feat(network): support custom relay servers

Add strict custom Iroh relay profiles with safe restart and rollback across the Rust core, Compose apps, and Apple apps. Preserve multi-relay invitations and fail closed on configuration or recovery mismatches.

Cargo.lock

@@ -61,12 +61,56 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anstream"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
 [[package]]
 name = "anstyle"
 version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
 
+[[package]]
+name = "anstyle-parse"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.103"
@@ -518,6 +562,7 @@ version = "4.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f09628afdcc538b57f3c6341e9c8e9970f18e4a481690a64974d7023bd33548b"
 dependencies = [
+ "anstream",
  "anstyle",
  "clap_lex",
  "strsim",
@@ -556,6 +601,12 @@ dependencies = [
  "thiserror 2.0.18",
 ]
 
+[[package]]
+name = "colorchoice"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
+
 [[package]]
 name = "combine"
 version = "4.6.7"
@@ -811,6 +862,20 @@ dependencies = [
  "syn 2.0.118",
 ]
 
+[[package]]
+name = "dashmap"
+version = "6.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6361d5c062261c78a176addb82d4c821ae42bed6089de0e12603cd25de2059c"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+ "hashbrown 0.14.5",
+ "lock_api",
+ "once_cell",
+ "parking_lot_core",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.11.0"
@@ -958,6 +1023,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f1dd6dbb5841937940781866fa1281a1ff7bd3bf827091440879f9994983d5c2"
 dependencies = [
  "block-buffer 0.12.1",
+ "const-oid 0.10.2",
  "crypto-common 0.2.2",
 ]
 
@@ -1474,6 +1540,12 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.14.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+
 [[package]]
 name = "hashbrown"
 version = "0.15.5"
@@ -2118,12 +2190,20 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "291065721ad7c477b972e581bbc528df031dc8eb5e39fe1ff3300ae5dfb157ef"
 dependencies = [
+ "http-body-util",
+ "hyper",
+ "hyper-util",
  "iroh-metrics-derive",
  "itoa",
  "n0-error",
  "portable-atomic",
+ "reqwest",
+ "rustls",
+ "rustls-platform-verifier",
  "ryu",
  "serde",
+ "tokio",
+ "tokio-util",
  "tracing",
 ]
 
@@ -2148,6 +2228,8 @@ dependencies = [
  "blake3",
  "bytes",
  "cfg_aliases",
+ "clap",
+ "dashmap",
  "data-encoding",
  "derive_more",
  "getrandom 0.4.3",
@@ -2168,17 +2250,28 @@ dependencies = [
  "pin-project",
  "postcard",
  "rand 0.10.2",
+ "rcgen",
+ "reloadable-state",
  "reqwest",
  "rustls",
+ "rustls-cert-file-reader",
+ "rustls-cert-reloadable-resolver",
  "rustls-pki-types",
  "serde",
  "serde_bytes",
+ "serde_json",
+ "sha1 0.11.0",
+ "simdutf8",
  "strum",
+ "time",
  "tokio",
  "tokio-rustls",
+ "tokio-rustls-acme",
  "tokio-util",
  "tokio-websockets",
+ "toml 1.1.2+spec-1.1.0",
  "tracing",
+ "tracing-subscriber",
  "url",
  "vergen-gitcl",
  "webpki-roots",
@@ -2264,6 +2357,12 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
 [[package]]
 name = "itoa"
 version = "1.0.18"
@@ -2997,6 +3096,12 @@ dependencies = [
  "portable-atomic",
 ]
 
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
 [[package]]
 name = "opaque-debug"
 version = "0.3.1"
@@ -3539,6 +3644,23 @@ version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6f6ff9a378485b298a5286656da665ba74413d36db0979633275d2e708145d4"
 
+[[package]]
+name = "reloadable-core"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1dc20ac1418988b60072d783c9f68e28a173fb63493c127952f6face3b40c6e0"
+
+[[package]]
+name = "reloadable-state"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3853ef78d45b50f8b989896304a85239539d39b7f866a000e8846b9b72d74ce8"
+dependencies = [
+ "arc-swap",
+ "reloadable-core",
+ "tokio",
+]
+
 [[package]]
 name = "reqwest"
 version = "0.13.4"
@@ -3562,6 +3684,8 @@ dependencies = [
  "rustls",
  "rustls-pki-types",
  "rustls-platform-verifier",
+ "serde",
+ "serde_json",
  "sync_wrapper",
  "tokio",
  "tokio-rustls",
@@ -3668,6 +3792,40 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rustls-cert-file-reader"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8bb47c2a50fdfdaf95b0ac8b12620fc327da1fd4adbb30d0c56d866b005873ff"
+dependencies = [
+ "rustls-cert-read",
+ "rustls-pki-types",
+ "thiserror 2.0.18",
+ "tokio",
+]
+
+[[package]]
+name = "rustls-cert-read"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd46e8c5ae4de3345c4786a83f99ec7aff287209b9e26fa883c473aeb28f19d5"
+dependencies = [
+ "rustls-pki-types",
+]
+
+[[package]]
+name = "rustls-cert-reloadable-resolver"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe1baa8a3a1f05eaa9fc55aed4342867f70e5c170ea3bfed1b38c51a4857c0c8"
+dependencies = [
+ "futures-util",
+ "reloadable-state",
+ "rustls",
+ "rustls-cert-read",
+ "thiserror 2.0.18",
+]
+
 [[package]]
 name = "rustls-native-certs"
 version = "0.8.4"
@@ -3898,6 +4056,15 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "serde_spanned"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6662b5879511e06e8999a8a235d848113e942c9124f211511b16466ee2995f26"
+dependencies = [
+ "serde_core",
+]
+
 [[package]]
 name = "serde_urlencoded"
 version = "0.7.1"
@@ -3931,6 +4098,17 @@ dependencies = [
  "digest 0.10.7",
 ]
 
+[[package]]
+name = "sha1"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aacc4cc499359472b4abe1bf11d0b12e688af9a805fa5e3016f9a386dc2d0214"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.0",
+ "digest 0.11.3",
+]
+
 [[package]]
 name = "sha1_smol"
 version = "1.0.1"
@@ -4234,7 +4412,7 @@ dependencies = [
  "percent-encoding",
  "rand 0.8.6",
  "rsa",
- "sha1",
+ "sha1 0.10.6",
  "sha2 0.10.9",
  "smallvec",
  "sqlx-core",
@@ -4614,6 +4792,34 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "tokio-rustls-acme"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1af8573b15fdad8d66da116198cd8fd8d87ff62a67c1c6c3df7f62da1170793f"
+dependencies = [
+ "async-trait",
+ "base64",
+ "chrono",
+ "futures",
+ "log",
+ "num-bigint",
+ "pem",
+ "proc-macro2",
+ "rcgen",
+ "reqwest",
+ "ring",
+ "rustls",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.18",
+ "time",
+ "tokio",
+ "tokio-rustls",
+ "webpki-roots",
+ "x509-parser",
+]
+
 [[package]]
 name = "tokio-stream"
 version = "0.1.18"
@@ -4672,6 +4878,21 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "toml"
+version = "1.1.2+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81f3d15e84cbcd896376e6730314d59fb5a87f31e4b038454184435cd57defee"
+dependencies = [
+ "indexmap",
+ "serde_core",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_parser",
+ "toml_writer",
+ "winnow 1.0.3",
+]
+
 [[package]]
 name = "toml_datetime"
 version = "1.1.1+spec-1.1.0"
@@ -4702,6 +4923,12 @@ dependencies = [
  "winnow 1.0.3",
 ]
 
+[[package]]
+name = "toml_writer"
+version = "1.1.1+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "756daf9b1013ebe47a8776667b466417e2d4c5679d441c26230efd9ef78692db"
+
 [[package]]
 name = "tower"
 version = "0.5.3"
@@ -4915,7 +5142,7 @@ dependencies = [
  "serde",
  "tempfile",
  "textwrap",
- "toml",
+ "toml 0.5.11",
  "uniffi_internal_macros",
  "uniffi_meta",
  "uniffi_pipeline",
@@ -4961,7 +5188,7 @@ dependencies = [
  "quote",
  "serde",
  "syn 2.0.118",
- "toml",
+ "toml 0.5.11",
  "uniffi_meta",
 ]
 
@@ -5037,6 +5264,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
 [[package]]
 name = "uuid"
 version = "1.23.4"
@@ -5117,6 +5350,7 @@ dependencies = [
  "futures-lite",
  "iroh",
  "iroh-blobs",
+ "iroh-relay",
  "irpc",
  "irpc-iroh",
  "libc",

README.md

@@ -50,6 +50,31 @@ mobile networks. If a direct path cannot be established, it can forward the
 same end-to-end encrypted connection through a relay. The relay forwards
 encrypted packets; it is not a VniDrop file store.
 
+### Custom relay servers
+
+VniDrop uses Iroh's public relay and discovery infrastructure by default. In
+**Settings → Network**, advanced users can instead configure up to eight custom
+HTTPS servers that implement Iroh's relay protocol. Custom mode is strict: the
+app uses only those relays and does not silently fall back to public relays or
+public discovery. Direct peer-to-peer paths remain available.
+
+Applying a relay change restarts VniDrop's network engine, so active transfers
+and shares must be stopped first. The app tests the new configuration and
+restores the previous one if it cannot connect. Invitations created for an old
+relay configuration may need to be shared again; stopped shares never expose
+their stale invitations. If a long relay profile makes an invitation too large
+for a QR code, use the native share action or export the invitation file.
+
+Relay credentials embedded in URLs are deliberately rejected and bearer-token
+authentication is not currently supported. A self-hosted relay must either
+accept the connecting endpoints or authorize their endpoint IDs independently;
+the current device ID is shown in **Settings → Network** for this purpose.
+Configure the same relay profile on participating devices. A custom relay needs
+a TLS certificate issued by a publicly trusted WebPKI certificate authority;
+private or enterprise CAs installed only in the operating system are not used
+in this version. For resilient deployments, configure at least two relays in
+different failure domains.
+
 ## Why Iroh and `iroh-blobs`?
 
 VniDrop combines a networking layer with its own sharing rules:
@@ -90,6 +115,7 @@ people, especially when using **Anyone with this transfer**.
 - Safe receive destinations that do not silently overwrite existing files
 - Native SwiftUI apps on iOS, iPadOS, and macOS; Compose apps on Android,
   Windows, and Linux
+- Strict custom HTTPS relay profiles with safe apply and rollback
 - Opt-in diagnostics with transfer contents, invitations, and file paths
   excluded
 

apple/Tests/AppModelTests.swift

@@ -20,6 +20,18 @@ final class AppModelTests: XCTestCase {
 		_ = makeModel(core, preferences: Fixtures.preferences())
 		await waitUntil { core.state.isInitialized }
 		XCTAssertTrue(core.state.isInitialized)
+		XCTAssertEqual(core.initializedNetworkConfigurations, [.automatic])
+	}
+
+	func testInitializesCoreWithSavedCustomRelayConfiguration() async {
+		let core = FakeCoreGateway()
+		let preferences = Fixtures.preferences()
+		let configuration = RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		preferences.setRelayConfiguration(configuration)
+		_ = makeModel(core, preferences: preferences)
+
+		await waitUntil { core.state.isInitialized }
+		XCTAssertEqual(core.initializedNetworkConfigurations, [configuration])
 	}
 
 	func testSelectDestination() {

apple/Tests/AppPreferencesRepositoryTests.swift

@@ -15,11 +15,12 @@ final class AppPreferencesRepositoryTests: XCTestCase {
 		)
 	}
 
-	func testFallbacksWhenEmpty() {
+	func testMissingRelayProfileDefaultsToAutomatic() {
 		let repo = AppPreferencesRepository(defaults: defaults(), fallback: fallback())
 		XCTAssertEqual(repo.preferences.username, "Default")
 		XCTAssertEqual(repo.preferences.themeMode, .system)
 		XCTAssertFalse(repo.preferences.notificationsEnabled)
+		XCTAssertEqual(repo.preferences.relayConfiguration, .automatic)
 	}
 
 	func testValuesPersistAndReload() {
@@ -30,6 +31,10 @@ final class AppPreferencesRepositoryTests: XCTestCase {
 		repo.setThemeMode(.dark)
 		repo.setNotificationsEnabled(true)
 		repo.setReceiveFolder(ReceiveFolder(kind: .iosSecurityScopedUrl, value: "file:///x", displayName: "Custom"))
+		repo.setRelayConfiguration(RelayConfiguration(
+			mode: .custom,
+			relayURLs: ["https://relay-one.example", "https://relay-two.example:443"]
+		))
 
 		// A fresh repository over the same store reflects the persisted values.
 		let reloaded = AppPreferencesRepository(defaults: store, fallback: fb)
@@ -38,6 +43,40 @@ final class AppPreferencesRepositoryTests: XCTestCase {
 		XCTAssertTrue(reloaded.preferences.notificationsEnabled)
 		XCTAssertEqual(reloaded.preferences.receiveFolder.displayName, "Custom")
 		XCTAssertEqual(reloaded.preferences.receiveFolder.kind, .iosSecurityScopedUrl)
+		XCTAssertEqual(reloaded.preferences.relayConfiguration, RelayConfiguration(
+			mode: .custom,
+			relayURLs: ["https://relay-one.example", "https://relay-two.example:443"]
+		))
+		XCTAssertNotNil(store.data(forKey: "relay_configuration"))
+		XCTAssertNil(store.object(forKey: "relay_mode"))
+		XCTAssertNil(store.object(forKey: "relay_urls"))
+	}
+
+	func testCorruptedRelayProfileFailsClosed() {
+		let store = defaults()
+		store.set(Data("{".utf8), forKey: "relay_configuration")
+
+		let repo = AppPreferencesRepository(defaults: store, fallback: fallback())
+
+		XCTAssertEqual(
+			repo.preferences.relayConfiguration,
+			RelayConfiguration(mode: .custom, relayURLs: [])
+		)
+	}
+
+	func testUnknownRelayModeFailsClosed() {
+		let store = defaults()
+		store.set(
+			Data(#"{"mode":"future-mode","relayURLs":["https://relay.example"]}"#.utf8),
+			forKey: "relay_configuration"
+		)
+
+		let repo = AppPreferencesRepository(defaults: store, fallback: fallback())
+
+		XCTAssertEqual(
+			repo.preferences.relayConfiguration,
+			RelayConfiguration(mode: .custom, relayURLs: [])
+		)
 	}
 
 	func testResetReceiveFolderRestoresFallback() {

apple/Tests/CoreRepositoryLifecycleTests.swift

@@ -0,0 +1,131 @@
+import Foundation
+import XCTest
+@preconcurrency import VnidropCore
+@testable import VniDrop
+
+private enum BlockingCoreFactoryError: Error {
+	case stopped
+}
+
+private final class BlockingCoreBindingFactory: CoreBindingFactory, @unchecked Sendable {
+	private let release = DispatchSemaphore(value: 0)
+	private let lock = NSLock()
+	private var initializeCallCount = 0
+	private var initializationStarted = false
+	private var startWaiters: [CheckedContinuation<Void, Never>] = []
+
+	var callCount: Int {
+		lock.lock()
+		defer { lock.unlock() }
+		return initializeCallCount
+	}
+
+	func initialize(
+		appDataDir: String,
+		eventSink: CoreEventSink,
+		networkConfiguration: RelayConfiguration
+	) throws -> VnidropCore {
+		lock.lock()
+		initializeCallCount += 1
+		let call = initializeCallCount
+		initializationStarted = true
+		let waiters = startWaiters
+		startWaiters.removeAll()
+		lock.unlock()
+		waiters.forEach { $0.resume() }
+
+		if call == 1 {
+			release.wait()
+		}
+		throw BlockingCoreFactoryError.stopped
+	}
+
+	func waitUntilInitializationStarts() async {
+		await withCheckedContinuation { continuation in
+			lock.lock()
+			if initializationStarted {
+				lock.unlock()
+				continuation.resume()
+			} else {
+				startWaiters.append(continuation)
+				lock.unlock()
+			}
+		}
+	}
+
+	func unblockInitialization() {
+		release.signal()
+	}
+}
+
+@MainActor
+final class CoreRepositoryLifecycleTests: XCTestCase {
+	func testIdleRequirementRejectsTransfersAndShares() throws {
+		XCTAssertNoThrow(try CoreNetworkLifecycle.requireIdle(activeTransfers: 0, activeShares: 0))
+		XCTAssertThrowsError(
+			try CoreNetworkLifecycle.requireIdle(activeTransfers: 1, activeShares: 0)
+		) { error in
+			XCTAssertEqual(error as? CoreNetworkLifecycleError, .activeNetworkWork)
+		}
+		XCTAssertThrowsError(
+			try CoreNetworkLifecycle.requireIdle(activeTransfers: 0, activeShares: 1)
+		) { error in
+			XCTAssertEqual(error as? CoreNetworkLifecycleError, .activeNetworkWork)
+		}
+	}
+
+	func testRestartSerializesInitializationAndRejectsNewNetworkWork() async {
+		let factory = BlockingCoreBindingFactory()
+		let repository = CoreRepository(coreFactory: factory)
+		let firstInitialization = Task {
+			await repository.initialize(appDataDir: "/tmp/first", networkConfiguration: .automatic)
+		}
+		await factory.waitUntilInitializationStarts()
+
+		let safetyRelease = Task.detached {
+			try? await Task.sleep(nanoseconds: 1_000_000_000)
+			guard !Task.isCancelled else { return }
+			factory.unblockInitialization()
+		}
+		defer {
+			safetyRelease.cancel()
+			factory.unblockInitialization()
+		}
+
+		let concurrentInitialization = await repository.initialize(
+			appDataDir: "/tmp/second",
+			networkConfiguration: RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		)
+		assertLifecycleFailure(concurrentInitialization, equals: .transitionInProgress)
+
+		let share = await repository.shareSources(
+			[],
+			transferName: "Blocked",
+			senderName: "Tester",
+			accessPolicy: .requireApproval
+		)
+		assertLifecycleFailure(share, equals: .transitionInProgress)
+
+		let receive = await repository.receive(ticket: "ticket", outputDir: "/tmp", receiverName: "Tester")
+		assertLifecycleFailure(receive, equals: .transitionInProgress)
+		XCTAssertEqual(factory.callCount, 1)
+
+		factory.unblockInitialization()
+		guard case .failure(let error) = await firstInitialization.value else {
+			return XCTFail("The blocking factory should fail the first initialization")
+		}
+		XCTAssertTrue(error is BlockingCoreFactoryError)
+	}
+
+	private func assertLifecycleFailure<T>(
+		_ result: Result<T, Error>,
+		equals expected: CoreNetworkLifecycleError,
+		file: StaticString = #filePath,
+		line: UInt = #line
+	) {
+		guard case .failure(let error) = result else {
+			return XCTFail("Expected lifecycle failure \(expected)", file: file, line: line)
+		}
+		XCTAssertEqual(error as? CoreNetworkLifecycleError, expected, file: file, line: line)
+	}
+}

apple/Tests/Fakes.swift

@@ -25,6 +25,8 @@ final class FakeCoreGateway: CoreGateway {
 	var cancelResult: Result<Void, Error> = .success(())
 	var deleteResult: Result<Void, Error> = .success(())
 	var clearReceiveHistoryResult: Result<UInt64, Error> = .success(0)
+	var initializeResult: Result<Void, Error> = .success(())
+	var initializeResults: [Result<Void, Error>] = []
 
 	// Recorded calls
 	private(set) var responses: [(id: String, accepted: Bool, reason: String?)] = []
@@ -35,11 +37,18 @@ final class FakeCoreGateway: CoreGateway {
 	private(set) var lastReceiveTicket: String?
 	private(set) var lastReceiveReceiverName: String?
 	private(set) var lastShareAccessPolicy: ShareAccessPolicy?
+	private(set) var initializedNetworkConfigurations: [RelayConfiguration] = []
 
 	func setState(_ state: CoreState) { stateSubject.send(state) }
 	func emit(_ signal: CoreSignal) { signalsSubject.send(signal) }
 
-	func initialize(appDataDir: String) async -> Result<Void, Error> {
+	func initialize(
+		appDataDir: String,
+		networkConfiguration: RelayConfiguration
+	) async -> Result<Void, Error> {
+		initializedNetworkConfigurations.append(networkConfiguration)
+		let result = initializeResults.isEmpty ? initializeResult : initializeResults.removeFirst()
+		guard case .success = result else { return result }
 		var s = stateSubject.value
 		s.isInitialized = true
 		stateSubject.send(s)

apple/Tests/RelayConfigurationTests.swift

@@ -0,0 +1,95 @@
+import XCTest
+@testable import VniDrop
+
+final class RelayConfigurationTests: XCTestCase {
+	func testAutomaticModeIgnoresRelayDrafts() throws {
+		let result = try RelayConfigurationValidator.validate(
+			mode: .automatic,
+			relayURLs: ["not a URL"]
+		)
+		XCTAssertEqual(result, .automatic)
+	}
+
+	func testAutomaticModeRetainsPreviouslySavedRelayURLs() throws {
+		let result = try RelayConfigurationValidator.validate(
+			mode: .automatic,
+			relayURLs: ["not a URL"],
+			retainedRelayURLs: ["https://relay.example"]
+		)
+		XCTAssertEqual(result, RelayConfiguration(
+			mode: .automatic,
+			relayURLs: ["https://relay.example"]
+		))
+	}
+
+	func testCustomModeTrimsValidHTTPSRelayURLs() throws {
+		let result = try RelayConfigurationValidator.validate(
+			mode: .custom,
+			relayURLs: ["  https://relay.example/  ", "https://backup.example:443"]
+		)
+		XCTAssertEqual(result, RelayConfiguration(
+			mode: .custom,
+			relayURLs: ["https://relay.example", "https://backup.example"]
+		))
+	}
+
+	func testCustomModeIgnoresEmptyURLRows() throws {
+		let result = try RelayConfigurationValidator.validate(
+			mode: .custom,
+			relayURLs: ["", "  ", "https://relay.example"]
+		)
+		XCTAssertEqual(result.relayURLs, ["https://relay.example"])
+	}
+
+	func testCustomModeRequiresAtLeastOneRelay() {
+		XCTAssertThrowsError(try RelayConfigurationValidator.validate(mode: .custom, relayURLs: [])) { error in
+			XCTAssertEqual(error as? RelayConfigurationValidationError, .missingURL)
+		}
+	}
+
+	func testCustomModeRequiresHTTPS() {
+		XCTAssertThrowsError(try RelayConfigurationValidator.validate(
+			mode: .custom,
+			relayURLs: ["http://relay.example"]
+		)) { error in
+			XCTAssertEqual(error as? RelayConfigurationValidationError, .httpsRequired(index: 0))
+		}
+	}
+
+	func testCustomModeRejectsCredentialsQueryFragmentAndPath() {
+		let invalidURLs = [
+			"https://user:password@relay.example",
+			"https://relay.example?token=secret",
+			"https://relay.example#fragment",
+			"https://relay.example/custom/path",
+			"https://relay.example:0",
+			"https://relay.example:99999",
+		]
+		for relayURL in invalidURLs {
+			XCTAssertThrowsError(
+				try RelayConfigurationValidator.validate(mode: .custom, relayURLs: [relayURL]),
+				"Expected \(relayURL) to be rejected"
+			) { error in
+				XCTAssertEqual(error as? RelayConfigurationValidationError, .invalidURL(index: 0))
+			}
+		}
+	}
+
+	func testCustomModeRejectsNormalizedDuplicate() {
+		XCTAssertThrowsError(try RelayConfigurationValidator.validate(
+			mode: .custom,
+			relayURLs: ["https://relay.example", "https://RELAY.example:443/"]
+		)) { error in
+			XCTAssertEqual(error as? RelayConfigurationValidationError, .duplicateURL(index: 1))
+		}
+	}
+
+	func testCustomModeRejectsMoreThanEightRelays() {
+		let relayURLs = (0...RelayConfigurationValidator.maximumRelayCount).map {
+			"https://relay-\($0).example"
+		}
+		XCTAssertThrowsError(try RelayConfigurationValidator.validate(mode: .custom, relayURLs: relayURLs)) { error in
+			XCTAssertEqual(error as? RelayConfigurationValidationError, .tooManyURLs)
+		}
+	}
+}

apple/Tests/SendModelTests.swift

@@ -55,4 +55,25 @@ final class SendModelTests: XCTestCase {
 		let response = core.responses.first { $0.id == "req-1" }
 		XCTAssertEqual(response?.accepted, false)
 	}
+
+	func testOnlyActiveShareExposesStoredInvitationTicket() {
+		XCTAssertEqual(
+			Fixtures.transfer(id: 1, direction: .send, status: .sharing).invitationPresentation,
+			.ready("ticket")
+		)
+		XCTAssertEqual(
+			Fixtures.transfer(id: 2, direction: .send, status: .importing).invitationPresentation,
+			.preparing
+		)
+		for status in [TransferStatus.stopped, .failed, .cancelled, .done] {
+			XCTAssertEqual(
+				Fixtures.transfer(id: 3, direction: .send, status: status).invitationPresentation,
+				.unavailable
+			)
+		}
+	}
+
+	func testOversizedInvitationReportsQRCodeUnavailable() {
+		XCTAssertNil(QRCode.generate(from: String(repeating: "x", count: 10_000)))
+	}
 }

apple/Tests/SettingsModelTests.swift

@@ -42,4 +42,107 @@ final class SettingsModelTests: XCTestCase {
 		await waitUntil { core.deletedTransfers.count == 2 }
 		XCTAssertEqual(Set(core.deletedTransfers), [2, 3])
 	}
+
+	func testNetworkSettingsExposeCurrentEndpointId() {
+		let core = FakeCoreGateway()
+		let model = makeModel(core, preferences: Fixtures.preferences())
+
+		core.setState(CoreState(
+			isInitialized: true,
+			status: CoreStatus(endpointId: "endpoint-for-allowlist", activeTransfers: 0, activeShares: 0)
+		))
+
+		XCTAssertEqual(model.state.endpointId, "endpoint-for-allowlist")
+	}
+
+	func testApplyCustomRelayRestartsCoreThenPersistsConfiguration() async {
+		let core = FakeCoreGateway()
+		let preferences = Fixtures.preferences()
+		let model = makeModel(core, preferences: preferences)
+		model.setRelayMode(.custom)
+		model.setRelayURL("  https://relay.example/  ", at: 0)
+
+		model.applyRelayConfiguration()
+
+		await waitUntil { preferences.preferences.relayConfiguration.mode == .custom }
+		let expected = RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		XCTAssertEqual(preferences.preferences.relayConfiguration, expected)
+		XCTAssertEqual(core.initializedNetworkConfigurations, [expected])
+		XCTAssertFalse(model.state.relayConfigurationIsDirty)
+	}
+
+	func testApplyingAutomaticRetainsLastCustomRelayURLs() async {
+		let core = FakeCoreGateway()
+		let preferences = Fixtures.preferences()
+		let relayURLs = ["https://relay.example", "https://backup.example"]
+		preferences.setRelayConfiguration(RelayConfiguration(mode: .custom, relayURLs: relayURLs))
+		let model = makeModel(core, preferences: preferences)
+
+		model.setRelayMode(.automatic)
+		model.applyRelayConfiguration()
+
+		await waitUntil { preferences.preferences.relayConfiguration.mode == .automatic }
+		XCTAssertEqual(preferences.preferences.relayConfiguration.relayURLs, relayURLs)
+		XCTAssertEqual(core.initializedNetworkConfigurations, [
+			RelayConfiguration(mode: .automatic, relayURLs: relayURLs),
+		])
+		model.setRelayMode(.custom)
+		XCTAssertEqual(model.state.relayURLs, relayURLs)
+	}
+
+	func testApplyRelayIsBlockedWhileShareIsActive() async {
+		let core = FakeCoreGateway()
+		let preferences = Fixtures.preferences()
+		let model = makeModel(core, preferences: preferences)
+		core.setState(CoreState(
+			isInitialized: true,
+			status: CoreStatus(endpointId: "endpoint", activeTransfers: 0, activeShares: 1)
+		))
+		model.setRelayMode(.custom)
+		model.setRelayURL("https://relay.example", at: 0)
+
+		model.applyRelayConfiguration()
+		await Task.yield()
+
+		XCTAssertTrue(core.initializedNetworkConfigurations.isEmpty)
+		XCTAssertEqual(preferences.preferences.relayConfiguration, .automatic)
+		XCTAssertEqual(model.state.relayApplyErrorKey, "relay_apply_active_transfers")
+	}
+
+	func testRepositoryActiveWorkRejectionDoesNotAttemptRollback() async {
+		let core = FakeCoreGateway()
+		core.initializeResult = .failure(CoreNetworkLifecycleError.activeNetworkWork)
+		let preferences = Fixtures.preferences()
+		let model = makeModel(core, preferences: preferences)
+		let attempted = RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		model.setRelayMode(.custom)
+		model.setRelayURL(attempted.relayURLs[0], at: 0)
+
+		model.applyRelayConfiguration()
+		await waitUntil {
+			core.initializedNetworkConfigurations.count == 1 && !model.state.isApplyingRelayConfiguration
+		}
+
+		XCTAssertEqual(core.initializedNetworkConfigurations, [attempted])
+		XCTAssertEqual(preferences.preferences.relayConfiguration, .automatic)
+		XCTAssertTrue(model.state.hasActiveNetworkWork)
+		XCTAssertEqual(model.state.relayApplyErrorKey, "relay_apply_active_transfers")
+	}
+
+	func testFailedRelayApplyRollsBackWithoutPersisting() async {
+		let core = FakeCoreGateway()
+		core.initializeResults = [.failure(TestError.unimplemented), .success(())]
+		let preferences = Fixtures.preferences()
+		let model = makeModel(core, preferences: preferences)
+		let attempted = RelayConfiguration(mode: .custom, relayURLs: ["https://relay.example"])
+		model.setRelayMode(.custom)
+		model.setRelayURL(attempted.relayURLs[0], at: 0)
+
+		model.applyRelayConfiguration()
+		await waitUntil { core.initializedNetworkConfigurations.count == 2 }
+
+		XCTAssertEqual(core.initializedNetworkConfigurations, [attempted, .automatic])
+		XCTAssertEqual(preferences.preferences.relayConfiguration, .automatic)
+		XCTAssertEqual(model.state.relayApplyErrorKey, "relay_apply_failed")
+	}
 }

apple/VniDrop/Core/AppPreferences.swift

@@ -19,6 +19,95 @@ enum FolderAccessStatus {
 	case unavailable
 }
 
+enum RelayPreferenceMode: String, Codable, CaseIterable, Sendable {
+	case automatic
+	case custom
+}
+
+struct RelayConfiguration: Equatable, Codable, Sendable {
+	var mode: RelayPreferenceMode
+	var relayURLs: [String]
+
+	static let automatic = RelayConfiguration(mode: .automatic, relayURLs: [])
+}
+
+enum RelayConfigurationValidationError: Error, Equatable, Sendable {
+	case missingURL
+	case tooManyURLs
+	case httpsRequired(index: Int)
+	case invalidURL(index: Int)
+	case duplicateURL(index: Int)
+
+	var urlIndex: Int? {
+		switch self {
+		case .httpsRequired(let index), .invalidURL(let index), .duplicateURL(let index): return index
+		case .missingURL, .tooManyURLs: return nil
+		}
+	}
+}
+
+enum RelayConfigurationValidator {
+	static let maximumRelayCount = 8
+	static let maximumRelayURLBytes = 2_048
+
+	static func validate(
+		mode: RelayPreferenceMode,
+		relayURLs: [String],
+		retainedRelayURLs: [String] = []
+	) throws -> RelayConfiguration {
+		guard mode == .custom else {
+			return RelayConfiguration(mode: .automatic, relayURLs: retainedRelayURLs)
+		}
+
+		let relayEntries = relayURLs.enumerated().compactMap { index, value -> (Int, String)? in
+			let trimmed = value.trimmingCharacters(in: .whitespacesAndNewlines)
+			return trimmed.isEmpty ? nil : (index, trimmed)
+		}
+		guard !relayEntries.isEmpty else {
+			throw RelayConfigurationValidationError.missingURL
+		}
+		guard relayEntries.count <= maximumRelayCount else {
+			throw RelayConfigurationValidationError.tooManyURLs
+		}
+
+		var seen = Set<String>()
+		var normalizedURLs: [String] = []
+		for (index, relayURL) in relayEntries {
+			guard relayURL.lengthOfBytes(using: .utf8) <= maximumRelayURLBytes,
+				relayURL.rangeOfCharacter(from: .whitespacesAndNewlines.union(.controlCharacters)) == nil,
+				var components = URLComponents(string: relayURL) else {
+				throw RelayConfigurationValidationError.invalidURL(index: index)
+			}
+			guard components.scheme?.lowercased() == "https" else {
+				throw RelayConfigurationValidationError.httpsRequired(index: index)
+			}
+			guard
+				let host = components.host,
+				!host.isEmpty,
+				components.port.map({ (1...65_535).contains($0) }) ?? true,
+				components.user == nil,
+				components.password == nil,
+				components.query == nil,
+				components.fragment == nil,
+				components.path.isEmpty || components.path == "/"
+			else {
+				throw RelayConfigurationValidationError.invalidURL(index: index)
+			}
+
+			components.scheme = "https"
+			components.host = host.lowercased()
+			if components.port == 443 { components.port = nil }
+			if components.path == "/" { components.path = "" }
+			guard let canonicalURL = components.string, seen.insert(canonicalURL).inserted else {
+				throw RelayConfigurationValidationError.duplicateURL(index: index)
+			}
+			normalizedURLs.append(canonicalURL)
+		}
+
+		return RelayConfiguration(mode: .custom, relayURLs: normalizedURLs)
+	}
+}
+
 /// Persisted app preferences, ported from `preferences/AppPreferencesRepository.kt`.
 /// Backed by `UserDefaults` instead of DataStore; keys and semantics match.
 struct AppPreferences: Equatable {
@@ -28,6 +117,7 @@ struct AppPreferences: Equatable {
 	var notificationsEnabled: Bool
 	var diagnosticsEnabled: Bool
 	var diagnosticsInstallId: String
+	var relayConfiguration: RelayConfiguration
 }
 
 struct AppPreferencesDefaults {
@@ -54,6 +144,7 @@ final class AppPreferencesRepository: ObservableObject {
 		static let notificationsEnabled = "notifications_enabled"
 		static let diagnosticsEnabled = "diagnostics_enabled"
 		static let diagnosticsInstallId = "diagnostics_install_id"
+		static let relayConfiguration = "relay_configuration"
 	}
 
 	init(defaults: UserDefaults = .standard, fallback: AppPreferencesDefaults) {
@@ -75,10 +166,25 @@ final class AppPreferencesRepository: ObservableObject {
 			themeMode: themeMode,
 			notificationsEnabled: notifications,
 			diagnosticsEnabled: diagnostics,
-			diagnosticsInstallId: installId
+			diagnosticsInstallId: installId,
+			relayConfiguration: resolveRelayConfiguration(defaults)
 		)
 	}
 
+	private static func resolveRelayConfiguration(_ defaults: UserDefaults) -> RelayConfiguration {
+		guard defaults.object(forKey: Key.relayConfiguration) != nil else { return .automatic }
+		guard
+			let data = defaults.data(forKey: Key.relayConfiguration),
+			let configuration = try? JSONDecoder().decode(RelayConfiguration.self, from: data)
+		else {
+			// A stored profile must never silently fall back to public relays. Keeping
+			// Custom selected with no URLs makes startup fail closed and lets Settings
+			// offer an explicit repair or reset to Automatic.
+			return RelayConfiguration(mode: .custom, relayURLs: [])
+		}
+		return configuration
+	}
+
 	private static func resolveReceiveFolder(_ defaults: UserDefaults, fallback: ReceiveFolder) -> ReceiveFolder {
 		let kind = defaults.string(forKey: Key.receiveFolderKind)
 			.flatMap(ReceiveFolderKind.init(rawValue:)) ?? fallback.kind
@@ -123,6 +229,12 @@ final class AppPreferencesRepository: ObservableObject {
 		reload()
 	}
 
+	func setRelayConfiguration(_ configuration: RelayConfiguration) {
+		guard let encoded = try? JSONEncoder().encode(configuration) else { return }
+		defaults.set(encoded, forKey: Key.relayConfiguration)
+		reload()
+	}
+
 	@discardableResult
 	func ensureDiagnosticsInstallId() -> String {
 		let existing = preferences.diagnosticsInstallId

apple/VniDrop/Core/CoreGateway.swift

@@ -24,7 +24,7 @@ protocol CoreGateway: AnyObject {
 	/// Coalesced change hints emitted by the event sink.
 	var signals: AnyPublisher<CoreSignal, Never> { get }
 
-	func initialize(appDataDir: String) async -> Result<Void, Error>
+	func initialize(appDataDir: String, networkConfiguration: RelayConfiguration) async -> Result<Void, Error>
 	func shutdown()
 	func shareSources(
 		_ sources: [ShareSource],

apple/VniDrop/Core/CoreRepository.swift

@@ -2,6 +2,58 @@ import Foundation
 import Combine
 @preconcurrency import VnidropCore
 
+enum CoreNetworkLifecycleError: Error, Equatable, LocalizedError, Sendable {
+	case transitionInProgress
+	case activeNetworkWork
+
+	var errorDescription: String? {
+		switch self {
+		case .transitionInProgress: return "A network restart is already in progress."
+		case .activeNetworkWork: return "Stop active transfers and shares before restarting the network."
+		}
+	}
+}
+
+enum CoreNetworkLifecycle {
+	nonisolated static func requireIdle(activeTransfers: UInt64, activeShares: UInt64) throws {
+		guard activeTransfers == 0, activeShares == 0 else {
+			throw CoreNetworkLifecycleError.activeNetworkWork
+		}
+	}
+}
+
+protocol CoreBindingFactory: Sendable {
+	func initialize(
+		appDataDir: String,
+		eventSink: CoreEventSink,
+		networkConfiguration: RelayConfiguration
+	) throws -> VnidropCore
+}
+
+struct NativeCoreBindingFactory: CoreBindingFactory {
+	func initialize(
+		appDataDir: String,
+		eventSink: CoreEventSink,
+		networkConfiguration: RelayConfiguration
+	) throws -> VnidropCore {
+		let nativeConfiguration: CoreNetworkConfig
+		switch networkConfiguration.mode {
+		case .automatic:
+			nativeConfiguration = defaultCoreNetworkConfig()
+		case .custom:
+			nativeConfiguration = CoreNetworkConfig(
+				mode: .custom,
+				relayUrls: networkConfiguration.relayURLs
+			)
+		}
+		return try VnidropCore.initializeWithNetworkConfig(
+			appDataDir: appDataDir,
+			eventSink: eventSink,
+			networkConfig: nativeConfiguration
+		)
+	}
+}
+
 /// Swift port of `core/CoreRepository.kt`. Owns the `VnidropCore` handle, maps the
 /// generated UniFFI records into app domain models, publishes an observable
 /// `CoreState`, and emits coalesced `CoreSignal`s from the event sink.
@@ -17,28 +69,63 @@ final class CoreRepository: ObservableObject, CoreGateway {
 	/// Coalesced change hints; subscribe to react to approval/history/transfer changes.
 	var signals: AnyPublisher<CoreSignal, Never> { signalsSubject.eraseToAnyPublisher() }
 
-	// Set on the main actor (initialize/shutdown) but read from `queue` inside
+	// Initialization swaps happen on `queue`; shutdown and snapshot reads may also
-	// `runCore`; the underlying core is internally synchronized, so this crossing
+	// access the handle from the main actor. The underlying core is internally
-	// is safe. `nonisolated(unsafe)` documents that contract for Swift 6.
+	// synchronized, and `nonisolated(unsafe)` documents that crossing for Swift 6.
 	private nonisolated(unsafe) var core: VnidropCore?
 	private let queue = DispatchQueue(label: "com.vnidrop.core", qos: .userInitiated)
+	private let coreFactory: any CoreBindingFactory
+	private var isNetworkTransitionInProgress = false
 	private lazy var sink = RepositoryEventSink { [weak self] event in
 		Task { @MainActor in self?.handle(event: event) }
 	}
 
 	private nonisolated static let maxEvents = 200
 
+	init(coreFactory: any CoreBindingFactory = NativeCoreBindingFactory()) {
+		self.coreFactory = coreFactory
+	}
+
 	// MARK: - Lifecycle
 
-	func initialize(appDataDir: String) async -> Result<Void, Error> {
+	func initialize(
-		await runCore { [sink] in
+		appDataDir: String,
-			self.core?.shutdown()
+		networkConfiguration: RelayConfiguration
-			let created = try VnidropCore.initialize(appDataDir: appDataDir, eventSink: sink)
+	) async -> Result<Void, Error> {
-			return created
+		guard !isNetworkTransitionInProgress else {
-		}.map { created in
+			return .failure(CoreNetworkLifecycleError.transitionInProgress)
+		}
+		isNetworkTransitionInProgress = true
+		defer { isNetworkTransitionInProgress = false }
+
+		let result = await runCore { [sink] in
+			if let existing = self.core {
+				let status = existing.status()
+				try CoreNetworkLifecycle.requireIdle(
+					activeTransfers: status.activeTransfers,
+					activeShares: status.activeShares
+				)
+				existing.shutdown()
+				self.core = nil
+			}
+			let created = try self.coreFactory.initialize(
+				appDataDir: appDataDir,
+				eventSink: sink,
+				networkConfiguration: networkConfiguration
+			)
 			self.core = created
+			return created
+		}
+		switch result {
+		case .success:
 			self.refreshSnapshot()
 			self.state.isInitialized = true
+			return .success(())
+		case .failure(let error):
+			if error as? CoreNetworkLifecycleError != .activeNetworkWork {
+				self.state = CoreState()
+			}
+			return .failure(error)
 		}
 	}
 
@@ -56,6 +143,9 @@ final class CoreRepository: ObservableObject, CoreGateway {
 		senderName: String,
 		accessPolicy: ShareAccessPolicy
 	) async -> Result<Share, Error> {
+		guard !isNetworkTransitionInProgress else {
+			return .failure(CoreNetworkLifecycleError.transitionInProgress)
+		}
 		guard !sources.isEmpty else {
 			return .failure(InvitationError.message("Select at least one file to share"))
 		}
@@ -89,7 +179,10 @@ final class CoreRepository: ObservableObject, CoreGateway {
 	}
 
 	func receive(ticket: String, outputDir: String, receiverName: String) async -> Result<Void, Error> {
-		await runCore {
+		guard !isNetworkTransitionInProgress else {
+			return .failure(CoreNetworkLifecycleError.transitionInProgress)
+		}
+		return await runCore {
 			try self.requireCore().receive(
 				ticket: ticket,
 				outputDir: outputDir,
@@ -105,7 +198,10 @@ final class CoreRepository: ObservableObject, CoreGateway {
 		outputDirectoryUrl: String,
 		receiverName: String
 	) async -> Result<Void, Error> {
-		await runCore {
+		guard !isNetworkTransitionInProgress else {
+			return .failure(CoreNetworkLifecycleError.transitionInProgress)
+		}
+		return await runCore {
 			try withSecurityScopedAccess(pathOrUrl: outputDirectoryUrl) {
 				try self.requireCore().receive(
 					ticket: ticket,

apple/VniDrop/Features/App/AppModel.swift

@@ -26,7 +26,10 @@ final class AppModel: ObservableObject {
 		AppLogger.info("lifecycle", "app started", ["platform": environment.name])
 
 		Task {
-			let result = await repository.initialize(appDataDir: environment.defaultCoreDataDir)
+			let result = await repository.initialize(
+				appDataDir: environment.defaultCoreDataDir,
+				networkConfiguration: preferences.preferences.relayConfiguration
+			)
 			if case .failure(let error) = result { messages.error(error) }
 		}
 

apple/VniDrop/Features/Send/TransferDetailsView.swift

@@ -43,12 +43,14 @@ struct TransferDetailsView: View {
 					count: pendingReceivers + completedReceivers,
 					onTap: model.openReceivers
 				)
-				DetailDestination(
+				if transfer.invitationPresentation != .unavailable {
-					title: String(localized: "transfer_share_title"),
+					DetailDestination(
-					description: String(localized: "transfer_share_description"),
+						title: String(localized: "transfer_share_title"),
-					count: 0,
+						description: String(localized: "transfer_share_description"),
-					onTap: model.openShare
+						count: 0,
-				)
+						onTap: model.openShare
+					)
+				}
 			}
 
 			if isActiveShare {
@@ -276,24 +278,41 @@ struct TransferSharePanel: View {
 
 	var body: some View {
 		PanelContainer(title: String(localized: "transfer_share_title")) {
-			if let ticket = transfer.ticket {
+			switch transfer.invitationPresentation {
-				qrCard(ticket: ticket)
+			case .ready(let ticket):
-				Text(LocalizedStringKey("transfer_scan_qr"))
+				let qrImage = QRCode.generate(from: ticket)
-					.font(VniType.bodySmall).foregroundStyle(colors.foregroundLighter)
+				qrCard(image: qrImage)
-					.frame(maxWidth: .infinity)
+				if qrImage != nil {
+					Text(LocalizedStringKey("transfer_scan_qr"))
+						.font(VniType.bodySmall).foregroundStyle(colors.foregroundLighter)
+						.frame(maxWidth: .infinity)
+				}
 				ShareActionsView(model: model, transfer: transfer, ticket: ticket)
-			} else {
+			case .preparing:
 				Text(LocalizedStringKey("transfer_event_preparing")).foregroundStyle(colors.foregroundLighter)
+			case .unavailable:
+				Text(LocalizedStringKey(
+					transfer.status == .failed ? "transfer_event_failed" : "transfer_event_stopped"
+				))
+				.foregroundStyle(colors.foregroundLighter)
 			}
 		}
 	}
 
-	private func qrCard(ticket: String) -> some View {
+	private func qrCard(image: Image?) -> some View {
 		ZStack {
-			if let qr = QRCode.generate(from: ticket) {
+			if let image {
-				qr.interpolation(.none).resizable().scaledToFit().padding(14)
+				image.interpolation(.none).resizable().scaledToFit().padding(14)
 			} else {
-				ProgressView()
+				VStack(spacing: 10) {
+					Image(systemName: "qrcode")
+						.font(.system(size: 36, weight: .medium))
+					Text(LocalizedStringKey("transfer_qr_unavailable"))
+						.font(VniType.bodySmall)
+						.multilineTextAlignment(.center)
+				}
+				.foregroundStyle(.black.opacity(0.72))
+				.padding(22)
 			}
 		}
 		.frame(width: 268, height: 268)
@@ -302,6 +321,26 @@ struct TransferSharePanel: View {
 	}
 }
 
+enum TransferInvitationPresentation: Equatable {
+	case preparing
+	case ready(String)
+	case unavailable
+}
+
+extension Transfer {
+	var invitationPresentation: TransferInvitationPresentation {
+		switch status {
+		case .importing:
+			return .preparing
+		case .sharing:
+			guard let ticket, !ticket.isEmpty else { return .preparing }
+			return .ready(ticket)
+		case .receiving, .done, .failed, .cancelled, .stopped:
+			return .unavailable
+		}
+	}
+}
+
 // MARK: - QR generation (CoreImage)
 
 enum QRCode {

apple/VniDrop/Features/Settings/SettingsModel.swift

@@ -7,6 +7,7 @@ enum SettingsSection: Hashable {
 	case preferences
 	case appearance
 	case notifications
+	case network
 	case storage
 	case about
 	case bugReport
@@ -17,6 +18,7 @@ enum SettingsSection: Hashable {
 		case .preferences: return "preferences_title"
 		case .appearance: return "appearance_title"
 		case .notifications: return "notifications_title"
+		case .network: return "settings_network_title"
 		case .storage: return "storage_title"
 		case .about: return "about_title"
 		case .bugReport: return "about_bug_report"
@@ -44,6 +46,14 @@ struct SettingsState: Equatable {
 	var notificationsEnabled = false
 	var notificationPermission: NotificationPermission = .notDetermined
 	var diagnosticsEnabled = false
+	var relayMode: RelayPreferenceMode = .automatic
+	var relayURLs: [String] = []
+	var relayValidationError: RelayConfigurationValidationError?
+	var relayConfigurationIsDirty = false
+	var isApplyingRelayConfiguration = false
+	var hasActiveNetworkWork = false
+	var endpointId: String?
+	var relayApplyErrorKey: String?
 	var deviceInfo: DeviceInfo?
 	var appVersion = ""
 	var isLoadingDeviceInfo = false
@@ -66,6 +76,13 @@ struct SettingsState: Equatable {
 			&& lhs.themeMode == rhs.themeMode && lhs.notificationsEnabled == rhs.notificationsEnabled
 			&& lhs.notificationPermission == rhs.notificationPermission
 			&& lhs.diagnosticsEnabled == rhs.diagnosticsEnabled && lhs.appVersion == rhs.appVersion
+			&& lhs.relayMode == rhs.relayMode && lhs.relayURLs == rhs.relayURLs
+			&& lhs.relayValidationError == rhs.relayValidationError
+			&& lhs.relayConfigurationIsDirty == rhs.relayConfigurationIsDirty
+			&& lhs.isApplyingRelayConfiguration == rhs.isApplyingRelayConfiguration
+			&& lhs.hasActiveNetworkWork == rhs.hasActiveNetworkWork
+			&& lhs.endpointId == rhs.endpointId
+			&& lhs.relayApplyErrorKey == rhs.relayApplyErrorKey
 			&& lhs.isLoadingDeviceInfo == rhs.isLoadingDeviceInfo
 			&& lhs.bugWhatHappened == rhs.bugWhatHappened && lhs.bugExpected == rhs.bugExpected
 			&& lhs.bugSteps == rhs.bugSteps && lhs.bugContact == rhs.bugContact
@@ -96,6 +113,7 @@ final class SettingsModel: ObservableObject {
 	private var enableNotificationsAfterSettings = false
 	private var usernamePersistTask: Task<Void, Never>?
 	private var hasLocalUsernameDraft = false
+	private var hasRelayConfigurationDraft = false
 	private var cancellables = Set<AnyCancellable>()
 
 	init(
@@ -133,10 +151,29 @@ final class SettingsModel: ObservableObject {
 				self.state.themeMode = prefs.themeMode
 				self.state.notificationsEnabled = prefs.notificationsEnabled
 				self.state.diagnosticsEnabled = prefs.diagnosticsEnabled
+				if !self.hasRelayConfigurationDraft {
+					self.state.relayMode = prefs.relayConfiguration.mode
+					self.state.relayURLs = prefs.relayConfiguration.relayURLs
+					self.state.relayConfigurationIsDirty = false
+				}
 				if folder != previousFolder { Task { await self.validateFolder(folder) } }
 			}
 			.store(in: &cancellables)
 
+		repository.statePublisher
+			.sink { [weak self] coreState in
+				guard let self else { return }
+				let hasActiveWork = (coreState.status?.activeTransfers ?? 0) > 0
+					|| (coreState.status?.activeShares ?? 0) > 0
+					|| coreState.transfers.contains(where: { $0.status.isActiveTransfer })
+				self.state.hasActiveNetworkWork = hasActiveWork
+				self.state.endpointId = coreState.status?.endpointId
+				if !hasActiveWork && self.state.relayApplyErrorKey == "relay_apply_active_transfers" {
+					self.state.relayApplyErrorKey = nil
+				}
+			}
+			.store(in: &cancellables)
+
 		refreshNotificationPermission()
 		loadDeviceInfo()
 	}
@@ -206,6 +243,119 @@ final class SettingsModel: ObservableObject {
 		}
 	}
 
+	// MARK: - Network
+
+	func setRelayMode(_ mode: RelayPreferenceMode) {
+		hasRelayConfigurationDraft = true
+		state.relayMode = mode
+		if mode == .custom && state.relayURLs.isEmpty { state.relayURLs = [""] }
+		updateRelayConfigurationDraft()
+	}
+
+	func setRelayURL(_ value: String, at index: Int) {
+		guard state.relayURLs.indices.contains(index) else { return }
+		hasRelayConfigurationDraft = true
+		state.relayURLs[index] = value
+		updateRelayConfigurationDraft()
+	}
+
+	func addRelayURL() {
+		guard state.relayURLs.count < RelayConfigurationValidator.maximumRelayCount else { return }
+		hasRelayConfigurationDraft = true
+		state.relayURLs.append("")
+		updateRelayConfigurationDraft()
+	}
+
+	func removeRelayURL(at index: Int) {
+		guard state.relayURLs.indices.contains(index) else { return }
+		hasRelayConfigurationDraft = true
+		state.relayURLs.remove(at: index)
+		if state.relayURLs.isEmpty { state.relayURLs = [""] }
+		updateRelayConfigurationDraft()
+	}
+
+	func applyRelayConfiguration() {
+		guard !state.isApplyingRelayConfiguration, state.relayConfigurationIsDirty else { return }
+
+		let configuration: RelayConfiguration
+		do {
+			configuration = try RelayConfigurationValidator.validate(
+				mode: state.relayMode,
+				relayURLs: state.relayURLs,
+				retainedRelayURLs: preferences.preferences.relayConfiguration.relayURLs
+			)
+		} catch let error as RelayConfigurationValidationError {
+			state.relayValidationError = error
+			state.relayApplyErrorKey = nil
+			return
+		} catch {
+			return
+		}
+
+		let coreState = repository.state
+		let hasActiveWork = (coreState.status?.activeTransfers ?? 0) > 0
+			|| (coreState.status?.activeShares ?? 0) > 0
+			|| coreState.transfers.contains(where: { $0.status.isActiveTransfer })
+		guard !hasActiveWork else {
+			state.hasActiveNetworkWork = true
+			state.relayApplyErrorKey = "relay_apply_active_transfers"
+			messages.show(UiMessage(text: .resource("relay_apply_active_transfers"), tone: .warning))
+			return
+		}
+
+		let previousConfiguration = preferences.preferences.relayConfiguration
+		state.relayValidationError = nil
+		state.relayApplyErrorKey = nil
+		state.isApplyingRelayConfiguration = true
+		Task {
+			let applyResult = await repository.initialize(
+				appDataDir: environment.defaultCoreDataDir,
+				networkConfiguration: configuration
+			)
+			switch applyResult {
+			case .success:
+				hasRelayConfigurationDraft = false
+				preferences.setRelayConfiguration(configuration)
+				state.isApplyingRelayConfiguration = false
+				state.relayConfigurationIsDirty = false
+				messages.show(UiMessage(text: .resource("relay_settings_applied"), tone: .success))
+			case .failure(let error):
+				if let lifecycleError = error as? CoreNetworkLifecycleError {
+					state.isApplyingRelayConfiguration = false
+					switch lifecycleError {
+					case .activeNetworkWork:
+						state.hasActiveNetworkWork = true
+						state.relayApplyErrorKey = "relay_apply_active_transfers"
+					case .transitionInProgress:
+						state.relayApplyErrorKey = "relay_apply_failed"
+					}
+					return
+				}
+				let rollbackResult = await repository.initialize(
+					appDataDir: environment.defaultCoreDataDir,
+					networkConfiguration: previousConfiguration
+				)
+				state.isApplyingRelayConfiguration = false
+				if case .success = rollbackResult {
+					state.relayApplyErrorKey = "relay_apply_failed"
+					messages.show(UiMessage(text: .resource("relay_apply_failed"), tone: .error))
+				} else {
+					state.relayApplyErrorKey = "relay_restore_failed"
+					messages.show(UiMessage(text: .resource("relay_restore_failed"), tone: .error))
+				}
+			}
+		}
+	}
+
+	private func updateRelayConfigurationDraft() {
+		state.relayValidationError = nil
+		state.relayApplyErrorKey = nil
+		let saved = preferences.preferences.relayConfiguration
+		let draftURLs = state.relayMode == .automatic ? saved.relayURLs : state.relayURLs
+		state.relayConfigurationIsDirty = saved != RelayConfiguration(mode: state.relayMode, relayURLs: draftURLs)
+		hasRelayConfigurationDraft = state.relayConfigurationIsDirty
+	}
+
 	func setBugWhatHappened(_ value: String) { state.bugWhatHappened = value }
 	func setBugExpected(_ value: String) { state.bugExpected = value }
 	func setBugSteps(_ value: String) { state.bugSteps = value }

apple/VniDrop/Features/Settings/SettingsScreen.swift

@@ -38,6 +38,17 @@ struct SettingsScreen: View {
 					NavigationLink(value: SettingsSection.storage) {
 						SettingsRow(icon: "internaldrive", title: String(localized: "storage_title"), value: nil)
 					}
+				}
+				Section(String(localized: "settings_advanced_title")) {
+					NavigationLink(value: SettingsSection.network) {
+						SettingsRow(
+							icon: "network",
+							title: String(localized: "settings_network_title"),
+							value: relayModeLabel(model.state.relayMode)
+						)
+					}
+				}
+				Section {
 					NavigationLink(value: SettingsSection.about) {
 						SettingsRow(icon: "info.circle", title: String(localized: "about_title"), value: nil)
 					}
@@ -99,6 +110,8 @@ private struct SettingsSectionContent: View {
 			AppearanceSettings(model: model)
 		case .notifications:
 			NotificationSettings(model: model)
+		case .network:
+			NetworkSettings(model: model)
 		case .storage:
 			StorageSettings(model: model)
 		case .about:
@@ -109,6 +122,13 @@ private struct SettingsSectionContent: View {
 	}
 }
 
+func relayModeLabel(_ mode: RelayPreferenceMode) -> String {
+	switch mode {
+	case .automatic: return String(localized: "relay_mode_automatic")
+	case .custom: return String(localized: "relay_mode_custom")
+	}
+}
+
 struct SettingsRow: View {
 	let icon: String
 	let title: String

apple/VniDrop/Features/Settings/SettingsSections.swift

@@ -57,6 +57,178 @@ struct NotificationSettings: View {
 	}
 }
 
+struct NetworkSettings: View {
+	@ObservedObject var model: SettingsModel
+
+	var body: some View {
+		Section {
+			Picker(
+				String(localized: "settings_network_title"),
+				selection: Binding(get: { model.state.relayMode }, set: { model.setRelayMode($0) })
+			) {
+				ForEach(RelayPreferenceMode.allCases, id: \.self) { mode in
+					Text(relayModeLabel(mode)).tag(mode)
+				}
+			}
+			.pickerStyle(.segmented)
+			.labelsHidden()
+			.disabled(model.state.isApplyingRelayConfiguration)
+		} footer: {
+			Text(LocalizedStringKey(
+				model.state.relayMode == .automatic
+					? "relay_mode_automatic_description"
+					: "relay_mode_custom_description"
+			))
+		}
+
+		Section {
+			Label {
+				Text(LocalizedStringKey("relay_privacy_description"))
+					.fixedSize(horizontal: false, vertical: true)
+			} icon: {
+				Image(systemName: "lock.shield")
+			}
+			.foregroundStyle(.secondary)
+		}
+
+		if let endpointId = model.state.endpointId, !endpointId.isEmpty {
+			Section {
+				Text(String(format: String(localized: "approval_endpoint_id"), endpointId))
+					.font(.footnote.monospaced())
+					.textSelection(.enabled)
+			}
+		}
+
+		if model.state.relayMode == .custom {
+			Section {
+				Label {
+					Text(LocalizedStringKey("relay_strict_warning"))
+						.fixedSize(horizontal: false, vertical: true)
+				} icon: {
+					Image(systemName: "exclamationmark.shield.fill")
+				}
+				.foregroundStyle(.orange)
+
+				ForEach(Array(model.state.relayURLs.indices), id: \.self) { index in
+					VStack(alignment: .leading, spacing: 6) {
+						HStack {
+							TextField(
+								"https://relay.example.com",
+								text: Binding(
+									get: {
+										model.state.relayURLs.indices.contains(index)
+											? model.state.relayURLs[index]
+											: ""
+									},
+									set: { model.setRelayURL($0, at: index) }
+								)
+							)
+							#if os(iOS)
+							.keyboardType(.URL)
+							.textInputAutocapitalization(.never)
+							#endif
+							.autocorrectionDisabled()
+							.disabled(model.state.isApplyingRelayConfiguration)
+
+							Button(role: .destructive) {
+								model.removeRelayURL(at: index)
+							} label: {
+								Image(systemName: "minus.circle.fill")
+							}
+							.buttonStyle(.borderless)
+							.accessibilityLabel(Text(LocalizedStringKey("relay_remove_url")))
+							.disabled(model.state.isApplyingRelayConfiguration)
+						}
+
+						if let error = model.state.relayValidationError, error.urlIndex == index {
+							Text(relayValidationMessage(error))
+								.font(.caption)
+								.foregroundStyle(.red)
+						}
+					}
+				}
+
+				Button(action: model.addRelayURL) {
+					Label(String(localized: "relay_add_url"), systemImage: "plus.circle")
+				}
+				.disabled(
+					model.state.relayURLs.count >= RelayConfigurationValidator.maximumRelayCount
+						|| model.state.isApplyingRelayConfiguration
+				)
+			} header: {
+				Text(LocalizedStringKey("relay_custom_urls_label"))
+			} footer: {
+				Text(LocalizedStringKey("relay_custom_urls_help"))
+			}
+		}
+
+		if let error = model.state.relayValidationError, error.urlIndex == nil {
+			Section {
+				Label {
+					Text(relayValidationMessage(error))
+				} icon: {
+					Image(systemName: "exclamationmark.triangle.fill")
+				}
+				.foregroundStyle(.red)
+			}
+		}
+
+		if model.state.hasActiveNetworkWork || model.state.relayApplyErrorKey != nil {
+			Section {
+				Label {
+					Text(LocalizedStringKey(
+						model.state.hasActiveNetworkWork
+							? "relay_apply_active_transfers"
+							: model.state.relayApplyErrorKey ?? "relay_apply_failed"
+					))
+				} icon: {
+					Image(systemName: "exclamationmark.triangle.fill")
+				}
+				.foregroundStyle(.red)
+			}
+		}
+
+		Section {
+			Button(action: model.applyRelayConfiguration) {
+				HStack {
+					Text(LocalizedStringKey(
+						model.state.isApplyingRelayConfiguration ? "relay_applying" : "relay_apply"
+					))
+					if model.state.isApplyingRelayConfiguration {
+						Spacer()
+						ProgressView()
+					}
+				}
+			}
+			.disabled(
+				!model.state.relayConfigurationIsDirty
+					|| model.state.isApplyingRelayConfiguration
+					|| model.state.hasActiveNetworkWork
+			)
+		} footer: {
+			Text(LocalizedStringKey("relay_apply_restart_description"))
+		}
+	}
+}
+
+private func relayValidationMessage(_ error: RelayConfigurationValidationError) -> String {
+	switch error {
+	case .missingURL:
+		return String(localized: "relay_validation_missing_url")
+	case .tooManyURLs:
+		return String(
+			format: String(localized: "relay_validation_too_many_urls"),
+			RelayConfigurationValidator.maximumRelayCount
+		)
+	case .httpsRequired(let index):
+		return String(format: String(localized: "relay_validation_https_required"), index + 1)
+	case .invalidURL(let index):
+		return String(format: String(localized: "relay_validation_invalid_url"), index + 1)
+	case .duplicateURL(let index):
+		return String(format: String(localized: "relay_validation_duplicate_url"), index + 1)
+	}
+}
+
 struct StorageSettings: View {
 	@ObservedObject var model: SettingsModel
 	@State private var showDeleteConfirmation = false

crates/vnidrop/Cargo.toml

@@ -36,4 +36,5 @@ uuid = { version = "1.23.3", features = ["v4", "serde"] }
 walkdir = "2.5.0"
 
 [dev-dependencies]
+iroh-relay = { version = "1.0.0", features = ["server"] }
 tempfile = "3.27.0"

crates/vnidrop/src/api.rs

@@ -1,9 +1,121 @@
 use anyhow::Context;
+use iroh::RelayUrl;
 use iroh_blobs::Hash;
 use serde::{Deserialize, Serialize};
+use std::{collections::BTreeSet, net::IpAddr, str::FromStr};
 
 use crate::util::{non_empty, now_ms};
 
+pub(crate) const MAX_CUSTOM_RELAYS: usize = 8;
+pub(crate) const MAX_RELAY_URL_BYTES: usize = 2_048;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, uniffi::Enum)]
+pub enum CoreRelayMode {
+    Automatic,
+    Custom,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, uniffi::Record)]
+pub struct CoreNetworkConfig {
+    pub mode: CoreRelayMode,
+    pub relay_urls: Vec<String>,
+}
+
+impl Default for CoreNetworkConfig {
+    fn default() -> Self {
+        Self {
+            mode: CoreRelayMode::Automatic,
+            relay_urls: Vec::new(),
+        }
+    }
+}
+
+impl CoreNetworkConfig {
+    pub(crate) fn validated_relay_urls(&self) -> anyhow::Result<Vec<RelayUrl>> {
+        match self.mode {
+            CoreRelayMode::Automatic => {
+                if !self.relay_urls.is_empty() {
+                    anyhow::bail!("automatic relay mode must not include custom relay URLs");
+                }
+                Ok(Vec::new())
+            }
+            CoreRelayMode::Custom => {
+                if self.relay_urls.is_empty() {
+                    anyhow::bail!("custom relay mode requires at least one relay URL");
+                }
+                if self.relay_urls.len() > MAX_CUSTOM_RELAYS {
+                    anyhow::bail!(
+                        "custom relay mode supports at most {MAX_CUSTOM_RELAYS} relay URLs"
+                    );
+                }
+
+                let mut seen = BTreeSet::new();
+                let mut validated = Vec::with_capacity(self.relay_urls.len());
+                for (index, value) in self.relay_urls.iter().enumerate() {
+                    if value.is_empty()
+                        || value
+                            .chars()
+                            .any(|character| character.is_whitespace() || character.is_control())
+                    {
+                        anyhow::bail!(
+                            "relay URL must be non-empty and contain no whitespace or control characters"
+                        );
+                    }
+                    if value.len() > MAX_RELAY_URL_BYTES {
+                        anyhow::bail!(
+                            "relay URL is {} bytes, limit is {MAX_RELAY_URL_BYTES}",
+                            value.len()
+                        );
+                    }
+                    let url = RelayUrl::from_str(value)
+                        .with_context(|| format!("invalid relay URL at position {}", index + 1))?;
+                    let secure = url.scheme() == "https";
+                    let loopback_http = url.scheme() == "http"
+                        && url.host_str().is_some_and(|host| {
+                            host.eq_ignore_ascii_case("localhost")
+                                || host
+                                    .trim_start_matches('[')
+                                    .trim_end_matches(']')
+                                    .parse::<IpAddr>()
+                                    .is_ok_and(|address| address.is_loopback())
+                        });
+                    if !secure && !loopback_http {
+                        anyhow::bail!(
+                            "relay URL must use HTTPS; HTTP is allowed only for loopback development relays"
+                        );
+                    }
+                    if url.host_str().is_none() {
+                        anyhow::bail!("relay URL must include a host");
+                    }
+                    if url.port() == Some(0) {
+                        anyhow::bail!("relay URL port must be between 1 and 65535");
+                    }
+                    if value.contains('@') || !url.username().is_empty() || url.password().is_some()
+                    {
+                        anyhow::bail!("relay URL must not contain credentials");
+                    }
+                    if url.query().is_some() || url.fragment().is_some() {
+                        anyhow::bail!("relay URL must not contain a query or fragment");
+                    }
+                    if url.path() != "/" {
+                        anyhow::bail!("relay URL must not contain a path");
+                    }
+                    if !seen.insert(url.clone()) {
+                        anyhow::bail!("custom relay URLs must not contain duplicates");
+                    }
+                    validated.push(url);
+                }
+                Ok(validated)
+            }
+        }
+    }
+}
+
+#[uniffi::export]
+pub fn default_core_network_config() -> CoreNetworkConfig {
+    CoreNetworkConfig::default()
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, uniffi::Record)]
 pub struct CoreLimits {
     pub max_sources: u64,

crates/vnidrop/src/lib.rs

@@ -14,10 +14,11 @@ mod transfer_state;
 mod util;
 
 pub use api::{
-    default_core_limits, CoreEvent, CoreEventSink, CoreLimits, CoreStorageUsage, PublishedOutput,
+    default_core_limits, default_core_network_config, CoreEvent, CoreEventSink, CoreLimits,
-    ReceiveOutputSink, ReceiveOutputSinkV2, ReceivedArtifact, ReceivedLocatorKind, ReceiverRequest,
+    CoreNetworkConfig, CoreRelayMode, CoreStorageUsage, PublishedOutput, ReceiveOutputSink,
-    RuntimeStatus, ShareMetadataInput, ShareResult, ShareSource, SourceKind, StoredTransfer,
+    ReceiveOutputSinkV2, ReceivedArtifact, ReceivedLocatorKind, ReceiverRequest, RuntimeStatus,
-    TicketInspection, TransferAccessMode, TransferMetadata,
+    ShareMetadataInput, ShareResult, ShareSource, SourceKind, StoredTransfer, TicketInspection,
+    TransferAccessMode, TransferMetadata,
 };
 pub use error::VnidropError;
 pub use runtime::VnidropCore;

crates/vnidrop/src/repository.rs

@@ -49,6 +49,7 @@ pub(crate) struct PersistedShare {
     pub(crate) transfer_id: u64,
     pub(crate) local_id: String,
     pub(crate) content_hash: String,
+    pub(crate) ticket: Option<String>,
     pub(crate) access_mode: String,
 }
 
@@ -709,7 +710,7 @@ impl Repository {
     pub(crate) async fn list_active_shares(&self) -> Result<Vec<PersistedShare>> {
         let rows = sqlx::query(
             r#"
-            SELECT transfer_id, local_id, content_hash, access_mode
+            SELECT transfer_id, local_id, content_hash, ticket, access_mode
             FROM transfers
             WHERE direction = 'send'
               AND status = 'sharing'
@@ -724,7 +725,8 @@ impl Repository {
                 transfer_id: row.get::<i64, _>(0) as u64,
                 local_id: row.get::<String, _>(1),
                 content_hash: row.get::<String, _>(2),
-                access_mode: row.get::<String, _>(3),
+                ticket: row.get::<Option<String>, _>(3),
+                access_mode: row.get::<String, _>(4),
             })
             .collect())
     }

crates/vnidrop/src/runtime/delivery.rs

@@ -1,12 +1,12 @@
-use std::{str::FromStr, sync::Arc, time::Duration};
+use std::{sync::Arc, time::Duration};
 
-use iroh_blobs::ticket::BlobTicket;
 use serde_json::json;
 
-use super::CoreInner;
+use super::{filter_peer_addr_for_relay_mode, CoreInner};
 use crate::{
     handshake::{DeliveryReceipt, DeliveryReceiptResponse, HandshakeService},
     repository::PendingDeliveryReceipt,
+    ticket::parse_persisted_sender_address,
 };
 
 const DELIVERY_RECEIPT_TIMEOUT: Duration = Duration::from_secs(5);
@@ -60,8 +60,8 @@ impl CoreInner {
     }
 
     async fn deliver_pending_receipt(&self, pending: PendingDeliveryReceipt) {
-        let blob_ticket = match BlobTicket::from_str(&pending.sender_blob_ticket) {
+        let sender_addr = match parse_persisted_sender_address(&pending.sender_blob_ticket) {
-            Ok(ticket) => ticket,
+            Ok(addr) => addr,
             Err(error) => {
                 tracing::warn!(%error, request_id = %pending.request_id, "discarded invalid pending delivery receipt");
                 let _ = self
@@ -78,7 +78,24 @@ impl CoreInner {
                 return;
             }
         };
-        let client = HandshakeService::client(self.endpoint.clone(), blob_ticket.addr().clone());
+        let sender_addr = match filter_peer_addr_for_relay_mode(
+            &sender_addr,
+            self.relay_mode,
+            &self.custom_relay_urls,
+        ) {
+            Ok(addr) => addr,
+            Err(error) => {
+                self.emit_transfer(
+                    pending.local_transfer_id,
+                    "receive",
+                    "delivery",
+                    "receipt-failed",
+                    json!({ "reason": error.to_string() }),
+                );
+                return;
+            }
+        };
+        let client = HandshakeService::client(self.endpoint.clone(), sender_addr);
         let receipt = DeliveryReceipt {
             request_id: pending.request_id.clone(),
             transfer_id: pending.sender_transfer_id,

crates/vnidrop/src/runtime/facade.rs

@@ -6,9 +6,10 @@ use serde_json::json;
 use super::CoreInner;
 use crate::{
     api::{
-        CoreEvent, CoreEventSink, CoreLimits, CoreStorageUsage, ReceiveOutputSink,
+        CoreEvent, CoreEventSink, CoreLimits, CoreNetworkConfig, CoreStorageUsage,
-        ReceiveOutputSinkV2, ReceivedArtifact, ReceiverRequest, RuntimeStatus, ShareMetadataInput,
+        ReceiveOutputSink, ReceiveOutputSinkV2, ReceivedArtifact, ReceiverRequest, RuntimeStatus,
-        ShareResult, ShareSource, StoredTransfer, TicketInspection, TransferAccessMode,
+        ShareMetadataInput, ShareResult, ShareSource, StoredTransfer, TicketInspection,
+        TransferAccessMode,
     },
     error::VnidropError,
     filesystem::platform_path,
@@ -42,7 +43,26 @@ impl VnidropCore {
         app_data_dir: String,
         event_sink: Arc<dyn CoreEventSink>,
     ) -> Result<Arc<Self>, VnidropError> {
-        Self::initialize_with_limits(app_data_dir, event_sink, CoreLimits::default())
+        Self::initialize_with_limits_and_network_config(
+            app_data_dir,
+            event_sink,
+            CoreLimits::default(),
+            CoreNetworkConfig::default(),
+        )
+    }
+
+    #[uniffi::constructor]
+    pub fn initialize_with_network_config(
+        app_data_dir: String,
+        event_sink: Arc<dyn CoreEventSink>,
+        network_config: CoreNetworkConfig,
+    ) -> Result<Arc<Self>, VnidropError> {
+        Self::initialize_with_limits_and_network_config(
+            app_data_dir,
+            event_sink,
+            CoreLimits::default(),
+            network_config,
+        )
     }
 
     #[uniffi::constructor]
@@ -50,15 +70,39 @@ impl VnidropCore {
         app_data_dir: String,
         event_sink: Arc<dyn CoreEventSink>,
         limits: CoreLimits,
+    ) -> Result<Arc<Self>, VnidropError> {
+        Self::initialize_with_limits_and_network_config(
+            app_data_dir,
+            event_sink,
+            limits,
+            CoreNetworkConfig::default(),
+        )
+    }
+
+    #[uniffi::constructor]
+    pub fn initialize_with_limits_and_network_config(
+        app_data_dir: String,
+        event_sink: Arc<dyn CoreEventSink>,
+        limits: CoreLimits,
+        network_config: CoreNetworkConfig,
     ) -> Result<Arc<Self>, VnidropError> {
         limits.validate().map_err(VnidropError::initialization)?;
+        let relay_urls = network_config
+            .validated_relay_urls()
+            .map_err(VnidropError::initialization)?;
         let runtime = tokio::runtime::Builder::new_multi_thread()
             .enable_all()
             .thread_name("vnidrop")
             .build()?;
         let app_data_dir = PathBuf::from(app_data_dir);
         let inner = runtime
-            .block_on(CoreInner::start(app_data_dir, event_sink, limits))
+            .block_on(CoreInner::start(
+                app_data_dir,
+                event_sink,
+                limits,
+                network_config.mode,
+                relay_urls,
+            ))
             .map_err(VnidropError::initialization)?;
         Ok(Arc::new(Self { runtime, inner }))
     }

crates/vnidrop/src/runtime/mod.rs

@@ -27,7 +27,10 @@ use std::{
 
 use anyhow::Result;
 use futures_lite::StreamExt as _;
-use iroh::{endpoint::presets, protocol::Router, Endpoint};
+use iroh::{
+    endpoint::presets, protocol::Router, tls::CaTlsConfig, Endpoint, EndpointAddr, RelayConfig,
+    RelayMap, RelayMode, RelayUrl,
+};
 use iroh_blobs::{
     format::collection::Collection,
     provider::events::{EventMask, EventSender},
@@ -45,16 +48,19 @@ use tokio::{
 
 use crate::{
     access_policy::{mode_from_storage, AccessPolicy},
-    api::{CoreEvent, CoreEventSink, CoreLimits},
+    api::{CoreEvent, CoreEventSink, CoreLimits, CoreRelayMode},
     approval::ApprovalService,
     event_hub::EventHub,
     handshake::HandshakeService,
     logging::init_logging,
     repository::Repository,
     secret::load_or_create_secret,
+    ticket::ticket_matches_relay_profile,
     transfer_state::{TransferDirection, TransferStatus},
 };
 
+const RELAY_CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
+
 /// Owns the Iroh endpoint, blob store, transfer history, and byte streaming.
 /// Kotlin owns app lifecycle and platform file picking.
 pub(super) struct CoreInner {
@@ -66,6 +72,8 @@ pub(super) struct CoreInner {
     pub(super) event_hub: Arc<EventHub>,
     pub(super) approval: ApprovalService,
     pub(super) limits: CoreLimits,
+    pub(super) relay_mode: CoreRelayMode,
+    pub(super) custom_relay_urls: Vec<RelayUrl>,
     pub(super) transfer_slots: Semaphore,
     pub(super) access_policy: Arc<AccessPolicy>,
     /// Sync mutex so cancel can remove + signal without awaiting (and without
@@ -93,6 +101,8 @@ impl CoreInner {
         app_data_dir: PathBuf,
         event_sink: Arc<dyn CoreEventSink>,
         limits: CoreLimits,
+        relay_mode: CoreRelayMode,
+        relay_urls: Vec<RelayUrl>,
     ) -> Result<Arc<Self>> {
         tokio::fs::create_dir_all(&app_data_dir).await?;
         init_logging(&app_data_dir)?;
@@ -105,11 +115,39 @@ impl CoreInner {
             add_protected: None,
         });
         let store = FsStore::load_with_opts(store_root.join("blobs.db"), store_options).await?;
-        let endpoint = Endpoint::builder(presets::N0)
+        let endpoint = match relay_mode {
-            .secret_key(secret_key)
+            CoreRelayMode::Automatic => {
-            .bind()
+                Endpoint::builder(presets::N0)
-            .await?;
+                    .secret_key(secret_key)
-        endpoint.online().await;
+                    .bind()
+                    .await?
+            }
+            CoreRelayMode::Custom => {
+                let relay_map = RelayMap::from_iter(relay_urls.iter().cloned().map(|url| {
+                    // Loopback HTTP is a development escape hatch. Without TLS the
+                    // relay cannot serve Iroh's QUIC address-discovery endpoint.
+                    if url.scheme() == "http" {
+                        RelayConfig::new(url, None)
+                    } else {
+                        RelayConfig::from(url)
+                    }
+                }));
+                // Minimal leaves address lookup empty, so strict custom mode
+                // cannot silently publish or resolve addresses through N0.
+                Endpoint::builder(presets::Minimal)
+                    .relay_mode(RelayMode::Custom(relay_map))
+                    .ca_tls_config(CaTlsConfig::embedded())
+                    .secret_key(secret_key)
+                    .bind()
+                    .await?
+            }
+        };
+        if let Err(error) =
+            wait_for_relay(&endpoint, relay_mode, &relay_urls, RELAY_CONNECT_TIMEOUT).await
+        {
+            endpoint.close().await;
+            return Err(error);
+        }
 
         // Provider events are where the sender sees remote readers.  The core
         // uses them for send progress and for the current approval gate.
@@ -189,6 +227,27 @@ impl CoreInner {
                 );
                 continue;
             };
+            let relay_profile_matches = share.ticket.as_deref().is_some_and(|ticket| {
+                ticket_matches_relay_profile(ticket, &limits, relay_mode, &relay_urls)
+                    .unwrap_or(false)
+            });
+            if !relay_profile_matches {
+                repository
+                    .transition_transfer_status(
+                        transfer_id,
+                        TransferStatus::Sharing,
+                        TransferStatus::Stopped,
+                    )
+                    .await?;
+                event_hub.emit_transfer(
+                    transfer_id,
+                    TransferDirection::Send.as_str(),
+                    "recovery",
+                    "share-stopped-network-profile-changed",
+                    json!({ "reason": "saved ticket does not match the active relay profile" }),
+                );
+                continue;
+            }
             let tag_name = share_tag_name(&share.local_id);
             store
                 .tags()
@@ -239,6 +298,8 @@ impl CoreInner {
             repository,
             event_hub,
             approval,
+            relay_mode,
+            custom_relay_urls: relay_urls,
             transfer_slots: Semaphore::new(limits.max_concurrent_transfers as usize),
             limits,
             access_policy,
@@ -309,6 +370,66 @@ impl CoreInner {
     }
 }
 
+pub(crate) fn filter_peer_addr_for_relay_mode(
+    addr: &EndpointAddr,
+    relay_mode: CoreRelayMode,
+    custom_relay_urls: &[RelayUrl],
+) -> Result<EndpointAddr> {
+    match relay_mode {
+        CoreRelayMode::Automatic => Ok(addr.clone()),
+        CoreRelayMode::Custom => {
+            let mut filtered = EndpointAddr::new(addr.id);
+            for ip_addr in addr.ip_addrs().copied() {
+                filtered = filtered.with_ip_addr(ip_addr);
+            }
+            for relay_url in addr
+                .relay_urls()
+                .filter(|relay_url| custom_relay_urls.contains(relay_url))
+                .cloned()
+            {
+                filtered = filtered.with_relay_url(relay_url);
+            }
+            if filtered.is_empty() {
+                anyhow::bail!(
+                    "invitation has no direct address or relay allowed by strict custom relay mode"
+                );
+            }
+            Ok(filtered)
+        }
+    }
+}
+
+pub(crate) async fn wait_for_relay(
+    endpoint: &Endpoint,
+    relay_mode: CoreRelayMode,
+    relay_urls: &[RelayUrl],
+    timeout: Duration,
+) -> Result<()> {
+    if tokio::time::timeout(timeout, endpoint.online())
+        .await
+        .is_err()
+    {
+        match relay_mode {
+            CoreRelayMode::Automatic => anyhow::bail!(
+                "timed out after {} seconds while connecting to automatic relays; verify network access and relay availability",
+                timeout.as_secs_f32(),
+            ),
+            CoreRelayMode::Custom => {
+                let configured_relays = relay_urls
+                    .iter()
+                    .map(ToString::to_string)
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                anyhow::bail!(
+                    "timed out after {} seconds while connecting to custom relays [{configured_relays}]; verify the URLs, TLS certificates, network access, and relay availability",
+                    timeout.as_secs_f32(),
+                );
+            }
+        }
+    }
+    Ok(())
+}
+
 pub(super) fn share_tag_name(local_id: &str) -> String {
     format!("vnidrop/share/{local_id}")
 }

crates/vnidrop/src/runtime/receive.rs

@@ -9,12 +9,12 @@ use bytes::Bytes;
 use futures_lite::StreamExt as _;
 use iroh_blobs::{
     api::proto::ExportRangesItem, api::remote::GetProgressItem, format::collection::Collection,
-    get::request::get_hash_seq_and_sizes, Hash,
+    get::request::get_hash_seq_and_sizes, ticket::BlobTicket, Hash,
 };
 use serde_json::json;
 use tokio::sync::oneshot;
 
-use super::{ActiveTransfer, CoreInner};
+use super::{filter_peer_addr_for_relay_mode, ActiveTransfer, CoreInner};
 use crate::{
     access_policy::mode_to_storage,
     api::{
@@ -28,7 +28,9 @@ use crate::{
     },
     handshake::{DeliveryReceipt, HandshakeResponse, HandshakeService},
     repository::{PendingDeliveryReceiptInsert, ReceivedArtifactInsert, TransferUpsert},
-    ticket::{parse_transfer_ticket_with_limits, ParsedTransferTicket},
+    ticket::{
+        encode_persisted_sender_address, parse_transfer_ticket_with_limits, ParsedTransferTicket,
+    },
     transfer_state::{TransferDirection, TransferStatus},
 };
 
@@ -192,7 +194,7 @@ impl CoreInner {
             .await
             .context("transfer limiter is closed")
             .map_err(VnidropError::internal)?;
-        let parsed = match parse_transfer_ticket_with_limits(&ticket, &self.limits)
+        let mut parsed = match parse_transfer_ticket_with_limits(&ticket, &self.limits)
             .context("failed to parse transfer ticket")
         {
             Ok(parsed) => parsed,
@@ -205,6 +207,17 @@ impl CoreInner {
                 return Err(error);
             }
         };
+        let sender_addr = filter_peer_addr_for_relay_mode(
+            parsed.blob_ticket.addr(),
+            self.relay_mode,
+            &self.custom_relay_urls,
+        )
+        .map_err(VnidropError::network)?;
+        parsed.blob_ticket = BlobTicket::new(
+            sender_addr,
+            parsed.blob_ticket.hash(),
+            parsed.blob_ticket.format(),
+        );
         let transfer_id = parsed.metadata.transfer_id;
         self.persist_receive_start(transfer_id, &parsed, receiver_name.as_deref())
             .await
@@ -271,7 +284,8 @@ impl CoreInner {
                 .map_err(VnidropError::filesystem)?;
         }
         let sender_addr = parsed.blob_ticket.addr().clone();
-        let sender_blob_ticket = parsed.blob_ticket.to_string();
+        let persisted_sender_address = encode_persisted_sender_address(&sender_addr)
+            .context("failed to encode sender address for delivery receipt")?;
 
         self.emit_transfer(transfer_id, "receive", "network", "connecting", json!({}));
         // Every VniDrop ticket carries metadata and must complete the handshake.
@@ -355,7 +369,7 @@ impl CoreInner {
         self.repository
             .complete_receive_with_pending_receipt(PendingDeliveryReceiptInsert {
                 local_transfer_id: transfer_id,
-                sender_blob_ticket: &sender_blob_ticket,
+                sender_blob_ticket: &persisted_sender_address,
                 request_id: &delivery_receipt.request_id,
                 sender_transfer_id: delivery_receipt.transfer_id,
                 token: &delivery_receipt.token,

crates/vnidrop/src/runtime/share.rs

@@ -149,9 +149,13 @@ impl CoreInner {
             import.file_count,
             import.total_size,
         );
-        let ticket = VnidropTicket::new(blob_ticket, ticket_metadata)
+        let ticket = VnidropTicket::new_with_relay_urls(
-            .encode()
+            blob_ticket,
-            .context("failed to encode VniDrop transfer ticket")?;
+            ticket_metadata,
+            &self.custom_relay_urls,
+        )
+        .encode()
+        .context("failed to encode VniDrop transfer ticket")?;
         let content_hash = import.root_hash.to_string();
         let local_id = self
             .repository

crates/vnidrop/src/tests.rs

@@ -8,6 +8,8 @@ mod filesystem_tests;
 mod handshake_tests;
 #[path = "tests/limits.rs"]
 mod limits_tests;
+#[path = "tests/network_config.rs"]
+mod network_config_tests;
 #[path = "tests/repository.rs"]
 mod repository_tests;
 #[path = "tests/runtime.rs"]

crates/vnidrop/src/tests/network_config.rs

@@ -0,0 +1,186 @@
+use std::time::{Duration, Instant};
+
+use iroh::{endpoint::presets, Endpoint, EndpointAddr, RelayMode, RelayUrl, SecretKey};
+
+use crate::{
+    api::{
+        default_core_network_config, CoreNetworkConfig, CoreRelayMode, MAX_CUSTOM_RELAYS,
+        MAX_RELAY_URL_BYTES,
+    },
+    runtime::{filter_peer_addr_for_relay_mode, wait_for_relay},
+};
+
+#[test]
+fn default_network_config_uses_automatic_relays() {
+    assert_eq!(
+        default_core_network_config(),
+        CoreNetworkConfig {
+            mode: CoreRelayMode::Automatic,
+            relay_urls: Vec::new(),
+        }
+    );
+    default_core_network_config()
+        .validated_relay_urls()
+        .unwrap();
+}
+
+#[test]
+fn relay_mode_and_url_list_must_be_consistent() {
+    let automatic_with_url = CoreNetworkConfig {
+        mode: CoreRelayMode::Automatic,
+        relay_urls: vec!["https://relay.example.com".to_string()],
+    };
+    assert!(automatic_with_url.validated_relay_urls().is_err());
+
+    let custom_without_url = CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: Vec::new(),
+    };
+    assert!(custom_without_url.validated_relay_urls().is_err());
+}
+
+#[test]
+fn custom_relay_urls_allow_https_and_loopback_http() {
+    let config = CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: vec![
+            "https://relay.example.com".to_string(),
+            "http://localhost:3340".to_string(),
+            "http://127.0.0.1:3341".to_string(),
+            "http://[::1]:3342".to_string(),
+        ],
+    };
+
+    assert_eq!(config.validated_relay_urls().unwrap().len(), 4);
+}
+
+#[test]
+fn custom_relay_urls_reject_unsafe_or_ambiguous_values() {
+    for value in [
+        "http://relay.example.com",
+        "https://user:password@relay.example.com",
+        "https://relay.example.com/path",
+        "https://relay.example.com?token=secret",
+        "https://relay.example.com#fragment",
+        "https://relay.example.com:0",
+        "https://relay.exa\tmple.com",
+        "https://@relay.example.com",
+        " https://relay.example.com",
+    ] {
+        let config = CoreNetworkConfig {
+            mode: CoreRelayMode::Custom,
+            relay_urls: vec![value.to_string()],
+        };
+        assert!(
+            config.validated_relay_urls().is_err(),
+            "{value} should be rejected"
+        );
+    }
+}
+
+#[test]
+fn custom_relay_urls_are_bounded_and_unique_after_normalization() {
+    let duplicates = CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: vec![
+            "https://relay.example.com".to_string(),
+            "https://relay.example.com/".to_string(),
+        ],
+    };
+    assert!(duplicates.validated_relay_urls().is_err());
+
+    let too_many = CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: (0..=MAX_CUSTOM_RELAYS)
+            .map(|index| format!("https://relay-{index}.example.com"))
+            .collect(),
+    };
+    assert!(too_many.validated_relay_urls().is_err());
+
+    let too_long = CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: vec![format!(
+            "https://{}.example.com",
+            "a".repeat(MAX_RELAY_URL_BYTES)
+        )],
+    };
+    assert!(too_long.validated_relay_urls().is_err());
+}
+
+#[test]
+fn strict_custom_mode_filters_peer_relays_but_retains_direct_addresses() {
+    let allowed: RelayUrl = "https://allowed.relay.example.com".parse().unwrap();
+    let disallowed: RelayUrl = "https://disallowed.relay.example.com".parse().unwrap();
+    let direct = "192.0.2.1:4433".parse().unwrap();
+    let addr = EndpointAddr::new(SecretKey::generate().public())
+        .with_relay_url(allowed.clone())
+        .with_relay_url(disallowed.clone())
+        .with_ip_addr(direct);
+
+    let filtered = filter_peer_addr_for_relay_mode(
+        &addr,
+        CoreRelayMode::Custom,
+        std::slice::from_ref(&allowed),
+    )
+    .unwrap();
+    assert_eq!(
+        filtered.relay_urls().cloned().collect::<Vec<_>>(),
+        vec![allowed.clone()]
+    );
+    assert_eq!(
+        filtered.ip_addrs().copied().collect::<Vec<_>>(),
+        vec![direct]
+    );
+    assert_eq!(
+        filter_peer_addr_for_relay_mode(&addr, CoreRelayMode::Automatic, &[]).unwrap(),
+        addr
+    );
+
+    let disallowed_only =
+        EndpointAddr::new(SecretKey::generate().public()).with_relay_url(disallowed);
+    assert!(filter_peer_addr_for_relay_mode(
+        &disallowed_only,
+        CoreRelayMode::Custom,
+        std::slice::from_ref(&allowed),
+    )
+    .is_err());
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn unreachable_relay_wait_is_bounded_and_actionable_for_each_mode() {
+    let relay_url: RelayUrl = "http://127.0.0.1:9".parse().unwrap();
+    let endpoint = Endpoint::builder(presets::Minimal)
+        .relay_mode(RelayMode::custom([relay_url.clone()]))
+        .bind()
+        .await
+        .unwrap();
+    let started = Instant::now();
+
+    let error = wait_for_relay(
+        &endpoint,
+        CoreRelayMode::Custom,
+        std::slice::from_ref(&relay_url),
+        Duration::from_millis(50),
+    )
+    .await
+    .unwrap_err();
+
+    assert!(started.elapsed() < Duration::from_secs(1));
+    assert!(error.to_string().contains(relay_url.as_str()));
+    assert!(error.to_string().contains("verify the URLs"));
+
+    let automatic_error = wait_for_relay(
+        &endpoint,
+        CoreRelayMode::Automatic,
+        &[],
+        Duration::from_millis(50),
+    )
+    .await
+    .unwrap_err();
+    assert!(started.elapsed() < Duration::from_secs(1));
+    assert!(automatic_error.to_string().contains("automatic relays"));
+    assert!(automatic_error
+        .to_string()
+        .contains("verify network access"));
+    endpoint.close().await;
+}

crates/vnidrop/src/tests/repository.rs

@@ -80,6 +80,7 @@ async fn persists_transfers_and_events_across_reopen() {
     assert_eq!(shares.len(), 1);
     assert_eq!(shares[0].transfer_id, 7);
     assert_eq!(shares[0].content_hash, "hash");
+    assert_eq!(shares[0].ticket.as_deref(), Some("ticket"));
     assert_eq!(shares[0].access_mode, "approval_required");
 
     repository

crates/vnidrop/src/tests/ticket.rs

@@ -1,11 +1,16 @@
+use std::net::{Ipv4Addr, SocketAddr};
+
 use data_encoding::BASE64URL_NOPAD;
-use iroh::SecretKey;
+use iroh::{RelayUrl, SecretKey};
 use iroh_blobs::{ticket::BlobTicket, BlobFormat, Hash};
 use serde_json::json;
 
 use crate::{
-    api::{CoreLimits, TransferMetadata},
+    api::{CoreLimits, CoreRelayMode, TransferMetadata},
-    ticket::{parse_transfer_ticket, parse_transfer_ticket_with_limits, VnidropTicket},
+    ticket::{
+        encode_persisted_sender_address, parse_persisted_sender_address, parse_transfer_ticket,
+        parse_transfer_ticket_with_limits, ticket_matches_relay_profile, VnidropTicket,
+    },
 };
 
 fn blob_ticket(hash_byte: u8) -> BlobTicket {
@@ -25,7 +30,7 @@ fn metadata_ticket_round_trips() {
         3,
         2048,
     );
-    let encoded = VnidropTicket::new(blob_ticket.clone(), metadata.clone())
+    let encoded = VnidropTicket::new_with_relay_urls(blob_ticket.clone(), metadata.clone(), &[])
         .encode()
         .unwrap();
     let parsed = parse_transfer_ticket(&encoded).unwrap();
@@ -38,7 +43,7 @@ fn metadata_ticket_round_trips() {
 fn metadata_ticket_tolerates_wrapped_whitespace() {
     let blob_ticket = blob_ticket(9);
     let metadata = TransferMetadata::new(7, "Wrapped", None, blob_ticket.hash(), 1, 10);
-    let encoded = VnidropTicket::new(blob_ticket.clone(), metadata)
+    let encoded = VnidropTicket::new_with_relay_urls(blob_ticket.clone(), metadata, &[])
         .encode()
         .unwrap();
     let wrapped = encoded
@@ -52,6 +57,129 @@ fn metadata_ticket_tolerates_wrapped_whitespace() {
     assert_eq!(parsed.blob_ticket.hash(), blob_ticket.hash());
 }
 
+#[test]
+fn metadata_ticket_restores_backup_relays_without_losing_direct_addresses() {
+    let secret = SecretKey::generate();
+    let primary: RelayUrl = "https://a.relay.example.com".parse().unwrap();
+    let backup: RelayUrl = "https://b.relay.example.com".parse().unwrap();
+    let direct = SocketAddr::from((Ipv4Addr::LOCALHOST, 49152));
+    let addr = iroh::EndpointAddr::new(secret.public())
+        .with_relay_url(primary.clone())
+        .with_ip_addr(direct);
+    let blob_ticket = BlobTicket::new(addr, Hash::new([11; 32]), BlobFormat::HashSeq);
+    let metadata = TransferMetadata::new(11, "Backed up", None, blob_ticket.hash(), 1, 10);
+
+    let encoded = VnidropTicket::new_with_relay_urls(
+        blob_ticket,
+        metadata,
+        &[primary.clone(), backup.clone()],
+    )
+    .encode()
+    .unwrap();
+    let parsed = parse_transfer_ticket(&encoded).unwrap();
+
+    assert_eq!(
+        parsed
+            .blob_ticket
+            .addr()
+            .relay_urls()
+            .cloned()
+            .collect::<Vec<_>>(),
+        vec![primary, backup]
+    );
+    assert_eq!(
+        parsed
+            .blob_ticket
+            .addr()
+            .ip_addrs()
+            .copied()
+            .collect::<Vec<_>>(),
+        vec![direct]
+    );
+}
+
+#[test]
+fn saved_ticket_relay_profile_matching_is_mode_aware_and_order_insensitive() {
+    let relay_a: RelayUrl = "https://a.relay.example.com".parse().unwrap();
+    let relay_b: RelayUrl = "https://b.relay.example.com".parse().unwrap();
+    let relay_c: RelayUrl = "https://c.relay.example.com".parse().unwrap();
+    let blob_ticket = blob_ticket(13);
+    let metadata = TransferMetadata::new(13, "Relay profile", None, blob_ticket.hash(), 1, 10);
+    let custom_ticket = VnidropTicket::new_with_relay_urls(
+        blob_ticket.clone(),
+        metadata.clone(),
+        &[relay_a.clone(), relay_b.clone()],
+    )
+    .encode()
+    .unwrap();
+    let automatic_ticket = VnidropTicket::new_with_relay_urls(blob_ticket, metadata, &[])
+        .encode()
+        .unwrap();
+    let limits = CoreLimits::default();
+
+    assert!(ticket_matches_relay_profile(
+        &custom_ticket,
+        &limits,
+        CoreRelayMode::Custom,
+        &[relay_b.clone(), relay_a.clone()],
+    )
+    .unwrap());
+    assert!(!ticket_matches_relay_profile(
+        &custom_ticket,
+        &limits,
+        CoreRelayMode::Custom,
+        &[relay_a.clone(), relay_c],
+    )
+    .unwrap());
+    assert!(
+        !ticket_matches_relay_profile(&custom_ticket, &limits, CoreRelayMode::Automatic, &[],)
+            .unwrap()
+    );
+    assert!(ticket_matches_relay_profile(
+        &automatic_ticket,
+        &limits,
+        CoreRelayMode::Automatic,
+        &[],
+    )
+    .unwrap());
+    assert!(!ticket_matches_relay_profile(
+        &automatic_ticket,
+        &limits,
+        CoreRelayMode::Custom,
+        &[relay_a],
+    )
+    .unwrap());
+}
+
+#[test]
+fn persisted_sender_address_preserves_relays_and_accepts_legacy_blob_ticket() {
+    let secret = SecretKey::generate();
+    let primary: RelayUrl = "https://a.relay.example.com".parse().unwrap();
+    let backup: RelayUrl = "https://b.relay.example.com".parse().unwrap();
+    let direct = SocketAddr::from((Ipv4Addr::LOCALHOST, 49153));
+    let addr = iroh::EndpointAddr::new(secret.public())
+        .with_relay_url(primary.clone())
+        .with_relay_url(backup)
+        .with_ip_addr(direct);
+
+    let encoded = encode_persisted_sender_address(&addr).unwrap();
+    assert_eq!(parse_persisted_sender_address(&encoded).unwrap(), addr);
+
+    let legacy_addr = iroh::EndpointAddr::new(secret.public())
+        .with_relay_url(primary)
+        .with_ip_addr(direct);
+    let legacy = BlobTicket::new(
+        legacy_addr.clone(),
+        Hash::new([12; 32]),
+        BlobFormat::HashSeq,
+    )
+    .to_string();
+    assert_eq!(
+        parse_persisted_sender_address(&legacy).unwrap(),
+        legacy_addr
+    );
+}
+
 #[test]
 fn invalid_ticket_is_rejected() {
     assert!(parse_transfer_ticket("not-a-ticket").is_err());

crates/vnidrop/src/ticket.rs

@@ -1,27 +1,38 @@
-use std::str::FromStr;
+use std::{collections::BTreeSet, str::FromStr};
 
 use anyhow::{Context, Result};
 use data_encoding::BASE64URL_NOPAD;
+use iroh::{EndpointAddr, RelayUrl};
 use iroh_blobs::ticket::BlobTicket;
 use serde::{Deserialize, Serialize};
 
-use crate::api::{CoreLimits, TransferMetadata};
+use crate::api::{CoreLimits, CoreNetworkConfig, CoreRelayMode, TransferMetadata};
 
 const VNIDROP_TICKET_PREFIX: &str = "vnd1:";
 const VNIDROP_TICKET_VERSION: u8 = 1;
+const PERSISTED_SENDER_ADDRESS_PREFIX: &str = "vndaddr1:";
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub(crate) struct VnidropTicket {
     version: u8,
     blob_ticket: String,
+    // BlobTicket's current wire format retains only one relay URL. The outer
+    // envelope carries backups so new receivers can rebuild the full address.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    relay_urls: Vec<String>,
     metadata: TransferMetadata,
 }
 
 impl VnidropTicket {
-    pub(crate) fn new(blob_ticket: BlobTicket, metadata: TransferMetadata) -> Self {
+    pub(crate) fn new_with_relay_urls(
+        blob_ticket: BlobTicket,
+        metadata: TransferMetadata,
+        relay_urls: &[RelayUrl],
+    ) -> Self {
         Self {
             version: VNIDROP_TICKET_VERSION,
             blob_ticket: blob_ticket.to_string(),
+            relay_urls: relay_urls.iter().map(ToString::to_string).collect(),
             metadata,
         }
     }
@@ -50,6 +61,35 @@ impl VnidropTicket {
 pub(crate) struct ParsedTransferTicket {
     pub(crate) blob_ticket: BlobTicket,
     pub(crate) metadata: TransferMetadata,
+    pub(crate) advertised_custom_relay_urls: Vec<RelayUrl>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct PersistedSenderAddress {
+    addr: EndpointAddr,
+}
+
+pub(crate) fn encode_persisted_sender_address(addr: &EndpointAddr) -> Result<String> {
+    let bytes = serde_json::to_vec(&PersistedSenderAddress { addr: addr.clone() })?;
+    Ok(format!(
+        "{PERSISTED_SENDER_ADDRESS_PREFIX}{}",
+        BASE64URL_NOPAD.encode(&bytes)
+    ))
+}
+
+pub(crate) fn parse_persisted_sender_address(value: &str) -> Result<EndpointAddr> {
+    if let Some(encoded) = value.strip_prefix(PERSISTED_SENDER_ADDRESS_PREFIX) {
+        let bytes = BASE64URL_NOPAD
+            .decode(encoded.as_bytes())
+            .context("invalid persisted sender address encoding")?;
+        let persisted: PersistedSenderAddress =
+            serde_json::from_slice(&bytes).context("invalid persisted sender address payload")?;
+        return Ok(persisted.addr);
+    }
+
+    // Rows created before multi-relay invitations stored a raw BlobTicket.
+    let legacy = BlobTicket::from_str(value).context("invalid legacy sender BlobTicket")?;
+    Ok(legacy.addr().clone())
 }
 
 #[cfg(test)]
@@ -93,17 +133,55 @@ pub(crate) fn parse_transfer_ticket_with_limits(
         Some(ticket.metadata.transfer_name.as_str()),
     )?;
     limits.validate_metadata_text("sender name", ticket.metadata.sender_name.as_deref())?;
-    let blob_ticket = BlobTicket::from_str(&ticket.blob_ticket)
+    let mut blob_ticket = BlobTicket::from_str(&ticket.blob_ticket)
         .context("invalid BlobTicket inside VniDrop ticket")?;
     if ticket.metadata.content_hash != blob_ticket.hash().to_string() {
         anyhow::bail!("VniDrop ticket metadata hash does not match BlobTicket hash");
     }
+    let advertised_custom_relay_urls = if ticket.relay_urls.is_empty() {
+        Vec::new()
+    } else {
+        CoreNetworkConfig {
+            mode: CoreRelayMode::Custom,
+            relay_urls: ticket.relay_urls,
+        }
+        .validated_relay_urls()
+        .context("invalid relay URLs inside VniDrop ticket")?
+    };
+    if !advertised_custom_relay_urls.is_empty() {
+        let (mut addr, hash, format) = blob_ticket.into_parts();
+        for relay_url in advertised_custom_relay_urls.iter().cloned() {
+            addr = addr.with_relay_url(relay_url);
+        }
+        blob_ticket = BlobTicket::new(addr, hash, format);
+    }
     Ok(ParsedTransferTicket {
         blob_ticket,
         metadata: ticket.metadata,
+        advertised_custom_relay_urls,
     })
 }
 
+pub(crate) fn ticket_matches_relay_profile(
+    value: &str,
+    limits: &CoreLimits,
+    relay_mode: CoreRelayMode,
+    custom_relay_urls: &[RelayUrl],
+) -> Result<bool> {
+    let parsed = parse_transfer_ticket_with_limits(value, limits)?;
+    match relay_mode {
+        CoreRelayMode::Automatic => Ok(parsed.advertised_custom_relay_urls.is_empty()),
+        CoreRelayMode::Custom => {
+            let advertised = parsed
+                .advertised_custom_relay_urls
+                .into_iter()
+                .collect::<BTreeSet<_>>();
+            let configured = custom_relay_urls.iter().cloned().collect::<BTreeSet<_>>();
+            Ok(advertised == configured)
+        }
+    }
+}
+
 fn normalize_ticket_input(value: &str) -> String {
     // Tickets are commonly copied from text views or chat apps that insert line
     // breaks.  Strip whitespace only; other corrupt characters should still be

crates/vnidrop/tests/custom_relay.rs

@@ -0,0 +1,106 @@
+mod support;
+
+use std::str::FromStr;
+
+use data_encoding::BASE64URL_NOPAD;
+use iroh::{EndpointAddr, RelayUrl};
+use iroh_blobs::ticket::BlobTicket;
+use serde_json::Value;
+use support::{receive_with_response, share_path, TestNode, TestRelay};
+use vnidrop::{CoreNetworkConfig, CoreRelayMode};
+
+fn custom_config(relay_urls: &[&str]) -> CoreNetworkConfig {
+    CoreNetworkConfig {
+        mode: CoreRelayMode::Custom,
+        relay_urls: relay_urls.iter().map(ToString::to_string).collect(),
+    }
+}
+
+fn read_blob_ticket(ticket: &str) -> (Value, BlobTicket) {
+    let encoded = ticket.strip_prefix("vnd1:").unwrap();
+    let payload = BASE64URL_NOPAD.decode(encoded.as_bytes()).unwrap();
+    let value: Value = serde_json::from_slice(&payload).unwrap();
+    let blob_ticket = BlobTicket::from_str(value["blob_ticket"].as_str().unwrap()).unwrap();
+    let (mut addr, hash, format) = blob_ticket.into_parts();
+    for relay_url in value["relay_urls"].as_array().unwrap() {
+        addr = addr.with_relay_url(relay_url.as_str().unwrap().parse().unwrap());
+    }
+    let blob_ticket = BlobTicket::new(addr, hash, format);
+    (value, blob_ticket)
+}
+
+fn with_relay_only_address(ticket: &str, relay_url: &str) -> String {
+    let (mut value, blob_ticket) = read_blob_ticket(ticket);
+    let relay_url: RelayUrl = relay_url.parse().unwrap();
+    let relay_only_addr = EndpointAddr::new(blob_ticket.addr().id).with_relay_url(relay_url);
+    let relay_only_ticket =
+        BlobTicket::new(relay_only_addr, blob_ticket.hash(), blob_ticket.format());
+    value["blob_ticket"] = Value::String(relay_only_ticket.to_string());
+    let payload = serde_json::to_vec(&value).unwrap();
+    format!("vnd1:{}", BASE64URL_NOPAD.encode(&payload))
+}
+
+#[test]
+fn strict_custom_relay_is_advertised_and_transfers_without_direct_ticket_addresses() {
+    let relay = TestRelay::start();
+    let backup_relay = "http://127.0.0.1:9";
+    let relay_urls = [relay.url.as_str(), backup_relay];
+    let sender = TestNode::with_network_config(custom_config(&relay_urls));
+    let receiver = TestNode::with_network_config(custom_config(&[relay.url.as_str()]));
+    let source_dir = tempfile::tempdir().unwrap();
+    let output_dir = tempfile::tempdir().unwrap();
+    let source_path = source_dir.path().join("custom-relay.txt");
+    std::fs::write(&source_path, b"through the custom relay").unwrap();
+
+    let share = share_path(&sender.core, &source_path, 401, "custom-relay.txt", false);
+    let (ticket_value, blob_ticket) = read_blob_ticket(&share.ticket);
+    let advertised_relays: Vec<_> = blob_ticket
+        .addr()
+        .relay_urls()
+        .map(ToString::to_string)
+        .collect();
+    let configured_relay = RelayUrl::from_str(&relay.url).unwrap().to_string();
+    let configured_backup = RelayUrl::from_str(backup_relay).unwrap().to_string();
+    let envelope_relays = ticket_value["relay_urls"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|value| value.as_str().unwrap().to_string())
+        .collect::<Vec<_>>();
+    assert_eq!(
+        envelope_relays,
+        vec![configured_relay.clone(), configured_backup.clone()]
+    );
+    let mut configured_relays = vec![configured_relay.clone(), configured_backup];
+    configured_relays.sort();
+    assert_eq!(advertised_relays, configured_relays.clone());
+    assert!(!advertised_relays.iter().any(|url| url.contains("n0")));
+    assert!(!sender.core.status().addr.contains("iroh.link"));
+
+    let relay_only_ticket = with_relay_only_address(&share.ticket, &relay.url);
+    let (_, relay_only_blob_ticket) = read_blob_ticket(&relay_only_ticket);
+    assert_eq!(relay_only_blob_ticket.addr().ip_addrs().count(), 0);
+    assert_eq!(
+        relay_only_blob_ticket
+            .addr()
+            .relay_urls()
+            .map(ToString::to_string)
+            .collect::<Vec<_>>(),
+        configured_relays
+    );
+
+    receive_with_response(
+        &sender.core,
+        share.transfer_id,
+        receiver.core.arc(),
+        relay_only_ticket,
+        output_dir.path(),
+        true,
+    )
+    .unwrap();
+
+    assert_eq!(
+        std::fs::read(output_dir.path().join("custom-relay.txt")).unwrap(),
+        b"through the custom relay"
+    );
+}

crates/vnidrop/tests/lifecycle.rs

@@ -5,10 +5,10 @@ use std::time::Duration;
 
 use futures_lite::StreamExt as _;
 use iroh_blobs::store::fs::FsStore;
-use support::{share_path, CoreGuard, RecordingSink, TestNode};
+use support::{share_path, CoreGuard, RecordingSink, TestNode, TestRelay};
 use vnidrop::{
-    CoreEvent, CoreEventSink, CoreLimits, ShareMetadataInput, ShareSource, SourceKind,
+    CoreEvent, CoreEventSink, CoreLimits, CoreNetworkConfig, CoreRelayMode, ShareMetadataInput,
-    TransferAccessMode,
+    ShareSource, SourceKind, TransferAccessMode,
 };
 
 #[test]
@@ -137,6 +137,56 @@ fn persisted_share_is_recovered_and_can_be_stopped_after_restart() {
     assert_eq!(restarted.status().active_shares, 0);
 }
 
+#[test]
+fn persisted_share_is_revoked_when_restarted_with_a_different_relay_profile() {
+    let relay_a = TestRelay::start();
+    let relay_b = TestRelay::start();
+    assert_ne!(relay_a.url, relay_b.url);
+
+    let source_dir = tempfile::tempdir().unwrap();
+    let core_dir = tempfile::tempdir().unwrap();
+    let source_path = source_dir.path().join("stale-relay.txt");
+    std::fs::write(&source_path, b"must not survive a relay profile change").unwrap();
+    let sender = CoreGuard::start_with_network_config(
+        core_dir.path(),
+        Arc::new(RecordingSink::default()),
+        CoreNetworkConfig {
+            mode: CoreRelayMode::Custom,
+            relay_urls: vec![relay_a.url.clone()],
+        },
+    );
+    let share = share_path(&sender, &source_path, 120, "stale-relay.txt", false);
+    drop(sender);
+    drop(relay_a);
+
+    let restarted = CoreGuard::start_with_network_config(
+        core_dir.path(),
+        Arc::new(RecordingSink::default()),
+        CoreNetworkConfig {
+            mode: CoreRelayMode::Custom,
+            relay_urls: vec![relay_b.url.clone()],
+        },
+    );
+
+    assert_eq!(restarted.status().active_shares, 0);
+    let transfer = restarted
+        .list_transfers()
+        .unwrap()
+        .into_iter()
+        .find(|transfer| transfer.transfer_id == share.transfer_id)
+        .unwrap();
+    assert_eq!(transfer.status, "stopped");
+    assert!(restarted
+        .list_events(Some(share.transfer_id))
+        .unwrap()
+        .iter()
+        .any(|event| {
+            event.phase == "recovery" && event.kind == "share-stopped-network-profile-changed"
+        }));
+    drop(restarted);
+    assert_eq!(share_tag_count(core_dir.path()), 0);
+}
+
 #[test]
 fn stopped_share_rejects_receive() {
     let source_dir = tempfile::tempdir().unwrap();

crates/vnidrop/tests/support/mod.rs

@@ -8,15 +8,16 @@ use std::{
     path::Path,
     sync::{
         atomic::{AtomicBool, Ordering},
-        Arc, Condvar, Mutex,
+        mpsc, Arc, Condvar, Mutex,
     },
+    thread::JoinHandle,
     time::{Duration, Instant},
 };
 
 use vnidrop::{
-    CoreEvent, CoreEventSink, CoreLimits, PublishedOutput, ReceiveOutputSink, ReceiveOutputSinkV2,
+    CoreEvent, CoreEventSink, CoreLimits, CoreNetworkConfig, PublishedOutput, ReceiveOutputSink,
-    ReceivedLocatorKind, ReceiverRequest, ShareMetadataInput, ShareResult, ShareSource, SourceKind,
+    ReceiveOutputSinkV2, ReceivedLocatorKind, ReceiverRequest, ShareMetadataInput, ShareResult,
-    TransferAccessMode, VnidropCore, VnidropError,
+    ShareSource, SourceKind, TransferAccessMode, VnidropCore, VnidropError,
 };
 
 #[derive(Default)]
@@ -57,6 +58,21 @@ impl CoreGuard {
         )
     }
 
+    pub fn start_with_network_config(
+        path: &Path,
+        sink: Arc<dyn CoreEventSink>,
+        network_config: CoreNetworkConfig,
+    ) -> Self {
+        Self(
+            VnidropCore::initialize_with_network_config(
+                path.to_string_lossy().to_string(),
+                sink,
+                network_config,
+            )
+            .expect("test core should initialize with network config"),
+        )
+    }
+
     pub fn arc(&self) -> Arc<VnidropCore> {
         self.0.clone()
     }
@@ -93,6 +109,80 @@ impl TestNode {
             sink,
         }
     }
+
+    pub fn with_network_config(network_config: CoreNetworkConfig) -> Self {
+        let data_dir = tempfile::tempdir().unwrap();
+        let sink = Arc::new(RecordingSink::default());
+        let core =
+            CoreGuard::start_with_network_config(data_dir.path(), sink.clone(), network_config);
+        Self {
+            _data_dir: data_dir,
+            core,
+            sink,
+        }
+    }
+}
+
+pub struct TestRelay {
+    pub url: String,
+    shutdown: Option<tokio::sync::oneshot::Sender<()>>,
+    thread: Option<JoinHandle<()>>,
+}
+
+impl TestRelay {
+    pub fn start() -> Self {
+        let (ready_tx, ready_rx) = mpsc::sync_channel(1);
+        let (shutdown_tx, shutdown_rx) = tokio::sync::oneshot::channel();
+        let thread = std::thread::spawn(move || {
+            let runtime = tokio::runtime::Builder::new_multi_thread()
+                .enable_all()
+                .thread_name("vnidrop-test-relay")
+                .build()
+                .unwrap();
+            runtime.block_on(async move {
+                let relay =
+                    iroh_relay::server::RelayConfig::new((std::net::Ipv4Addr::LOCALHOST, 0));
+                let mut config = iroh_relay::server::ServerConfig::default();
+                config.relay = Some(relay);
+                let server = match iroh_relay::server::Server::spawn(config).await {
+                    Ok(server) => server,
+                    Err(error) => {
+                        ready_tx.send(Err(error.to_string())).ok();
+                        return;
+                    }
+                };
+                let url = format!(
+                    "http://{}",
+                    server.http_addr().expect("HTTP relay should be bound")
+                );
+                if ready_tx.send(Ok(url)).is_err() {
+                    return;
+                }
+                shutdown_rx.await.ok();
+                drop(server);
+            });
+        });
+        let url = ready_rx
+            .recv_timeout(Duration::from_secs(5))
+            .expect("test relay should start")
+            .expect("test relay should bind");
+        Self {
+            url,
+            shutdown: Some(shutdown_tx),
+            thread: Some(thread),
+        }
+    }
+}
+
+impl Drop for TestRelay {
+    fn drop(&mut self) {
+        if let Some(shutdown) = self.shutdown.take() {
+            shutdown.send(()).ok();
+        }
+        if let Some(thread) = self.thread.take() {
+            thread.join().unwrap();
+        }
+    }
 }
 
 #[derive(Default)]

localization/strings.json

@@ -2483,6 +2483,338 @@
         "ru": "Передача VniDrop"
       }
     },
+    "relay_add_url": {
+      "context": "Apple Network settings button that appends another custom relay URL field.",
+      "translations": {
+        "en": "Add relay server",
+        "fr": "Ajouter un serveur relais",
+        "es": "Añadir servidor de retransmisión",
+        "it": "Aggiungi server relay",
+        "de": "Relay-Server hinzufügen",
+        "pt": "Adicionar servidor de retransmissão",
+        "pl": "Dodaj serwer przekaźnikowy",
+        "nl": "Relayserver toevoegen",
+        "ru": "Добавить сервер-ретранслятор"
+      }
+    },
+    "relay_apply": {
+      "context": "Network settings button that activates the selected relay configuration.",
+      "translations": {
+        "en": "Apply network settings",
+        "fr": "Appliquer les réglages réseau",
+        "es": "Aplicar ajustes de red",
+        "it": "Applica impostazioni di rete",
+        "de": "Netzwerkeinstellungen anwenden",
+        "pt": "Aplicar definições de rede",
+        "pl": "Zastosuj ustawienia sieci",
+        "nl": "Netwerkinstellingen toepassen",
+        "ru": "Применить настройки сети"
+      }
+    },
+    "relay_applying": {
+      "context": "Network settings button label while a relay configuration is being activated.",
+      "translations": {
+        "en": "Applying…",
+        "fr": "Application…",
+        "es": "Aplicando…",
+        "it": "Applicazione…",
+        "de": "Wird angewendet…",
+        "pt": "A aplicar…",
+        "pl": "Stosowanie…",
+        "nl": "Toepassen…",
+        "ru": "Применение…"
+      }
+    },
+    "relay_apply_active_transfers": {
+      "context": "Network settings warning when relay configuration cannot change during active work.",
+      "translations": {
+        "en": "Stop all active transfers and shares before applying network settings.",
+        "fr": "Arrêtez tous les transferts et partages actifs avant d’appliquer les réglages réseau.",
+        "es": "Detenga todas las transferencias y elementos compartidos activos antes de aplicar los ajustes de red.",
+        "it": "Interrompa tutti i trasferimenti e le condivisioni attivi prima di applicare le impostazioni di rete.",
+        "de": "Beenden Sie alle aktiven Übertragungen und Freigaben, bevor Sie die Netzwerkeinstellungen anwenden.",
+        "pt": "Pare todas as transferências e partilhas ativas antes de aplicar as definições de rede.",
+        "pl": "Zatrzymaj wszystkie aktywne transfery i udostępnienia przed zastosowaniem ustawień sieci.",
+        "nl": "Stop alle actieve overdrachten en gedeelde items voordat u de netwerkinstellingen toepast.",
+        "ru": "Остановите все активные передачи и раздачи перед применением настроек сети."
+      }
+    },
+    "relay_apply_failed": {
+      "context": "Network settings error after a relay configuration fails and the previous one is restored.",
+      "translations": {
+        "en": "Could not apply these settings. The previous network settings were restored.",
+        "fr": "Impossible d’appliquer ces réglages. Les réglages réseau précédents ont été restaurés.",
+        "es": "No se han podido aplicar estos ajustes. Se han restaurado los ajustes de red anteriores.",
+        "it": "Impossibile applicare queste impostazioni. Sono state ripristinate le impostazioni di rete precedenti.",
+        "de": "Diese Einstellungen konnten nicht angewendet werden. Die vorherigen Netzwerkeinstellungen wurden wiederhergestellt.",
+        "pt": "Não foi possível aplicar estas definições. As definições de rede anteriores foram restauradas.",
+        "pl": "Nie udało się zastosować tych ustawień. Przywrócono poprzednie ustawienia sieci.",
+        "nl": "Deze instellingen konden niet worden toegepast. De vorige netwerkinstellingen zijn hersteld.",
+        "ru": "Не удалось применить эти настройки. Предыдущие настройки сети восстановлены."
+      }
+    },
+    "relay_apply_restart_description": {
+      "context": "Network settings explanation of restart and invitation effects when applying relay changes.",
+      "translations": {
+        "en": "Applying restarts VniDrop’s network connection. Stop active transfers and shares first. Existing invitations may need to be shared again.",
+        "fr": "L’application de ces réglages redémarre la connexion réseau de VniDrop. Arrêtez d’abord les transferts et partages actifs. Il peut être nécessaire de partager à nouveau les invitations existantes.",
+        "es": "Al aplicar los ajustes, se reinicia la conexión de red de VniDrop. Detenga primero las transferencias y los elementos compartidos activos. Es posible que tenga que volver a compartir las invitaciones existentes.",
+        "it": "L’applicazione riavvia la connessione di rete di VniDrop. Interrompa prima i trasferimenti e le condivisioni attivi. Potrebbe essere necessario condividere di nuovo gli inviti esistenti.",
+        "de": "Beim Anwenden wird die Netzwerkverbindung von VniDrop neu gestartet. Beenden Sie zuerst aktive Übertragungen und Freigaben. Vorhandene Einladungen müssen eventuell erneut geteilt werden.",
+        "pt": "A aplicação reinicia a ligação de rede do VniDrop. Pare primeiro as transferências e partilhas ativas. Poderá ser necessário voltar a partilhar os convites existentes.",
+        "pl": "Zastosowanie ustawień ponownie uruchamia połączenie sieciowe VniDrop. Najpierw zatrzymaj aktywne transfery i udostępnienia. Istniejące zaproszenia mogą wymagać ponownego udostępnienia.",
+        "nl": "Bij het toepassen wordt de netwerkverbinding van VniDrop opnieuw gestart. Stop eerst actieve overdrachten en gedeelde items. Bestaande uitnodigingen moeten mogelijk opnieuw worden gedeeld.",
+        "ru": "При применении сетевое соединение VniDrop перезапускается. Сначала остановите активные передачи и раздачи. Возможно, существующие приглашения потребуется отправить повторно."
+      }
+    },
+    "relay_custom_urls_help": {
+      "context": "Network settings help for entering custom relay server URLs.",
+      "translations": {
+        "en": "Enter one HTTPS relay URL per line. URL credentials are not supported. The TLS certificate must be issued by a publicly trusted certificate authority.",
+        "fr": "Saisissez une URL de relais HTTPS par ligne. Les identifiants dans les URL ne sont pas pris en charge. Le certificat TLS doit être émis par une autorité de certification reconnue publiquement.",
+        "es": "Introduzca una URL HTTPS de relé por línea. No se admiten credenciales en las URL. El certificado TLS debe ser emitido por una autoridad de certificación de confianza pública.",
+        "it": "Inserisca un URL relay HTTPS per riga. Le credenziali negli URL non sono supportate. Il certificato TLS deve essere emesso da un’autorità di certificazione pubblicamente attendibile.",
+        "de": "Geben Sie pro Zeile eine HTTPS-Relay-URL ein. Anmeldedaten in URLs werden nicht unterstützt. Das TLS-Zertifikat muss von einer öffentlich vertrauenswürdigen Zertifizierungsstelle ausgestellt sein.",
+        "pt": "Introduza um URL HTTPS de retransmissor por linha. Não são suportadas credenciais nos URLs. O certificado TLS tem de ser emitido por uma autoridade de certificação publicamente reconhecida.",
+        "pl": "Wprowadź po jednym adresie URL HTTPS przekaźnika w każdym wierszu. Dane logowania w adresach URL nie są obsługiwane. Certyfikat TLS musi być wystawiony przez publicznie zaufany urząd certyfikacji.",
+        "nl": "Voer per regel één HTTPS-relay-URL in. Aanmeldgegevens in URL's worden niet ondersteund. Het TLS-certificaat moet zijn uitgegeven door een openbaar vertrouwde certificeringsinstantie.",
+        "ru": "Введите по одному HTTPS-адресу ретранслятора в строке. Учётные данные в URL-адресах не поддерживаются. Сертификат TLS должен быть выдан общедоступным доверенным центром сертификации."
+      }
+    },
+    "relay_custom_urls_label": {
+      "context": "Network settings label for the custom relay URL input.",
+      "translations": {
+        "en": "Relay URLs",
+        "fr": "URL des relais",
+        "es": "URL de relés",
+        "it": "URL relay",
+        "de": "Relay-URLs",
+        "pt": "URLs dos retransmissores",
+        "pl": "Adresy URL przekaźników",
+        "nl": "Relay-URL's",
+        "ru": "URL-адреса ретрансляторов"
+      }
+    },
+    "relay_mode_automatic": {
+      "context": "Network settings label for VniDrop's automatic public relay mode.",
+      "translations": {
+        "en": "Automatic",
+        "fr": "Automatique",
+        "es": "Automático",
+        "it": "Automatica",
+        "de": "Automatisch",
+        "pt": "Automático",
+        "pl": "Automatyczny",
+        "nl": "Automatisch",
+        "ru": "Автоматически"
+      }
+    },
+    "relay_mode_automatic_description": {
+      "context": "Network settings description of automatic public relay behavior.",
+      "translations": {
+        "en": "Use VniDrop’s default public relay infrastructure when a direct connection is unavailable.",
+        "fr": "Utiliser l’infrastructure de relais publique par défaut de VniDrop lorsqu’une connexion directe est indisponible.",
+        "es": "Usa la infraestructura pública de relés predeterminada de VniDrop cuando no haya una conexión directa disponible.",
+        "it": "Usa l’infrastruttura relay pubblica predefinita di VniDrop quando non è disponibile una connessione diretta.",
+        "de": "Verwendet die öffentliche Standard-Relay-Infrastruktur von VniDrop, wenn keine direkte Verbindung möglich ist.",
+        "pt": "Utiliza a infraestrutura pública de retransmissores predefinida do VniDrop quando não está disponível uma ligação direta.",
+        "pl": "Używa domyślnej publicznej infrastruktury przekaźników VniDrop, gdy połączenie bezpośrednie jest niedostępne.",
+        "nl": "Gebruikt de standaard openbare relay-infrastructuur van VniDrop wanneer geen directe verbinding beschikbaar is.",
+        "ru": "Использовать стандартную публичную инфраструктуру ретрансляторов VniDrop, если прямое соединение недоступно."
+      }
+    },
+    "relay_mode_custom": {
+      "context": "Network settings label for strict custom relay mode.",
+      "translations": {
+        "en": "Custom",
+        "fr": "Personnalisé",
+        "es": "Personalizado",
+        "it": "Personalizzata",
+        "de": "Benutzerdefiniert",
+        "pt": "Personalizado",
+        "pl": "Niestandardowy",
+        "nl": "Aangepast",
+        "ru": "Пользовательский"
+      }
+    },
+    "relay_mode_custom_description": {
+      "context": "Network settings description of strict custom relay behavior.",
+      "translations": {
+        "en": "Use only the relay servers below.",
+        "fr": "Utiliser uniquement les serveurs relais ci-dessous.",
+        "es": "Usa únicamente los servidores de retransmisión indicados a continuación.",
+        "it": "Usa solo i server relay indicati di seguito.",
+        "de": "Verwendet ausschließlich die unten aufgeführten Relay-Server.",
+        "pt": "Utiliza apenas os servidores de retransmissão abaixo.",
+        "pl": "Używa wyłącznie poniższych serwerów przekaźnikowych.",
+        "nl": "Gebruikt alleen de onderstaande relayservers.",
+        "ru": "Использовать только указанные ниже серверы-ретрансляторы."
+      }
+    },
+    "relay_privacy_description": {
+      "context": "Network settings privacy note about what relay operators can observe.",
+      "translations": {
+        "en": "Relays forward encrypted traffic and cannot read your files, but their operator can observe connection metadata.",
+        "fr": "Les relais transmettent du trafic chiffré et ne peuvent pas lire vos fichiers, mais leur opérateur peut observer les métadonnées de connexion.",
+        "es": "Los relés reenvían tráfico cifrado y no pueden leer sus archivos, pero su operador puede observar los metadatos de conexión.",
+        "it": "I relay inoltrano traffico cifrato e non possono leggere i suoi file, ma il loro operatore può osservare i metadati di connessione.",
+        "de": "Relays leiten verschlüsselten Datenverkehr weiter und können Ihre Dateien nicht lesen, ihr Betreiber kann jedoch Verbindungsmetadaten sehen.",
+        "pt": "Os retransmissores encaminham tráfego cifrado e não conseguem ler os seus ficheiros, mas o operador pode observar metadados da ligação.",
+        "pl": "Przekaźniki przesyłają zaszyfrowany ruch i nie mogą odczytać plików, ale ich operator może obserwować metadane połączenia.",
+        "nl": "Relays sturen versleuteld verkeer door en kunnen uw bestanden niet lezen, maar de beheerder kan verbindingsmetadata bekijken.",
+        "ru": "Ретрансляторы передают зашифрованный трафик и не могут читать ваши файлы, но их оператор может видеть метаданные соединения."
+      }
+    },
+    "relay_remove_url": {
+      "context": "Apple Network settings accessibility label for removing one custom relay URL field.",
+      "translations": {
+        "en": "Remove relay server",
+        "fr": "Supprimer le serveur relais",
+        "es": "Eliminar servidor de retransmisión",
+        "it": "Rimuovi server relay",
+        "de": "Relay-Server entfernen",
+        "pt": "Remover servidor de retransmissão",
+        "pl": "Usuń serwer przekaźnikowy",
+        "nl": "Relayserver verwijderen",
+        "ru": "Удалить сервер-ретранслятор"
+      }
+    },
+    "relay_restore_failed": {
+      "context": "Network settings severe error when neither new nor previous relay settings can initialize.",
+      "translations": {
+        "en": "Could not restore the previous network settings. Restart VniDrop and review your relay configuration.",
+        "fr": "Impossible de restaurer les réglages réseau précédents. Redémarrez VniDrop et vérifiez votre configuration de relais.",
+        "es": "No se han podido restaurar los ajustes de red anteriores. Reinicie VniDrop y revise la configuración de relés.",
+        "it": "Impossibile ripristinare le impostazioni di rete precedenti. Riavvii VniDrop e verifichi la configurazione dei relay.",
+        "de": "Die vorherigen Netzwerkeinstellungen konnten nicht wiederhergestellt werden. Starten Sie VniDrop neu und prüfen Sie Ihre Relay-Konfiguration.",
+        "pt": "Não foi possível restaurar as definições de rede anteriores. Reinicie o VniDrop e reveja a configuração dos retransmissores.",
+        "pl": "Nie udało się przywrócić poprzednich ustawień sieci. Uruchom ponownie VniDrop i sprawdź konfigurację przekaźników.",
+        "nl": "De vorige netwerkinstellingen konden niet worden hersteld. Start VniDrop opnieuw en controleer uw relayconfiguratie.",
+        "ru": "Не удалось восстановить предыдущие настройки сети. Перезапустите VniDrop и проверьте конфигурацию ретрансляторов."
+      }
+    },
+    "relay_settings_applied": {
+      "context": "Network settings confirmation after a relay configuration is activated.",
+      "translations": {
+        "en": "Network settings applied.",
+        "fr": "Réglages réseau appliqués.",
+        "es": "Ajustes de red aplicados.",
+        "it": "Impostazioni di rete applicate.",
+        "de": "Netzwerkeinstellungen angewendet.",
+        "pt": "Definições de rede aplicadas.",
+        "pl": "Zastosowano ustawienia sieci.",
+        "nl": "Netwerkinstellingen toegepast.",
+        "ru": "Настройки сети применены."
+      }
+    },
+    "relay_strict_warning": {
+      "context": "Network settings warning that custom relay mode has no public fallback or discovery.",
+      "translations": {
+        "en": "Custom mode is strict: VniDrop will not fall back to public relays or public discovery. Other devices must be able to reach your configured relays.",
+        "fr": "Le mode personnalisé est strict : VniDrop n’utilisera ni les relais publics ni la découverte publique comme solution de repli. Les autres appareils doivent pouvoir accéder aux relais configurés.",
+        "es": "El modo personalizado es estricto: VniDrop no recurrirá a relés públicos ni al descubrimiento público. Los demás dispositivos deben poder acceder a los relés configurados.",
+        "it": "La modalità personalizzata è rigorosa: VniDrop non userà relay pubblici o il rilevamento pubblico come ripiego. Gli altri dispositivi devono poter raggiungere i relay configurati.",
+        "de": "Der benutzerdefinierte Modus ist strikt: VniDrop greift weder auf öffentliche Relays noch auf öffentliche Erkennung zurück. Andere Geräte müssen Ihre konfigurierten Relays erreichen können.",
+        "pt": "O modo personalizado é estrito: o VniDrop não recorrerá a retransmissores públicos nem à descoberta pública. Os outros dispositivos têm de conseguir aceder aos retransmissores configurados.",
+        "pl": "Tryb niestandardowy jest rygorystyczny: VniDrop nie użyje awaryjnie publicznych przekaźników ani publicznego wykrywania. Inne urządzenia muszą mieć dostęp do skonfigurowanych przekaźników.",
+        "nl": "De aangepaste modus is strikt: VniDrop valt niet terug op openbare relays of openbare detectie. Andere apparaten moeten uw ingestelde relays kunnen bereiken.",
+        "ru": "Пользовательский режим работает строго: VniDrop не будет переключаться на публичные ретрансляторы или публичное обнаружение. Другие устройства должны иметь доступ к настроенным ретрансляторам."
+      }
+    },
+    "relay_validation_duplicate_url": {
+      "context": "Network settings validation error for a repeated custom relay URL.",
+      "args": [
+        {
+          "name": "line",
+          "type": "int"
+        }
+      ],
+      "translations": {
+        "en": "Relay URL on line {line} duplicates an earlier entry.",
+        "fr": "L’URL de relais à la ligne {line} est identique à une entrée précédente.",
+        "es": "La URL de relé de la línea {line} duplica una entrada anterior.",
+        "it": "L’URL relay alla riga {line} duplica una voce precedente.",
+        "de": "Die Relay-URL in Zeile {line} ist bereits zuvor eingetragen.",
+        "pt": "O URL do retransmissor na linha {line} duplica uma entrada anterior.",
+        "pl": "Adres URL przekaźnika w wierszu {line} powtarza wcześniejszy wpis.",
+        "nl": "De relay-URL op regel {line} is gelijk aan een eerdere invoer.",
+        "ru": "URL-адрес ретранслятора в строке {line} повторяет предыдущую запись."
+      }
+    },
+    "relay_validation_https_required": {
+      "context": "Network settings validation error when a custom relay URL is not HTTPS.",
+      "args": [
+        {
+          "name": "line",
+          "type": "int"
+        }
+      ],
+      "translations": {
+        "en": "Relay URL on line {line} must start with https://.",
+        "fr": "L’URL de relais à la ligne {line} doit commencer par https://.",
+        "es": "La URL de relé de la línea {line} debe empezar por https://.",
+        "it": "L’URL relay alla riga {line} deve iniziare con https://.",
+        "de": "Die Relay-URL in Zeile {line} muss mit https:// beginnen.",
+        "pt": "O URL do retransmissor na linha {line} tem de começar por https://.",
+        "pl": "Adres URL przekaźnika w wierszu {line} musi zaczynać się od https://.",
+        "nl": "De relay-URL op regel {line} moet beginnen met https://.",
+        "ru": "URL-адрес ретранслятора в строке {line} должен начинаться с https://."
+      }
+    },
+    "relay_validation_invalid_url": {
+      "context": "Network settings validation error for a malformed custom relay URL.",
+      "args": [
+        {
+          "name": "line",
+          "type": "int"
+        }
+      ],
+      "translations": {
+        "en": "Relay URL on line {line} is not valid.",
+        "fr": "L’URL de relais à la ligne {line} n’est pas valide.",
+        "es": "La URL de relé de la línea {line} no es válida.",
+        "it": "L’URL relay alla riga {line} non è valido.",
+        "de": "Die Relay-URL in Zeile {line} ist ungültig.",
+        "pt": "O URL do retransmissor na linha {line} não é válido.",
+        "pl": "Adres URL przekaźnika w wierszu {line} jest nieprawidłowy.",
+        "nl": "De relay-URL op regel {line} is ongeldig.",
+        "ru": "URL-адрес ретранслятора в строке {line} недействителен."
+      }
+    },
+    "relay_validation_missing_url": {
+      "context": "Network settings validation error when custom mode has no relay URL.",
+      "translations": {
+        "en": "Add at least one relay URL.",
+        "fr": "Ajoutez au moins une URL de relais.",
+        "es": "Añada al menos una URL de relé.",
+        "it": "Aggiunga almeno un URL relay.",
+        "de": "Fügen Sie mindestens eine Relay-URL hinzu.",
+        "pt": "Adicione pelo menos um URL de retransmissor.",
+        "pl": "Dodaj co najmniej jeden adres URL przekaźnika.",
+        "nl": "Voeg ten minste één relay-URL toe.",
+        "ru": "Добавьте хотя бы один URL-адрес ретранслятора."
+      }
+    },
+    "relay_validation_too_many_urls": {
+      "context": "Network settings validation error when too many custom relay URLs are entered.",
+      "args": [
+        {
+          "name": "maximum",
+          "type": "int"
+        }
+      ],
+      "translations": {
+        "en": "You can configure up to {maximum} relay servers.",
+        "fr": "Vous pouvez configurer jusqu’à {maximum} serveurs relais.",
+        "es": "Puede configurar hasta {maximum} servidores de retransmisión.",
+        "it": "Può configurare fino a {maximum} server relay.",
+        "de": "Sie können bis zu {maximum} Relay-Server konfigurieren.",
+        "pt": "Pode configurar até {maximum} servidores de retransmissão.",
+        "pl": "Możesz skonfigurować maksymalnie {maximum} serwerów przekaźnikowych.",
+        "nl": "U kunt maximaal {maximum} relayservers instellen.",
+        "ru": "Можно настроить до {maximum} серверов-ретрансляторов."
+      }
+    },
     "send_access_anyone": {
       "context": "Send access option: anyone with the invitation can receive.",
       "translations": {
@@ -2811,6 +3143,34 @@
         "ru": "Ваши передачи"
       }
     },
+    "settings_advanced_title": {
+      "context": "Settings overview section header for expert configuration.",
+      "translations": {
+        "en": "Advanced",
+        "fr": "Avancé",
+        "es": "Avanzado",
+        "it": "Avanzate",
+        "de": "Erweitert",
+        "pt": "Avançado",
+        "pl": "Zaawansowane",
+        "nl": "Geavanceerd",
+        "ru": "Дополнительно"
+      }
+    },
+    "settings_network_title": {
+      "context": "Settings overview row and Network settings screen title.",
+      "translations": {
+        "en": "Network",
+        "fr": "Réseau",
+        "es": "Red",
+        "it": "Rete",
+        "de": "Netzwerk",
+        "pt": "Rede",
+        "pl": "Sieć",
+        "nl": "Netwerk",
+        "ru": "Сеть"
+      }
+    },
     "settings_subtitle": {
       "context": "Settings screen: subtitle summarizing what's configurable.",
       "translations": {
@@ -3692,6 +4052,20 @@
         "ru": "Получатели"
       }
     },
+    "transfer_qr_unavailable": {
+      "context": "Transfer share: shown when an invitation is too large to encode as a QR code.",
+      "translations": {
+        "en": "QR unavailable for this invitation. Use Share or Download instead.",
+        "fr": "Le code QR n’est pas disponible pour cette invitation. Utilisez plutôt Partager ou Télécharger.",
+        "es": "El QR no está disponible para esta invitación. Use Compartir o Descargar.",
+        "it": "Il codice QR non è disponibile per questo invito. Utilizzi invece Condividi o Scarica.",
+        "de": "Für diese Einladung ist kein QR-Code verfügbar. Verwenden Sie stattdessen Teilen oder Herunterladen.",
+        "pt": "O código QR não está disponível para este convite. Utilize Partilhar ou Transferir.",
+        "pl": "Kod QR jest niedostępny dla tego zaproszenia. Zamiast tego użyj opcji Udostępnij lub Pobierz.",
+        "nl": "QR is niet beschikbaar voor deze uitnodiging. Gebruik in plaats daarvan Delen of Downloaden.",
+        "ru": "QR-код недоступен для этого приглашения. Используйте «Поделиться» или «Скачать»."
+      }
+    },
     "transfer_scan_qr": {
       "context": "Transfer share: caption under the QR code.",
       "translations": {

shared/src/commonMain/composeResources/values-de/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Übertragung prüfen</string>
     <string name="receive_title">Empfangen</string>
     <string name="receive_unknown_transfer">VniDrop-Übertragung</string>
+    <string name="relay_add_url">Relay-Server hinzufügen</string>
+    <string name="relay_apply">Netzwerkeinstellungen anwenden</string>
+    <string name="relay_applying">Wird angewendet…</string>
+    <string name="relay_apply_active_transfers">Beenden Sie alle aktiven Übertragungen und Freigaben, bevor Sie die Netzwerkeinstellungen anwenden.</string>
+    <string name="relay_apply_failed">Diese Einstellungen konnten nicht angewendet werden. Die vorherigen Netzwerkeinstellungen wurden wiederhergestellt.</string>
+    <string name="relay_apply_restart_description">Beim Anwenden wird die Netzwerkverbindung von VniDrop neu gestartet. Beenden Sie zuerst aktive Übertragungen und Freigaben. Vorhandene Einladungen müssen eventuell erneut geteilt werden.</string>
+    <string name="relay_custom_urls_help">Geben Sie pro Zeile eine HTTPS-Relay-URL ein. Anmeldedaten in URLs werden nicht unterstützt. Das TLS-Zertifikat muss von einer öffentlich vertrauenswürdigen Zertifizierungsstelle ausgestellt sein.</string>
+    <string name="relay_custom_urls_label">Relay-URLs</string>
+    <string name="relay_mode_automatic">Automatisch</string>
+    <string name="relay_mode_automatic_description">Verwendet die öffentliche Standard-Relay-Infrastruktur von VniDrop, wenn keine direkte Verbindung möglich ist.</string>
+    <string name="relay_mode_custom">Benutzerdefiniert</string>
+    <string name="relay_mode_custom_description">Verwendet ausschließlich die unten aufgeführten Relay-Server.</string>
+    <string name="relay_privacy_description">Relays leiten verschlüsselten Datenverkehr weiter und können Ihre Dateien nicht lesen, ihr Betreiber kann jedoch Verbindungsmetadaten sehen.</string>
+    <string name="relay_remove_url">Relay-Server entfernen</string>
+    <string name="relay_restore_failed">Die vorherigen Netzwerkeinstellungen konnten nicht wiederhergestellt werden. Starten Sie VniDrop neu und prüfen Sie Ihre Relay-Konfiguration.</string>
+    <string name="relay_settings_applied">Netzwerkeinstellungen angewendet.</string>
+    <string name="relay_strict_warning">Der benutzerdefinierte Modus ist strikt: VniDrop greift weder auf öffentliche Relays noch auf öffentliche Erkennung zurück. Andere Geräte müssen Ihre konfigurierten Relays erreichen können.</string>
+    <string name="relay_validation_duplicate_url">Die Relay-URL in Zeile %1$d ist bereits zuvor eingetragen.</string>
+    <string name="relay_validation_https_required">Die Relay-URL in Zeile %1$d muss mit https:// beginnen.</string>
+    <string name="relay_validation_invalid_url">Die Relay-URL in Zeile %1$d ist ungültig.</string>
+    <string name="relay_validation_missing_url">Fügen Sie mindestens eine Relay-URL hinzu.</string>
+    <string name="relay_validation_too_many_urls">Sie können bis zu %1$d Relay-Server konfigurieren.</string>
     <string name="send_access_anyone">Jeder mit dieser Übertragung</string>
     <string name="send_access_anyone_description">Keine Genehmigung erforderlich. Verwenden Sie dies nur für Objekte, die Sie unbedenklich teilen können.</string>
     <string name="send_access_anyone_warning">Jeder mit der Einladung kann herunterladen, bis Sie die Freigabe beenden. Verwenden Sie dies nicht für private oder sensible Objekte.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Übertragung erstellt.</string>
     <string name="send_transfer_details_title">Übertragungsdetails</string>
     <string name="send_transfers_title">Ihre Übertragungen</string>
+    <string name="settings_advanced_title">Erweitert</string>
+    <string name="settings_network_title">Netzwerk</string>
     <string name="settings_subtitle">Ihr Name, wo Übertragungen gesichert werden, Darstellung und Mitteilungen.</string>
     <string name="settings_title">Einstellungen</string>
     <string name="snackbar_dismiss">Ausblenden</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Anfragen, Genehmigungen und abgeschlossene Zustellungen</string>
     <string name="transfer_receivers_pending">%1$d warten</string>
     <string name="transfer_receivers_title">Empfänger</string>
+    <string name="transfer_qr_unavailable">Für diese Einladung ist kein QR-Code verfügbar. Verwenden Sie stattdessen Teilen oder Herunterladen.</string>
     <string name="transfer_scan_qr">Mit VniDrop scannen, um diese Übertragung zu empfangen</string>
     <string name="transfer_share_description">QR-Code, Einladungsdatei und Optionen in der Nähe</string>
     <string name="transfer_share_title">Teilen</string>

shared/src/commonMain/composeResources/values-es/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Revisar transferencia</string>
     <string name="receive_title">Recibir</string>
     <string name="receive_unknown_transfer">Transferencia de VniDrop</string>
+    <string name="relay_add_url">Añadir servidor de retransmisión</string>
+    <string name="relay_apply">Aplicar ajustes de red</string>
+    <string name="relay_applying">Aplicando…</string>
+    <string name="relay_apply_active_transfers">Detenga todas las transferencias y elementos compartidos activos antes de aplicar los ajustes de red.</string>
+    <string name="relay_apply_failed">No se han podido aplicar estos ajustes. Se han restaurado los ajustes de red anteriores.</string>
+    <string name="relay_apply_restart_description">Al aplicar los ajustes, se reinicia la conexión de red de VniDrop. Detenga primero las transferencias y los elementos compartidos activos. Es posible que tenga que volver a compartir las invitaciones existentes.</string>
+    <string name="relay_custom_urls_help">Introduzca una URL HTTPS de relé por línea. No se admiten credenciales en las URL. El certificado TLS debe ser emitido por una autoridad de certificación de confianza pública.</string>
+    <string name="relay_custom_urls_label">URL de relés</string>
+    <string name="relay_mode_automatic">Automático</string>
+    <string name="relay_mode_automatic_description">Usa la infraestructura pública de relés predeterminada de VniDrop cuando no haya una conexión directa disponible.</string>
+    <string name="relay_mode_custom">Personalizado</string>
+    <string name="relay_mode_custom_description">Usa únicamente los servidores de retransmisión indicados a continuación.</string>
+    <string name="relay_privacy_description">Los relés reenvían tráfico cifrado y no pueden leer sus archivos, pero su operador puede observar los metadatos de conexión.</string>
+    <string name="relay_remove_url">Eliminar servidor de retransmisión</string>
+    <string name="relay_restore_failed">No se han podido restaurar los ajustes de red anteriores. Reinicie VniDrop y revise la configuración de relés.</string>
+    <string name="relay_settings_applied">Ajustes de red aplicados.</string>
+    <string name="relay_strict_warning">El modo personalizado es estricto: VniDrop no recurrirá a relés públicos ni al descubrimiento público. Los demás dispositivos deben poder acceder a los relés configurados.</string>
+    <string name="relay_validation_duplicate_url">La URL de relé de la línea %1$d duplica una entrada anterior.</string>
+    <string name="relay_validation_https_required">La URL de relé de la línea %1$d debe empezar por https://.</string>
+    <string name="relay_validation_invalid_url">La URL de relé de la línea %1$d no es válida.</string>
+    <string name="relay_validation_missing_url">Añada al menos una URL de relé.</string>
+    <string name="relay_validation_too_many_urls">Puede configurar hasta %1$d servidores de retransmisión.</string>
     <string name="send_access_anyone">Cualquiera que tenga esta transferencia</string>
     <string name="send_access_anyone_description">No se requiere aprobación. Úselo solo para elementos que no le importe compartir.</string>
     <string name="send_access_anyone_warning">Cualquiera que tenga la invitación puede descargar hasta que deje de compartir. No lo use para elementos privados o sensibles.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Transferencia creada.</string>
     <string name="send_transfer_details_title">Detalles de la transferencia</string>
     <string name="send_transfers_title">Sus transferencias</string>
+    <string name="settings_advanced_title">Avanzado</string>
+    <string name="settings_network_title">Red</string>
     <string name="settings_subtitle">Su nombre, dónde se guardan las transferencias, la apariencia y las notificaciones.</string>
     <string name="settings_title">Ajustes</string>
     <string name="snackbar_dismiss">Descartar</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Solicitudes, aprobaciones y entregas completadas</string>
     <string name="transfer_receivers_pending">%1$d en espera</string>
     <string name="transfer_receivers_title">Destinatarios</string>
+    <string name="transfer_qr_unavailable">El QR no está disponible para esta invitación. Use Compartir o Descargar.</string>
     <string name="transfer_scan_qr">Escanee con VniDrop para recibir esta transferencia</string>
     <string name="transfer_share_description">Código QR, archivo de invitación y opciones cercanas</string>
     <string name="transfer_share_title">Compartir</string>

shared/src/commonMain/composeResources/values-fr/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Vérifier le transfert</string>
     <string name="receive_title">Recevoir</string>
     <string name="receive_unknown_transfer">Transfert VniDrop</string>
+    <string name="relay_add_url">Ajouter un serveur relais</string>
+    <string name="relay_apply">Appliquer les réglages réseau</string>
+    <string name="relay_applying">Application…</string>
+    <string name="relay_apply_active_transfers">Arrêtez tous les transferts et partages actifs avant d’appliquer les réglages réseau.</string>
+    <string name="relay_apply_failed">Impossible d’appliquer ces réglages. Les réglages réseau précédents ont été restaurés.</string>
+    <string name="relay_apply_restart_description">L’application de ces réglages redémarre la connexion réseau de VniDrop. Arrêtez d’abord les transferts et partages actifs. Il peut être nécessaire de partager à nouveau les invitations existantes.</string>
+    <string name="relay_custom_urls_help">Saisissez une URL de relais HTTPS par ligne. Les identifiants dans les URL ne sont pas pris en charge. Le certificat TLS doit être émis par une autorité de certification reconnue publiquement.</string>
+    <string name="relay_custom_urls_label">URL des relais</string>
+    <string name="relay_mode_automatic">Automatique</string>
+    <string name="relay_mode_automatic_description">Utiliser l’infrastructure de relais publique par défaut de VniDrop lorsqu’une connexion directe est indisponible.</string>
+    <string name="relay_mode_custom">Personnalisé</string>
+    <string name="relay_mode_custom_description">Utiliser uniquement les serveurs relais ci-dessous.</string>
+    <string name="relay_privacy_description">Les relais transmettent du trafic chiffré et ne peuvent pas lire vos fichiers, mais leur opérateur peut observer les métadonnées de connexion.</string>
+    <string name="relay_remove_url">Supprimer le serveur relais</string>
+    <string name="relay_restore_failed">Impossible de restaurer les réglages réseau précédents. Redémarrez VniDrop et vérifiez votre configuration de relais.</string>
+    <string name="relay_settings_applied">Réglages réseau appliqués.</string>
+    <string name="relay_strict_warning">Le mode personnalisé est strict : VniDrop n’utilisera ni les relais publics ni la découverte publique comme solution de repli. Les autres appareils doivent pouvoir accéder aux relais configurés.</string>
+    <string name="relay_validation_duplicate_url">L’URL de relais à la ligne %1$d est identique à une entrée précédente.</string>
+    <string name="relay_validation_https_required">L’URL de relais à la ligne %1$d doit commencer par https://.</string>
+    <string name="relay_validation_invalid_url">L’URL de relais à la ligne %1$d n’est pas valide.</string>
+    <string name="relay_validation_missing_url">Ajoutez au moins une URL de relais.</string>
+    <string name="relay_validation_too_many_urls">Vous pouvez configurer jusqu’à %1$d serveurs relais.</string>
     <string name="send_access_anyone">Toute personne disposant de ce transfert</string>
     <string name="send_access_anyone_description">Aucune approbation requise. À n’utiliser que pour des éléments que vous êtes à l’aise de partager.</string>
     <string name="send_access_anyone_warning">Toute personne disposant de l’invitation peut télécharger jusqu’à ce que vous arrêtiez le partage. Ne l’utilisez pas pour des éléments privés ou sensibles.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Transfert créé.</string>
     <string name="send_transfer_details_title">Détails du transfert</string>
     <string name="send_transfers_title">Vos transferts</string>
+    <string name="settings_advanced_title">Avancé</string>
+    <string name="settings_network_title">Réseau</string>
     <string name="settings_subtitle">Votre nom, l’emplacement d’enregistrement des transferts, l’apparence et les notifications.</string>
     <string name="settings_title">Réglages</string>
     <string name="snackbar_dismiss">Ignorer</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Demandes, approbations et livraisons terminées</string>
     <string name="transfer_receivers_pending">%1$d en attente</string>
     <string name="transfer_receivers_title">Destinataires</string>
+    <string name="transfer_qr_unavailable">Le code QR n’est pas disponible pour cette invitation. Utilisez plutôt Partager ou Télécharger.</string>
     <string name="transfer_scan_qr">Scannez avec VniDrop pour recevoir ce transfert</string>
     <string name="transfer_share_description">QR code, fichier d’invitation et options à proximité</string>
     <string name="transfer_share_title">Partager</string>

shared/src/commonMain/composeResources/values-it/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Rivedi trasferimento</string>
     <string name="receive_title">Ricevi</string>
     <string name="receive_unknown_transfer">Trasferimento VniDrop</string>
+    <string name="relay_add_url">Aggiungi server relay</string>
+    <string name="relay_apply">Applica impostazioni di rete</string>
+    <string name="relay_applying">Applicazione…</string>
+    <string name="relay_apply_active_transfers">Interrompa tutti i trasferimenti e le condivisioni attivi prima di applicare le impostazioni di rete.</string>
+    <string name="relay_apply_failed">Impossibile applicare queste impostazioni. Sono state ripristinate le impostazioni di rete precedenti.</string>
+    <string name="relay_apply_restart_description">L’applicazione riavvia la connessione di rete di VniDrop. Interrompa prima i trasferimenti e le condivisioni attivi. Potrebbe essere necessario condividere di nuovo gli inviti esistenti.</string>
+    <string name="relay_custom_urls_help">Inserisca un URL relay HTTPS per riga. Le credenziali negli URL non sono supportate. Il certificato TLS deve essere emesso da un’autorità di certificazione pubblicamente attendibile.</string>
+    <string name="relay_custom_urls_label">URL relay</string>
+    <string name="relay_mode_automatic">Automatica</string>
+    <string name="relay_mode_automatic_description">Usa l’infrastruttura relay pubblica predefinita di VniDrop quando non è disponibile una connessione diretta.</string>
+    <string name="relay_mode_custom">Personalizzata</string>
+    <string name="relay_mode_custom_description">Usa solo i server relay indicati di seguito.</string>
+    <string name="relay_privacy_description">I relay inoltrano traffico cifrato e non possono leggere i suoi file, ma il loro operatore può osservare i metadati di connessione.</string>
+    <string name="relay_remove_url">Rimuovi server relay</string>
+    <string name="relay_restore_failed">Impossibile ripristinare le impostazioni di rete precedenti. Riavvii VniDrop e verifichi la configurazione dei relay.</string>
+    <string name="relay_settings_applied">Impostazioni di rete applicate.</string>
+    <string name="relay_strict_warning">La modalità personalizzata è rigorosa: VniDrop non userà relay pubblici o il rilevamento pubblico come ripiego. Gli altri dispositivi devono poter raggiungere i relay configurati.</string>
+    <string name="relay_validation_duplicate_url">L’URL relay alla riga %1$d duplica una voce precedente.</string>
+    <string name="relay_validation_https_required">L’URL relay alla riga %1$d deve iniziare con https://.</string>
+    <string name="relay_validation_invalid_url">L’URL relay alla riga %1$d non è valido.</string>
+    <string name="relay_validation_missing_url">Aggiunga almeno un URL relay.</string>
+    <string name="relay_validation_too_many_urls">Può configurare fino a %1$d server relay.</string>
     <string name="send_access_anyone">Chiunque abbia questo trasferimento</string>
     <string name="send_access_anyone_description">Nessuna approvazione richiesta. Da usare solo per elementi che non ha problemi a condividere.</string>
     <string name="send_access_anyone_warning">Chiunque abbia l’invito può scaricare finché non interrompe la condivisione. Non lo usi per elementi privati o sensibili.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Trasferimento creato.</string>
     <string name="send_transfer_details_title">Dettagli del trasferimento</string>
     <string name="send_transfers_title">I suoi trasferimenti</string>
+    <string name="settings_advanced_title">Avanzate</string>
+    <string name="settings_network_title">Rete</string>
     <string name="settings_subtitle">Il suo nome, dove vengono salvati i trasferimenti, l’aspetto e le notifiche.</string>
     <string name="settings_title">Impostazioni</string>
     <string name="snackbar_dismiss">Ignora</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Richieste, approvazioni e consegne completate</string>
     <string name="transfer_receivers_pending">%1$d in attesa</string>
     <string name="transfer_receivers_title">Destinatari</string>
+    <string name="transfer_qr_unavailable">Il codice QR non è disponibile per questo invito. Utilizzi invece Condividi o Scarica.</string>
     <string name="transfer_scan_qr">Scansioni con VniDrop per ricevere questo trasferimento</string>
     <string name="transfer_share_description">Codice QR, file di invito e opzioni nelle vicinanze</string>
     <string name="transfer_share_title">Condividi</string>

shared/src/commonMain/composeResources/values-nl/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Overdracht controleren</string>
     <string name="receive_title">Ontvangen</string>
     <string name="receive_unknown_transfer">VniDrop-overdracht</string>
+    <string name="relay_add_url">Relayserver toevoegen</string>
+    <string name="relay_apply">Netwerkinstellingen toepassen</string>
+    <string name="relay_applying">Toepassen…</string>
+    <string name="relay_apply_active_transfers">Stop alle actieve overdrachten en gedeelde items voordat u de netwerkinstellingen toepast.</string>
+    <string name="relay_apply_failed">Deze instellingen konden niet worden toegepast. De vorige netwerkinstellingen zijn hersteld.</string>
+    <string name="relay_apply_restart_description">Bij het toepassen wordt de netwerkverbinding van VniDrop opnieuw gestart. Stop eerst actieve overdrachten en gedeelde items. Bestaande uitnodigingen moeten mogelijk opnieuw worden gedeeld.</string>
+    <string name="relay_custom_urls_help">Voer per regel één HTTPS-relay-URL in. Aanmeldgegevens in URL\'s worden niet ondersteund. Het TLS-certificaat moet zijn uitgegeven door een openbaar vertrouwde certificeringsinstantie.</string>
+    <string name="relay_custom_urls_label">Relay-URL\'s</string>
+    <string name="relay_mode_automatic">Automatisch</string>
+    <string name="relay_mode_automatic_description">Gebruikt de standaard openbare relay-infrastructuur van VniDrop wanneer geen directe verbinding beschikbaar is.</string>
+    <string name="relay_mode_custom">Aangepast</string>
+    <string name="relay_mode_custom_description">Gebruikt alleen de onderstaande relayservers.</string>
+    <string name="relay_privacy_description">Relays sturen versleuteld verkeer door en kunnen uw bestanden niet lezen, maar de beheerder kan verbindingsmetadata bekijken.</string>
+    <string name="relay_remove_url">Relayserver verwijderen</string>
+    <string name="relay_restore_failed">De vorige netwerkinstellingen konden niet worden hersteld. Start VniDrop opnieuw en controleer uw relayconfiguratie.</string>
+    <string name="relay_settings_applied">Netwerkinstellingen toegepast.</string>
+    <string name="relay_strict_warning">De aangepaste modus is strikt: VniDrop valt niet terug op openbare relays of openbare detectie. Andere apparaten moeten uw ingestelde relays kunnen bereiken.</string>
+    <string name="relay_validation_duplicate_url">De relay-URL op regel %1$d is gelijk aan een eerdere invoer.</string>
+    <string name="relay_validation_https_required">De relay-URL op regel %1$d moet beginnen met https://.</string>
+    <string name="relay_validation_invalid_url">De relay-URL op regel %1$d is ongeldig.</string>
+    <string name="relay_validation_missing_url">Voeg ten minste één relay-URL toe.</string>
+    <string name="relay_validation_too_many_urls">U kunt maximaal %1$d relayservers instellen.</string>
     <string name="send_access_anyone">Iedereen met deze overdracht</string>
     <string name="send_access_anyone_description">Geen goedkeuring vereist. Gebruik dit alleen voor items die u gerust kunt delen.</string>
     <string name="send_access_anyone_warning">Iedereen met de uitnodiging kan downloaden totdat u stopt met delen. Gebruik dit niet voor privé- of gevoelige items.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Overdracht aangemaakt.</string>
     <string name="send_transfer_details_title">Overdrachtsdetails</string>
     <string name="send_transfers_title">Uw overdrachten</string>
+    <string name="settings_advanced_title">Geavanceerd</string>
+    <string name="settings_network_title">Netwerk</string>
     <string name="settings_subtitle">Uw naam, waar overdrachten worden bewaard, weergave en meldingen.</string>
     <string name="settings_title">Instellingen</string>
     <string name="snackbar_dismiss">Sluiten</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Verzoeken, goedkeuringen en voltooide leveringen</string>
     <string name="transfer_receivers_pending">%1$d in behandeling</string>
     <string name="transfer_receivers_title">Ontvangers</string>
+    <string name="transfer_qr_unavailable">QR is niet beschikbaar voor deze uitnodiging. Gebruik in plaats daarvan Delen of Downloaden.</string>
     <string name="transfer_scan_qr">Scan met VniDrop om deze overdracht te ontvangen</string>
     <string name="transfer_share_description">QR-code, uitnodigingsbestand en opties in de buurt</string>
     <string name="transfer_share_title">Delen</string>

shared/src/commonMain/composeResources/values-pl/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Przejrzyj transfer</string>
     <string name="receive_title">Odbierz</string>
     <string name="receive_unknown_transfer">Transfer VniDrop</string>
+    <string name="relay_add_url">Dodaj serwer przekaźnikowy</string>
+    <string name="relay_apply">Zastosuj ustawienia sieci</string>
+    <string name="relay_applying">Stosowanie…</string>
+    <string name="relay_apply_active_transfers">Zatrzymaj wszystkie aktywne transfery i udostępnienia przed zastosowaniem ustawień sieci.</string>
+    <string name="relay_apply_failed">Nie udało się zastosować tych ustawień. Przywrócono poprzednie ustawienia sieci.</string>
+    <string name="relay_apply_restart_description">Zastosowanie ustawień ponownie uruchamia połączenie sieciowe VniDrop. Najpierw zatrzymaj aktywne transfery i udostępnienia. Istniejące zaproszenia mogą wymagać ponownego udostępnienia.</string>
+    <string name="relay_custom_urls_help">Wprowadź po jednym adresie URL HTTPS przekaźnika w każdym wierszu. Dane logowania w adresach URL nie są obsługiwane. Certyfikat TLS musi być wystawiony przez publicznie zaufany urząd certyfikacji.</string>
+    <string name="relay_custom_urls_label">Adresy URL przekaźników</string>
+    <string name="relay_mode_automatic">Automatyczny</string>
+    <string name="relay_mode_automatic_description">Używa domyślnej publicznej infrastruktury przekaźników VniDrop, gdy połączenie bezpośrednie jest niedostępne.</string>
+    <string name="relay_mode_custom">Niestandardowy</string>
+    <string name="relay_mode_custom_description">Używa wyłącznie poniższych serwerów przekaźnikowych.</string>
+    <string name="relay_privacy_description">Przekaźniki przesyłają zaszyfrowany ruch i nie mogą odczytać plików, ale ich operator może obserwować metadane połączenia.</string>
+    <string name="relay_remove_url">Usuń serwer przekaźnikowy</string>
+    <string name="relay_restore_failed">Nie udało się przywrócić poprzednich ustawień sieci. Uruchom ponownie VniDrop i sprawdź konfigurację przekaźników.</string>
+    <string name="relay_settings_applied">Zastosowano ustawienia sieci.</string>
+    <string name="relay_strict_warning">Tryb niestandardowy jest rygorystyczny: VniDrop nie użyje awaryjnie publicznych przekaźników ani publicznego wykrywania. Inne urządzenia muszą mieć dostęp do skonfigurowanych przekaźników.</string>
+    <string name="relay_validation_duplicate_url">Adres URL przekaźnika w wierszu %1$d powtarza wcześniejszy wpis.</string>
+    <string name="relay_validation_https_required">Adres URL przekaźnika w wierszu %1$d musi zaczynać się od https://.</string>
+    <string name="relay_validation_invalid_url">Adres URL przekaźnika w wierszu %1$d jest nieprawidłowy.</string>
+    <string name="relay_validation_missing_url">Dodaj co najmniej jeden adres URL przekaźnika.</string>
+    <string name="relay_validation_too_many_urls">Możesz skonfigurować maksymalnie %1$d serwerów przekaźnikowych.</string>
     <string name="send_access_anyone">Każdy, kto ma ten transfer</string>
     <string name="send_access_anyone_description">Nie jest wymagane zatwierdzenie. Używaj tylko dla elementów, które możesz swobodnie udostępniać.</string>
     <string name="send_access_anyone_warning">Każdy, kto ma zaproszenie, może pobierać, dopóki nie zatrzymasz udostępniania. Nie używaj tego dla prywatnych ani wrażliwych elementów.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Transfer utworzony.</string>
     <string name="send_transfer_details_title">Szczegóły transferu</string>
     <string name="send_transfers_title">Twoje transfery</string>
+    <string name="settings_advanced_title">Zaawansowane</string>
+    <string name="settings_network_title">Sieć</string>
     <string name="settings_subtitle">Twoja nazwa, miejsce zapisu transferów, wygląd i powiadomienia.</string>
     <string name="settings_title">Ustawienia</string>
     <string name="snackbar_dismiss">Zamknij</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Prośby, zatwierdzenia i ukończone dostawy</string>
     <string name="transfer_receivers_pending">Oczekujące: %1$d</string>
     <string name="transfer_receivers_title">Odbiorcy</string>
+    <string name="transfer_qr_unavailable">Kod QR jest niedostępny dla tego zaproszenia. Zamiast tego użyj opcji Udostępnij lub Pobierz.</string>
     <string name="transfer_scan_qr">Zeskanuj za pomocą VniDrop, aby odebrać ten transfer</string>
     <string name="transfer_share_description">Kod QR, plik zaproszenia i opcje w pobliżu</string>
     <string name="transfer_share_title">Udostępnij</string>

shared/src/commonMain/composeResources/values-pt/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Rever transferência</string>
     <string name="receive_title">Receber</string>
     <string name="receive_unknown_transfer">Transferência VniDrop</string>
+    <string name="relay_add_url">Adicionar servidor de retransmissão</string>
+    <string name="relay_apply">Aplicar definições de rede</string>
+    <string name="relay_applying">A aplicar…</string>
+    <string name="relay_apply_active_transfers">Pare todas as transferências e partilhas ativas antes de aplicar as definições de rede.</string>
+    <string name="relay_apply_failed">Não foi possível aplicar estas definições. As definições de rede anteriores foram restauradas.</string>
+    <string name="relay_apply_restart_description">A aplicação reinicia a ligação de rede do VniDrop. Pare primeiro as transferências e partilhas ativas. Poderá ser necessário voltar a partilhar os convites existentes.</string>
+    <string name="relay_custom_urls_help">Introduza um URL HTTPS de retransmissor por linha. Não são suportadas credenciais nos URLs. O certificado TLS tem de ser emitido por uma autoridade de certificação publicamente reconhecida.</string>
+    <string name="relay_custom_urls_label">URLs dos retransmissores</string>
+    <string name="relay_mode_automatic">Automático</string>
+    <string name="relay_mode_automatic_description">Utiliza a infraestrutura pública de retransmissores predefinida do VniDrop quando não está disponível uma ligação direta.</string>
+    <string name="relay_mode_custom">Personalizado</string>
+    <string name="relay_mode_custom_description">Utiliza apenas os servidores de retransmissão abaixo.</string>
+    <string name="relay_privacy_description">Os retransmissores encaminham tráfego cifrado e não conseguem ler os seus ficheiros, mas o operador pode observar metadados da ligação.</string>
+    <string name="relay_remove_url">Remover servidor de retransmissão</string>
+    <string name="relay_restore_failed">Não foi possível restaurar as definições de rede anteriores. Reinicie o VniDrop e reveja a configuração dos retransmissores.</string>
+    <string name="relay_settings_applied">Definições de rede aplicadas.</string>
+    <string name="relay_strict_warning">O modo personalizado é estrito: o VniDrop não recorrerá a retransmissores públicos nem à descoberta pública. Os outros dispositivos têm de conseguir aceder aos retransmissores configurados.</string>
+    <string name="relay_validation_duplicate_url">O URL do retransmissor na linha %1$d duplica uma entrada anterior.</string>
+    <string name="relay_validation_https_required">O URL do retransmissor na linha %1$d tem de começar por https://.</string>
+    <string name="relay_validation_invalid_url">O URL do retransmissor na linha %1$d não é válido.</string>
+    <string name="relay_validation_missing_url">Adicione pelo menos um URL de retransmissor.</string>
+    <string name="relay_validation_too_many_urls">Pode configurar até %1$d servidores de retransmissão.</string>
     <string name="send_access_anyone">Qualquer pessoa com esta transferência</string>
     <string name="send_access_anyone_description">Não é necessária aprovação. Utilize apenas para itens que não se importe de partilhar.</string>
     <string name="send_access_anyone_warning">Qualquer pessoa com o convite pode descarregar até parar de partilhar. Não utilize para itens privados ou sensíveis.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Transferência criada.</string>
     <string name="send_transfer_details_title">Detalhes da transferência</string>
     <string name="send_transfers_title">As suas transferências</string>
+    <string name="settings_advanced_title">Avançado</string>
+    <string name="settings_network_title">Rede</string>
     <string name="settings_subtitle">O seu nome, onde as transferências são guardadas, o aspeto e as notificações.</string>
     <string name="settings_title">Definições</string>
     <string name="snackbar_dismiss">Ignorar</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Pedidos, aprovações e entregas concluídas</string>
     <string name="transfer_receivers_pending">%1$d em espera</string>
     <string name="transfer_receivers_title">Destinatários</string>
+    <string name="transfer_qr_unavailable">O código QR não está disponível para este convite. Utilize Partilhar ou Transferir.</string>
     <string name="transfer_scan_qr">Leia com o VniDrop para receber esta transferência</string>
     <string name="transfer_share_description">Código QR, ficheiro de convite e opções por perto</string>
     <string name="transfer_share_title">Partilhar</string>

shared/src/commonMain/composeResources/values-ru/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Проверить передачу</string>
     <string name="receive_title">Получить</string>
     <string name="receive_unknown_transfer">Передача VniDrop</string>
+    <string name="relay_add_url">Добавить сервер-ретранслятор</string>
+    <string name="relay_apply">Применить настройки сети</string>
+    <string name="relay_applying">Применение…</string>
+    <string name="relay_apply_active_transfers">Остановите все активные передачи и раздачи перед применением настроек сети.</string>
+    <string name="relay_apply_failed">Не удалось применить эти настройки. Предыдущие настройки сети восстановлены.</string>
+    <string name="relay_apply_restart_description">При применении сетевое соединение VniDrop перезапускается. Сначала остановите активные передачи и раздачи. Возможно, существующие приглашения потребуется отправить повторно.</string>
+    <string name="relay_custom_urls_help">Введите по одному HTTPS-адресу ретранслятора в строке. Учётные данные в URL-адресах не поддерживаются. Сертификат TLS должен быть выдан общедоступным доверенным центром сертификации.</string>
+    <string name="relay_custom_urls_label">URL-адреса ретрансляторов</string>
+    <string name="relay_mode_automatic">Автоматически</string>
+    <string name="relay_mode_automatic_description">Использовать стандартную публичную инфраструктуру ретрансляторов VniDrop, если прямое соединение недоступно.</string>
+    <string name="relay_mode_custom">Пользовательский</string>
+    <string name="relay_mode_custom_description">Использовать только указанные ниже серверы-ретрансляторы.</string>
+    <string name="relay_privacy_description">Ретрансляторы передают зашифрованный трафик и не могут читать ваши файлы, но их оператор может видеть метаданные соединения.</string>
+    <string name="relay_remove_url">Удалить сервер-ретранслятор</string>
+    <string name="relay_restore_failed">Не удалось восстановить предыдущие настройки сети. Перезапустите VniDrop и проверьте конфигурацию ретрансляторов.</string>
+    <string name="relay_settings_applied">Настройки сети применены.</string>
+    <string name="relay_strict_warning">Пользовательский режим работает строго: VniDrop не будет переключаться на публичные ретрансляторы или публичное обнаружение. Другие устройства должны иметь доступ к настроенным ретрансляторам.</string>
+    <string name="relay_validation_duplicate_url">URL-адрес ретранслятора в строке %1$d повторяет предыдущую запись.</string>
+    <string name="relay_validation_https_required">URL-адрес ретранслятора в строке %1$d должен начинаться с https://.</string>
+    <string name="relay_validation_invalid_url">URL-адрес ретранслятора в строке %1$d недействителен.</string>
+    <string name="relay_validation_missing_url">Добавьте хотя бы один URL-адрес ретранслятора.</string>
+    <string name="relay_validation_too_many_urls">Можно настроить до %1$d серверов-ретрансляторов.</string>
     <string name="send_access_anyone">Любой, у кого есть эта передача</string>
     <string name="send_access_anyone_description">Одобрение не требуется. Используйте только для объектов, которыми вы готовы поделиться.</string>
     <string name="send_access_anyone_warning">Любой, у кого есть приглашение, может загружать, пока вы не остановите общий доступ. Не используйте это для личных или конфиденциальных объектов.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Передача создана.</string>
     <string name="send_transfer_details_title">Сведения о передаче</string>
     <string name="send_transfers_title">Ваши передачи</string>
+    <string name="settings_advanced_title">Дополнительно</string>
+    <string name="settings_network_title">Сеть</string>
     <string name="settings_subtitle">Ваше имя, место сохранения передач, оформление и уведомления.</string>
     <string name="settings_title">Настройки</string>
     <string name="snackbar_dismiss">Закрыть</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Запросы, одобрения и завершённые доставки</string>
     <string name="transfer_receivers_pending">Ожидают: %1$d</string>
     <string name="transfer_receivers_title">Получатели</string>
+    <string name="transfer_qr_unavailable">QR-код недоступен для этого приглашения. Используйте «Поделиться» или «Скачать».</string>
     <string name="transfer_scan_qr">Отсканируйте с помощью VniDrop, чтобы получить эту передачу</string>
     <string name="transfer_share_description">QR-код, файл приглашения и варианты поблизости</string>
     <string name="transfer_share_title">Поделиться</string>

shared/src/commonMain/composeResources/values/strings.xml

@@ -169,6 +169,28 @@
     <string name="receive_review_title">Review transfer</string>
     <string name="receive_title">Receive</string>
     <string name="receive_unknown_transfer">VniDrop transfer</string>
+    <string name="relay_add_url">Add relay server</string>
+    <string name="relay_apply">Apply network settings</string>
+    <string name="relay_applying">Applying…</string>
+    <string name="relay_apply_active_transfers">Stop all active transfers and shares before applying network settings.</string>
+    <string name="relay_apply_failed">Could not apply these settings. The previous network settings were restored.</string>
+    <string name="relay_apply_restart_description">Applying restarts VniDrop’s network connection. Stop active transfers and shares first. Existing invitations may need to be shared again.</string>
+    <string name="relay_custom_urls_help">Enter one HTTPS relay URL per line. URL credentials are not supported. The TLS certificate must be issued by a publicly trusted certificate authority.</string>
+    <string name="relay_custom_urls_label">Relay URLs</string>
+    <string name="relay_mode_automatic">Automatic</string>
+    <string name="relay_mode_automatic_description">Use VniDrop’s default public relay infrastructure when a direct connection is unavailable.</string>
+    <string name="relay_mode_custom">Custom</string>
+    <string name="relay_mode_custom_description">Use only the relay servers below.</string>
+    <string name="relay_privacy_description">Relays forward encrypted traffic and cannot read your files, but their operator can observe connection metadata.</string>
+    <string name="relay_remove_url">Remove relay server</string>
+    <string name="relay_restore_failed">Could not restore the previous network settings. Restart VniDrop and review your relay configuration.</string>
+    <string name="relay_settings_applied">Network settings applied.</string>
+    <string name="relay_strict_warning">Custom mode is strict: VniDrop will not fall back to public relays or public discovery. Other devices must be able to reach your configured relays.</string>
+    <string name="relay_validation_duplicate_url">Relay URL on line %1$d duplicates an earlier entry.</string>
+    <string name="relay_validation_https_required">Relay URL on line %1$d must start with https://.</string>
+    <string name="relay_validation_invalid_url">Relay URL on line %1$d is not valid.</string>
+    <string name="relay_validation_missing_url">Add at least one relay URL.</string>
+    <string name="relay_validation_too_many_urls">You can configure up to %1$d relay servers.</string>
     <string name="send_access_anyone">Anyone with this transfer</string>
     <string name="send_access_anyone_description">No approval is required. Only use this for items you are comfortable sharing.</string>
     <string name="send_access_anyone_warning">Anyone with the invitation can download until you stop sharing. Do not use this for private or sensitive items.</string>
@@ -192,6 +214,8 @@
     <string name="send_transfer_created">Transfer created.</string>
     <string name="send_transfer_details_title">Transfer details</string>
     <string name="send_transfers_title">Your transfers</string>
+    <string name="settings_advanced_title">Advanced</string>
+    <string name="settings_network_title">Network</string>
     <string name="settings_subtitle">Your name, where transfers are saved, appearance, and notifications.</string>
     <string name="settings_title">Settings</string>
     <string name="snackbar_dismiss">Dismiss</string>
@@ -250,6 +274,7 @@
     <string name="transfer_receivers_description">Requests, approvals, and completed deliveries</string>
     <string name="transfer_receivers_pending">%1$d waiting</string>
     <string name="transfer_receivers_title">Receivers</string>
+    <string name="transfer_qr_unavailable">QR unavailable for this invitation. Use Share or Download instead.</string>
     <string name="transfer_scan_qr">Scan with VniDrop to receive this transfer</string>
     <string name="transfer_share_description">QR code, invitation file, and nearby options</string>
     <string name="transfer_share_title">Share</string>

shared/src/commonMain/kotlin/com/vnidrop/app/core/CoreLifecycleGate.kt

@@ -0,0 +1,51 @@
+package com.vnidrop.app.core
+
+import kotlinx.coroutines.NonCancellable
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+
+internal class CoreLifecycleBusyException(message: String) : IllegalStateException(message)
+
+internal class CoreLifecycleGate {
+	private val mutex = Mutex()
+	private var reconfiguring = false
+	private var inFlightCalls = 0
+
+	suspend fun <C, T> withCall(
+		capture: () -> C,
+		block: suspend (C) -> T,
+	): T {
+		val captured = mutex.withLock {
+			if (reconfiguring) throw CoreLifecycleBusyException("Core network configuration is changing")
+			val value = capture()
+			inFlightCalls += 1
+			value
+		}
+		return try {
+			block(captured)
+		} finally {
+			withContext(NonCancellable) {
+				mutex.withLock {
+					check(inFlightCalls > 0)
+					inFlightCalls -= 1
+				}
+			}
+		}
+	}
+
+	suspend fun <T> withReconfiguration(block: suspend () -> T): T {
+		mutex.withLock {
+			if (reconfiguring) throw CoreLifecycleBusyException("Core network configuration is already changing")
+			if (inFlightCalls > 0) throw CoreLifecycleBusyException("Core calls are still active")
+			reconfiguring = true
+		}
+		return try {
+			block()
+		} finally {
+			withContext(NonCancellable) {
+				mutex.withLock { reconfiguring = false }
+			}
+		}
+	}
+}

shared/src/commonMain/kotlin/com/vnidrop/app/core/CoreModels.kt

@@ -27,6 +27,16 @@ enum class ShareAccessPolicy {
 	AnyoneWithTransfer,
 }
 
+enum class RelayMode {
+	Automatic,
+	Custom,
+}
+
+data class RelaySettings(
+	val mode: RelayMode = RelayMode.Automatic,
+	val relayUrls: List<String> = emptyList(),
+)
+
 enum class TransferDirection {
 	Send,
 	Receive,
@@ -142,7 +152,10 @@ interface CoreGateway {
 	val state: StateFlow<CoreState>
 	val signals: SharedFlow<CoreSignal>
 
-	suspend fun initialize(appDataDir: String): Result<Unit>
+	suspend fun initialize(
+		appDataDir: String,
+		relaySettings: RelaySettings = RelaySettings(),
+	): Result<Unit>
 	fun shutdown()
 	suspend fun sharePath(path: String, transferName: String, senderName: String, accessPolicy: ShareAccessPolicy): Result<Share>
 	suspend fun shareFileDescriptor(

shared/src/commonMain/kotlin/com/vnidrop/app/core/CoreRepository.kt

@@ -16,6 +16,8 @@ import kotlinx.coroutines.withContext
 import kotlin.random.Random
 import uniffi.vnidrop.CoreEvent
 import uniffi.vnidrop.CoreEventSink
+import uniffi.vnidrop.CoreNetworkConfig
+import uniffi.vnidrop.CoreRelayMode
 import uniffi.vnidrop.ReceiveOutputSink
 import uniffi.vnidrop.ReceiveOutputSinkV2
 import uniffi.vnidrop.ReceiverRequest
@@ -28,6 +30,7 @@ import uniffi.vnidrop.TicketInspection
 import uniffi.vnidrop.TransferMetadata
 import uniffi.vnidrop.TransferAccessMode
 import uniffi.vnidrop.VnidropCore
+import uniffi.vnidrop.defaultCoreNetworkConfig
 
 class CoreRepository(
 	private val dispatcher: CoroutineDispatcher = Dispatchers.IO,
@@ -42,6 +45,7 @@ class CoreRepository(
 	override val signals: SharedFlow<CoreSignal> = _signals.asSharedFlow()
 
 	private var core: VnidropCore? = null
+	private val lifecycleGate = CoreLifecycleGate()
 
 	private val sink = object : CoreEventSink {
 		override fun onEvent(event: CoreEvent) {
@@ -60,12 +64,22 @@ class CoreRepository(
 		}
 	}
 
-	override suspend fun initialize(appDataDir: String): Result<Unit> = runCore {
+	override suspend fun initialize(appDataDir: String, relaySettings: RelaySettings): Result<Unit> =
-		core?.shutdown()
+		runReconfiguration {
-		core = VnidropCore.initialize(appDataDir, sink)
+			val previousCore = core
-		refreshSnapshot()
+			if (previousCore != null) {
-		_state.update { it.copy(isInitialized = true) }
+				val status = previousCore.status()
-	}
+				require(status.activeTransfers == 0UL && status.activeShares == 0UL) {
+					"Stop active transfers and shares before changing relay settings"
+				}
+			}
+			_state.update { it.copy(isInitialized = false, status = null) }
+			previousCore?.shutdown()
+			core = null
+			core = VnidropCore.initializeWithNetworkConfig(appDataDir, sink, relaySettings.toNative())
+			refreshSnapshot(requireCore())
+			_state.update { it.copy(isInitialized = true) }
+		}
 
 	override fun shutdown() {
 		core?.shutdown()
@@ -114,37 +128,37 @@ class CoreRepository(
 			accessPolicy = accessPolicy,
 		)
 
-	override suspend fun inspectTicket(ticket: String): Result<TicketInspectionModel> = runCore {
+	override suspend fun inspectTicket(ticket: String): Result<TicketInspectionModel> = runCore { activeCore ->
-		requireCore().inspectTicket(ticket).toModel().also { inspection ->
+		activeCore.inspectTicket(ticket).toModel().also { inspection ->
 			_state.update { it.copy(lastInspection = inspection) }
 		}
 	}
 
-	override suspend fun receive(ticket: String, outputDir: String, receiverName: String): Result<Unit> = runCore {
+	override suspend fun receive(ticket: String, outputDir: String, receiverName: String): Result<Unit> = runCore { activeCore ->
-		requireCore().receive(ticket, outputDir, receiverName.ifBlank { null })
+		activeCore.receive(ticket, outputDir, receiverName.ifBlank { null })
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 	}
 
 	override suspend fun receiveWithOutputSink(
 		ticket: String,
 		outputSink: ReceiveOutputSink,
 		receiverName: String,
-	): Result<Unit> = runCore {
+	): Result<Unit> = runCore { activeCore ->
-		requireCore().receiveWithOutputSink(ticket, outputSink, receiverName.ifBlank { null })
+		activeCore.receiveWithOutputSink(ticket, outputSink, receiverName.ifBlank { null })
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 	}
 
 	override suspend fun receiveWithOutputSinkV2(
 		ticket: String,
 		outputSink: ReceiveOutputSinkV2,
 		receiverName: String,
-	): Result<Unit> = runCore {
+	): Result<Unit> = runCore { activeCore ->
-		requireCore().receiveWithOutputSinkV2(ticket, outputSink, receiverName.ifBlank { null })
+		activeCore.receiveWithOutputSinkV2(ticket, outputSink, receiverName.ifBlank { null })
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 	}
 
-	override suspend fun storageUsage(): Result<CoreStorageUsageModel> = runCore {
+	override suspend fun storageUsage(): Result<CoreStorageUsageModel> = runCore { activeCore ->
-		val usage = requireCore().storageUsage()
+		val usage = activeCore.storageUsage()
 		CoreStorageUsageModel(
 			blobStoreBytes = usage.blobStoreBytes,
 			databaseBytes = usage.databaseBytes,
@@ -154,8 +168,8 @@ class CoreRepository(
 		)
 	}
 
-	override suspend fun receivedArtifacts(): Result<List<ReceivedArtifactModel>> = runCore {
+	override suspend fun receivedArtifacts(): Result<List<ReceivedArtifactModel>> = runCore { activeCore ->
-		requireCore().listReceivedArtifacts().map { artifact ->
+		activeCore.listReceivedArtifacts().map { artifact ->
 			ReceivedArtifactModel(
 				id = artifact.id,
 				locator = artifact.locator,
@@ -165,47 +179,47 @@ class CoreRepository(
 		}
 	}
 
-	override suspend fun cancel(transferId: ULong): Result<Unit> = runCore {
+	override suspend fun cancel(transferId: ULong): Result<Unit> = runCore { activeCore ->
-		requireCore().cancelTransfer(transferId)
+		activeCore.cancelTransfer(transferId)
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 	}
 
-	override suspend fun delete(transferId: ULong): Result<Unit> = runCore {
+	override suspend fun delete(transferId: ULong): Result<Unit> = runCore { activeCore ->
-		requireCore().deleteTransfer(transferId)
+		activeCore.deleteTransfer(transferId)
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 		_signals.tryEmit(CoreSignal.ApprovalChanged(transferId))
 		_signals.tryEmit(CoreSignal.ReceiverHistoryChanged(transferId))
 	}
 
-	override suspend fun clearReceiveHistory(): Result<ULong> = runCore {
+	override suspend fun clearReceiveHistory(): Result<ULong> = runCore { activeCore ->
-		val deleted = requireCore().deleteReceiveHistory()
+		val deleted = activeCore.deleteReceiveHistory()
-		refreshSnapshot()
+		refreshSnapshot(activeCore)
 		deleted
 	}
 
-	override suspend fun receiverRequests(transferId: ULong): Result<List<ReceiverRequestModel>> = runCore {
+	override suspend fun receiverRequests(transferId: ULong): Result<List<ReceiverRequestModel>> = runCore { activeCore ->
-		requireCore().listReceiverRequests(transferId).map(ReceiverRequest::toModel)
+		activeCore.listReceiverRequests(transferId).map(ReceiverRequest::toModel)
 	}
 
 	override suspend fun respondReceiverRequest(
 		requestId: String,
 		accepted: Boolean,
 		reason: String?,
-	): Result<Unit> = runCore {
+	): Result<Unit> = runCore { activeCore ->
-		requireCore().respondReceiverRequest(requestId, accepted, reason)
+		activeCore.respondReceiverRequest(requestId, accepted, reason)
 	}
 
-	override suspend fun refresh(): Result<Unit> = runCore { refreshSnapshot() }
+	override suspend fun refresh(): Result<Unit> = runCore(::refreshSnapshot)
 
 	override suspend fun shareSources(
 		sources: List<ShareSource>,
 		transferName: String,
 		senderName: String,
 		accessPolicy: ShareAccessPolicy,
-	): Result<Share> = runCore {
+	): Result<Share> = runCore { activeCore ->
 		require(sources.isNotEmpty()) { "Select at least one file to share" }
 		withPlatformPathAccess(sources) {
-			requireCore().shareFiles(
+			activeCore.shareFiles(
 				sources = sources,
 				metadata = ShareMetadataInput(
 					transferId = nextTransferId(),
@@ -215,7 +229,7 @@ class CoreRepository(
 				),
 			).toModel()
 		}.also { share ->
-			refreshSnapshot()
+			refreshSnapshot(activeCore)
 			_state.update { it.copy(lastShare = share) }
 		}
 	}
@@ -232,8 +246,7 @@ class CoreRepository(
 		}
 	}
 
-	private fun refreshSnapshot() {
+	private fun refreshSnapshot(activeCore: VnidropCore) {
-		val activeCore = requireCore()
 		val status = activeCore.status()
 		_state.update {
 			it.copy(
@@ -244,10 +257,25 @@ class CoreRepository(
 		}
 	}
 
-	private suspend fun <T> runCore(block: suspend () -> T): Result<T> =
+	private suspend fun <T> runCore(block: suspend (VnidropCore) -> T): Result<T> =
 		withContext(dispatcher) {
 			try {
-				Result.success(block())
+				Result.success(
+					lifecycleGate.withCall(
+						capture = ::requireCore,
+						block = block,
+					),
+				)
+			} catch (error: Throwable) {
+				if (error is CancellationException) throw error
+				Result.failure(error)
+			}
+		}
+
+	private suspend fun <T> runReconfiguration(block: suspend () -> T): Result<T> =
+		withContext(dispatcher) {
+			try {
+				Result.success(lifecycleGate.withReconfiguration(block))
 			} catch (error: Throwable) {
 				if (error is CancellationException) throw error
 				Result.failure(error)
@@ -263,6 +291,14 @@ class CoreRepository(
 	}
 }
 
+private fun RelaySettings.toNative(): CoreNetworkConfig = when (mode) {
+	RelayMode.Automatic -> defaultCoreNetworkConfig()
+	RelayMode.Custom -> CoreNetworkConfig(
+		mode = CoreRelayMode.CUSTOM,
+		relayUrls = relayUrls,
+	)
+}
+
 private fun CoreEvent.toModel(): CoreEventModel = CoreEventModel(
 	id = id,
 	timestamp = timestamp,

shared/src/commonMain/kotlin/com/vnidrop/app/feature/app/AppViewModel.kt

@@ -15,6 +15,7 @@ import com.vnidrop.app.ui.theme.ThemeMode
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
@@ -46,7 +47,8 @@ class AppViewModel(
 		AppLogger.info("lifecycle", "app started", mapOf("platform" to environment.name))
 		diagnostics?.record("app_open", mapOf("platform" to environment.name, "version" to environment.appVersion))
 		viewModelScope.launch {
-			repository.initialize(environment.defaultCoreDataDir).onFailure(messages::error)
+			val relaySettings = preferencesRepository.preferences.first().relaySettings
+			repository.initialize(environment.defaultCoreDataDir, relaySettings).onFailure(messages::error)
 		}
 		viewModelScope.launch {
 			preferencesRepository.preferences.collect { preferences ->

shared/src/commonMain/kotlin/com/vnidrop/app/feature/send/SendScreen.kt

@@ -12,6 +12,7 @@ import com.vnidrop.app.core.CoreState
 import com.vnidrop.app.core.ReceiverDeliveryStatus
 import com.vnidrop.app.core.ShareAccessPolicy
 import com.vnidrop.app.core.TransferDirection
+import com.vnidrop.app.core.TransferStatus
 import com.vnidrop.app.ui.components.AdaptiveDrawer
 import com.vnidrop.app.ui.state.WindowClass
 
@@ -96,7 +97,12 @@ fun SendScreen(
 		}
 	}
 
-	if (selectedTransfer != null && state.detailPanel != null) {
+	val canShowDetailPanel = selectedTransfer != null && when (state.detailPanel) {
+		TransferDetailPanel.Share -> selectedTransfer.status in setOf(TransferStatus.Importing, TransferStatus.Sharing)
+		TransferDetailPanel.Activity, TransferDetailPanel.Receivers -> true
+		null -> false
+	}
+	if (selectedTransfer != null && state.detailPanel != null && canShowDetailPanel) {
 		AdaptiveDrawer(windowClass = windowClass, onDismissRequest = onCloseDetailPanel) {
 			when (state.detailPanel) {
 				TransferDetailPanel.Activity -> TransferActivityPanel(coreState.events, selectedTransfer.transferId)

shared/src/commonMain/kotlin/com/vnidrop/app/feature/send/SendViewModel.kt

@@ -209,7 +209,12 @@ class SendViewModel(
 		)
 	}
 	fun openActivity() = _state.update { it.copy(detailPanel = TransferDetailPanel.Activity) }
-	fun openShare() = _state.update { it.copy(detailPanel = TransferDetailPanel.Share) }
+	fun openShare() {
+		val selectedId = _state.value.selectedTransferId ?: return
+		val selected = coreState.value.transfers.firstOrNull { it.transferId == selectedId } ?: return
+		if (selected.status !in setOf(TransferStatus.Importing, TransferStatus.Sharing)) return
+		_state.update { it.copy(detailPanel = TransferDetailPanel.Share) }
+	}
 	fun openReceivers() {
 		val transferId = _state.value.selectedTransferId ?: return
 		_state.update { it.copy(detailPanel = TransferDetailPanel.Receivers) }

shared/src/commonMain/kotlin/com/vnidrop/app/feature/send/TransferDetails.kt

@@ -46,6 +46,7 @@ import com.vnidrop.app.core.ReceiverDeliveryStatus
 import com.vnidrop.app.core.ReceiverRequestModel
 import com.vnidrop.app.core.ShareAccessPolicy
 import com.vnidrop.app.core.Transfer
+import com.vnidrop.app.core.TransferStatus
 import com.vnidrop.app.ui.components.AppCard
 import com.vnidrop.app.ui.components.DestructiveButton
 import com.vnidrop.app.ui.components.PrimaryButton
@@ -60,12 +61,19 @@ import com.vnidrop.app.ui.state.progressForReceiver
 import com.vnidrop.app.ui.theme.LocalVniDropColors
 import org.jetbrains.compose.resources.decodeToImageBitmap
 import org.jetbrains.compose.resources.stringResource
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import vnidrop.shared.generated.resources.*
 
 enum class InvitationAction { Export, Share, Nfc }
 
+private sealed interface TransferQrRenderState {
+	data object Loading : TransferQrRenderState
+	data object Unavailable : TransferQrRenderState
+	data class Ready(val bitmap: androidx.compose.ui.graphics.ImageBitmap) : TransferQrRenderState
+}
+
 @Composable
 internal fun TransferDetails(
 	transfer: Transfer,
@@ -122,12 +130,29 @@ internal fun TransferDetails(
 						count = pendingReceivers + completedReceivers,
 						onClick = onReceivers,
 					)
-					HorizontalDivider(color = LocalVniDropColors.current.borderDefault)
+					when (transfer.status) {
-					DetailDestination(
+						TransferStatus.Sharing -> {
-						title = stringResource(Res.string.transfer_share_title),
+							HorizontalDivider(color = LocalVniDropColors.current.borderDefault)
-						description = stringResource(Res.string.transfer_share_description),
+							DetailDestination(
-						onClick = onShare,
+								title = stringResource(Res.string.transfer_share_title),
-					)
+								description = stringResource(Res.string.transfer_share_description),
+								onClick = onShare,
+							)
+						}
+						TransferStatus.Importing -> {
+							HorizontalDivider(color = LocalVniDropColors.current.borderDefault)
+							DetailDestination(
+								title = stringResource(Res.string.transfer_share_title),
+								description = stringResource(Res.string.transfer_event_preparing),
+							)
+						}
+						TransferStatus.Receiving,
+						TransferStatus.Done,
+						TransferStatus.Failed,
+						TransferStatus.Cancelled,
+						TransferStatus.Stopped,
+						-> Unit
+					}
 				}
 			}
 		}
@@ -144,9 +169,12 @@ private fun receiversDescription(pending: Int, completed: Int): String = when {
 }
 
 @Composable
-private fun DetailDestination(title: String, description: String, count: Int? = null, onClick: () -> Unit) {
+private fun DetailDestination(title: String, description: String, count: Int? = null, onClick: (() -> Unit)? = null) {
 	Row(
-		Modifier.fillMaxWidth().clickable(onClick = onClick).padding(16.dp),
+		Modifier
+			.fillMaxWidth()
+			.then(if (onClick == null) Modifier else Modifier.clickable(onClick = onClick))
+			.padding(16.dp),
 		verticalAlignment = Alignment.CenterVertically,
 	) {
 		Column(Modifier.weight(1f), verticalArrangement = Arrangement.spacedBy(3.dp)) {
@@ -157,7 +185,9 @@ private fun DetailDestination(title: String, description: String, count: Int? =
 			Text(count.toString(), modifier = Modifier.background(LocalVniDropColors.current.backgroundSelection, RoundedCornerShape(20.dp)).padding(horizontal = 9.dp, vertical = 3.dp))
 			Spacer(Modifier.width(8.dp))
 		}
-		PlatformIcon(AppIcon.ChevronRight, null, tint = LocalVniDropColors.current.foregroundLighter, modifier = Modifier.size(18.dp))
+		if (onClick != null) {
+			PlatformIcon(AppIcon.ChevronRight, null, tint = LocalVniDropColors.current.foregroundLighter, modifier = Modifier.size(18.dp))
+		}
 	}
 }
 
@@ -240,41 +270,71 @@ internal fun TransferSharePanel(
 	DisposableEffect(actions) { onDispose(actions::cancelNfcWrite) }
 	val ticket = transfer.ticket
 	PanelContainer(stringResource(Res.string.transfer_share_title)) {
+		if (transfer.status == TransferStatus.Importing) {
+			Text(stringResource(Res.string.transfer_event_preparing), color = LocalVniDropColors.current.foregroundLighter)
+			return@PanelContainer
+		}
+		if (transfer.status != TransferStatus.Sharing) return@PanelContainer
 		if (ticket == null) {
 			Text(stringResource(Res.string.transfer_event_preparing), color = LocalVniDropColors.current.foregroundLighter)
 			return@PanelContainer
 		}
-		val renderedBitmap by produceState(qrBitmap, ticket, qrBitmap) {
+		val qrRenderState by produceState<TransferQrRenderState>(
-			if (value == null) {
+			initialValue = qrBitmap?.let(TransferQrRenderState::Ready) ?: TransferQrRenderState.Loading,
-				value = withContext(Dispatchers.Default) {
+			key1 = ticket,
-					runCatching { buildTransferQrCode(ticket).renderToBytes().decodeToImageBitmap() }.getOrNull()
+			key2 = qrBitmap,
+		) {
+			if (qrBitmap != null) {
+				value = TransferQrRenderState.Ready(qrBitmap)
+				return@produceState
+			}
+			value = try {
+				val bitmap = withContext(Dispatchers.Default) {
+					buildTransferQrCode(ticket).renderToBytes().decodeToImageBitmap()
 				}
-				value?.let { onQrRendered(ticket, it) }
+				onQrRendered(ticket, bitmap)
+				TransferQrRenderState.Ready(bitmap)
+			} catch (error: CancellationException) {
+				throw error
+			} catch (_: Throwable) {
+				TransferQrRenderState.Unavailable
 			}
 		}
-		val renderedQr = renderedBitmap
+		when (val qrState = qrRenderState) {
-		Surface(
+			is TransferQrRenderState.Ready -> Surface(
-			modifier = Modifier.align(Alignment.CenterHorizontally).size(268.dp),
+				modifier = Modifier.align(Alignment.CenterHorizontally).size(268.dp),
-			shape = RoundedCornerShape(18.dp),
+				shape = RoundedCornerShape(18.dp),
-			color = Color.White,
+				color = Color.White,
-		) {
+			) {
-			if (renderedQr != null) {
 				Image(
-					bitmap = renderedQr,
+					bitmap = qrState.bitmap,
 					contentDescription = null,
 					modifier = Modifier.padding(14.dp).fillMaxSize(),
 					filterQuality = FilterQuality.None,
 				)
-			} else {
+			}
+			TransferQrRenderState.Loading -> Surface(
+				modifier = Modifier.align(Alignment.CenterHorizontally).size(268.dp),
+				shape = RoundedCornerShape(18.dp),
+				color = Color.White,
+			) {
 				Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) { CircularProgressIndicator() }
 			}
+			TransferQrRenderState.Unavailable -> Text(
+				stringResource(Res.string.transfer_qr_unavailable),
+				modifier = Modifier.align(Alignment.CenterHorizontally),
+				color = LocalVniDropColors.current.foregroundLighter,
+				style = MaterialTheme.typography.bodySmall,
+			)
+		}
+		if (qrRenderState is TransferQrRenderState.Ready) {
+			Text(
+				stringResource(Res.string.transfer_scan_qr),
+				modifier = Modifier.align(Alignment.CenterHorizontally),
+				color = LocalVniDropColors.current.foregroundLighter,
+				style = MaterialTheme.typography.bodySmall,
+			)
 		}
-		Text(
-			stringResource(Res.string.transfer_scan_qr),
-			modifier = Modifier.align(Alignment.CenterHorizontally),
-			color = LocalVniDropColors.current.foregroundLighter,
-			style = MaterialTheme.typography.bodySmall,
-		)
 		if (actions.nfcAvailability != NfcShareAvailability.Hidden) {
 			var writingNfc by remember(ticket) { mutableStateOf(false) }
 			SecondaryButton(

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/NetworkSettings.kt

@@ -0,0 +1,199 @@
+package com.vnidrop.app.feature.settings
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.text.selection.SelectionContainer
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.ui.components.Field
+import com.vnidrop.app.ui.components.PrimaryButton
+import com.vnidrop.app.ui.icons.AppIcon
+import com.vnidrop.app.ui.icons.PlatformIcon
+import com.vnidrop.app.ui.theme.LocalVniDropColors
+import org.jetbrains.compose.resources.stringResource
+import vnidrop.shared.generated.resources.Res
+import vnidrop.shared.generated.resources.approval_endpoint_id
+import vnidrop.shared.generated.resources.relay_apply
+import vnidrop.shared.generated.resources.relay_apply_active_transfers
+import vnidrop.shared.generated.resources.relay_apply_failed
+import vnidrop.shared.generated.resources.relay_apply_restart_description
+import vnidrop.shared.generated.resources.relay_applying
+import vnidrop.shared.generated.resources.relay_custom_urls_help
+import vnidrop.shared.generated.resources.relay_custom_urls_label
+import vnidrop.shared.generated.resources.relay_mode_automatic
+import vnidrop.shared.generated.resources.relay_mode_automatic_description
+import vnidrop.shared.generated.resources.relay_mode_custom
+import vnidrop.shared.generated.resources.relay_mode_custom_description
+import vnidrop.shared.generated.resources.relay_privacy_description
+import vnidrop.shared.generated.resources.relay_restore_failed
+import vnidrop.shared.generated.resources.relay_strict_warning
+import vnidrop.shared.generated.resources.relay_validation_duplicate_url
+import vnidrop.shared.generated.resources.relay_validation_https_required
+import vnidrop.shared.generated.resources.relay_validation_invalid_url
+import vnidrop.shared.generated.resources.relay_validation_missing_url
+import vnidrop.shared.generated.resources.relay_validation_too_many_urls
+import vnidrop.shared.generated.resources.settings_network_title
+
+@Composable
+internal fun NetworkSettings(
+	state: SettingsState,
+	onModeChanged: (RelayMode) -> Unit,
+	onUrlsChanged: (String) -> Unit,
+	onApply: () -> Unit,
+	onBack: () -> Unit,
+	showBack: Boolean,
+) {
+	val colors = LocalVniDropColors.current
+	Column(verticalArrangement = Arrangement.spacedBy(16.dp)) {
+		SettingsTopBar(stringResource(Res.string.settings_network_title), onBack, showBack)
+		state.endpointId?.takeIf(String::isNotBlank)?.let { endpointId ->
+			SelectionContainer {
+				Text(
+					stringResource(Res.string.approval_endpoint_id, endpointId),
+					color = colors.foregroundLighter,
+					style = MaterialTheme.typography.bodySmall,
+				)
+			}
+		}
+		SettingsGroup {
+			RelayModeRow(
+				icon = AppIcon.Globe,
+				title = stringResource(Res.string.relay_mode_automatic),
+				description = stringResource(Res.string.relay_mode_automatic_description),
+				selected = state.relayMode == RelayMode.Automatic,
+				enabled = !state.isApplyingRelaySettings,
+				onClick = { onModeChanged(RelayMode.Automatic) },
+			)
+			SettingsDivider()
+			RelayModeRow(
+				icon = AppIcon.Radio,
+				title = stringResource(Res.string.relay_mode_custom),
+				description = stringResource(Res.string.relay_mode_custom_description),
+				selected = state.relayMode == RelayMode.Custom,
+				enabled = !state.isApplyingRelaySettings,
+				onClick = { onModeChanged(RelayMode.Custom) },
+			)
+		}
+		if (state.relayMode == RelayMode.Custom) {
+			Field(
+				value = state.relayUrlsText,
+				onValueChange = onUrlsChanged,
+				label = stringResource(Res.string.relay_custom_urls_label),
+				minLines = 3,
+				enabled = !state.isApplyingRelaySettings,
+			)
+			Text(
+				stringResource(Res.string.relay_custom_urls_help),
+				color = colors.foregroundLighter,
+				style = MaterialTheme.typography.bodySmall,
+			)
+			Text(
+				stringResource(Res.string.relay_strict_warning),
+				color = colors.foregroundLight,
+				style = MaterialTheme.typography.bodySmall,
+				fontWeight = FontWeight.Medium,
+			)
+			Text(
+				stringResource(Res.string.relay_privacy_description),
+				color = colors.foregroundLighter,
+				style = MaterialTheme.typography.bodySmall,
+			)
+		}
+		relayErrorText(state)?.let { error ->
+			Text(
+				error,
+				color = colors.destructiveDefault,
+				style = MaterialTheme.typography.bodySmall,
+				fontWeight = FontWeight.Medium,
+			)
+		}
+		Text(
+			stringResource(Res.string.relay_apply_restart_description),
+			color = colors.foregroundLighter,
+			style = MaterialTheme.typography.bodySmall,
+		)
+		PrimaryButton(
+			text = stringResource(
+				if (state.isApplyingRelaySettings) Res.string.relay_applying else Res.string.relay_apply,
+			),
+			onClick = onApply,
+			modifier = Modifier.fillMaxWidth(),
+			enabled = state.hasRelaySettingsChanges &&
+				!state.isApplyingRelaySettings &&
+				!state.hasActiveNetworkWork,
+		)
+	}
+}
+
+@Composable
+private fun RelayModeRow(
+	icon: AppIcon,
+	title: String,
+	description: String,
+	selected: Boolean,
+	enabled: Boolean,
+	onClick: () -> Unit,
+) {
+	SettingsRow(
+		icon = icon,
+		title = title,
+		subtitle = description,
+		selected = selected,
+		onClick = onClick.takeIf { enabled },
+		showsDisclosure = false,
+		trailing = if (selected) {
+			{
+				PlatformIcon(
+					AppIcon.Check,
+					contentDescription = null,
+					tint = LocalVniDropColors.current.brandLink,
+					modifier = Modifier.size(20.dp),
+				)
+			}
+		} else {
+			null
+		},
+	)
+}
+
+@Composable
+private fun relayErrorText(state: SettingsState): String? {
+	if (state.hasActiveNetworkWork || state.relayApplyError == RelaySettingsApplyError.ActiveTransfers) {
+		return stringResource(Res.string.relay_apply_active_transfers)
+	}
+	state.relayInputError?.let { error ->
+		return when (error) {
+			RelaySettingsInputError.MissingUrl -> stringResource(Res.string.relay_validation_missing_url)
+			is RelaySettingsInputError.TooManyUrls -> stringResource(
+				Res.string.relay_validation_too_many_urls,
+				error.maximum,
+			)
+			is RelaySettingsInputError.HttpsRequired -> stringResource(
+				Res.string.relay_validation_https_required,
+				error.line,
+			)
+			is RelaySettingsInputError.InvalidUrl -> stringResource(
+				Res.string.relay_validation_invalid_url,
+				error.line,
+			)
+			is RelaySettingsInputError.DuplicateUrl -> stringResource(
+				Res.string.relay_validation_duplicate_url,
+				error.line,
+			)
+		}
+	}
+	return when (state.relayApplyError) {
+		RelaySettingsApplyError.ApplyFailed -> stringResource(Res.string.relay_apply_failed)
+		RelaySettingsApplyError.RestoreFailed -> stringResource(Res.string.relay_restore_failed)
+		RelaySettingsApplyError.ActiveTransfers,
+		null,
+		-> null
+	}
+}

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/RelaySettingsValidation.kt

@@ -0,0 +1,147 @@
+package com.vnidrop.app.feature.settings
+
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
+
+sealed interface RelaySettingsInputError {
+	data object MissingUrl : RelaySettingsInputError
+	data class TooManyUrls(val maximum: Int) : RelaySettingsInputError
+	data class HttpsRequired(val line: Int) : RelaySettingsInputError
+	data class InvalidUrl(val line: Int) : RelaySettingsInputError
+	data class DuplicateUrl(val line: Int) : RelaySettingsInputError
+}
+
+data class RelaySettingsValidation(
+	val settings: RelaySettings? = null,
+	val error: RelaySettingsInputError? = null,
+)
+
+fun validateRelaySettings(
+	mode: RelayMode,
+	urlsText: String,
+	retainedUrls: List<String> = emptyList(),
+): RelaySettingsValidation {
+	if (mode == RelayMode.Automatic) {
+		return RelaySettingsValidation(RelaySettings(mode, retainedUrls))
+	}
+	val lines = urlsText.lineSequence()
+		.mapIndexedNotNull { index, raw -> raw.trim().takeIf(String::isNotEmpty)?.let { index + 1 to it } }
+		.toList()
+	if (lines.isEmpty()) return RelaySettingsValidation(error = RelaySettingsInputError.MissingUrl)
+	if (lines.size > MaximumRelayUrls) {
+		return RelaySettingsValidation(error = RelaySettingsInputError.TooManyUrls(MaximumRelayUrls))
+	}
+
+	val normalized = mutableListOf<String>()
+	for ((line, raw) in lines) {
+		when (val result = normalizeRelayUrl(raw)) {
+			RelayUrlResult.HttpsRequired -> {
+				return RelaySettingsValidation(error = RelaySettingsInputError.HttpsRequired(line))
+			}
+			RelayUrlResult.Invalid -> {
+				return RelaySettingsValidation(error = RelaySettingsInputError.InvalidUrl(line))
+			}
+			is RelayUrlResult.Valid -> {
+				if (result.url in normalized) {
+					return RelaySettingsValidation(error = RelaySettingsInputError.DuplicateUrl(line))
+				}
+				normalized += result.url
+			}
+		}
+	}
+	return RelaySettingsValidation(RelaySettings(RelayMode.Custom, normalized))
+}
+
+private sealed interface RelayUrlResult {
+	data object HttpsRequired : RelayUrlResult
+	data object Invalid : RelayUrlResult
+	data class Valid(val url: String) : RelayUrlResult
+}
+
+private fun normalizeRelayUrl(raw: String): RelayUrlResult {
+	if (!raw.startsWith(HttpsPrefix, ignoreCase = true)) return RelayUrlResult.HttpsRequired
+	if (raw.encodeToByteArray().size > MaximumRelayUrlLength || raw.any { it.isWhitespace() || it.isISOControl() }) {
+		return RelayUrlResult.Invalid
+	}
+	val remainder = raw.substring(HttpsPrefix.length)
+	if (remainder.isEmpty() || '?' in remainder || '#' in remainder) return RelayUrlResult.Invalid
+	val authority = remainder.substringBefore('/')
+	val path = remainder.removePrefix(authority)
+	if (!isValidAuthority(authority) || path !in setOf("", "/")) return RelayUrlResult.Invalid
+
+	val normalizedAuthority = if (authority.startsWith('[')) {
+		val closingBracket = authority.indexOf(']')
+		authority.substring(0, closingBracket + 1).lowercase() + authority.substring(closingBracket + 1)
+	} else {
+		val portSeparator = authority.lastIndexOf(':').takeIf { authority.count { char -> char == ':' } == 1 }
+		if (portSeparator == null) authority.lowercase()
+		else authority.substring(0, portSeparator).lowercase() + authority.substring(portSeparator)
+	}
+	return RelayUrlResult.Valid("$HttpsPrefix${normalizedAuthority.removeSuffix(":443")}")
+}
+
+private fun isValidAuthority(authority: String): Boolean {
+	if (authority.isBlank() || '@' in authority) return false
+	if (authority.startsWith('[')) {
+		val closingBracket = authority.indexOf(']')
+		if (closingBracket <= 1) return false
+		val address = authority.substring(1, closingBracket)
+		if (!isValidIpv6Address(address)) return false
+		return isValidPortSuffix(authority.substring(closingBracket + 1))
+	}
+	if (authority.count { it == ':' } > 1) return false
+	val host = authority.substringBeforeLast(':', authority)
+	val portSuffix = authority.removePrefix(host)
+	if (host.isBlank() || host.startsWith('.') || host.endsWith('.') || host.startsWith('-') || host.endsWith('-')) return false
+	if (host.any { !it.isLetterOrDigit() && it != '.' && it != '-' }) return false
+	return isValidPortSuffix(portSuffix)
+}
+
+private fun isValidIpv6Address(address: String): Boolean {
+	if (address.isEmpty() || ":::" in address) return false
+	val compressionIndex = address.indexOf("::")
+	val hasCompression = compressionIndex >= 0
+	if (hasCompression && address.indexOf("::", compressionIndex + 2) >= 0) return false
+	if (!hasCompression && (address.startsWith(':') || address.endsWith(':'))) return false
+
+	val left = if (hasCompression) address.substring(0, compressionIndex) else address
+	val right = if (hasCompression) address.substring(compressionIndex + 2) else ""
+	val segments = buildList {
+		if (left.isNotEmpty()) addAll(left.split(':'))
+		if (right.isNotEmpty()) addAll(right.split(':'))
+	}
+	if (segments.any(String::isEmpty)) return false
+
+	var addressUnits = 0
+	for ((index, segment) in segments.withIndex()) {
+		if ('.' in segment) {
+			if (index != segments.lastIndex || !isValidIpv4Tail(segment)) return false
+			addressUnits += 2
+		} else {
+			if (segment.length !in 1..4 || segment.any { !it.isHexDigit() }) return false
+			addressUnits += 1
+		}
+	}
+	return if (hasCompression) addressUnits < 8 else addressUnits == 8
+}
+
+private fun isValidIpv4Tail(address: String): Boolean {
+	val octets = address.split('.')
+	return octets.size == 4 && octets.all { octet ->
+		octet.isNotEmpty() && octet.all(Char::isDigit) && octet.toIntOrNull() in 0..255
+	}
+}
+
+private fun Char.isHexDigit(): Boolean =
+	this in '0'..'9' || lowercaseChar() in 'a'..'f'
+
+private fun isValidPortSuffix(suffix: String): Boolean {
+	if (suffix.isEmpty()) return true
+	if (!suffix.startsWith(':')) return false
+	val port = suffix.drop(1).toIntOrNull() ?: return false
+	return port in 1..65535
+}
+
+private const val HttpsPrefix = "https://"
+private const val MaximumRelayUrls = 8
+private const val MaximumRelayUrlLength = 2_048

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/SettingsOverview.kt

@@ -7,6 +7,7 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
+import com.vnidrop.app.core.RelayMode
 import com.vnidrop.app.ui.icons.AppIcon
 import com.vnidrop.app.ui.theme.ThemeMode
 import org.jetbrains.compose.resources.stringResource
@@ -18,7 +19,10 @@ import vnidrop.shared.generated.resources.appearance_system_mode
 import vnidrop.shared.generated.resources.appearance_title
 import vnidrop.shared.generated.resources.notifications_title
 import vnidrop.shared.generated.resources.preferences_title
+import vnidrop.shared.generated.resources.relay_mode_automatic
+import vnidrop.shared.generated.resources.relay_mode_custom
 import vnidrop.shared.generated.resources.settings_title
+import vnidrop.shared.generated.resources.settings_network_title
 import vnidrop.shared.generated.resources.storage_title
 
 @Composable
@@ -34,6 +38,14 @@ internal fun SettingsOverview(
 			fontWeight = FontWeight.Bold,
 		)
 		SettingsGroup {
+			SettingsRow(
+				icon = AppIcon.Globe,
+				title = stringResource(Res.string.settings_network_title),
+				value = relayModeLabel(state.savedRelaySettings.mode),
+				selected = state.selectedSection == SettingsSection.Network,
+				onClick = { onSectionSelected(SettingsSection.Network) },
+			)
+			SettingsDivider()
 			SettingsRow(
 				icon = AppIcon.User,
 				title = stringResource(Res.string.preferences_title),
@@ -76,6 +88,12 @@ internal fun SettingsOverview(
 	}
 }
 
+@Composable
+private fun relayModeLabel(mode: RelayMode): String = when (mode) {
+	RelayMode.Automatic -> stringResource(Res.string.relay_mode_automatic)
+	RelayMode.Custom -> stringResource(Res.string.relay_mode_custom)
+}
+
 @Composable
 private fun themeModeLabel(mode: ThemeMode): String = when (mode) {
 	ThemeMode.System -> stringResource(Res.string.appearance_system_mode)

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/SettingsRoute.kt

@@ -24,6 +24,9 @@ fun SettingsRoute(viewModel: SettingsViewModel, windowClass: WindowClass) {
 		onSectionSelected = viewModel::selectSection,
 		onUsernameChanged = viewModel::setUsername,
 		onThemeModeChanged = viewModel::setThemeMode,
+		onRelayModeChanged = viewModel::setRelayMode,
+		onRelayUrlsChanged = viewModel::setRelayUrlsText,
+		onApplyRelaySettings = viewModel::applyRelaySettings,
 		onChooseFolder = viewModel::chooseReceiveFolder,
 		onResetFolder = viewModel::resetReceiveFolder,
 		onNotificationsChanged = viewModel::setNotificationsEnabled,

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/SettingsScreen.kt

@@ -9,6 +9,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import com.vnidrop.app.ui.state.WindowClass
+import com.vnidrop.app.core.RelayMode
 import com.vnidrop.app.ui.theme.ThemeMode
 
 @Composable
@@ -30,6 +31,9 @@ fun SettingsScreen(
 	onBugIncludeLogsChanged: (Boolean) -> Unit,
 	onSubmitBugReport: () -> Unit,
 	onDeleteAllTransfers: () -> Unit = {},
+	onRelayModeChanged: (RelayMode) -> Unit = {},
+	onRelayUrlsChanged: (String) -> Unit = {},
+	onApplyRelaySettings: () -> Unit = {},
 ) {
 	if (windowClass == WindowClass.Desktop) {
 		Row(
@@ -60,6 +64,9 @@ fun SettingsScreen(
 					onBugIncludeLogsChanged = onBugIncludeLogsChanged,
 					onSubmitBugReport = onSubmitBugReport,
 					onDeleteAllTransfers = onDeleteAllTransfers,
+					onRelayModeChanged = onRelayModeChanged,
+					onRelayUrlsChanged = onRelayUrlsChanged,
+					onApplyRelaySettings = onApplyRelaySettings,
 				)
 			}
 		}
@@ -94,6 +101,9 @@ fun SettingsScreen(
 				onBugIncludeLogsChanged = onBugIncludeLogsChanged,
 				onSubmitBugReport = onSubmitBugReport,
 				onDeleteAllTransfers = onDeleteAllTransfers,
+				onRelayModeChanged = onRelayModeChanged,
+				onRelayUrlsChanged = onRelayUrlsChanged,
+				onApplyRelaySettings = onApplyRelaySettings,
 			)
 		}
 	}
@@ -120,11 +130,22 @@ private fun SettingsSectionContent(
 	onBugIncludeLogsChanged: (Boolean) -> Unit,
 	onSubmitBugReport: () -> Unit,
 	onDeleteAllTransfers: () -> Unit,
+	onRelayModeChanged: (RelayMode) -> Unit,
+	onRelayUrlsChanged: (String) -> Unit,
+	onApplyRelaySettings: () -> Unit,
 ) {
 	when (section) {
 		SettingsSection.Overview -> Unit
 		SettingsSection.Preferences -> PreferencesSettings(state, onUsernameChanged, onChooseFolder, onResetFolder, onBack, showBack)
 		SettingsSection.Appearance -> AppearanceSettings(state.themeMode, onThemeModeChanged, onBack, showBack)
+		SettingsSection.Network -> NetworkSettings(
+			state = state,
+			onModeChanged = onRelayModeChanged,
+			onUrlsChanged = onRelayUrlsChanged,
+			onApply = onApplyRelaySettings,
+			onBack = onBack,
+			showBack = showBack,
+		)
 		SettingsSection.Notifications -> NotificationSettings(state, onNotificationsChanged, onOpenNotificationSettings, onBack, showBack)
 		SettingsSection.Storage -> StorageSettings(state, onDeleteAllTransfers, onBack, showBack)
 		SettingsSection.About -> AboutSettings(

shared/src/commonMain/kotlin/com/vnidrop/app/feature/settings/SettingsViewModel.kt

@@ -7,8 +7,12 @@ import com.vnidrop.app.DeviceInfoProvider
 import com.vnidrop.app.PlatformEnvironment
 import com.vnidrop.app.core.FileSystemService
 import com.vnidrop.app.core.CoreGateway
+import com.vnidrop.app.core.CoreLifecycleBusyException
 import com.vnidrop.app.core.FolderAccessStatus
 import com.vnidrop.app.core.ReceiveFolder
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
+import com.vnidrop.app.core.TransferStatus
 import com.vnidrop.app.diagnostics.BugReportDraft
 import com.vnidrop.app.diagnostics.BugReportService
 import com.vnidrop.app.diagnostics.DiagnosticsBuildConfig
@@ -43,17 +47,25 @@ import vnidrop.shared.generated.resources.notifications_enabled_message
 import vnidrop.shared.generated.resources.notifications_permission_denied
 import vnidrop.shared.generated.resources.notifications_settings_open_failed
 import vnidrop.shared.generated.resources.notifications_unsupported
+import vnidrop.shared.generated.resources.relay_settings_applied
 
 enum class SettingsSection {
 	Overview,
 	Preferences,
 	Appearance,
+	Network,
 	Notifications,
 	Storage,
 	About,
 	BugReport,
 }
 
+enum class RelaySettingsApplyError {
+	ActiveTransfers,
+	ApplyFailed,
+	RestoreFailed,
+}
+
 data class StorageBreakdown(
 	val transferCacheBytes: ULong,
 	val appDataBytes: ULong,
@@ -74,6 +86,14 @@ data class SettingsState(
 	val isValidatingFolder: Boolean = false,
 	val supportsCustomReceiveFolders: Boolean = true,
 	val themeMode: ThemeMode = ThemeMode.System,
+	val savedRelaySettings: RelaySettings = RelaySettings(),
+	val relayMode: RelayMode = RelayMode.Automatic,
+	val relayUrlsText: String = "",
+	val relayInputError: RelaySettingsInputError? = null,
+	val relayApplyError: RelaySettingsApplyError? = null,
+	val isApplyingRelaySettings: Boolean = false,
+	val hasActiveNetworkWork: Boolean = false,
+	val endpointId: String? = null,
 	val notificationsEnabled: Boolean = false,
 	val notificationPermission: NotificationPermission = NotificationPermission.NotDetermined,
 	val diagnosticsEnabled: Boolean = false,
@@ -90,7 +110,11 @@ data class SettingsState(
 	val storage: StorageBreakdown? = null,
 	val isCalculatingStorage: Boolean = false,
 	val isDeletingTransfers: Boolean = false,
-)
+) {
+	val hasRelaySettingsChanges: Boolean
+		get() = relayMode != savedRelaySettings.mode ||
+			(relayMode == RelayMode.Custom && relayUrlsText != savedRelaySettings.relayUrls.joinToString("\n"))
+}
 
 sealed interface SettingsEffect {
 	data object OpenReceiveFolderPicker : SettingsEffect
@@ -121,6 +145,7 @@ class SettingsViewModel(
 	private var enableNotificationsAfterSettings = false
 	private var usernamePersistJob: Job? = null
 	private var hasLocalUsernameDraft = false
+	private var hasLocalRelayDraft = false
 
 	init {
 		viewModelScope.launch {
@@ -134,6 +159,13 @@ class SettingsViewModel(
 						themeMode = preferences.themeMode,
 						notificationsEnabled = preferences.notificationsEnabled,
 						diagnosticsEnabled = preferences.diagnosticsEnabled,
+						savedRelaySettings = preferences.relaySettings,
+						relayMode = if (hasLocalRelayDraft) current.relayMode else preferences.relaySettings.mode,
+						relayUrlsText = if (hasLocalRelayDraft) {
+							current.relayUrlsText
+						} else {
+							preferences.relaySettings.relayUrls.joinToString("\n")
+						},
 					)
 				}
 				if (receiveFolder != previousFolder) {
@@ -141,6 +173,19 @@ class SettingsViewModel(
 				}
 			}
 		}
+		viewModelScope.launch {
+			repository.state.collect { coreState ->
+				val status = coreState.status
+				val hasActiveWork = status?.let { it.activeTransfers > 0UL || it.activeShares > 0UL } == true ||
+					coreState.transfers.any { it.status in ActiveTransferStatuses }
+				_state.update {
+					it.copy(
+						hasActiveNetworkWork = hasActiveWork,
+						endpointId = coreState.status?.endpointId,
+					)
+				}
+			}
+		}
 		refreshNotificationPermission()
 		loadDeviceInfo()
 	}
@@ -218,6 +263,103 @@ class SettingsViewModel(
 		viewModelScope.launch { preferencesRepository.setThemeMode(mode) }
 	}
 
+	fun setRelayMode(mode: RelayMode) {
+		hasLocalRelayDraft = true
+		_state.update {
+			it.copy(
+				relayMode = mode,
+				relayInputError = null,
+				relayApplyError = null,
+			)
+		}
+		hasLocalRelayDraft = _state.value.hasRelaySettingsChanges
+	}
+
+	fun setRelayUrlsText(value: String) {
+		hasLocalRelayDraft = true
+		_state.update {
+			it.copy(
+				relayUrlsText = value,
+				relayInputError = null,
+				relayApplyError = null,
+			)
+		}
+		hasLocalRelayDraft = _state.value.hasRelaySettingsChanges
+	}
+
+	fun applyRelaySettings() {
+		val snapshot = _state.value
+		if (snapshot.isApplyingRelaySettings || !snapshot.hasRelaySettingsChanges) return
+		val validation = validateRelaySettings(
+			mode = snapshot.relayMode,
+			urlsText = snapshot.relayUrlsText,
+			retainedUrls = snapshot.savedRelaySettings.relayUrls,
+		)
+		val desired = validation.settings
+		if (desired == null) {
+			_state.update { it.copy(relayInputError = validation.error, relayApplyError = null) }
+			return
+		}
+		if (snapshot.hasActiveNetworkWork) {
+			_state.update {
+				it.copy(relayInputError = null, relayApplyError = RelaySettingsApplyError.ActiveTransfers)
+			}
+			return
+		}
+
+		_state.update {
+			it.copy(
+				isApplyingRelaySettings = true,
+				relayInputError = null,
+				relayApplyError = null,
+			)
+		}
+		viewModelScope.launch {
+			val previous = snapshot.savedRelaySettings
+			val applied = repository.initialize(environment.defaultCoreDataDir, desired)
+			if (applied.isFailure) {
+				val busy = applied.exceptionOrNull() is CoreLifecycleBusyException
+				if (busy || repository.state.value.isInitialized) {
+					_state.update {
+						it.copy(
+							isApplyingRelaySettings = false,
+							relayApplyError = if (repository.state.value.isInitialized) {
+								RelaySettingsApplyError.ActiveTransfers
+							} else {
+								RelaySettingsApplyError.ApplyFailed
+							},
+						)
+					}
+				} else {
+					finishFailedRelayApply(previous)
+				}
+				return@launch
+			}
+			try {
+				preferencesRepository.setRelaySettings(desired)
+			} catch (error: CancellationException) {
+				throw error
+			} catch (_: Throwable) {
+				finishFailedRelayApply(previous)
+				return@launch
+			}
+			hasLocalRelayDraft = false
+			_state.update {
+				it.copy(
+					savedRelaySettings = desired,
+					relayMode = desired.mode,
+					relayUrlsText = desired.relayUrls.joinToString("\n"),
+					isApplyingRelaySettings = false,
+					relayInputError = null,
+					relayApplyError = null,
+				)
+			}
+			messages.show(
+				UiMessage(UiText.Resource(Res.string.relay_settings_applied), UiMessageTone.Success),
+			)
+		}
+	}
+
 	fun chooseReceiveFolder() {
 		if (!fileSystemService.supportsCustomReceiveFolders) return
 		viewModelScope.launch { effects.send(SettingsEffect.OpenReceiveFolderPicker) }
@@ -417,7 +559,22 @@ class SettingsViewModel(
 		_state.update { it.copy(folderAccessStatus = status, isValidatingFolder = false) }
 	}
 
+	private suspend fun finishFailedRelayApply(previous: RelaySettings) {
+		val restored = repository.initialize(environment.defaultCoreDataDir, previous).isSuccess
+		_state.update {
+			it.copy(
+				isApplyingRelaySettings = false,
+				relayApplyError = if (restored) {
+					RelaySettingsApplyError.ApplyFailed
+				} else {
+					RelaySettingsApplyError.RestoreFailed
+				},
+			)
+		}
+	}
+
 	private companion object {
 		const val UsernamePersistDebounceMs = 350L
+		val ActiveTransferStatuses = setOf(TransferStatus.Importing, TransferStatus.Sharing, TransferStatus.Receiving)
 	}
 }

shared/src/commonMain/kotlin/com/vnidrop/app/preferences/AppPreferencesRepository.kt

@@ -3,12 +3,14 @@ package com.vnidrop.app.preferences
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
 import androidx.datastore.preferences.core.PreferenceDataStoreFactory
-import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.core.emptyPreferences
-import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.datastore.preferences.core.booleanPreferencesKey
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.preferencesOf
+import androidx.datastore.preferences.core.stringPreferencesKey
 import com.vnidrop.app.core.ReceiveFolder
 import com.vnidrop.app.core.ReceiveFolderKind
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
 import com.vnidrop.app.ui.theme.ThemeMode
 import com.vnidrop.app.util.randomUuidString
 import kotlinx.coroutines.flow.Flow
@@ -26,6 +28,7 @@ data class AppPreferences(
 	val diagnosticsEnabled: Boolean = false,
 	/** Stable anonymous install id; never an account or advertising id. */
 	val diagnosticsInstallId: String = "",
+	val relaySettings: RelaySettings = RelaySettings(),
 )
 
 class AppPreferencesDefaults(
@@ -44,6 +47,7 @@ interface PreferencesRepository {
 	suspend fun setThemeMode(mode: ThemeMode)
 	suspend fun setNotificationsEnabled(enabled: Boolean)
 	suspend fun setDiagnosticsEnabled(enabled: Boolean)
+	suspend fun setRelaySettings(settings: RelaySettings)
 	/** Ensures a durable install id exists and returns it. */
 	suspend fun ensureDiagnosticsInstallId(): String
 }
@@ -53,8 +57,27 @@ class AppPreferencesRepository(
 	private val defaults: AppPreferencesDefaults,
 ) : PreferencesRepository {
 	override val preferences: Flow<AppPreferences> = dataStore.data
-		.catch { emit(emptyPreferences()) }
+		.catch {
+			emit(preferencesOf(PreferenceKeys.RelayMode to RelayMode.Custom.name))
+		}
 		.map { prefs ->
+			val storedRelayMode = prefs[PreferenceKeys.RelayMode]
+			val parsedRelayMode = storedRelayMode?.let(::relayModeOrNull)
+			val relayMode = when (storedRelayMode) {
+				null -> RelayMode.Automatic
+				else -> parsedRelayMode ?: RelayMode.Custom
+			}
+			val relayUrls = if (storedRelayMode != null && parsedRelayMode == null) {
+				emptyList()
+			} else {
+				prefs[PreferenceKeys.RelayUrls]
+					.orEmpty()
+					.lineSequence()
+					.map(String::trim)
+					.filter(String::isNotEmpty)
+					.distinct()
+					.toList()
+			}
 			AppPreferences(
 				username = prefs[PreferenceKeys.Username]?.takeIf { it.isNotBlank() } ?: defaults.username,
 				receiveFolder = resolveReceiveFolder(prefs, defaults.receiveFolder),
@@ -62,6 +85,10 @@ class AppPreferencesRepository(
 				notificationsEnabled = prefs[PreferenceKeys.NotificationsEnabled] ?: defaults.notificationsEnabled,
 				diagnosticsEnabled = prefs[PreferenceKeys.DiagnosticsEnabled] ?: defaults.diagnosticsEnabled,
 				diagnosticsInstallId = prefs[PreferenceKeys.DiagnosticsInstallId].orEmpty(),
+				relaySettings = RelaySettings(
+					mode = relayMode,
+					relayUrls = relayUrls,
+				),
 			)
 		}
 
@@ -101,6 +128,13 @@ class AppPreferencesRepository(
 		}
 	}
 
+	override suspend fun setRelaySettings(settings: RelaySettings) {
+		dataStore.edit { prefs ->
+			prefs[PreferenceKeys.RelayMode] = settings.mode.name
+			prefs[PreferenceKeys.RelayUrls] = settings.relayUrls.joinToString("\n")
+		}
+	}
+
 	override suspend fun ensureDiagnosticsInstallId(): String {
 		val existing = preferences.first().diagnosticsInstallId
 		if (existing.isNotBlank()) return existing
@@ -128,6 +162,8 @@ private object PreferenceKeys {
 	val NotificationsEnabled = booleanPreferencesKey("notifications_enabled")
 	val DiagnosticsEnabled = booleanPreferencesKey("diagnostics_enabled")
 	val DiagnosticsInstallId = stringPreferencesKey("diagnostics_install_id")
+	val RelayMode = stringPreferencesKey("relay_mode")
+	val RelayUrls = stringPreferencesKey("relay_urls")
 }
 
 private fun resolveReceiveFolder(prefs: Preferences, defaults: ReceiveFolder): ReceiveFolder {
@@ -162,4 +198,7 @@ private fun receiveFolderKindOrNull(raw: String): ReceiveFolderKind? =
 private fun themeModeOrNull(raw: String): ThemeMode? =
 	runCatching { ThemeMode.valueOf(raw) }.getOrNull()
 
+private fun relayModeOrNull(raw: String): RelayMode? =
+	runCatching { RelayMode.valueOf(raw) }.getOrNull()
+
 private const val AppPreferencesFileName = "app_preferences.preferences_pb"

shared/src/commonTest/kotlin/com/vnidrop/app/core/CoreLifecycleGateTest.kt

@@ -0,0 +1,82 @@
+package com.vnidrop.app.core
+
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.awaitCancellation
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+class CoreLifecycleGateTest {
+	@Test
+	fun concurrentCallsHoldIndependentLeasesAndBlockReconfiguration() = runTest {
+		val gate = CoreLifecycleGate()
+		val firstEntered = CompletableDeferred<Unit>()
+		val secondEntered = CompletableDeferred<Unit>()
+		val release = CompletableDeferred<Unit>()
+		val first = launch {
+			gate.withCall(capture = { "core" }) { captured ->
+				assertEquals("core", captured)
+				firstEntered.complete(Unit)
+				release.await()
+			}
+		}
+		firstEntered.await()
+		val second = launch {
+			gate.withCall(capture = { "core" }) {
+				secondEntered.complete(Unit)
+				release.await()
+			}
+		}
+		secondEntered.await()
+
+		assertFailsWith<CoreLifecycleBusyException> {
+			gate.withReconfiguration { error("must not run") }
+		}
+
+		release.complete(Unit)
+		first.join()
+		second.join()
+		gate.withReconfiguration { }
+	}
+
+	@Test
+	fun callsCannotStartDuringReconfiguration() = runTest {
+		val gate = CoreLifecycleGate()
+		val entered = CompletableDeferred<Unit>()
+		val release = CompletableDeferred<Unit>()
+		val reconfiguration = launch {
+			gate.withReconfiguration {
+				entered.complete(Unit)
+				release.await()
+			}
+		}
+		entered.await()
+
+		assertFailsWith<CoreLifecycleBusyException> {
+			gate.withCall(capture = { "core" }) { error("must not run") }
+		}
+
+		release.complete(Unit)
+		reconfiguration.join()
+	}
+
+	@Test
+	fun cancellingCallReleasesItsLease() = runTest {
+		val gate = CoreLifecycleGate()
+		val entered = CompletableDeferred<Unit>()
+		val call = launch {
+			gate.withCall(capture = { "core" }) {
+				entered.complete(Unit)
+				awaitCancellation()
+			}
+		}
+		entered.await()
+
+		call.cancel()
+		call.join()
+
+		gate.withReconfiguration { }
+	}
+}

shared/src/commonTest/kotlin/com/vnidrop/app/feature/ViewModelsTest.kt

@@ -3,12 +3,15 @@ package com.vnidrop.app.feature
 import com.vnidrop.app.DeviceInfo
 import com.vnidrop.app.PlatformEnvironment
 import com.vnidrop.app.core.CoreState
+import com.vnidrop.app.core.CoreStatus
 import com.vnidrop.app.core.CoreSignal
 import com.vnidrop.app.core.PickedShareFile
 import com.vnidrop.app.core.ReceiveFolder
 import com.vnidrop.app.core.ReceiveFolderKind
 import com.vnidrop.app.core.ReceiverDeliveryStatus
 import com.vnidrop.app.core.ReceiverRequestModel
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
 import com.vnidrop.app.core.Share
 import com.vnidrop.app.core.ShareAccessPolicy
 import com.vnidrop.app.core.Transfer
@@ -24,6 +27,7 @@ import com.vnidrop.app.feature.receive.ReceiveHistoryDeleteTarget
 import com.vnidrop.app.feature.receive.ReceiveViewModel
 import com.vnidrop.app.feature.send.SendViewModel
 import com.vnidrop.app.feature.settings.SettingsSection
+import com.vnidrop.app.feature.settings.RelaySettingsApplyError
 import com.vnidrop.app.feature.settings.SettingsViewModel
 import com.vnidrop.app.notifications.NotificationPermission
 import com.vnidrop.app.preferences.AppPreferences
@@ -74,10 +78,26 @@ class ViewModelsTest {
 		val viewModel = AppViewModel(environment(), core, preferences(), UiMessageController())
 		advanceUntilIdle()
 		assertTrue(core.state.value.isInitialized)
+		assertEquals(listOf(RelaySettings()), core.initializedRelaySettings)
 		viewModel.selectDestination(AppDestination.Settings)
 		assertEquals(AppDestination.Settings, viewModel.state.value.destination)
 	}
 
+	@Test
+	fun appViewModelInitializesCoreWithSavedRelaySettings() = runTest {
+		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
+		val custom = RelaySettings(RelayMode.Custom, listOf("https://relay.example.com"))
+		val preferences = preferences().apply {
+			mutablePreferences.value = mutablePreferences.value.copy(relaySettings = custom)
+		}
+		val core = FakeCoreGateway()
+
+		AppViewModel(environment(), core, preferences, UiMessageController())
+		advanceUntilIdle()
+
+		assertEquals(listOf(custom), core.initializedRelaySettings)
+	}
+
 	@Test
 	fun settingsEnablesNotificationsOnlyAfterPermission() = runTest {
 		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
@@ -116,6 +136,94 @@ class ViewModelsTest {
 		assertEquals("Ada ", viewModel.state.value.username)
 	}
 
+	@Test
+	fun settingsAppliesNormalizedCustomRelaysAndPersistsThem() = runTest {
+		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
+		val preferences = preferences()
+		val core = FakeCoreGateway()
+		val viewModel = settingsViewModel(preferences = preferences, repository = core)
+		advanceUntilIdle()
+
+		viewModel.setRelayMode(RelayMode.Custom)
+		viewModel.setRelayUrlsText(" HTTPS://Relay.Example.com/ \nhttps://backup.example.com:443")
+		viewModel.applyRelaySettings()
+		advanceUntilIdle()
+
+		val expected = RelaySettings(
+			RelayMode.Custom,
+			listOf("https://relay.example.com", "https://backup.example.com"),
+		)
+		assertEquals(expected, preferences.mutablePreferences.value.relaySettings)
+		assertEquals(listOf(expected), core.initializedRelaySettings)
+		assertEquals(expected, viewModel.state.value.savedRelaySettings)
+		assertFalse(viewModel.state.value.hasRelaySettingsChanges)
+	}
+
+	@Test
+	fun settingsIgnoresDuplicateApplyBeforeRestartBegins() = runTest {
+		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
+		val core = FakeCoreGateway()
+		val viewModel = settingsViewModel(repository = core)
+		advanceUntilIdle()
+
+		viewModel.setRelayMode(RelayMode.Custom)
+		viewModel.setRelayUrlsText("https://relay.example.com")
+		viewModel.applyRelaySettings()
+		viewModel.applyRelaySettings()
+		assertTrue(viewModel.state.value.isApplyingRelaySettings)
+		advanceUntilIdle()
+
+		assertEquals(1, core.initializedRelaySettings.size)
+	}
+
+	@Test
+	fun settingsDoesNotRestartNetworkWhileTransfersAreActive() = runTest {
+		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
+		val core = FakeCoreGateway().apply {
+			mutableState.value = CoreState(status = CoreStatus("endpoint", 0UL, 1UL))
+		}
+		val viewModel = settingsViewModel(repository = core)
+		advanceUntilIdle()
+		assertEquals("endpoint", viewModel.state.value.endpointId)
+
+		viewModel.setRelayMode(RelayMode.Custom)
+		viewModel.setRelayUrlsText("https://relay.example.com")
+		viewModel.applyRelaySettings()
+		advanceUntilIdle()
+
+		assertEquals(emptyList(), core.initializedRelaySettings)
+		assertEquals(RelaySettingsApplyError.ActiveTransfers, viewModel.state.value.relayApplyError)
+	}
+
+	@Test
+	fun settingsRestoresPreviousNetworkConfigurationWhenApplyFails() = runTest {
+		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
+		val core = FakeCoreGateway().apply {
+			initializeHandler = { settings ->
+				if (settings.mode == RelayMode.Custom) Result.failure(IllegalStateException("unreachable"))
+				else Result.success(Unit)
+			}
+		}
+		val preferences = preferences()
+		val viewModel = settingsViewModel(preferences = preferences, repository = core)
+		advanceUntilIdle()
+
+		viewModel.setRelayMode(RelayMode.Custom)
+		viewModel.setRelayUrlsText("https://relay.example.com")
+		viewModel.applyRelaySettings()
+		advanceUntilIdle()
+
+		assertEquals(
+			listOf(
+				RelaySettings(RelayMode.Custom, listOf("https://relay.example.com")),
+				RelaySettings(),
+			),
+			core.initializedRelaySettings,
+		)
+		assertEquals(RelaySettings(), preferences.mutablePreferences.value.relaySettings)
+		assertEquals(RelaySettingsApplyError.ApplyFailed, viewModel.state.value.relayApplyError)
+	}
+
 	@Test
 	fun settingsKeepsNotificationsDisabledWhenPermissionIsDenied() = runTest {
 		Dispatchers.setMain(StandardTestDispatcher(testScheduler))
@@ -722,11 +830,12 @@ class ViewModelsTest {
 		transport: DiagnosticsTransport = RecordingDiagnosticsTransport(),
 		fileSystem: FakeFileSystemService = FakeFileSystemService(folder),
 		diagnosticsIncluded: Boolean = false,
+		repository: FakeCoreGateway = FakeCoreGateway(),
 	) = SettingsViewModel(
 		environment(),
 		{ DeviceInfo("Device", "Model", "OS", "Wi-Fi", "80%") },
 		fileSystem,
-		FakeCoreGateway(),
+		repository,
 		preferences,
 		notifications,
 		UiMessageController(),

shared/src/commonTest/kotlin/com/vnidrop/app/feature/send/TransferQrCodeTest.kt

@@ -2,6 +2,7 @@ package com.vnidrop.app.feature.send
 
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
 
 class TransferQrCodeTest {
 	@Test
@@ -19,4 +20,12 @@ class TransferQrCodeTest {
 		assertEquals(101, qrCode.rawData.size)
 		assertEquals(872, qrCode.canvasSize)
 	}
+
+	@Test
+	fun versionFortyCapacityBoundaryRejectsOversizedTicket() {
+		assertEquals(40, transferQrInformationDensity("a".repeat(2_953)))
+		assertFailsWith<IllegalArgumentException> {
+			transferQrInformationDensity("a".repeat(2_954))
+		}
+	}
 }

shared/src/commonTest/kotlin/com/vnidrop/app/feature/settings/RelaySettingsValidationTest.kt

@@ -0,0 +1,83 @@
+package com.vnidrop.app.feature.settings
+
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class RelaySettingsValidationTest {
+	@Test
+	fun customRelayUrlsAreNormalized() {
+		val result = validateRelaySettings(
+			mode = RelayMode.Custom,
+			urlsText = " HTTPS://Relay.Example.com/ \nhttps://[2001:DB8::1]:443",
+		)
+
+		assertEquals(
+			RelaySettings(
+				RelayMode.Custom,
+				listOf("https://relay.example.com", "https://[2001:db8::1]"),
+			),
+			result.settings,
+		)
+		assertEquals(null, result.error)
+	}
+
+	@Test
+	fun customRelayUrlsRequireHttpsAndRootPath() {
+		assertEquals(
+			RelaySettingsInputError.HttpsRequired(1),
+			validateRelaySettings(RelayMode.Custom, "http://relay.example.com").error,
+		)
+		assertEquals(
+			RelaySettingsInputError.InvalidUrl(1),
+			validateRelaySettings(RelayMode.Custom, "https://relay.example.com/custom").error,
+		)
+	}
+
+	@Test
+	fun duplicateNormalizedRelayUrlsAreRejected() {
+		val result = validateRelaySettings(
+			RelayMode.Custom,
+			"https://relay.example.com\nHTTPS://RELAY.EXAMPLE.COM:443/",
+		)
+
+		assertEquals(RelaySettingsInputError.DuplicateUrl(2), result.error)
+	}
+
+	@Test
+	fun structurallyValidIpv6RelayUrlsAreAccepted() {
+		val result = validateRelaySettings(
+			RelayMode.Custom,
+			"https://[::1]:443\nhttps://[2001:db8::1]\nhttps://[::ffff:192.0.2.1]",
+		)
+
+		assertEquals(
+			RelaySettings(
+				RelayMode.Custom,
+				listOf(
+					"https://[::1]",
+					"https://[2001:db8::1]",
+					"https://[::ffff:192.0.2.1]",
+				),
+			),
+			result.settings,
+		)
+	}
+
+	@Test
+	fun malformedIpv6RelayUrlsAreRejected() {
+		listOf(
+			"https://[::::]",
+			"https://[1::2::3]",
+			"https://[1:2:3:4:5:6:7]",
+			"https://[1:2:3:4:5:6:7:8::]",
+		).forEach { url ->
+			assertEquals(
+				RelaySettingsInputError.InvalidUrl(1),
+				validateRelaySettings(RelayMode.Custom, url).error,
+				url,
+			)
+		}
+	}
+}

shared/src/commonTest/kotlin/com/vnidrop/app/support/Fakes.kt

@@ -10,6 +10,7 @@ import com.vnidrop.app.core.PickedShareFile
 import com.vnidrop.app.core.ReceiveFolder
 import com.vnidrop.app.core.ReceivedArtifactModel
 import com.vnidrop.app.core.ReceivedStorageInspection
+import com.vnidrop.app.core.RelaySettings
 import com.vnidrop.app.core.ReceiverRequestModel
 import com.vnidrop.app.core.Share
 import com.vnidrop.app.core.ShareAccessPolicy
@@ -54,6 +55,8 @@ class FakeCoreGateway : CoreGateway {
 	var lastReceiveTicket: String? = null
 	var lastReceiveReceiverName: String? = null
 	var lastShareAccessPolicy: ShareAccessPolicy? = null
+	val initializedRelaySettings = mutableListOf<RelaySettings>()
+	var initializeHandler: (RelaySettings) -> Result<Unit> = { Result.success(Unit) }
 
 	fun completeSuspendedReceive() {
 		receiveGate?.complete(Unit)
@@ -66,9 +69,11 @@ class FakeCoreGateway : CoreGateway {
 		gate.await()
 	}
 
-	override suspend fun initialize(appDataDir: String): Result<Unit> {
+	override suspend fun initialize(appDataDir: String, relaySettings: RelaySettings): Result<Unit> {
-		mutableState.value = mutableState.value.copy(isInitialized = true)
+		initializedRelaySettings += relaySettings
-		return Result.success(Unit)
+		return initializeHandler(relaySettings).onSuccess {
+			mutableState.value = mutableState.value.copy(isInitialized = true)
+		}
 	}
 	override fun shutdown() = Unit
 	var lastShareSourceCount: Int = 0
@@ -201,6 +206,9 @@ class FakePreferencesRepository(
 	override suspend fun setDiagnosticsEnabled(enabled: Boolean) {
 		mutablePreferences.value = mutablePreferences.value.copy(diagnosticsEnabled = enabled)
 	}
+	override suspend fun setRelaySettings(settings: RelaySettings) {
+		mutablePreferences.value = mutablePreferences.value.copy(relaySettings = settings)
+	}
 	override suspend fun ensureDiagnosticsInstallId(): String {
 		val existing = mutablePreferences.value.diagnosticsInstallId
 		if (existing.isNotBlank()) return existing

shared/src/jvmTest/kotlin/com/vnidrop/app/preferences/AppPreferencesRepositoryTest.kt

@@ -1,12 +1,19 @@
 package com.vnidrop.app.preferences
 
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringPreferencesKey
 import com.vnidrop.app.core.ReceiveFolder
 import com.vnidrop.app.core.ReceiveFolderKind
+import com.vnidrop.app.core.RelayMode
+import com.vnidrop.app.core.RelaySettings
 import com.vnidrop.app.ui.theme.ThemeMode
 import java.nio.file.Files
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.runBlocking
 
 class AppPreferencesRepositoryTest {
@@ -19,6 +26,66 @@ class AppPreferencesRepositoryTest {
 		assertEquals("Device Name", preferences.username)
 		assertEquals(defaultFolder, preferences.receiveFolder)
 		assertEquals(ThemeMode.System, preferences.themeMode)
+		assertEquals(RelaySettings(), preferences.relaySettings)
+	}
+
+	@Test
+	fun customRelaySettingsArePersisted() = runBlocking {
+		val repository = repositoryForTest()
+		val custom = RelaySettings(
+			mode = RelayMode.Custom,
+			relayUrls = listOf("https://relay.example.com", "https://backup.example.com:443"),
+		)
+
+		repository.setRelaySettings(custom)
+
+		assertEquals(custom, repository.preferences.first().relaySettings)
+	}
+
+	@Test
+	fun unknownStoredRelayModeFailsClosedAndCanBeReset() = runBlocking {
+		val directory = Files.createTempDirectory("vnidrop-preferences-test").toString()
+		val dataStore = createAppPreferencesDataStore(directory)
+		dataStore.edit { preferences ->
+			preferences[stringPreferencesKey("relay_mode")] = "FUTURE_MODE"
+			preferences[stringPreferencesKey("relay_urls")] = "https://relay.example.com"
+		}
+		val repository = AppPreferencesRepository(
+			dataStore = dataStore,
+			defaults = AppPreferencesDefaults(
+				username = "Device Name",
+				receiveFolder = defaultFolder,
+				themeMode = ThemeMode.System,
+			),
+		)
+
+		assertEquals(RelaySettings(RelayMode.Custom), repository.preferences.first().relaySettings)
+
+		repository.setRelaySettings(RelaySettings())
+		assertEquals(RelaySettings(), repository.preferences.first().relaySettings)
+	}
+
+	@Test
+	fun unreadablePreferencesFailClosedInsteadOfUsingPublicRelays() = runBlocking {
+		val dataStore = object : DataStore<Preferences> {
+			override val data = flow<Preferences> {
+				throw IllegalStateException("corrupt preferences")
+			}
+
+			override suspend fun updateData(
+				transform: suspend (t: Preferences) -> Preferences,
+			): Preferences = error("not used")
+		}
+		val repository = AppPreferencesRepository(
+			dataStore = dataStore,
+			defaults = AppPreferencesDefaults(
+				username = "Device Name",
+				receiveFolder = defaultFolder,
+				themeMode = ThemeMode.System,
+			),
+		)
+
+		assertEquals(RelaySettings(RelayMode.Custom), repository.preferences.first().relaySettings)
 	}
 
 	@Test

shared/src/jvmTest/kotlin/com/vnidrop/app/ui/FoundationComposeTest.kt

@@ -113,6 +113,47 @@ class FoundationComposeTest {
 		onNodeWithText("Get notified about new receive requests while VniDrop is in the background.").assertIsDisplayed()
 	}
 
+	@Test
+	fun phoneSettingsOpensCustomRelayConfiguration() = runComposeUiTest {
+		val state = mutableStateOf(SettingsState(endpointId = "endpoint-for-allowlist"))
+		var applied = false
+		setContent {
+			VniDropTheme(isDarkTheme = false) {
+				SettingsScreen(
+					state = state.value,
+					windowClass = WindowClass.Phone,
+					onSectionSelected = { state.value = state.value.copy(selectedSection = it) },
+					onUsernameChanged = {},
+					onThemeModeChanged = {},
+					onChooseFolder = {},
+					onResetFolder = {},
+					onNotificationsChanged = {},
+					onOpenNotificationSettings = {},
+					onDiagnosticsChanged = {},
+					onBugWhatChanged = {},
+					onBugExpectedChanged = {},
+					onBugStepsChanged = {},
+					onBugContactChanged = {},
+					onBugIncludeLogsChanged = {},
+					onSubmitBugReport = {},
+					onRelayModeChanged = { state.value = state.value.copy(relayMode = it) },
+					onRelayUrlsChanged = { state.value = state.value.copy(relayUrlsText = it) },
+					onApplyRelaySettings = { applied = true },
+				)
+			}
+		}
+
+		onNodeWithText("Network").performClick()
+		onNodeWithText("Device ID: endpoint-for-allowlist").assertIsDisplayed()
+		onNodeWithText("Custom").performClick()
+		onNodeWithText(
+			"Custom mode is strict: VniDrop will not fall back to public relays or public discovery. " +
+				"Other devices must be able to reach your configured relays.",
+		).assertIsDisplayed()
+		onNodeWithText("Apply network settings").performClick()
+		runOnIdle { assertTrue(applied) }
+	}
+
 	@Test
 	fun aboutSettingsShowsTheSharedProductAndPrivacyContent() = runComposeUiTest {
 		setContent {
@@ -536,6 +577,56 @@ class FoundationComposeTest {
 		onNodeWithContentDescription("Close").assertIsDisplayed()
 	}
 
+	@Test
+	fun stoppedAndFailedTransfersDoNotExposeStaleInvitations() = runComposeUiTest {
+		val transfer = mutableStateOf(outgoingTransfer().copy(status = TransferStatus.Stopped))
+		setContent {
+			VniDropTheme(isDarkTheme = false) {
+				SendScreen(
+					coreState = CoreState(isInitialized = true, transfers = listOf(transfer.value)),
+					state = SendState(
+						selectedTransferId = transfer.value.transferId,
+						detailPanel = com.vnidrop.app.feature.send.TransferDetailPanel.Share,
+					),
+					windowClass = WindowClass.Desktop,
+					onOpenComposer = {}, onDismissComposer = {}, onSelectFile = {}, onClearFile = {},
+					onTransferNameChanged = {}, onSenderNameChanged = {}, onAccessPolicyChanged = {},
+					onCreateShare = {}, onTransferSelected = {}, onCloseTransferDetails = {}, onCopyTicket = {},
+				)
+			}
+		}
+
+		onAllNodesWithText("Share").assertCountEquals(0)
+		onAllNodesWithText("Save .vnd file").assertCountEquals(0)
+
+		runOnIdle { transfer.value = transfer.value.copy(status = TransferStatus.Failed) }
+		onAllNodesWithText("Share").assertCountEquals(0)
+		onAllNodesWithText("Save .vnd file").assertCountEquals(0)
+	}
+
+	@Test
+	fun oversizedInvitationShowsQrUnavailableInsteadOfLoadingForever() = runComposeUiTest {
+		val transfer = outgoingTransfer().copy(ticket = "a".repeat(2_954))
+		setContent {
+			VniDropTheme(isDarkTheme = false) {
+				SendScreen(
+					coreState = CoreState(isInitialized = true, transfers = listOf(transfer)),
+					state = SendState(
+						selectedTransferId = transfer.transferId,
+						detailPanel = com.vnidrop.app.feature.send.TransferDetailPanel.Share,
+					),
+					windowClass = WindowClass.Desktop,
+					onOpenComposer = {}, onDismissComposer = {}, onSelectFile = {}, onClearFile = {},
+					onTransferNameChanged = {}, onSenderNameChanged = {}, onAccessPolicyChanged = {},
+					onCreateShare = {}, onTransferSelected = {}, onCloseTransferDetails = {}, onCopyTicket = {},
+				)
+			}
+		}
+
+		onNodeWithText("QR unavailable for this invitation. Use Share or Download instead.").assertIsDisplayed()
+		onNodeWithText("Save .vnd file").assertIsDisplayed()
+	}
+
 	@Test
 	fun phoneReceiveEmptyStateOpensAcquisitionMethods() = runComposeUiTest {
 		val state = mutableStateOf(ReceiveState())