desktop layout, and TestApp has nothing but the root navigator. A test that guards where a route opens hosts the page in a nested Navigator, as the desktop case of a new custom profile in test/features/profile_views_test.dart does.

Settings Rows

lib/widgets/config_item.dart holds the shared settings-row vocabulary: ConfigToggleItem, ConfigOptionsItem, ConfigTextItem, and ConfigListEditItem. Each takes a selector (a ProviderListenable, normally someProvider.select(...)) and an onChanged(ref, value) writer, and watches its own selector so changing one setting rebuilds one row instead of the whole section. Titles and subtitles are ConfigLabel callbacks that receive AppLocalizations, which keeps literal labels such as IPv6 and localized labels in the same shape.

Build settings screens from these directly, or from a file-local helper that binds one provider once — see _networkToggle in lib/views/config/network.dart and _appSettingToggle in lib/views/config/general.dart. Declare a named ConsumerWidget only when a row is genuinely reused across screens. Rows with bespoke behaviour — a custom dialog, a derived value, or a second provider write — stay hand-written rather than growing extra parameters on the shared items.

In an inset grouped list (generateSection, generateAnimatedSection), a row's subtitle shows its value or state, never what the setting does. As iOS settings do, the explanation goes in the group's footer, drawn by ListFooter, one sentence per setting that names it. A section header carries its title and at most a few actions on the group, as IconButtonData: ListHeader draws them as 36 dp tonal buttons (TonalButtonSize.section), the first two grouped, centered on the title. Every header stands as tall as one with a button, 6 dp clear of the group below, so headers match whether or not they carry actions. A group with a selection swaps them for delete and select all, never a text button. generateSection is the only section builder, and a sheet lays its groups inside the 16 dp inset the pages use.

A row that opens a page, ListItem.open or ListItem.next, ends in AppGlyphs.chevronForward unless it passes its own trailing, as iOS settings rows do. A row that opens a dialog in place, ListItem.input, has no chevron. A setting that takes one of a few values is an iOS pop-up row, ListItem.options or ConfigOptionsItem: it ends in its value and AppGlyphs.picker, and a tap anywhere on it opens a CommonPopupMenu out of that value with the current option checked. Its items are text alone, as an iOS picker's are; glyphs belong to menus of actions. One value is never picked from a radio dialog or a row of selectable chips; a button that picks one, as the theme's scheme variant does, opens the same menu through a CommonPopupBox. A pick from a menu that returns into its control runs only once the popup has landed, so a setting that rebuilds the app, such as the language, never does so under the returning platter; the control shows its value with PopupValueText, which blurs across to the new value while the control eases to its width. A menu opened at a point, as a context menu or the editor's is, runs its pick at once. A menu capped by maxVisibleItems, such as the proxy group tabs' more menu with every group in it, builds only the rows in view and takes its width from its labels measured as EmojiText lays them out.

Forms

A form that edits more than one value opens with showFormSheet (lib/ui/sheet.dart): a bottom sheet in the mobile layout, and elsewhere a card FormSheetRoute centers over the navigator, as iPad and macOS present a form sheet, moving as an alert does. Both give the page SheetType.bottomSheet or SheetType.formSheet, compact sheets that share CommonScaffold's sheet bar, so one page serves both: FormPage for a plain form, or the page a NestedPagedSheet pushes for the custom profile editors. Its values sit in FormRows inside generateSection groups, each field a FormRowTextField, bare and set against the end in both, so a focused field's only outline is its row's focus ring. RenderEditable ends a field's text short of its end by the caret's margin, so the field ends its hint as short and reaches as far into the row's padding: the caret follows the hint or the text, and the text ends where another row's value does. The save is the scaffold's confirmationAction: last in a bottom sheet's bar, and in a form sheet the filled default beside Cancel, which takes the close's place, in a row of alert buttons at the first page's foot, as SwiftUI places a confirmation action on macOS; other actions, such as quick edit, stay in the bar. A row cannot hold an error line, so a save the form refuses marks the row invalid and says why in the ErrorBanner above the groups, which follows each edit from then on. A prompt for one value, such as a URL import, a rename or a password, stays an alert (CommonDialog, InputDialog), as on every Apple platform; a key with its value, as MapEditView adds, is two values and a form. An alert raised while focus is in a form sheet opens on the sheet's navigator, centered on the card rather than on the window: Dialogs follows the focused route when it is an AlertHostRoute, which the form sheet and every alert are.

Keyboard Insets

The soft keyboard moves MediaQuery.viewInsets on every frame of its animation, so whatever depends on them rebuilds and relays out at frame rate for a few hundred milliseconds. ThemeManager wraps the whole app in a LayoutBuilder, which runs every one of those rebuilds inside the layout phase; in a profile trace they show up there, not under BUILD.

• A page the user is not typing in holds its bottom inset through KeyboardInsetHold (lib/ui/keyboard_inset_hold.dart). Pages under another route and inactive tabs are still laid out, offstage or not, and without it every page the app keeps relaid out, and rebuilt under its LayoutBuilders, with each frame of a keyboard raised by a dialog or sheet on top. The home route, each home tab, CommonRoute, CommonDesktopRoute and the open-container route wrap their page in one; a new page route type does the same.
• A widget high in the tree reads the aspect it needs (MediaQuery.paddingOf, viewInsetsOf, ...), never MediaQuery.of or MediaQuery.removePadding(context: ...) on its own context, which subscribes it to every inset change. Move such a read into a small widget of its own below it, as _AppMediaQuery in ThemeManager, _BodyPadding in lib/pages/home.dart, _KeyboardViewport in lib/ui/snap_sheet.dart and the SafeArea around the docked search field in CommonScaffold do.
• A bottom sheet makes room for the keyboard itself: the keyboard raises the sheet's foot (Bottom Sheet Motion), and _WithoutKeyboard removes the bottom inset from the content's MediaQuery, so nothing inside a sheet, CommonScaffold included, adds keyboard space. A nested sheet must not carry the keyboard through its pages: NavigatorResizable learns a page's new size a frame late, and the sheet would trail the keyboard by a frame.
• The keyboard moves a bottom sheet as it is painted. _RenderSheetViewport lays the surface out as tall as the view whatever the keyboard, and a fit sheet keeps the limit its short content was laid out within while the keyboard changes the room above it, until the content reaches either (releaseLimit). A keyboard frame then lays out and paints nothing inside the sheet unless what it shows changes.
• A field without a label says floatingLabelBehavior: FloatingLabelBehavior.never, as FormRowTextField and SearchField do. InputDecorator animates the floating label of an empty field on focus even when there is none, InputDecoration.collapsed included, and each frame of it lays the decorator out and, inside a sheet, the whole form, through the first frames of the keyboard.

Rebuild Scopes

A LayoutBuilder runs the rebuilds of everything under it inside its own layout, so a widget rebuilding there marks the builder for layout, and that climbs to the nearest relayout boundary. Flutter marks every render object it lays out for paint, so the nearest repaint boundary above that path repaints too. Under the material Scaffold's body LayoutBuilder (it has one with extendBodyBehindAppBar) that was the page and its background, and under the home shell's LayoutBuilder the whole home route: a spinner turning in a page, or the dock's lens moving, relaid out and repainted the page on every frame, and the glass over it captured every band again, the bar's included, though nothing under the bar had changed.

So the body and the dock each take their rebuilds in a scope of their own: a LayoutBuilder under a repaint boundary that is also a relayout boundary. CommonScaffold's _BodyScope sizes itself to the most the scaffold allows, which the scaffold never reads back, and lays the body out under it as before; NavigationDock sizes itself as it always was, full width and its bar's height, and lays its boundary out tight. A rebuild inside either relays out and repaints only that layer.

Bottom Sheet Motion

SnapSheetRoute follows UISheetPresentationController as measured on the iOS 27 simulator (a UIKit probe app driven by the simulator's touch injection, logging the presented view's presentation layer every frame).

• One spring moves a sheet: UIKit's mass 3, stiffness 1000, which runs critically damped (ω ≈ 18.26 rad/s, done in about 0.5 s). Presenting, closing, a detent change and a spring back all trace it within a point. A release thrown toward its target keeps its velocity and lands with UIKit's slight overshoot, about damping ratio 0.8 at full strength; a release away from its target loses its velocity and lands dead.
• A release lands on the detent, or the dismissal, nearest to where UIScrollView.DecelerationRate.fast projects it. With no velocity a sheet closes once it is let go past half of its shortest detent; a flick of 1000 pt/s 85 pt down springs back on iOS, one of 1500 pt/s closes.
• The sheet follows the finger one to one below its shortest detent and stops at its tallest, with no stretch.
• On the content, a drag up grows the sheet first and scrolls the content with what is left, in one gesture. A drag down moves the sheet only when it began with the content at its top; one that scrolls the content back to its top stops there, as iOS bounces it rather than handing it to the sheet.
• The keyboard raises the sheet's foot: a detent keeps what it shows above the keyboard, as a custom detent does on iOS, up to a peek below the top. iOS lifts a medium sheet to its large detent instead, which a phone's keyboard, about as tall as the gap between them, makes nearly the same. Since the sheet's height is a function of the inset, it moves with the keyboard on every frame and lands back where it was.
• Where the keyboard starts or stops carrying the sheet, that function rounds its corner (_rounded), so the sheet's speed changes smoothly. With a sharp corner a sheet stood still while the keyboard slid over the blank below short content and then jumped, and on the way down halted in mid-flight; the tallest detent hit the peek at the keyboard's full speed. Short content now eases into the rise over half its blank, which can leave the sheet up to an eighth of the blank higher than its content needs, and the tallest detent slows into the peek over as much keyboard again as it takes to get there, up to _peakEase.

_SheetModel keeps the sheet as an activity, resting at a detent, held at a height or settling toward a detent as an offset from it, and layout resolves the detents again every frame from the view, the keyboard and the content. A resting or settling sheet therefore follows a page transition's size or the keyboard without being told, where a stored height would have to be patched after each change. Below the shortest detent a drag moves the route's own animation, so the barrier, a sheet stepped back behind this one, and the page bar under it follow the finger, and the close continues from the release on the presentation spring (createSimulation).

Page Arrival

A pushed page is built, laid out and painted through every frame of its transition. Impeller has no raster cache, and every offscreen pass is paid again each frame on a phone GPU. Even so, a page loads what it shows as it mounts: content held back until the route settles slides in as an empty page and pops in once the motion has stopped, which reads worse than the frames a load costs. What a transition must not carry is work that repeats on every refresh or every frame.

• Loads start as the widget mounts, never behind whenRouteSettled. CommonTargetIcon and PackageIcon show what is already in memory at once and load the rest right away; the editor reads its file and mounts CodeForge as soon as the content is in. An icon still loading leaves a blank slot of its size and shows its fallback only once the load ends without an image, so a grid of placeholders is never painted only to be replaced. whenRouteSettled (lib/ui/navigator.dart) is left for sequencing navigation, such as opening a page once the sheet above it is gone.
• A live feed holds its refreshes while its page moves and replays the latest once it is still, so a list does not re-rank, reorder or grow under a transition. RouteMotionHoldMixin (lib/ui/route_motion_hold.dart) holds them while isRouteMoving: the page's route or a sheet carrying it is pushed, popped or dragged, a page is pushed over it, or a sheet covers it (sheetCoverOf). The connections, requests, logs and DNS pages and the dashboard's live connections table use it. A feed's first content is no refresh and shows at once, as ConnectionsView applies its first poll, and a held poll keeps the time it was read at, which TrackerSpeedRanker derives speeds from. Per-frame work spread over frames pauses the same way: the font family page switches one name to its own family per frame and stops while isRouteMoving.
• A scroll view of image tiles takes arrivalScrollCacheExtent(routeSettled) from RouteSettledMixin: the rows past the viewport would otherwise be built in the same frame as the ones on screen, which for a screen of icon cards is most of the push. The icon grids (IconGridScrollView) and the access control list do this, and so does ListEditorPage, whose rows are heavy enough that only its list rebuilds as the route settles, reusing the rows already built.
• A page whose content waits on what it loads (lists read from the database, file sizes, the installed fonts) shows nothing until all of it is in, then the finished content in one step: NullStatusSwitcher.isLoading. A load that can run long also gives the switcher a loadingStatus, its NullStatus illustration with no label, which takes the place of a first load still running after about a route transition (400 ms); one that ends sooner goes straight to its content, so the illustration never flashes. The custom profile, resources and font family pages set one. Never a skeleton screen of placeholder rows: it has to guess how many rows are coming, fills in piece by piece, and rebuilds every row it stood in for. SkeletonText is for a single value inside a card that is already on screen, such as the dashboard's service status.
• GlyphPainter paints a translucent glyph through an offscreen layer. A placeholder repeated in every tile blends its color over the surface instead of carrying an alpha.
• PagedSheetRoute and CommonRoute share SharedXPageTransition (lib/ui/page_transition.dart) and its pageSlide, a quarter of the page's width as Android 14 slides pages, so a page moves alike in a sheet and on its own. The transition fades a page by painting the surface over it and needs no opacity layer: the page on top shows only on its side of the point where the two fades cross, opaque over the other, so neither shows through the other. A page below that does not fade with it, such as the home route under a CommonRoute, is faded by the page on top painting the surface over it. CommonDesktopRoute fades in place through a plain 200 ms FadeTransition.

State Management

Provider files in lib/providers/:

• app.dart: runtime/UI state, logs, traffic, delays, loading, navigation.
• config.dart: persistent config providers, app settings, theme, VPN, proxy style.
• state.dart: derived/computed providers, navigation, proxy, tray, color scheme. Like action.dart, this is an entry point only: the providers live under lib/providers/state/ and are joined with part directives, so importing state.dart still reaches all of them.
  • state/proxies.dart: group and proxy lists, filter/sort, delay, selection.
  • state/navigation.dart: navigation items, current page, dashboard, more tools.
  • state/system.dart: tray, VPN params, access control, hot keys, shared state.
  • state/theme.dart: dynamic color, color scheme, brightness.
  • state/profile.dart: profiles, current profile, clash config, setup state.
  • state/custom.dart: custom profile validity and the staged group/rule notifiers.
• action.dart: business logic notifiers, setup, backup, core lifecycle, proxy selection.
• core.dart: coreHandlerProvider, the container-scoped handle on CoreController.
• route_state.dart and routed_probe.dart: the route tracker and the probe cache; see Route Consistency above.
• outbound_ip.dart and service_status.dart: the dashboard probes built on them.
• database.dart: Drift database provider wrappers.

Reaching Singletons

lib/common/ and lib/core/ publish process-wide singletons (coreController, system, preferences, appPath, request, and others). Code that already has a Ref or a WidgetRef reads them through a provider instead, so a test can scope a fake to one ProviderContainer rather than swapping a global and relying on a tearDown to put it back.

coreHandlerProvider is the established case. Every call site under lib/providers/, lib/manager/ and lib/views/ goes through it; notifiers and ConsumerState classes that touch Core repeatedly hold it as CoreController get _core => ref.read(coreHandlerProvider).

Tests override it with coreHandlerProvider.overrideWithValue(CoreController.scoped(fake)), which does not claim the singleton. CoreController.test does claim it, and is only for tests that have not moved yet. Prefer the scoped override even when a test passes either way: a test that claims the singleton makes the global and the provider resolve to the same fake, so it cannot tell a provider read from a leftover global read, and a half-migrated call site stays green.

One deliberate exception: globalState owns the ProviderContainer, so it cannot itself live in one. Code without a Ref reaches providers through globalState.container.read(...). The remaining call sites are lib/core/lib.dart, lib/common/print.dart, and the tray read callback in lib/providers/actions/system.dart — all singletons or platform callbacks with no Ref in scope.

lib/models/profile.dart does not reach Core. Profile.saveFile and Profile.update take a ValidateConfig callback, and every caller passes (path) => _core.validateConfig(path), keeping the Core handle lazy so a profile path that never validates never resolves the controller.

The UI layer must not reach a process-wide singleton directly. test/lint/ui_layer_singleton_test.dart scans lib/ui, lib/views, lib/widgets, lib/pages and lib/features for globalState.container and the bare coreController global and fails the run on either. Widgets that need Core hold CoreController get _core => ref.read(coreHandlerProvider).

globalState.measure and globalState.theme stay global on purpose. Both are context-derived caches assigned by ThemeManager, and tests already scope them by assigning in the app builder (see wrapAppScopes in test/helpers/test_app.dart); moving them into providers would touch every layout call site without changing behaviour. lib/ui cannot read globalState, so it takes the same Measure from MeasureScope; see UI Layer.

globalState in lib/state.dart is a singleton holding ambient app state — the package info, the measure and theme, the container, and the start/stop flags — plus safeRun/loadingRun. Startup orchestration is not on it: init and attach live in lib/bootstrap.dart, above lib/common, because they drive the window, the autostart entry, the tray and the permission prompts. Providers are generated into lib/providers/generated/.

The root navigator key lives in lib/ui/navigator.dart as rootNavigatorKey; globalState.navigatorKey is a getter onto it. lib/common/dialog.dart reaches the key directly and does not import lib/state.dart.

Platform Layering

lib/common/common.dart deliberately does not export tray.dart, window.dart, launch.dart, or system_dns.dart. Those four modules import tray, window, launch_at_startup, and screen_retriever; exporting them would put those packages in the compile graph of every file that imports the barrel for a string helper. Import the specific module instead.

test/lint/platform_layering_test.dart enforces four rules. Three are local: the barrel never re-exports one of those four modules, nothing under lib/common, lib/enum or lib/models other than those four imports a desktop platform package, and lib/common never imports the lib/manager/manager.dart barrel (import the single manager needed, as common/context.dart does with manager/status_manager.dart). The fourth walks the barrel's whole transitive closure and fails if any file in it imports one of those packages. That one is the real invariant — the local rules only stop the shortest path, and every leak found so far arrived through a longer one.

The shapes that keep the closure small:

• System.back and System.exit do not touch window; the window half of both lives in SystemAction.
• KeyboardModifier.toHotKeyModifier() lives in lib/manager/hotkey_manager.dart, its only consumer, not in lib/enum/enum.dart.
• Startup orchestration lives in lib/bootstrap.dart, not on GlobalState. common/print.dart and common/request.dart import state.dart for container and packageInfo/ua, so anything GlobalState reaches lands in the barrel's closure; the ambient state it holds reaches nothing platform-specific.
• SystemAction talks to WindowPort and TrayPort from lib/common/app_ports.dart instead of importing common/window.dart and common/tray.dart. lib/bootstrap.dart binds windowPort and trayPort to the real implementations; both stay null in tests, where every call through them is a no-op. A test that needs the real tray assigns trayPort itself, as test/common/tray_menu_test.dart does.
• lib/providers/providers.dart re-exports action.dart, so lib/common and providers/app.dart import providers/state.dart and providers/config.dart directly; the barrel would reach the whole action layer.
• A data type in a lower layer never holds the widget that renders it, because that drags the whole view tree into the barrel's closure. The route table is lib/views/navigation.dart implementing NavigationPort, which providers/state/navigation.dart reads through and bootstrap.init binds; unbound it yields no items, so a test that renders navigation assigns navigationPort itself, as test/pages/home_test.dart does. DashboardWidget is plain data, since it is persisted in the app settings; the card mapping lives in lib/views/dashboard/widget_registry.dart.

test/lint/platform_layering_test.dart also pins that the barrel's closure contains no lib/views file. Data the provider layer needs from the UI layer goes through a port in lib/common/app_ports.dart rather than an import in the other direction.

High-Frequency Buffers

logsProvider, requestsProvider, dnsQueriesProvider and trafficsProvider hold a FixedList (lib/common/fixed.dart), which trades a normal copy-on-write for a shared buffer tagged with a generation counter:

• append mutates the buffer in place and returns a new wrapper one generation ahead. That is what providers publish, so updateShouldNotify still fires.
• list returns an immutable copy, cached until the next mutation. It must stay eager: an older wrapper shares the buffer, so its contents move on. Anything that needs a stable view has to read list at the moment it is notified, not hold the wrapper and read later.
• Consumers that only need to know that the buffer changed watch revision, not list — selecting on the list snapshots and deep-compares the whole buffer on every arrival, which is what this design exists to avoid. See lib/views/logs.dart for the pattern: watch the generation, snapshot inside the throttled callback.

add/clear mutate in place without advancing the generation; use them only on a buffer you own outright (seeding, resets, tests), never on published state.

Background Work

A proxy client runs for days with nobody looking at it, so work that only feeds the UI stops when the UI cannot be seen. There are three levels of gating:

• appVisibleProvider is false while the desktop window is hidden or the Android activity is in the background (hidden, paused, detached). AppStateManager writes it. The one-second run-time and traffic ticker in SetupAction follows it. The macOS menu bar title is the exception: it shows the traffic while the window is hidden. RouteTracker and RoutedProbe follow it too, as described under Route Consistency.
• ActivePollingMixin is stricter for per-widget polls such as connections and memory. It polls only while the app is resumed, its home page is the current one, and no opaque route covers its page: the overlay turns tickers off on a covered page once the route over it has finished moving in, and the mixin follows TickerMode.
• _NavigationPage puts every page except the current one under a disabled TickerMode. Home pages are kept alive in the PageView, and Flutter does not mute tickers on a kept-alive page off screen. A spinner left on one would otherwise keep scheduling frames.

A provider's own ref.listen delivers nothing while no one listens to that provider. That is the usual state of an action notifier, which is only ever read. A derived provider it listens to is never recomputed, and even a ref.read of it returns a stale value. So an action that has to follow a signal listens to the keep-alive provider that holds it, as SetupAction does with appVisibleProvider, not to a provider derived from that.

On Android the Core does not react to the screen or to Doze. Doze's firewall keeps apps without an exemption off the network before their traffic reaches the TUN, so what still arrives is traffic Doze allows, FCM among it; suspending the tunnel rejects exactly that and stalls push reconnects until their backoff runs out. The VPN service keeps its own network as a foreground service (dumpsys netpolicy shows its DOZE block allowed by FOREGROUND), so health checks keep producing real results: holding them blocks the re-check mihomo runs after repeated dial failures, which is how a url-test group leaves a dead node, and hiding their failures hides the truth. Nothing re-probes on resume either: every proxy group is a provider, select groups included, and checking one tests every node in it. Should a ROM be shown to cut the VPN's own network while the screen is off, holding back failures measured then needs only a screen on/off signal.

Database

The app uses Drift/SQLite in lib/database/. schemaVersion in lib/database/database.dart is the migration counter; a schema change bumps it and goes into the one step the coming release takes, as the Migrations section of .agents/rules.md describes.

Tables:

• Profiles
• Scripts
• Rules
• DisabledRules (disabled_rules)
• ProxyGroups (proxy_groups)
• CustomProxies (custom_proxies)
• ProxyDialers (proxy_dialers)
• IconRecords (icon_records)
• IconSets (icon_sets)
• ClashProviders (clash_providers)

Profiles.type is file, url or custom, fixed when the profile is created. A rule belongs to whoever its profile_id names: no profile makes it global, a file or url profile's rules are what its standard extension adds, and a custom profile's rules are all the rules it has. DisabledRules lets a profile leave out a global rule. Proxy groups and dialers exist only on custom profiles. Every one of these rows cascades with its profile. Rule and proxy-group ordering use fractional indexing.

A custom profile has no file and no extension: SetupAction.getProfile builds its config from an empty map plus its groups and rules, and clashConfigProvider answers an empty ClashConfig for it. Its groups name app-level custom proxies directly, and the config declares only the ones some group names; they take nodes from every file or url profile too, each a file proxy provider under its label. A custom profile is never a provider itself. App-level ClashProviders rows are rule providers only, and only custom profiles are offered them.

A custom profile names groups, local proxies, provider profiles and rule sets by name, mihomo's own strings included (a DNS server's #proxy, a rule-set: policy key, the sniffer's lists). lib/models/references.dart reads and renames every such place, and renames, delete prompts, provider injection and the profile checks all go through it; test/models/references_test.dart fails when config.go reads a name somewhere it does not. A rename is detected where the row is written, so every path carries it. A local proxy may not share a name with any custom profile's group, as both live in mihomo's one namespace; where older data has both, the name means the group in that profile and a proxy rename leaves it alone. Profiles writes rows one at a time from the state as it then stands, so a rename rewriting custom profiles is never written over by a put issued before it landed.

An app-level rule set's behavior and format are what the Core's compileRuleSet found in its source, never a user choice. The source stays at getProviderCachePath(fileName); a domain or ipcidr set also gets an .mrs beside it, and that is what the config loads, while classical rules have no mrs form and load from the source. The Core downloads a remote set too and mihomo sees it as a file provider, so a sync goes through ClashProvidersAction, not mihomo's HTTP vehicle. ClashProvidersAction.prepare rebuilds a missing cache while the config is built, since backups carry only local sources and sets saved before compiling existed have no .mrs.

IconSets and IconRecords only feed the proxy-group icon picker. A set is an icon gallery in the format Quantumult X and Loon subscribe to, kept whole as one JSON column; a record is an icon the user saved on a group, written on save and never by merely displaying it. A group stores the icon string itself, a URL or a data URI, never a reference to a set, so renaming, syncing or deleting a set leaves every group as it was.

Generated Drift output lives in lib/database/generated/database.g.dart. After schema changes, run code generation and add or update focused database tests under test/database/ when converter or migration behavior changes.

Unreadable Stored Data

Preferences, database rows and backups can hold values this build cannot read: an enum a newer build wrote before a downgrade, a fork sharing the data directory, a hand edit. Reading them gives up the smallest unit it can and never fails startup or a whole restore.

• Config.fromJson and every safeFromJson decoder go through decodeSalvaging, which keeps each value the strict decoder accepts, descending into maps and lists, and leaves the rest at their defaults; a list or section none of whose entries can be read falls back to its default rather than to empty. Only the migration uses Config.strictFromJson, since it tells legacy data apart by the failure. A field's own fromJson throws on what it cannot read instead of restoring a default for the whole field, so the salvage around it drops just that entry.
• DAO entity queries read through TableInfo.readable, which skips a row it cannot map and leaves it in the table. A profile's JSON columns that hold selection state, subscription info or overrides fall back to empty instead, so the profile stays listed.
• Rules, disabled rules and proxy groups are the exception and read strictly, in the app and from a backup alike: skipping one would quietly change how traffic is routed, so a damaged row fails loudly instead.
• Code that deletes files or rows by comparing against what a query listed must use raw ids (ProfilesDao.ids, ScriptsDao.ids, ClashProvidersDao.fileNames), or it deletes what a skipped row owns. Startup reorders profiles with Profiles.reorder, which writes rows but never deletes them.

Manager Stack

Managers are nested InheritedWidget/StatefulWidget components built by buildManagerStack() in lib/application.dart:

AppEnvManager > LocaleManager > StatusManager > ThemeManager
  > [Desktop: WindowManager > TrayManager > HotKeyManager > ProxyManager]
    [Mobile:  AndroidManager > TileManager]
  > AppStateManager > CoreManager > ConnectivityManager
  > [Desktop: WindowHeaderContainer] [Mobile: VpnManager]
  > app content

Each manager in lib/manager/ handles a specific platform concern. The platform slots are exclusive: no desktop manager appears on mobile and no mobile manager appears on desktop.

The order is an ownership contract, not a layout detail. ConnectivityManager sits below CoreManager because its onConnectivityChanged callback reads Core-backed state, so Core must already be mounted when it fires. StatusManager and ThemeManager sit above the platform managers so a platform manager can surface a message or read the theme.

buildManagerStack() is a pure function of isDesktop, the connectivity callback, and the app content, so test/application_test.dart asserts the whole order by constructing the stack without mounting it. Changing the nesting means updating both this diagram and that test.

Core Controller and Actions

lib/core/controller.dart (CoreController) is a singleton facade over CoreHandlerInterface. Public methods delegate to the platform-specific interface, either the Android service channel (CoreLib) or the desktop socket. It has an @visibleForTesting constructor and resetInstance() for test injection.

lib/providers/action.dart is the public library entry point for action providers. The Riverpod notifier implementations are split by responsibility under lib/providers/actions/ and joined to the entry point with part directives, so consumers continue to import the same public API:

• CommonAction: update check and common UI operations.
• SetupAction: config setup and TUN management.
• BackupAction: backup/restore orchestration over a per-run temp work directory; the view supplies where an archive goes (local save, WebDAV upload) or comes from. The archive format lives in lib/common/backup.dart, which stages a restore without touching the data directory; files, database rows and settings are applied only after the whole archive has been read and validated.
• CoreAction: core lifecycle, initialization, coalesced restart, and post-restart profile/running-state application.
• SystemAction: system integration, tray, coordinated resource cleanup, terminal Core close, exit, and brightness.
• StoreAction: profile storage operations.
• ThemeAction: theme state updates.
• ProxiesAction: group management and proxy selection.
• ProfilesAction: profile CRUD, auto-update, import.
• GeoResourceAction: geo resource updates and URL configuration.
• UpdatingAction: stale sweep over UpdatingKeys.

UpdatingKeys in lib/providers/app.dart owns every per-entity updating flag; isUpdatingProvider(key) is the read-only view widgets watch. Callers pair start(key, scope: ...) with stop(key, operation) using the returned token, so overlapping operations on one key are reference counted and a late stop from a superseded operation cannot clear a newer one. Keys started with UpdatingScope.core depend on the Core to make progress, so UpdatingKeys discards them itself when coreStatusProvider leaves connected — that is the state's own invariant, not a policy, and it must stay inside the notifier where no warm-up ordering can miss it. UpdatingScope.local keys (profile updates run entirely in Dart) survive a Core restart. UpdatingAction holds only the policy half: the periodic sweep that discards a key stuck past updatingStaleTimeout. Do not move the timeout back into UpdatingKeys, and do not widen the disconnect reset to every scope.

Safe Mode

--dart-define=SAFE_MODE=true builds a FlClash that never changes the host network, so a development build can run next to an installed one. It is a compile-time constant with two faces: safeModeBuild in lib/common/constant.dart for the process-wide handles that exist before the provider container, and safeModeProvider in lib/providers/app.dart for everything reached through Riverpod, which is also what tests override. Settings are never rewritten; each owner reads the flag where it would otherwise act:

• Core config: SetupAction._effectivePatchConfig is the one place the profile path and updateConfig derive what the Core receives from the user's PatchClashConfig. In safe mode it reports tun.enable: false and ExternalControllerStatus.close, so the generated profile and every updateConfig carry no TUN and an empty external-controller (the Core's route.ReCreateServer binds no RESTful API port) while the settings keep the user's values and the installed app keeps 127.0.0.1:9090. SetupAction.requestAdmin skips authorization.
• System clock: _makeRealProfileTask sets write-to-system: false on whatever ntp section the generated profile ends up with, so neither the user's override nor the profile's own NTP config can move the host's time.
• Profile listeners and firewall rules: _makeRealProfileTask clears listeners, tunnels, ss-config, vmess-config, tuic-server and iptables, and closes dns.listen, preventing profile-only changes during apply.
• System proxy: the proxy plugin handle in lib/common/proxy.dart is null, so ProxyManager and exit cleanup never write the OS setting, not even the stopProxy that would clear what the installed app configured.
• System DNS: systemDnsCoordinator is null and shouldPatchSystemDnsProvider is false, so neither the apply nor the restore path runs. The restore path matters because a profile or release build shares the preferences of the installed app (only a macOS or Android debug build has its own bundle id) and would restore from its record.
• Login item: the autoLaunch handle in lib/common/launch.dart is null, so neither the boot sync nor the setting listener registers the build's executable or removes the installed app's entry, which on Windows is the same FlClash value in the user's Run key.
• Privileged Core: CoreService resolves the launcher with hasHelper: false, which is the direct child-process path on every desktop platform; the Helper keeps managing the installed app's Core.
• Core listeners: SetupAction never calls startListener or stopListener, for a run or for an on-demand suspension, so the Core's isRunning stays false and updateListeners binds nothing, while isStartProvider and applyProfile behave as usual. The installed app keeps the mixed, DNS and other loopback ports.
• Android: sharedStateProvider hands the service VpnOptions.enable: false and systemProxy: false, so the foreground service runs without a VpnService.
• Wi-Fi SSID: ConnectivityManager never reads the SSID and LocationPermissions.refresh neither checks nor requests location authorization, so currentSSIDProvider stays null and the excluded-network suspend never trips. The macOS wifi_ssid plugin builds its CLLocationManager and CWWiFiClient lazily, so a build that never asks never reaches locationd or wifid.
• Global hotkeys: HotKeyManager neither subscribes to hotkey events nor registers the configured shortcuts with the OS; the in-window Shortcuts (close window, escape) stay.
• URL schemes and launcher shortcuts: Window.init skips the Windows registry and Linux desktop-entry registration of the clash schemes, and Android never calls initShortcuts.
• Presentation: AppEnvManager shows a SAFE MODE banner ahead of the channel banner, and TrayState.safeMode gives the tray the status_4 bug icon, a suffixed tooltip and a menu of only show and exit. trayStateProvider and trayTitleStateProvider report showTrayTitle: false, so the macOS menu bar carries no traffic title.

A new host integration, anything that changes the OS's routes, proxy, DNS, login items, privileges or VPN state, or that asks the OS for a permission, a global shortcut or a registration, must consult the flag at its owner in the same way and get a test that overrides safeModeProvider.

Build System

setup.dart is the release build orchestrator: it writes env.json (APP_ENV), activates flutter_distributor from the chen08209/flutter_distributor fork pinned to a v<version>-flclash.<n> tag (cut a new tag there and bump --git-ref when the fork changes), and leaves the Core artifacts to the build hook.

The desktop Go core and the Rust helper are built by a Dart build hook; Android's Core is built by Gradle (see Android Core Build). plugins/setup/hook/build.dart only constructs CoreBuilder, a package:hooks Builder in plugins/setup/setup_hooks/, the same shape rust_api uses. Flutter runs it for every platform build and for flutter test, once per target architecture. CoreBuilder turns the hook input into a BuildRequest (repository root, Target) and hands it to buildPlatform. It lives in setup_hooks so dart test there can cover it; a test run of plugins/setup itself would execute the hook. Failures reach the runner as BuildError (Go or Cargo failed, no Core for the architecture) or InfraError (a toolchain could not start, the package is not at plugins/setup).

What the hook protocol forces:

• PATH arrives unextended, so runCommand appends the Homebrew, Go and rustup locations that Xcode's and Gradle's stripped PATH hides.
• The hook does not know the build mode: the protocol carries none and linkingEnabled only says whether link hooks run, so nothing in the hook branches on debug versus release. It cannot tell flutter test from a build either; the build_assets: false user-define in the root pubspec.yaml is the one switch (see .agents/commands.md), and setup.dart refuses to package while it is set.
• The hook declares the files it read but the directories it wrote: hooks_runner hashes a file by content and a directory by child names, so libclash/macos/ catches a deleted artifact without MD5-ing a 55 MB Core on every build. A rebuild touches those directories after the runner's cutoff, so the next build runs the hook once more and setup's cache answers it; that extra run is expected.
• The runner discards hook output on success, even under -v, so the hook mirrors it into .dart_tool/setup_build_cache/hook.log (rotated at 512 KB), one === header per invocation.

Platform projects copy the artifacts out of libclash/; application code must not import plugins/setup:

• Android: nothing. The hook returns without building, because it runs once per architecture while gomobile packs every ABI and one set of Java classes into a single AAR.
• macOS: a standalone FlClashCore. Release.xcconfig pins release and profile ARCHS to the host because flutter_tools otherwise builds a universal binary and every artifact ships one slice; the hook skips a non-host slice for the same reason. The Stage Core phase copies the Core after the hook may have rewritten it and fails when it is missing or lacks a slice for ARCHS, so a skipped hook cannot stage a stale Core silently.
• Linux and Windows: FlClashCore, the Rust FlClashHelperService, and a manifest.json holding coreSha256; the Core builds first because the Helper embeds its hash. The CMake install rules copy them, and the Windows bundle places manifest.json beside the executable. A Helper running from a Debug build keeps its exe open and the install fails behind an opaque MSB3073, so windows/CMakeLists.txt stops it from an install(CODE) step for the Debug configuration only, and only when the staged Helper differs from the installed one; that step is where the configuration is known, and a Release install never stops a registered service. The step matches the process by executable path rather than image name, so a Helper registered from an installed release keeps running.

Setup keeps its own cache under .dart_tool/setup_build_cache/v1/ because it builds a Go core and, on Windows and Linux, a Rust helper:

• Go fingerprints cover the target-specific go list -deps inputs in core/ and Clash.Meta, module files, the effective build configuration, setup_hooks sources, target flags and the Go toolchain. Helper fingerprints cover its Rust sources and manifests, Cargo/Rust toolchains and flags, and the expected Core SHA256.
• A hit requires the fingerprint and every recorded output's path, size and modification state to match, and skips compilation and copying.
• Records are written only after a successful build, under per-target locks. Compilation happens in a staging directory and moves into place on success, so a failed build never destroys the previous artifacts.
• flutter clean removes .dart_tool and forces one full rebuild; deleting .dart_tool/setup_build_cache/ does the same without a clean.

Windows helper integrity/version check:

• setup_hooks constructs the Core first, calculates its SHA256, and always builds the Rust Helper with release hardening and that expected hash.
• Flutter reads the Core SHA256 from the bundled manifest.json and sends it with /ping. Debug, Profile, and Release builds use the same Helper protocol and may use TUN through the same flow.
• /ping is loopback-only and requires no request token. The Helper compares the requested SHA256 with its embedded value and checks that the fixed FlClashCore.exe beside it exists; /start performs the actual Core SHA256 verification before every launch. The response includes the running Helper path and protocol header; Dart checks both against the current installation. The launcher selects the Helper only when /ping reports ready; any other readiness (missing manifest, unavailable Helper, or a Helper built for a different Core) falls back to the direct Core without requesting elevation. If /start reports a pre-spawn failure — coreVerificationFailed (the on-disk Core no longer matches the SHA the Helper and manifest agree on) or processLaunchFailed (the Core process could not be spawned) — the launcher degrades to the direct Core rather than failing the launch. /start releases the previously managed Core before it verifies, so the Helper owns no Core when either code is reported and the direct retry cannot race a Helper-managed Core. A mismatched Helper is reinstalled through the explicit TUN authorization flow, not at startup.
• TUN is not a required run condition. A direct Core runs unelevated and cannot bring up TUN, so any degrade to the direct Core — an unready Helper at resolve time, or a pre-spawn /start failure — silently drops TUN and keeps the Core running. Degrading is preferred over failing the launch: an unverified Core carries no privilege the direct launch path did not already have. manifestMissing is the one readiness that is surfaced to the user, because it means the installation itself is incomplete.
• Flutter creates a 128-bit lowercase-hex session ID and uses it as the random named-pipe suffix. /start receives only that address and session ID, validates the fixed FlClashCore_<session> namespace, starts the fixed Core beside the Helper, and returns the same session ID plus the spawned PID. Flutter verifies both the session and named-pipe peer PID.
• /stop requires the same session ID. A missing process returns notRunning; a different owner returns sessionMismatch without terminating that process. Session IDs are ownership tokens for lifecycle safety, not a claim that the loopback HTTP endpoints are authenticated.
• The Core must not outlive the Helper. On Linux the systemd unit's cgroup and Restart=on-failure cover that; on Windows the Helper puts the Core in a Job Object with KILL_ON_JOB_CLOSE, so the kernel kills the Core when the Helper process ends for any reason, and the install subcommand configures SCM failure actions (three restarts, 5 s apart, reset after 24 h). Stopping a Core sends SIGTERM first on Linux, because only a shutdown removes the policy routes sing-tun installed; the Core runs the same teardown itself when its IPC host disconnects or it receives a termination signal. HelperClient.stopTimeout must stay above the Helper's graceful-plus-kill budget.
• Never take MANAGED_CORE or LOGS with lock().unwrap(). The Helper is a long-lived service running as SYSTEM, so a single panic while a lock is held would poison it and turn every later request into another panic — the service stays dead until Windows restarts it. lock_surviving_poison recovers the guard through PoisonError::into_inner instead. hub.rs uses it at every lock site, tests included, and two tests in that file pin the behaviour.

Build configuration defaults live in plugins/setup/setup_hooks/lib/src/options.dart and can be overridden via the root build_config.yaml.

core_version in build_config.yaml is the mihomo release tag the core/Clash.Meta fork is based on. Upstream injects its version only from its own CI, so the fork alone reports the placeholder 1.10.0 in /version and in protocol user agents; GoBuilder passes the value as -X github.com/metacubex/mihomo/constant.Version=... for every build, local and CI alike. Bump it whenever the submodule moves onto a new upstream release.

Architecture detection is automatic. The --description flag passed to flutter_distributor adds arch suffixes to artifact names, such as FlClash-0.8.93-macos-arm64.dmg.

Android Core Build

android/core/build.gradle.kts registers bindCore, which runs gomobile bind on core/mobile. :core cannot depend on the AAR itself: bundleAar refuses a local AAR in a library, which would break ./gradlew assemble and Android Studio's Make Project. It takes the AAR apart instead, classes.jar as a file dependency and jni/ through an unpack<Variant>CoreJniLibs task per variant handed to variant.sources.jniLibs.addGeneratedSourceDirectory; the legacy sourceSets DSL rejects a task-built directory. Gradle therefore runs the Go build before any task that needs its classes or libraries, in every variant and whether or not Flutter started the build, and its up-to-date check over core/ (tests, testdata and cmd/ left out), build_config.yaml, the Go version, the ABIs, the API level and the NDK version stands in for the hook's cache.

• gomobile and gobind come from the tool directives in core/go.mod and are built into the task's temporary directory, so their version moves only with go.mod. bindCore finds go on PATH or in the Homebrew and Go installer locations that Android Studio's GUI PATH leaves out, and puts the JDK running Gradle first for gomobile's javac.
• The ABIs come from the target-platform property Flutter passes, and default to all three for a Gradle build Flutter did not start. ANDROID_HOME and ANDROID_NDK_HOME are AGP's SDK and its ndkVersion NDK, so the Core and the app share one NDK, and -androidapi is the app's minSdk.
• tags, go_ldflags and core_version come from build_config.yaml, the file the hook reads.
• Both Cores take their GODEBUG defaults from the go line of core/go.mod, whatever toolchain builds them. The desktop Core gets them from the Go command because core is its main module. gomobile links the library as the main package of a module it generates, whose go line is the toolchain's, so bindCore hands the desktop Core's DefaultGODEBUG (from go list on ./cmd/core) to the Android Core through -X=runtime.godebugDefault. Without it, a toolchain newer than that line would move only Android's TLS, x509 and runtime defaults. Raising the go line therefore changes both Cores' behaviour at once; pin a setting with a godebug line in core/go.mod to hold it back on both.
• The TLS settings among them do nothing for proxy traffic. Every TLS connection the Core makes goes through metacubex/tls or metacubex/utls, ports of crypto/tls that hard-code their version's defaults and never read GODEBUG, so tlssha1 and tlsmlkem cannot be held back. They still parse and verify through the standard crypto/x509 and crypto/rsa, and both run before skip-cert-verify is consulted, so core/go.mod keeps x509negativeserial=1 and rsa1024min=0: a server certificate with a negative serial number or an RSA key under 1024 bits would otherwise fail the handshake even on a proxy that skips verification.
• gomobile names the library gojni, both as the file it builds and in the System.loadLibrary of the go.Seq runtime, with no option to change it. bindCore rewrites that string constant in go/Seq.class to clash as it extracts classes.jar, and the unpack task renames libgojni.so to libclash.so; each fails the build unless it finds what it rewrites, the constant exactly once. Go writes no DT_SONAME into a c-shared library, so the ELF needs no change.
• The AAR's own proguard.txt goes with the rest of it. android/core/consumer-rules.pro keeps go.** and com.follow.clash.core.mobile.**, the classes gobind's C glue looks up by name.
• The CI android job compiles :core without Flutter, so it passes -Ptarget-platform=android-arm64 to build one ABI.

Local Plugins

• setup: build-time harness for Go core artifacts and the Rust helper, driven by a Dart build hook; no runtime Dart API.
• proxy: system proxy configuration. On Windows the package installer and uninstaller kill the app, and then run FlClash.exe --clear-stale-proxy, the installer once the new files are in place; the runner hands it to the plugin before any engine starts, and it turns off only a proxy still set to FlClash's 127.0.0.1:<port> with nothing listening on that port.
• rust_api: runtime Flutter Rust Bridge FFI package built through Native Assets. See below.
• tray: system tray for Linux, macOS and Windows. Written for FlClash; replaced the tray_manager fork.
• window: desktop window control for Linux, macOS and Windows. Written for FlClash; replaced the window_manager fork. See below.
• wifi_ssid: Wi-Fi SSID detection.
• code_forge: the text editor behind EditorPage, derived from upstream code_forge. See below.

code_forge Plugin

CodeForgeController is the document: text lives in the Rust RopeBridge, and the controller's methods are split by concern into lib/code_forge/controller/ extensions. CodeForge builds _CodeFieldRenderer, whose painting, layout, folding, caret, gutter and pointer code sit in lib/code_forge/code_area/ part files.

• loadText builds a document of 128K characters or more on a Rust worker thread (RopeBridge.createInBackground), so a large file does not stall the frame it arrives in; EditorView loads through it, and a later text = or loadText supersedes one still building.
• Rust counts offsets in Unicode scalars and Flutter in UTF-16 code units. Convert at the boundary with text_offsets.dart; a mixed-up offset only shows up with astral characters such as emoji, so tests use them.
• The renderer learns what changed from takeChange(), whose lines (first line, lines removed, lines inserted) let it follow edits without reading the whole text; a whole-text text = assignment marks the change replaced and resets the renderer instead.
• The input method is handed a window of the document around the caret, at most 4096 characters, and its deltas are mapped through that window, so the platform has to hold the current one: a caret move that shifts the window, the input method's own included, sends it again. A selection can reach past the window; when the platform removes the selection it sees, the controller removes the rest with it, as one undo step. Gboard does that by collapsing the selection and deleting what it saw, then composes the typed letter before a newly sent window reaches it: deltas made on a window already replaced are not mapped through the new one, and only what they typed is kept. A line longer than the window gets one cut by character count, which stays where it is until the caret nears an end of it, or every key would replace it. A caret move can put a window of the very same text further along; an edit the platform then makes at the caret it had is mapped through the window it still holds.
• A selection the input method collapsed is still the one to replace only while the caret rests at the end it was left at; Gboard's spacebar caret gesture collapses to the middle and moves on, which lets it go. The platform's own cut (Gboard's text-editing panel) arrives as a lone deletion of the live selection and copies only the window's part, so the controller rewrites the clipboard with the whole selection. That panel's select-all and copy still reach only the window. Gboard types over a selection in two batches, the removal and then the letter: the second joins the undo step of the first, and undoing it gives the selection back.
• A composition is drawn over the document and written into it only when it ends, so whatever reads or rewrites the document from outside the input method commits it first: saving, leaving the page, accepting a suggestion, a snippet, find's replace, and UndoRedoController's undo/redo through the settleInput callback the controller registers. Losing focus and a closing connection commit it too rather than drop it. Typing that ends a composition, Enter or a bracket, goes through the typing path so it still indents and pairs. Android ends one with an empty delta batch when the keyboard is hidden.
• A caret the input method moves has to set selection on the change record like any other move, or the renderer neither repaints nor follows it.
• A line's fold comes from the renderer's _computeFoldRangeForLine up to 10000 lines and from compute_all in rust_api's editor/folds.rs past that, and the two must find the same ranges; folding_test.dart compares them on one document. A folded range, and the folded ranges inside it that it folds again when it opens, outlive an edit only while the text still gives that range. An edit reports the lines it changed, not where in them, so a fold heading a line inside an edit that changes the line count is opened rather than guessed at; replaceText, which find's replace-all uses, rewrites only the span that differs to keep that to the lines between its matches.
• The caret never rests on a line a fold hides: folding over it moves it to the heading line, the keyboard steps over the fold, and a caret put there any other way opens it.
• The controller reaches the mounted editor only through the CodeForgeView it attaches, which the editor's state implements by forwarding to its renderer.
• FlClash supplies the suggestion popup, context menu and scrollbar; the package has no built-in versions of them.
• Tests live in test/plugins/code_forge/ at the repository root and need the rust_api library.
• isMobile comes from Platform, so host tests never reach the touch branches (selection handles, long press, magnifier); check those on an Android emulator.

window Plugin

plugins/window exposes desktopWindow (DesktopWindow) on the window method channel; plugins/window/README.md is the channel contract (methods, arguments, events, effects, runner hooks) and every platform implements exactly that table. lib/common/window.dart and lib/manager/window_manager.dart are the only application callers.

• Each platform keeps one style record (title bar style and button visibility everywhere, rounded corners on Windows, effect, tint and brightness on Windows and macOS) and reapplies it whole from a single apply routine, so DWM margins on Windows and isOpaque/effect views on macOS have one writer. Add a visual setting to that record, never a second code path.
• Method dispatch is a table on every platform, and every handler validates its arguments; a bad call answers with a bad_args PlatformException, a capability the platform lacks with unsupported. Coordinates cross the channel in logical pixels; Windows converts with GetDpiForWindow.
• Position and size changes surface as one geometry-changed event that each platform coalesces natively (150 ms after the last WM_WINDOWPOSCHANGED, did-move/did-resize, or configure-event); WindowManager only debounces the capture on top of it.
• Windows: with titleBarStyle: hidden, WM_NCCALCSIZE takes the frame insets from AdjustWindowRectExForDpi and keeps the client rect at the top edge (plus the frame height when maximized, so the taskbar stays uncovered; plus one physical pixel on Windows 11, which draws the top border only into a non-client strip; none on Windows 10, where DWM draws the whole caption over any strip shorter than one). Windows 10 gets its top border the Windows Terminal way instead: the DWM frame is extended over the caption height, the plugin places the Flutter view one physical pixel lower and paints that row black, which DWM treats as alpha 0, and hit-tests it as HTTOP; see plugins/window/README.md. The plugin therefore owns the view placement on WM_SIZE. Fullscreen is emulated by the plugin, which raises enter-full-screen and leave-full-screen itself and mutes WM_SIZE while it is on. The find-running-window IPC (WindowPluginFindRunningWindow/WindowPluginActivateWindow) registers a window message from the executable path and whitelists it through UIPI so a non-elevated launcher reaches an elevated instance.
• Linux: GTK drops the placement of an unmapped window, so hide saves the geometry and the map-event handler applies it, then corrects the placement for 150 ms while the window manager settles (it may place the window after the map handler ran). isPositionSupported is X11-only; Wayland owns placement and re-shown windows land where the compositor puts them. Linux supports no effect: GTK 3 has no desktop-neutral blur protocol, so isEffectSupported is true only for none and the runner keeps the default visual.
• macOS: WindowPlugin.instance is reached from AppDelegate for applicationShouldTerminate (emits should-terminate) and applicationShouldHandleReopen (emits activate); MainFlutterWindow calls hiddenWindowAtLaunch() so the first order keeps the window hidden until Dart shows it.
• Window effects (transparent, blur, acrylic, mica) are capability-gated by isEffectSupported; the Flutter content must paint a translucent background for them to show. ThemeProps.sidebarBlur (on by default) drives them: Window.setBlur picks blur on macOS and acrylic (or blur) on Windows and caches only a successful probe, so a platform that answered unsupported is asked again the next time blur is turned on. WindowManager reapplies it whenever the setting or the app brightness changes and records the outcome in windowBlurProvider, and only the sidebar and the caption strip paint translucently while it is on. On macOS the sidebar paints fully transparent and the effect view follows the window's active state, which is the flutter_acrylic TransparentMacOSSidebar look; Windows keeps a 50% tint because the accent effects blur too little for the rail to stay readable.
• Sidebar blur is soft-disabled: feature.sidebarBlur (lib/common/feature.dart) is off unless the build passes --dart-define=FEATURE_SIDEBAR_BLUR=true. While it is off the theme page hides the toggle and windowBlurRequestProvider asks for no effect whatever ThemeProps.sidebarBlur holds. WindowManager still sends that request at startup: the macOS plugin installs its effect view in ensureInitialized and leaves it active until the first setEffect, so the none request is what makes the window opaque and parks the effect view.

rust_api Crate Layout

plugins/rust_api has no platform folders. hook/build.dart is a Dart build hook: Flutter runs it for every platform build and for flutter test, and flutter_rust_bridge_hooks (over native_toolchain_rust) compiles the crate with Cargo and registers librust_api as a code asset that Flutter bundles and signs. The build runs rustup run <channel>, so rust/rust-toolchain.toml must pin an exact channel and list every target the project ships; the hook refuses stable and a target missing from that list. rustup show installs the pinned toolchain and those targets on first use.

flutter_rust_bridge_codegen generate (see .agents/commands.md) writes lib/src/rust/frb_generated.dart, frb_generated.io.dart, frb_generated.web.dart, one lib/src/rust/api/<module>.dart per Rust API module, and rust/src/frb_generated.rs; none of them is edited by hand. A new Rust function is a public function in rust/src/api/, plus pub mod <name>; in api/mod.rs and an export from lib/rust_api.dart when it starts a new module. RustLib is the singleton entry point: RustLib.init() runs before any call and RustLib.dispose() on teardown.

plugins/rust_api/rust/src/ separates the bridge boundary from the code behind it:

• api/ is the only input flutter_rust_bridge parses (rust_input: crate::api). Every function there is a thin delegation, so the generated bindings stay identical on every platform.
• ipc/ implements the desktop socket server: frame (length-prefixed framing), outbox (the byte-bounded send queue), access (socket mode, the Unix peer uid check, and the peer PID), and server (bind, the accept loop, and the read and write halves of a connection). Each Server runs a current-thread tokio runtime on an ipc-server thread of its own and holds no global state, so I/O is event-driven on every platform and closing or dropping the handle releases the socket. It serves one peer at a time; a second one waits in the backlog.
• script/ runs profile override scripts on QuickJS through rquickjs.
• editor/ backs plugins/code_forge: a ropey buffer, fold ranges and bracket matching, indent guides for the viewport, and completion words. api/editor.rs exposes the buffer as the opaque RopeBridge; the selection stays in Dart. Only the editor imports this module, through lib/editor.dart, so lib/rust_api.dart keeps its generic names such as GuideBlock out of app code.
• hotkey/ registers desktop global shortcuts through global-hotkey: keys maps Flutter USB HID usages to key codes, owner runs every registration on the thread the platform binds it to (a dedicated message-loop thread on Windows, the main dispatch queue on macOS, in place on Linux), and service owns the registry and forwards presses to Dart. Linux is X11 only; a Wayland session without XWayland gets an error rather than a silent no-op.

IpcServer.bind resolves once the address is bound, events() attaches the one event stream, send only enqueues and is a synchronous call so frames keep the order they were sent in, and close joins the thread. A bridge function that takes a StreamSink must not return an error: the generated Dart code drops that call's future, so an Err surfaces as an unhandled async error instead of reaching the caller. That is why binding is its own call and everything after it is reported as an event.

What a platform does not use, it does not compile. interprocess, tokio and global-hotkey are declared under cfg(not(target_os = "android")), and ipc/mod.rs and hotkey/mod.rs swap in their unsupported.rs there, because Android loads the Core in-process and has no global shortcuts. Adding a capability follows the same shape: implement it in its own module, gate the dependency by target, and keep the api/ entry point unconditional so one set of bindings still serves every platform.

RustLib.init() runs on every platform in main, because the script engine and the editor are shared; the editor shows its unavailable state when RustLib is not initialized rather than loading the library itself.

Profile Script Engine

lib/common/javascript.dart sends the profile as JSON to evaluate_script, which runs main(config) on QuickJS and returns the JSON the script produced. Nothing about the script runs in Dart.

• QuickJS is compiled from source for the target being built, which is what removed the prebuilt quickjs-c-bridge binaries: flutter_js shipped x64 Windows and desktop-only libraries, so Windows ARM64 could not start (#2361).
• rquickjs carries pre-generated bindings for every target this project builds except the Android ones, so Android builds enable its bindgen feature. That needs the NDK's own libclang and sysroot: native_toolchain_rust exports the sysroot through BINDGEN_EXTRA_CLANG_ARGS_<target>, and hook/build.dart adds LIBCLANG_PATH from the NDK toolchain Flutter hands the hook, because bindgen otherwise loads whatever libclang the host has, or none.
• Evaluation is bounded: a 10-second interrupt deadline and a memory ceiling, because a script that never returns would otherwise hold the profile forever. console is installed before the script runs, since scripts written for other clients log as they work.
• rust/tests/fixtures/profile_script.js is the compatibility regression: an extension script written for the suite that performs the transform real ones perform, so it exercises Map/Set, spread, destructuring, optional chaining, nullish coalescing, Object.fromEntries, named capture groups and lookbehind in one pass. Keep it first-party and free of external URLs — vendoring somebody's published script here carries their attribution and their links.

Rust Helper Service

services/helper/ is the privileged helper that starts the core elevated so TUN works. It ships on Windows and Linux and is built by the setup build hook alongside the Core, which always compiles the Helper in Rust release mode after calculating the SHA256 of the Core produced for the active Flutter configuration.

The helper owns its Windows Service Control Manager lifecycle through two elevated commands:

• FlClashHelperService.exe install --owner-pid <pid> reads the account of that process (the app, which Dart names with its own PID because the elevated installer may be another administrator), stops and removes any stale registration, creates the auto-start service for the current executable path with --owner-sid <SID> as its launch argument, starts it, and waits for the running state. A service started without an owner exits instead of serving anyone.
• FlClashHelperService.exe uninstall stops the service, waits for shutdown, removes its registration, and is also used by the Windows package uninstaller.

The Dart layer only launches the helper's install command through ShellExecuteW; it does not compose sc.exe, taskkill, or cmd.exe command lines.

Linux takes the same shape with systemd in place of the Service Control Manager, and the same install timing: nothing is registered at package install, and Linux.registerService asks for elevation only when TUN authorization needs it. Elevation goes through pkexec so polkit raises the system prompt. When pkexec is missing, or exits 127 because no polkit agent runs (common under tiling window managers), it falls back to sudo: cached credentials first, then a password the app asks for and hands to sudo -S on stdin. A 126 means the user dismissed the polkit dialog and is final.

• FlClashHelperService install, run through LinuxElevation (lib/common/linux_elevation.dart), writes /etc/systemd/system/flclash-helper.service for the current executable path and enables and restarts it. It reads PKEXEC_UID/SUDO_UID to learn who asked, and refuses to install without one — there would be no account to grant the socket to. It also refuses a Helper whose binary or directory is not root-owned and non-writable (a unit runs it as root at every boot, so an unpacked bundle would be a standing escalation), and refuses to replace a unit already installed for a different UID rather than restart the service out from under that account.
• That ownership check is why the flutter_distributor fork normalizes the packaging tree to 0755/0644 before dpkg-deb, rpmbuild and appimagetool run: they record modes verbatim, and Ubuntu's per-user default umask of 002 would otherwise ship /opt/FlClash as 0775, which the installer rejects as group-writable.
• The rpm spec sets debug_package and __os_install_post to nil for the same reason: rpmbuild's find-debuginfo and brp-strip rewrite FlClashCore, and a Core whose SHA256 no longer matches the Helper's embedded value is refused at /start, which silently degrades every launch to the direct Core.
• FlClashHelperService uninstall disables the unit, removes it and reloads systemd.
• The unit carries Group= (the owner's primary GID), RuntimeDirectory=flclash, the owner's UID/GID in FLCLASH_HELPER_OWNER_UID/_GID, a double-quoted ExecStart= with % escaped, and Restart=on-failure under a start limit so a broken unit ends up failed instead of restarting forever. The helper serves /run/flclash/helper.sock at mode 0660, additionally drops any connection whose SO_PEERCRED UID is not the owner's, logs and retries an accept failure instead of letting hyper end the server, and handles SIGTERM so systemctl stop still runs its own Core teardown.
• /start additionally requires the Core address to be a socket owned by the owner UID before spawning, since the Core connects to it as root.
• The Core is spawned with the owner's real UID and an effective UID of 0, which is what a setuid Core would have had. It is the signal core/ownership_unix.go uses to hand the files it created back to the user; without it a root service would leave a root-owned config tree in the owner's home.
• An AppImage has neither a stable executable path nor a writable Core, and its FUSE mount is nosuid, so system.isAppImage reports TUN authorization as unavailable instead of prompting for a password that cannot help.
• A Linux host without systemd (/run/systemd/system absent) has no Helper: system.hasHelperService is false there, readiness is the stat check, and the same elevation sets the setuid bit on the bundled Core as before.

A setuid Core is a root process for whoever gives it an address to dial (argv[1]), so its mode never lets others execute it: macOS runs chown root:admin and chmod 4750 (and refuses an account outside the admin group, which could not run the result), and a Linux host without systemd hands it to the primary group of the user that PKEXEC_UID or SUDO_UID names. System.isPrivilegedStatOutput reads a Core that others can execute as unauthorized, so one that an earlier version marked +sx is re-authorized on the next TUN enable.

In every Flutter build mode /start opens the fixed Core executable beside the Helper without write/delete sharing, validates it against the SHA256 embedded only in the Helper, and keeps that handle open through process creation. /ping only compares the requested coreSha256 with the Helper's embedded value and checks the fixed Core path exists; it never hashes the Core. Protocol version 6 (8 on Windows, where the owner check and the browser-origin check arrived and an older Helper must be reinstalled) uses 32-character lowercase-hex session ownership:

• GET /ping?coreSha256=... returns the current Helper executable path with x-flclash-helper-protocol when the requested SHA matches.
• POST /start rejects unknown JSON fields and validates {address, sessionId} and, on Linux, the socket owner, which leaves a running Core alone. It then releases any previously managed Core before verifying the Core — so every outcome of a request that passed validation, including a rejected one, leaves the Helper owning no Core — and returns {sessionId, pid}.
• POST /stop validates {sessionId} and only stops the matching managed Core. A session mismatch is HTTP 409.
• GET /logs exposes the bounded recent Helper/Core stderr buffer with no-store caching.

/start and /stop take at most 4096 bytes and need a Content-Length (HTTP 413 and 411 otherwise); HelperClient always sends one. All endpoints reject Origin headers and non-local Host values, preventing browser requests and DNS rebinding through an owner-account browser, which would otherwise pass the Windows account check. The accepted authorities are 127.0.0.1, localhost and the Linux Unix-socket placeholder FlClashHelperService. The Helper grants no CORS access.

Endpoints bind only to 127.0.0.1 on Windows and to /run/flclash/helper.sock on Linux, and do not use request-token authentication. The Windows port is picked by the system, because Hyper-V and WinNAT reserve ranges that can cover any fixed one, and published as the Port DWORD of a volatile Runtime key under the service's own registry key, which only administrators can write; HelperClient reads it per request and falls back to 47890, where a Helper from before listens. Who may call them is decided per connection, before any request is read: the Linux socket drops a peer whose SO_PEERCRED UID is not the owner's, and the Windows listener (service/peer.rs) traces the connection through the TCP table to the process holding its client end and drops it unless that process runs as the owner SID the service was registered with. The Windows Core runs as SYSTEM and dials whatever pipe /start names, so without that check any local account would host a SYSTEM Core. What no per-connection check closes is a process that runs as the owner itself, on either platform. Lifecycle safety also comes from the fixed executable/hash, the strict address namespace (\\.\pipe\FlClashCore_<32 hex> on Windows, /tmp/FlClashSocket_<digits>.sock on Linux), the session-scoped stop contract, Dart-side peer-PID verification on Windows and, on Unix, the Core socket that plugins/rust_api sets to mode 0600 so only the owning user (and the root-effective Core) can connect. When the Helper service itself shuts down, it unconditionally stops the Core process it owns; under systemd the unit's control group does the same.