Merge pull request 'feat(sso): App Links autoVerify callback + paired-host trust check' (#17) from feat/app-links into main

Reviewed-on: #17
Reviewed-by: Colby Whitlock <whitlocktech@gmail.com>

app/build.gradle.kts

@@ -48,6 +48,19 @@ android {
         versionName = (project.findProperty("versionName") as String?)?.takeIf { it.isNotBlank() } ?: "0.1.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+
+        // Android App Links host (docs/android/APP_LINKS.md). autoVerify needs a
+        // *literal* host at build time, so a single multi-tenant APK cannot verify
+        // open-ended shard domains: App Links are a build-time opt-in. Left empty for
+        // the generic build (custom scheme only); a white-label/first-party build
+        // bakes one host with `-PappLinkHost=play.myshard.com`.
+        //   • BuildConfig.APP_LINK_HOST — SsoAuthManager reads it to pick the redirect.
+        //   • manifestPlaceholder appLinkHost — substituted into the intent-filter host;
+        //     empty falls back to the reserved `.invalid` sentinel so the autoVerify
+        //     filter is inert (matches no real link, never verifies).
+        val appLinkHost = (project.findProperty("appLinkHost") as String?)?.trim().orEmpty()
+        buildConfigField("String", "APP_LINK_HOST", "\"$appLinkHost\"")
+        manifestPlaceholders["appLinkHost"] = appLinkHost.ifBlank { "runic-gateway.invalid" }
     }
 
     signingConfigs {

app/src/main/AndroidManifest.xml

@@ -6,6 +6,13 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
+    <!-- Opt-in push notifications (M7): the runtime notification permission (API 33+)
+         and a foreground service that holds the persistent ntfy connection open — the
+         embedded UnifiedPush distributor, so no separate app is needed (PLAN.md §11). -->
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
+
     <application
         android:name=".RunicGatewayApp"
         android:allowBackup="true"
@@ -17,15 +24,56 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.RunicGateway">
 
+        <!-- singleTop so the SSO Custom Tab returning via the deep link reuses the
+             running task (onNewIntent) instead of stacking a second activity. -->
         <activity
             android:name=".MainActivity"
             android:exported="true"
+            android:launchMode="singleTop"
             android:theme="@style/Theme.RunicGateway">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+
+            <!-- Native SSO callback (M9, PLAN.md §4.2). The bridge deep-links the
+                 one-time authorization code back to this fixed, app-owned custom
+                 scheme; it must match SsoAuthManager.REDIRECT_URI and the backend's
+                 MOBILE_AUTH_REDIRECT_URIS allowlist exactly. This is the permanent
+                 fallback on every build (docs/android/APP_LINKS.md). -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data
+                    android:scheme="runicgateway"
+                    android:host="auth"
+                    android:path="/callback" />
+            </intent-filter>
+
+            <!-- App Links hardening (docs/android/APP_LINKS.md): a verified https
+                 callback that only the domain's real owner can claim. autoVerify
+                 needs a literal host, so ${appLinkHost} is baked at build time
+                 (build.gradle.kts). The generic build leaves it as the reserved
+                 runic-gateway.invalid sentinel — the filter then matches no real
+                 link and never verifies. A white-label build sets -PappLinkHost. -->
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data
+                    android:scheme="https"
+                    android:host="${appLinkHost}"
+                    android:path="/mobile/callback" />
+            </intent-filter>
         </activity>
+
+        <!-- The embedded distributor's persistent ntfy connection (M7, PLAN.md §11).
+             dataSync foreground type; not exported — started only by PushManager. -->
+        <service
+            android:name=".core.push.PushService"
+            android:exported="false"
+            android:foregroundServiceType="dataSync" />
     </application>
 
 </manifest>

app/src/main/java/com/runicgateway/app/MainActivity.kt

@@ -3,18 +3,25 @@
  */
 package com.runicgateway.app
 
+import android.content.Intent
 import android.graphics.Color
+import android.net.Uri
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.SystemBarStyle
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.lifecycle.lifecycleScope
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
+import com.runicgateway.app.core.auth.sso.SsoAuthManager
+import com.runicgateway.app.core.push.PushNotifier
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.runicgateway.app.ui.AppViewModel
@@ -26,6 +33,8 @@ import com.runicgateway.app.ui.connect.ConnectScreen
 import com.runicgateway.app.ui.theme.RunicGatewayTheme
 import com.runicgateway.app.ui.theme.parseBrandColor
 import dagger.hilt.android.AndroidEntryPoint
+import kotlinx.coroutines.launch
+import javax.inject.Inject
 
 /**
  * Single-activity host (PLAN.md §2). Gates on [AppViewModel]: the first-run
@@ -35,8 +44,23 @@ import dagger.hilt.android.AndroidEntryPoint
  */
 @AndroidEntryPoint
 class MainActivity : ComponentActivity() {
+
+    // Native SSO bridge — handles the runicgateway://auth/callback deep link (M9,
+    // §4.2). Field-injected because the callback can arrive independent of any
+    // ViewModel; a successful exchange flips the SessionManager the whole app
+    // observes, and the login screen consumes SsoAuthManager.outcome.
+    @Inject
+    lateinit var ssoAuthManager: SsoAuthManager
+
+    // The stream a tapped push notification wants to open (§11, M7 Part 2 item 7).
+    // Set from the launching intent and from onNewIntent (the activity is singleTop),
+    // consumed once by RunicApp which navigates to the stream's screen.
+    private var pendingStream by mutableStateOf<String?>(null)
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        pendingStream = intent?.getStringExtra(PushNotifier.EXTRA_STREAM)
+        handleSsoCallback(intent)
         // Dark-only app (M5): force light system-bar icons over the transparent bars so
         // they stay legible on the deep blue-black surfaces regardless of system theme.
         val barStyle = SystemBarStyle.dark(Color.TRANSPARENT)
@@ -58,11 +82,47 @@ class MainActivity : ComponentActivity() {
                             AppState.NeedsConnection ->
                                 ConnectScreen(onConnected = appViewModel::onConnected)
                             is AppState.Ready ->
-                                RunicApp(brand = s.brand, onChangeServer = appViewModel::changeServer)
+                                RunicApp(
+                                    brand = s.brand,
+                                    onChangeServer = appViewModel::changeServer,
+                                    deepLinkStream = pendingStream,
+                                    onDeepLinkConsumed = { pendingStream = null },
+                                )
                         }
                     }
                 }
             }
         }
     }
+
+    /**
+     * A notification tap or an SSO callback arriving while the activity is already
+     * running (singleTop) — the common case, since the Custom Tab overlays the live
+     * app during sign-in.
+     */
+    override fun onNewIntent(intent: Intent) {
+        super.onNewIntent(intent)
+        setIntent(intent)
+        intent.getStringExtra(PushNotifier.EXTRA_STREAM)?.let { pendingStream = it }
+        handleSsoCallback(intent)
+    }
+
+    /**
+     * Route an SSO callback VIEW intent into the bridge (M9, §4.2): either the
+     * custom-scheme `runicgateway://auth/callback` (always) or the verified https
+     * App Link `https://<paired-host>/mobile/callback` (opt-in hardening —
+     * docs/android/APP_LINKS.md). Both feed the *same* exchange; the result surfaces
+     * on `SsoAuthManager.outcome` (success signs the session in; failure shows on the
+     * login screen). Non-callback intents are ignored.
+     */
+    private fun handleSsoCallback(intent: Intent?) {
+        val data: Uri = intent?.takeIf { it.action == Intent.ACTION_VIEW }?.data ?: return
+        val isCallback = ssoAuthManager.matchesCallback(data.scheme, data.host, data.path) ||
+            ssoAuthManager.matchesAppLinkCallback(data.scheme, data.host, data.path)
+        if (!isCallback) return
+        val state = data.getQueryParameter("state")
+        val code = data.getQueryParameter("code")
+        val error = data.getQueryParameter("error")
+        lifecycleScope.launch { ssoAuthManager.complete(state = state, code = code, error = error) }
+    }
 }

app/src/main/java/com/runicgateway/app/core/auth/sso/Pkce.kt

@@ -0,0 +1,50 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.auth.sso
+
+import java.security.MessageDigest
+import java.security.SecureRandom
+import java.util.Base64
+
+/**
+ * PKCE + CSRF-state primitives for the Mobile SSO Authorization Bridge — "Layer B"
+ * of the two PKCE layers (app ↔ website; PLAN.md §4.2, BACKEND_DESIGN "Two PKCE
+ * layers"). The app proves at `/exchange` that it holds the verifier for the
+ * challenge it registered at `/start`, so an intercepted callback code is useless
+ * to anyone but this app.
+ *
+ * Pure JVM (no Android framework types) so it unit-tests on the plain test runner.
+ * The encoding mirrors the backend exactly (RFC 7636 S256): the challenge is
+ * `base64url(SHA-256(verifier))` with no padding, matching Node's
+ * `crypto.createHash('sha256').update(verifier).digest('base64url')`.
+ */
+object Pkce {
+
+    private val random = SecureRandom()
+
+    // RFC 4648 §5 URL-safe base64 without padding — the base64url the backend uses.
+    private val encoder = Base64.getUrlEncoder().withoutPadding()
+
+    /**
+     * A fresh high-entropy `code_verifier`: 32 random bytes → 43 base64url chars,
+     * comfortably inside RFC 7636's 43–128 range and identical in form to the
+     * verifier the website generates for its own IdP layer.
+     */
+    fun newVerifier(): String = randomToken()
+
+    /** A fresh opaque CSRF `state` (same entropy/shape as a verifier). */
+    fun newState(): String = randomToken()
+
+    /** `code_challenge` for [verifier] using the S256 method. */
+    fun challengeOf(verifier: String): String {
+        val digest = MessageDigest.getInstance("SHA-256").digest(verifier.toByteArray(Charsets.US_ASCII))
+        return encoder.encodeToString(digest)
+    }
+
+    private fun randomToken(): String {
+        val bytes = ByteArray(32)
+        random.nextBytes(bytes)
+        return encoder.encodeToString(bytes)
+    }
+}

app/src/main/java/com/runicgateway/app/core/auth/sso/SsoAuthManager.kt

@@ -0,0 +1,238 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.auth.sso
+
+import com.runicgateway.app.BuildConfig
+import com.runicgateway.app.core.auth.SessionManager
+import com.runicgateway.app.core.net.BaseUrlHolder
+import com.runicgateway.app.data.api.SsoApi
+import com.runicgateway.app.data.api.dto.MobileSsoExchangeRequest
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import java.io.IOException
+import java.util.concurrent.atomic.AtomicReference
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Orchestrates the native "Sign in with Google/Discord" flow — the app half of the
+ * Mobile SSO Authorization Bridge (PLAN.md §4.2, BACKEND_DESIGN "Mobile SSO
+ * Authorization Bridge"). It never adds a parallel auth path: a successful exchange
+ * drives the *same* [SessionManager.onSignedIn] the password login uses, so the
+ * menu, push registration, and re-validation all react identically.
+ *
+ * The flow:
+ *  1. [buildStartUrl] mints PKCE (Layer B) + a CSRF `state`, stashes them, and
+ *     returns the `/auth/mobile/sso/start` URL the caller opens in a Custom Tab.
+ *  2. The website bounces through the IdP and deep-links back to
+ *     [REDIRECT_URI] with `?code&state` (success) or `?error&state` (failure).
+ *  3. [complete] verifies `state`, exchanges the `code` with the stashed verifier,
+ *     and signs the user in — publishing the result on [outcome]. `MainActivity`
+ *     parses the callback `Uri` (the Android edge) and hands the raw params here,
+ *     so this class stays free of framework types and unit-tests on the JVM.
+ *
+ * The pending `{state, verifier}` lives only in memory: if the process is killed
+ * while the Custom Tab is foreground it is lost and the exchange **fails closed**
+ * (the user simply retries) — never a security downgrade.
+ *
+ * Threading: [buildStartUrl] runs on the UI thread; [complete] runs on the
+ * activity's coroutine scope after a deep link. The pending holder is an
+ * [AtomicReference] and [outcome] a [StateFlow], so a ViewModel/activity recreation
+ * while the Custom Tab is open cannot drop a result.
+ */
+@Singleton
+class SsoAuthManager @Inject constructor(
+    private val ssoApi: SsoApi,
+    private val sessionManager: SessionManager,
+    private val baseUrlHolder: BaseUrlHolder,
+) {
+
+    /** Why an SSO attempt ended, for a friendly inline message on the login screen. */
+    enum class Failure {
+        /** The user cancelled or the IdP/website refused (e.g. no linked account). */
+        DENIED,
+
+        /** The callback `state` didn't match — CSRF guard, or the pending flow was lost. */
+        STATE_MISMATCH,
+
+        /** The one-time code was unknown / expired / already used, or PKCE failed. */
+        EXPIRED_CODE,
+
+        /** Offline / DNS / TLS / timeout during the exchange. */
+        NETWORK,
+
+        /** Any other server failure, or a missing base URL / malformed callback. */
+        SERVER,
+    }
+
+    /** The observable result of the most recent flow; the login screen consumes it. */
+    sealed interface Outcome {
+        data object Idle : Outcome
+        data object Success : Outcome
+        data class Failed(val reason: Failure) : Outcome
+    }
+
+    private data class Pending(val state: String, val verifier: String)
+
+    private val pending = AtomicReference<Pending?>(null)
+
+    /**
+     * The host this build baked an App Link intent-filter for (`BuildConfig.APP_LINK_HOST`,
+     * empty on the generic multi-tenant build — see docs/android/APP_LINKS.md).
+     * `internal var` only so unit tests can exercise the App Link path without a build
+     * flavor; production never reassigns it.
+     */
+    internal var appLinkHost: String = BuildConfig.APP_LINK_HOST
+
+    private val _outcome = MutableStateFlow<Outcome>(Outcome.Idle)
+    val outcome: StateFlow<Outcome> = _outcome.asStateFlow()
+
+    /** Ack a delivered [outcome] so it isn't re-handled after a recomposition. */
+    fun consumeOutcome() {
+        _outcome.value = Outcome.Idle
+    }
+
+    /**
+     * Build the `/auth/mobile/sso/start` URL for [providerId] and stash the pending
+     * PKCE verifier + CSRF state. Returns null when no shard site is configured yet
+     * (the caller then keeps the website hand-off fallback). Also resets [outcome]
+     * to [Outcome.Idle] so a stale prior result can't fire against the new attempt.
+     */
+    fun buildStartUrl(providerId: String): String? {
+        val base = baseUrlHolder.current ?: return null
+        val verifier = Pkce.newVerifier()
+        val challenge = Pkce.challengeOf(verifier)
+        val state = Pkce.newState()
+        pending.set(Pending(state = state, verifier = verifier))
+        _outcome.value = Outcome.Idle
+        return base.newBuilder()
+            .addPathSegments("api/v1/auth/mobile/sso/start")
+            .addQueryParameter("provider", providerId)
+            .addQueryParameter("code_challenge", challenge)
+            .addQueryParameter("state", state)
+            .addQueryParameter("redirect_uri", redirectUriFor(base.host))
+            .build()
+            .toString()
+    }
+
+    /**
+     * The `redirect_uri` to request for a shard on [pairedHost]: the verified https
+     * App Link callback **iff** this build baked an App Link host that matches the
+     * paired host (a white-label/first-party build for exactly this shard — which is
+     * also responsible for enabling `mobile_app_links_enabled` server-side); otherwise
+     * the fixed custom-scheme callback, which every build/shard always supports.
+     */
+    private fun redirectUriFor(pairedHost: String): String =
+        if (appLinkHost.isNotBlank() && appLinkHost.equals(pairedHost, ignoreCase = true)) {
+            "https://$pairedHost$APP_LINK_CALLBACK_PATH"
+        } else {
+            REDIRECT_URI
+        }
+
+    /** True if a deep link's scheme/host/path are our fixed custom-scheme SSO callback. */
+    fun matchesCallback(scheme: String?, host: String?, path: String?): Boolean =
+        scheme == CALLBACK_SCHEME && host == CALLBACK_HOST && path == CALLBACK_PATH
+
+    /**
+     * True if a deep link is a verified https App Link callback for the shard we are
+     * **currently paired to**. The `host == pairedHost` check is defense-in-depth:
+     * `autoVerify` already means only a real, opted-in shard domain can route here,
+     * but the app still refuses an https callback whose host isn't the paired shard.
+     * Returns false before a shard is configured (no paired host to trust).
+     */
+    fun matchesAppLinkCallback(scheme: String?, host: String?, path: String?): Boolean {
+        val pairedHost = baseUrlHolder.current?.host ?: return false
+        return scheme == "https" && path == APP_LINK_CALLBACK_PATH &&
+            host != null && host.equals(pairedHost, ignoreCase = true)
+    }
+
+    /**
+     * Handle the parsed callback params from a returned [REDIRECT_URI] deep link:
+     * verify `state`, map an `error`, else exchange the `code` and sign in.
+     * Publishes the result on [outcome]. Idempotent-safe: the pending is cleared on
+     * entry, so a duplicate delivery of the same callback finds no pending and fails
+     * as [Failure.STATE_MISMATCH] rather than double-exchanging (the backend also
+     * single-uses the code).
+     */
+    suspend fun complete(state: String?, code: String?, error: String?) {
+        val stashed = pending.getAndSet(null)
+
+        // CSRF: the callback must echo the exact state we generated at /start.
+        if (stashed == null || state.isNullOrEmpty() || state != stashed.state) {
+            _outcome.value = Outcome.Failed(Failure.STATE_MISMATCH)
+            return
+        }
+
+        // A website/IdP-side failure comes back as ?error=… (never with a code).
+        if (!error.isNullOrEmpty()) {
+            _outcome.value = Outcome.Failed(mapError(error))
+            return
+        }
+
+        if (code.isNullOrBlank()) {
+            _outcome.value = Outcome.Failed(Failure.SERVER)
+            return
+        }
+
+        val response = try {
+            ssoApi.exchange(MobileSsoExchangeRequest(code = code, codeVerifier = stashed.verifier))
+        } catch (e: CancellationException) {
+            throw e
+        } catch (_: IOException) {
+            _outcome.value = Outcome.Failed(Failure.NETWORK)
+            return
+        } catch (_: Exception) {
+            _outcome.value = Outcome.Failed(Failure.SERVER)
+            return
+        }
+
+        if (response.isSuccessful) {
+            val body = response.body()
+            if (body == null) {
+                _outcome.value = Outcome.Failed(Failure.SERVER)
+                return
+            }
+            sessionManager.onSignedIn(body.accessToken, body.refreshToken, body.user)
+            _outcome.value = Outcome.Success
+            return
+        }
+
+        _outcome.value = Outcome.Failed(if (response.code() == 401) Failure.EXPIRED_CODE else Failure.SERVER)
+    }
+
+    // The bridge's start + callback error codes → user-facing failure reasons.
+    // Start (mobileSso.controller): invalid_provider | provider_unavailable | server_error.
+    // Callback (sso.controller): not_linked | disabled | session_expired | error,
+    // plus a forwarded IdP access_denied.
+    private fun mapError(error: String): Failure = when (error) {
+        // Link-only policy refused, or the account is inactive, or the user declined.
+        "not_linked", "disabled", "access_denied" -> Failure.DENIED
+        // The bridge session aged out mid-flow — start over.
+        "session_expired" -> Failure.EXPIRED_CODE
+        // invalid_provider / provider_unavailable / server_error / error / anything else.
+        else -> Failure.SERVER
+    }
+
+    companion object {
+        const val CALLBACK_SCHEME = "runicgateway"
+        const val CALLBACK_HOST = "auth"
+        const val CALLBACK_PATH = "/callback"
+
+        /**
+         * The one fixed, application-owned callback the bridge redirects to. Must
+         * match the `MOBILE_AUTH_REDIRECT_URIS` allowlist entry on the backend and
+         * the intent-filter in `AndroidManifest.xml` exactly (PLAN.md §4.2).
+         */
+        const val REDIRECT_URI = "$CALLBACK_SCHEME://$CALLBACK_HOST$CALLBACK_PATH"
+
+        /**
+         * Path of the verified https App Link callback (`https://<shard-host>/mobile/callback`).
+         * Must match the app's `autoVerify` intent-filter in `AndroidManifest.xml` and the
+         * backend's self-origin allowlist entry (docs/android/APP_LINKS.md §3.2/§4.2).
+         */
+        const val APP_LINK_CALLBACK_PATH = "/mobile/callback"
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/NtfyStreamClient.kt

@@ -0,0 +1,116 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.channelFlow
+import kotlinx.coroutines.isActive
+import kotlinx.serialization.json.Json
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.Response
+import okhttp3.sse.EventSource
+import okhttp3.sse.EventSourceListener
+import okhttp3.sse.EventSources
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.atomic.AtomicBoolean
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * The embedded distributor's transport (PLAN.md §11, M7 Part 2 work item 1/3):
+ * a persistent connection to the shard's self-hosted ntfy that subscribes to the
+ * app's own topic and re-emits each content-free tickle. It reuses the same
+ * OkHttp-SSE + reconnect/backoff shape as [com.runicgateway.app.core.net.ShardStreamClient],
+ * but on a **bare** client — no host-retargeting or bearer interceptors — because it
+ * talks straight to ntfy (`<ntfy>/<topic>/sse`), not the website API. Held open by
+ * [PushService]'s foreground service so tickles arrive in the background without
+ * Google Play Services.
+ */
+@Singleton
+class NtfyStreamClient @Inject constructor(
+    private val json: Json,
+) {
+    // A dedicated client with the read timeout disabled for the mostly-idle stream
+    // (ntfy sends keepalive frames); no interceptors so nothing rewrites the host or
+    // attaches a bearer to the relay.
+    private val client: OkHttpClient = OkHttpClient.Builder()
+        .readTimeout(0, TimeUnit.MILLISECONDS)
+        .retryOnConnectionFailure(true)
+        .build()
+
+    private val factory = EventSources.createFactory(client)
+
+    /** Connection lifecycle + decoded tickles for a subscribed topic. */
+    sealed interface Event {
+        data object Open : Event
+        data object Closed : Event
+        data class Message(val tickle: PushTickle) : Event
+    }
+
+    /**
+     * A cold flow subscribing to `<ntfyBaseUrl>/<topic>/sse`, reconnecting with
+     * backoff until the collector cancels. A dropped relay simply reconnects; a bad
+     * config (null URL) idles rather than spinning.
+     */
+    fun events(ntfyBaseUrl: String?, topic: String): Flow<Event> = channelFlow {
+        var backoffMs = INITIAL_BACKOFF_MS
+        while (isActive) {
+            val url = NtfyTopic.sseUrl(ntfyBaseUrl, topic)
+            if (url == null) {
+                trySend(Event.Closed)
+                delay(backoffMs)
+                backoffMs = grow(backoffMs)
+                continue
+            }
+
+            val request = Request.Builder()
+                .url(url)
+                .header("Accept", "text/event-stream")
+                .build()
+
+            val opened = AtomicBoolean(false)
+            val ended = CompletableDeferred<Unit>()
+            val listener = object : EventSourceListener() {
+                override fun onOpen(eventSource: EventSource, response: Response) {
+                    opened.set(true)
+                    trySend(Event.Open)
+                }
+
+                override fun onEvent(eventSource: EventSource, id: String?, type: String?, data: String) {
+                    parseNtfyTickle(json, data)?.let { trySend(Event.Message(it)) }
+                }
+
+                override fun onClosed(eventSource: EventSource) {
+                    trySend(Event.Closed)
+                    ended.complete(Unit)
+                }
+
+                override fun onFailure(eventSource: EventSource, t: Throwable?, response: Response?) {
+                    trySend(Event.Closed)
+                    ended.complete(Unit)
+                }
+            }
+
+            val source = factory.newEventSource(request, listener)
+            try {
+                ended.await()
+            } finally {
+                source.cancel()
+            }
+
+            backoffMs = if (opened.get()) INITIAL_BACKOFF_MS else grow(backoffMs)
+            delay(backoffMs)
+        }
+    }
+
+    private fun grow(current: Long): Long = (current * 2).coerceAtMost(MAX_BACKOFF_MS)
+
+    private companion object {
+        const val INITIAL_BACKOFF_MS = 2_000L
+        const val MAX_BACKOFF_MS = 30_000L
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/NtfyTopic.kt

@@ -0,0 +1,48 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import java.security.SecureRandom
+
+/**
+ * The app's own ntfy topic — the heart of the embedded-distributor design
+ * (PLAN.md §11, M7 Part 2 work item 1). The app mints a **random, unguessable**
+ * topic and registers its public URL (`https://<ntfy-host>/<topic>`) as the device
+ * endpoint the backend POSTs tickles to; the app subscribes to the same topic's SSE
+ * stream to receive them. Security rests on the topic being unguessable plus the
+ * content-free tickle — a leaked topic name reveals nothing.
+ */
+object NtfyTopic {
+
+    // ntfy topic names allow [A-Za-z0-9_-]; keep to that set. The "up" prefix mirrors
+    // the UnifiedPush convention and makes topics recognizable in logs/relay.
+    private const val ALPHABET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+    private const val TOPIC_LEN = 24
+    private const val PREFIX = "up"
+
+    private val secureRandom by lazy { SecureRandom() }
+
+    /** Mint a fresh unguessable topic, e.g. "up7Qk3…" (≈143 bits of entropy). */
+    fun generate(random: java.util.Random = secureRandom): String {
+        val sb = StringBuilder(PREFIX.length + TOPIC_LEN)
+        sb.append(PREFIX)
+        repeat(TOPIC_LEN) { sb.append(ALPHABET[random.nextInt(ALPHABET.length)]) }
+        return sb.toString()
+    }
+
+    /**
+     * The endpoint URL the backend publishes to: `<ntfyBaseUrl>/<topic>`. [ntfyBaseUrl]
+     * is the client-facing base from `/public/settings.push.ntfyUrl`; a trailing slash
+     * is tolerated. Returns null for a blank base or topic.
+     */
+    fun endpointUrl(ntfyBaseUrl: String?, topic: String): String? {
+        val base = ntfyBaseUrl?.trim()?.trimEnd('/').orEmpty()
+        if (base.isEmpty() || topic.isBlank()) return null
+        return "$base/$topic"
+    }
+
+    /** The SSE subscribe URL the app connects to: `<ntfyBaseUrl>/<topic>/sse`. */
+    fun sseUrl(ntfyBaseUrl: String?, topic: String): String? =
+        endpointUrl(ntfyBaseUrl, topic)?.let { "$it/sse" }
+}

app/src/main/java/com/runicgateway/app/core/push/PushManager.kt

@@ -0,0 +1,156 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import android.content.Context
+import com.runicgateway.app.core.auth.Session
+import com.runicgateway.app.core.auth.SessionManager
+import com.runicgateway.app.core.result.ApiResult
+import com.runicgateway.app.data.repository.NotificationsRepository
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Orchestrates the app's opt-in push lifecycle (PLAN.md §11, M7 Part 2 work item 5):
+ * mint/keep the ntfy topic, register/unregister the device endpoint with the backend,
+ * and start/stop the foreground [PushService] — all keyed to the user's opt-in and
+ * the session. The endpoint the app registers is its own topic URL on the shard's
+ * ntfy (the embedded-distributor design, work item 1).
+ *
+ * Lifecycle rules:
+ *  - register only when **signed in** and the shard advertises a relay (`ntfyUrl`);
+ *  - a **sign-out** stops the service and forgets the ephemeral registration but keeps
+ *    the opt-in intent, so push re-registers on the next sign-in (mirrors the M3 token
+ *    teardown, and covers logout / dead-refresh / server switch uniformly via the
+ *    session-state observer);
+ *  - a **relay/base-URL change** re-registers on the new host with a fresh topic.
+ */
+@Singleton
+class PushManager @Inject constructor(
+    @param:ApplicationContext private val context: Context,
+    private val prefs: PushPreferences,
+    private val notifications: NotificationsRepository,
+    private val sessionManager: SessionManager,
+) {
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+
+    /** Whether the user has push turned on (drives the Notifications screen). */
+    val enabled: Flow<Boolean> = prefs.enabled
+
+    /** Whether this shard advertises a push relay at all (null ntfyUrl → unsupported). */
+    val supported: Flow<Boolean> = prefs.ntfyUrl.map { !it.isNullOrBlank() }
+
+    init {
+        // Uniform teardown/resume across every auth transition: logout, dead-refresh
+        // sign-out, and server switch all land on SignedOut; a fresh login re-asserts.
+        scope.launch {
+            sessionManager.state.collect { s ->
+                when (s) {
+                    is Session.SignedOut -> localTeardown()
+                    is Session.SignedIn -> maybeResume()
+                }
+            }
+        }
+    }
+
+    /** Record the shard's client-facing ntfy base URL (from `/public/settings`). */
+    suspend fun setNtfyUrl(url: String?) {
+        val previous = prefs.snapshot().ntfyUrl
+        prefs.setNtfyUrl(url)
+        // The relay host arriving (or changing) is what unblocks a pending resume.
+        if (!url.isNullOrBlank() && url != previous) maybeResume()
+    }
+
+    /**
+     * Turn push on (idempotent): ensure a topic on the current relay, register its
+     * endpoint with the backend, persist, and start the foreground service. Called
+     * when the user opts into ≥1 stream.
+     */
+    suspend fun enable(): PushResult = register(setIntent = true)
+
+    /** Turn push off (user opted out of every stream): clear intent + deregister. */
+    suspend fun disable() {
+        prefs.setEnabled(false)
+        deregisterDevice()
+    }
+
+    /**
+     * Deregister this device on an explicit sign-out / server switch, while the bearer
+     * is still valid, so no orphan device row is left behind. Keeps the opt-in intent
+     * (and ntfyUrl) so push re-registers on the next sign-in. Call this *before* the
+     * session is torn down.
+     */
+    suspend fun deregisterDevice() {
+        val snap = prefs.snapshot()
+        snap.deviceId?.let { notifications.deleteDevice(it) } // best-effort
+        stopService()
+        prefs.clearRegistration()
+    }
+
+    /** Re-assert registration if the user is opted in and the shard supports push. */
+    private suspend fun maybeResume() {
+        val snap = prefs.snapshot()
+        if (snap.enabled && sessionManager.isSignedIn && !snap.ntfyUrl.isNullOrBlank()) {
+            register(setIntent = false)
+        }
+    }
+
+    private suspend fun register(setIntent: Boolean): PushResult {
+        if (!sessionManager.isSignedIn) return PushResult.NotSignedIn
+        val snap = prefs.snapshot()
+        val ntfyUrl = snap.ntfyUrl
+        if (ntfyUrl.isNullOrBlank()) return PushResult.Unsupported
+
+        // Reuse an existing topic only if its endpoint still sits on the current relay
+        // origin; otherwise (first run, or a server switch) mint a fresh unguessable one.
+        val base = ntfyUrl.trimEnd('/')
+        val topic = snap.topic?.takeIf { snap.endpoint?.startsWith("$base/") == true }
+            ?: NtfyTopic.generate()
+        val endpoint = NtfyTopic.endpointUrl(ntfyUrl, topic) ?: return PushResult.Unsupported
+
+        return when (val res = notifications.registerDevice(endpoint, PLATFORM)) {
+            is ApiResult.Ok -> {
+                prefs.setRegistration(topic, endpoint, res.data.id)
+                if (setIntent) prefs.setEnabled(true)
+                startService()
+                PushResult.Enabled
+            }
+            // 400 = endpoint origin isn't on the shard's ntfy allow-set (misconfigured relay).
+            is ApiResult.HttpError -> PushResult.Failed(res.status)
+            is ApiResult.NetworkError -> PushResult.Failed(null)
+        }
+    }
+
+    /** Local-only teardown on sign-out — no backend DELETE (the bearer may be dead). */
+    private suspend fun localTeardown() {
+        stopService()
+        prefs.clearRegistration()
+    }
+
+    private fun startService() = runCatching { PushService.start(context) }
+    private fun stopService() = runCatching { PushService.stop(context) }
+
+    /** The outcome of enabling push, surfaced to the Notifications screen. */
+    sealed interface PushResult {
+        data object Enabled : PushResult
+
+        /** This shard advertises no push relay (`/public/settings.push.ntfyUrl` is null). */
+        data object Unsupported : PushResult
+        data object NotSignedIn : PushResult
+
+        /** Registration failed — [status] 400 = relay off the allow-set; null = network. */
+        data class Failed(val status: Int?) : PushResult
+    }
+
+    private companion object {
+        const val PLATFORM = "android"
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/PushNotifier.kt

@@ -0,0 +1,110 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationManagerCompat
+import com.runicgateway.app.MainActivity
+import com.runicgateway.app.R
+import dagger.hilt.android.qualifiers.ApplicationContext
+import java.util.concurrent.atomic.AtomicInteger
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Builds the notification channels and posts a notification for a received tickle
+ * (PLAN.md §11, M7 Part 2 work items 2/3/7). v1 shows a **generic per-stream**
+ * notification titled from the fixed [PushStreams] catalog — the content-free tickle
+ * carries nothing to render, so nothing is fetched to display the notification; tapping
+ * deep-links into [MainActivity] (which fetches fresh over the authenticated API).
+ */
+@Singleton
+class PushNotifier @Inject constructor(
+    @param:ApplicationContext private val context: Context,
+) {
+    private val manager = NotificationManagerCompat.from(context)
+    private val nextId = AtomicInteger(1)
+
+    /** Create both channels; safe to call repeatedly (creation is idempotent). */
+    fun ensureChannels() {
+        val system = context.getSystemService(NotificationManager::class.java) ?: return
+        system.createNotificationChannel(
+            NotificationChannel(
+                CHANNEL_MESSAGES,
+                context.getString(R.string.push_channel_messages),
+                NotificationManager.IMPORTANCE_DEFAULT,
+            ).apply { description = context.getString(R.string.push_channel_messages_desc) },
+        )
+        system.createNotificationChannel(
+            NotificationChannel(
+                CHANNEL_SERVICE,
+                context.getString(R.string.push_channel_service),
+                NotificationManager.IMPORTANCE_LOW,
+            ).apply {
+                description = context.getString(R.string.push_channel_service_desc)
+                setShowBadge(false)
+            },
+        )
+    }
+
+    /** The persistent low-importance notification the foreground service runs under. */
+    fun serviceNotification(): Notification =
+        NotificationCompat.Builder(context, CHANNEL_SERVICE)
+            .setContentTitle(context.getString(R.string.push_service_title))
+            .setContentText(context.getString(R.string.push_service_text))
+            .setSmallIcon(R.drawable.ic_stat_name)
+            .setOngoing(true)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .setContentIntent(deepLinkIntent(stream = null, ref = null))
+            .build()
+
+    /** Post a notification for a tickle, deep-linking to the stream's screen on tap. */
+    fun notify(tickle: PushTickle) {
+        if (!manager.areNotificationsEnabled()) return // POST_NOTIFICATIONS not granted
+        val title = context.getString(PushStreams.titleRes(tickle.stream))
+        val notification = NotificationCompat.Builder(context, CHANNEL_MESSAGES)
+            .setContentTitle(title)
+            .setSmallIcon(R.drawable.ic_stat_name)
+            .setAutoCancel(true)
+            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+            .setContentIntent(deepLinkIntent(tickle.stream, tickle.ref))
+            .build()
+        try {
+            manager.notify(nextId.getAndIncrement(), notification)
+        } catch (_: SecurityException) {
+            // Racing a permission revoke — drop silently rather than crash.
+        }
+    }
+
+    private fun deepLinkIntent(stream: String?, ref: String?): PendingIntent {
+        val intent = Intent(context, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP
+            if (stream != null) putExtra(EXTRA_STREAM, stream)
+            if (ref != null) putExtra(EXTRA_REF, ref)
+        }
+        // A distinct request code per stream so PendingIntents don't collapse into one.
+        val requestCode = stream?.hashCode() ?: 0
+        return PendingIntent.getActivity(
+            context,
+            requestCode,
+            intent,
+            PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT,
+        )
+    }
+
+    companion object {
+        const val CHANNEL_MESSAGES = "push_messages"
+        const val CHANNEL_SERVICE = "push_service"
+
+        /** Intent extras a tapped notification carries into [MainActivity] (§7 deep-links). */
+        const val EXTRA_STREAM = "com.runicgateway.app.push.STREAM"
+        const val EXTRA_REF = "com.runicgateway.app.push.REF"
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/PushPreferences.kt

@@ -0,0 +1,91 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import android.content.Context
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.booleanPreferencesKey
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.longPreferencesKey
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import javax.inject.Inject
+import javax.inject.Singleton
+
+private val Context.pushDataStore: DataStore<Preferences> by preferencesDataStore(name = "push")
+
+/**
+ * Persists the app's push state (PLAN.md §11, M7 Part 2 work item 5). None of it is
+ * secret — the ntfy topic/endpoint's protection is being unguessable plus the
+ * content-free tickle — so plain DataStore is fine (tokens stay in the encrypted
+ * store). Holds the shard's ntfy base URL (from `/public/settings`), the minted
+ * topic + its endpoint URL, the backend-assigned device id (to unregister), and the
+ * user's opt-in flag (the source of truth for "push should be running").
+ */
+@Singleton
+class PushPreferences @Inject constructor(
+    @param:ApplicationContext private val context: Context,
+) {
+    private val store = context.pushDataStore
+
+    val enabled: Flow<Boolean> = store.data.map { it[KEY_ENABLED] ?: false }
+    val ntfyUrl: Flow<String?> = store.data.map { it[KEY_NTFY_URL] }
+
+    suspend fun snapshot(): Snapshot {
+        val p = store.data.first()
+        return Snapshot(
+            enabled = p[KEY_ENABLED] ?: false,
+            ntfyUrl = p[KEY_NTFY_URL],
+            topic = p[KEY_TOPIC],
+            endpoint = p[KEY_ENDPOINT],
+            deviceId = p[KEY_DEVICE_ID],
+        )
+    }
+
+    suspend fun setNtfyUrl(url: String?) = store.edit {
+        if (url.isNullOrBlank()) it.remove(KEY_NTFY_URL) else it[KEY_NTFY_URL] = url
+    }
+
+    suspend fun setEnabled(value: Boolean) = store.edit { it[KEY_ENABLED] = value }
+
+    /** Record the minted topic + its endpoint URL and the assigned device id together. */
+    suspend fun setRegistration(topic: String, endpoint: String, deviceId: Long) = store.edit {
+        it[KEY_TOPIC] = topic
+        it[KEY_ENDPOINT] = endpoint
+        it[KEY_DEVICE_ID] = deviceId
+    }
+
+    /**
+     * Forget the ephemeral device registration (topic/endpoint/device id) — used on
+     * sign-out and on an explicit disable. Deliberately leaves [KEY_ENABLED] and
+     * [KEY_NTFY_URL] intact so the user's opt-in intent survives a sign-out and push
+     * re-registers on the next sign-in; an explicit disable also calls [setEnabled]`(false)`.
+     */
+    suspend fun clearRegistration() = store.edit {
+        it.remove(KEY_TOPIC)
+        it.remove(KEY_ENDPOINT)
+        it.remove(KEY_DEVICE_ID)
+    }
+
+    data class Snapshot(
+        val enabled: Boolean,
+        val ntfyUrl: String?,
+        val topic: String?,
+        val endpoint: String?,
+        val deviceId: Long?,
+    )
+
+    private companion object {
+        val KEY_ENABLED = booleanPreferencesKey("enabled")
+        val KEY_NTFY_URL = stringPreferencesKey("ntfy_url")
+        val KEY_TOPIC = stringPreferencesKey("topic")
+        val KEY_ENDPOINT = stringPreferencesKey("endpoint")
+        val KEY_DEVICE_ID = longPreferencesKey("device_id")
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/PushService.kt

@@ -0,0 +1,95 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.content.pm.ServiceInfo
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.ServiceCompat
+import dagger.hilt.android.AndroidEntryPoint
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.flow.collectLatest
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * The always-connected foreground service that IS the embedded distributor
+ * (PLAN.md §11, M7 Part 2 work item 1/3). It holds [NtfyStreamClient]'s persistent
+ * connection to the shard's ntfy open in the background — the price of Google-free,
+ * self-contained instant delivery — and posts a notification for each tickle. It runs
+ * under a low-importance ongoing notification and restarts sticky; [PushManager] starts
+ * and stops it as the user opts in/out or signs out.
+ */
+@AndroidEntryPoint
+class PushService : Service() {
+
+    @Inject lateinit var streamClient: NtfyStreamClient
+    @Inject lateinit var notifier: PushNotifier
+    @Inject lateinit var prefs: PushPreferences
+
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    private var connectionJob: Job? = null
+
+    override fun onCreate() {
+        super.onCreate()
+        notifier.ensureChannels()
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        startAsForeground()
+        if (connectionJob == null) connectionJob = scope.launch { run() }
+        return START_STICKY
+    }
+
+    private fun startAsForeground() {
+        val type = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+            ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC
+        } else {
+            0
+        }
+        ServiceCompat.startForeground(this, NOTIFICATION_ID, notifier.serviceNotification(), type)
+    }
+
+    private suspend fun run() {
+        val snapshot = prefs.snapshot()
+        val topic = snapshot.topic
+        if (topic.isNullOrBlank() || snapshot.ntfyUrl.isNullOrBlank()) {
+            // Nothing to subscribe to (should not happen — PushManager starts us only
+            // once a topic exists) — stop rather than hold a dead connection open.
+            stopSelf()
+            return
+        }
+        streamClient.events(snapshot.ntfyUrl, topic).collectLatest { event ->
+            if (event is NtfyStreamClient.Event.Message) notifier.notify(event.tickle)
+        }
+    }
+
+    override fun onDestroy() {
+        connectionJob?.cancel()
+        scope.cancel()
+        super.onDestroy()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    companion object {
+        private const val NOTIFICATION_ID = 42
+
+        fun start(context: Context) {
+            val intent = Intent(context, PushService::class.java)
+            context.startForegroundService(intent)
+        }
+
+        fun stop(context: Context) {
+            context.stopService(Intent(context, PushService::class.java))
+        }
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/PushStreams.kt

@@ -0,0 +1,39 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import androidx.annotation.StringRes
+import com.runicgateway.app.R
+
+/**
+ * The known push stream ids (mirrors the backend catalog in
+ * `config/notificationStreams.js`) and their localized notification titles.
+ * The subscribable catalog itself is fetched from
+ * `GET /auth/me/notifications/streams`; this fixed set is only what the receiver
+ * needs to title a content-free tickle without a network round-trip (§11).
+ */
+object PushStreams {
+    const val NEWS_POST = "news.post"
+    const val SERVER_STATUS = "server.status"
+    const val IDOC_WARNING = "idoc.warning"
+    const val CHAMP_START = "champ.start"
+    const val GOVERNOR_ELECTION = "governor.election"
+    const val VENDOR_SALE = "vendor.sale"
+    const val HOUSE_IDOC = "house.idoc"
+    const val ACCOUNT_LOGIN = "account.login"
+
+    /** A short, localized notification title for [streamId]; a generic fallback otherwise. */
+    @StringRes
+    fun titleRes(streamId: String): Int = when (streamId) {
+        NEWS_POST -> R.string.push_stream_news_post
+        SERVER_STATUS -> R.string.push_stream_server_status
+        IDOC_WARNING -> R.string.push_stream_idoc_warning
+        CHAMP_START -> R.string.push_stream_champ_start
+        GOVERNOR_ELECTION -> R.string.push_stream_governor_election
+        VENDOR_SALE -> R.string.push_stream_vendor_sale
+        HOUSE_IDOC -> R.string.push_stream_house_idoc
+        ACCOUNT_LOGIN -> R.string.push_stream_account_login
+        else -> R.string.push_stream_generic
+    }
+}

app/src/main/java/com/runicgateway/app/core/push/PushTickle.kt

@@ -0,0 +1,54 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonNull
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.jsonPrimitive
+
+/**
+ * The content-free push tickle the backend publishes (PLAN.md §11): `{ stream, ref }`
+ * and nothing sensitive. [ref] is an opaque hint (a serial / city / timestamp) the
+ * app *could* use to pull real content over the authenticated API; v1 just deep-links
+ * to the stream's screen, so it is carried but not otherwise interpreted.
+ */
+@Serializable
+data class PushTickle(
+    val stream: String,
+    val ref: String? = null,
+)
+
+/**
+ * Parse a tickle out of an ntfy SSE `data:` frame. ntfy wraps our published body in
+ * its own envelope — `{ event, topic, message, … }` — where `message` is the exact
+ * string we POSTed (our `{ stream, ref }` JSON). Only `event == "message"` frames
+ * carry a payload; `open` / `keepalive` frames return null, as does any malformed or
+ * unrecognized body (dropped, never thrown — §7). Pure + `internal` for unit testing.
+ */
+internal fun parseNtfyTickle(json: Json, data: String): PushTickle? {
+    val trimmed = data.trim()
+    if (trimmed.isEmpty() || trimmed.startsWith(":")) return null
+    return try {
+        val envelope = json.parseToJsonElement(trimmed) as? JsonObject ?: return null
+        val event = envelope["event"]?.jsonPrimitive?.content
+        // ntfy lifecycle frames ("open", "keepalive", "poll_request") carry no message.
+        if (event != null && event != "message") return null
+        val messageEl = envelope["message"] ?: return null
+        if (messageEl is JsonNull) return null
+        val message = messageEl.jsonPrimitive.content
+        decodeTickle(json, message)
+    } catch (_: Exception) {
+        null
+    }
+}
+
+/** Decode our own `{ stream, ref }` body; a blank/missing stream is not a tickle. */
+internal fun decodeTickle(json: Json, body: String): PushTickle? = try {
+    val tickle = json.decodeFromString(PushTickle.serializer(), body.trim())
+    tickle.takeIf { it.stream.isNotBlank() }
+} catch (_: Exception) {
+    null
+}

app/src/main/java/com/runicgateway/app/data/api/NotificationsApi.kt

@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api
+
+import com.runicgateway.app.data.api.dto.NotificationStreamsDto
+import com.runicgateway.app.data.api.dto.NotificationSubscriptionsDto
+import com.runicgateway.app.data.api.dto.PushDeviceDto
+import com.runicgateway.app.data.api.dto.RegisterDeviceRequest
+import retrofit2.http.Body
+import retrofit2.http.DELETE
+import retrofit2.http.GET
+import retrofit2.http.POST
+import retrofit2.http.PUT
+import retrofit2.http.Path
+
+/**
+ * The opt-in push surface under `/auth/me` (PLAN.md §11, M7 Part 2): device
+ * (endpoint) registration and per-user stream subscriptions. Every call rides the
+ * main client, so [com.runicgateway.app.core.net.AuthInterceptor] attaches the
+ * bearer and [com.runicgateway.app.core.net.TokenAuthenticator] refreshes on 401 —
+ * registration only ever succeeds while signed in.
+ */
+interface NotificationsApi {
+
+    @POST("api/v1/auth/me/devices")
+    suspend fun registerDevice(@Body body: RegisterDeviceRequest): PushDeviceDto
+
+    @GET("api/v1/auth/me/devices")
+    suspend fun listDevices(): List<PushDeviceDto>
+
+    @DELETE("api/v1/auth/me/devices/{id}")
+    suspend fun deleteDevice(@Path("id") id: Long): Unit
+
+    @GET("api/v1/auth/me/notifications/streams")
+    suspend fun streams(): NotificationStreamsDto
+
+    @GET("api/v1/auth/me/notifications/subscriptions")
+    suspend fun subscriptions(): NotificationSubscriptionsDto
+
+    @PUT("api/v1/auth/me/notifications/subscriptions")
+    suspend fun putSubscriptions(@Body body: NotificationSubscriptionsDto): NotificationSubscriptionsDto
+}

app/src/main/java/com/runicgateway/app/data/api/SsoApi.kt

@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api
+
+import com.runicgateway.app.data.api.dto.MobileSsoExchangeRequest
+import com.runicgateway.app.data.api.dto.MobileTokenResponse
+import com.runicgateway.app.data.api.dto.SsoProviderDto
+import retrofit2.Response
+import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.Headers
+import retrofit2.http.POST
+
+/**
+ * The native SSO bridge surface (PLAN.md §4.2, M9). Discovery lists the shard's
+ * enabled providers; exchange trades a callback authorization code (+ its PKCE
+ * verifier) for the same bearer pair as `/auth/mobile/login`.
+ *
+ * The redirect leg (`/auth/mobile/sso/start`) is **not** here — it is opened in a
+ * Custom Tab as a URL (the browser follows the 302 through the IdP), not called as
+ * an XHR. See [com.runicgateway.app.core.auth.sso.SsoAuthManager].
+ *
+ * Exchange is tagged [com.runicgateway.app.core.net.Http.NO_SESSION_HEADER]: it
+ * carries no bearer (the user isn't signed in yet) and a `401` (bad/expired code or
+ * PKCE mismatch) must never be misread as an expired session or trip the refresh
+ * [com.runicgateway.app.core.net.TokenAuthenticator]. It returns a raw [Response]
+ * so the caller can distinguish `401` from other failures.
+ */
+interface SsoApi {
+
+    /** Public discovery — the enabled providers to render login buttons for. */
+    @GET("api/v1/auth/providers")
+    suspend fun providers(): List<SsoProviderDto>
+
+    // Literal header value required by Retrofit @Headers; matches Http.NO_SESSION_HEADER.
+    @Headers("X-Runic-No-Session: 1")
+    @POST("api/v1/auth/mobile/sso/exchange")
+    suspend fun exchange(@Body body: MobileSsoExchangeRequest): Response<MobileTokenResponse>
+}

app/src/main/java/com/runicgateway/app/data/api/dto/NotificationsDto.kt

@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api.dto
+
+import kotlinx.serialization.Serializable
+
+/**
+ * Wire shapes for the opt-in push surface under `/auth/me` (PLAN.md §11, M7
+ * Part 2). Field names match the backend's `notifications.controller` /
+ * `pushDevices.model` exactly; every DTO ignores unknown keys (NetworkModule's
+ * lenient Json), so additive backend fields are safe (recorded for M1).
+ */
+
+/**
+ * `POST /auth/me/devices` body. [endpoint] is the ntfy topic URL the app's
+ * embedded distributor owns (`https://<ntfy-host>/<topic>`); the backend
+ * SSRF-validates it is HTTPS on the shard's allow-set before storing. [transport]
+ * is `unifiedpush` for the direct-ntfy relay (fcm reserved for a future flavor).
+ */
+@Serializable
+data class RegisterDeviceRequest(
+    val endpoint: String,
+    val transport: String = "unifiedpush",
+    val platform: String? = null,
+)
+
+/** `POST/GET /auth/me/devices` — one registered device (endpoint) for this user. */
+@Serializable
+data class PushDeviceDto(
+    val id: Long = 0,
+    val transport: String = "",
+    val endpoint: String = "",
+    val platform: String? = null,
+    val createdAt: String? = null,
+    val lastSeenAt: String? = null,
+)
+
+/**
+ * One subscribable stream from `GET /auth/me/notifications/streams`. A [personal]
+ * stream is delivered only to the owning user and [requiresLinkedAccount] — the app
+ * greys its toggle until a game account is linked (§11).
+ */
+@Serializable
+data class NotificationStreamDto(
+    val id: String = "",
+    val label: String = "",
+    val description: String = "",
+    val personal: Boolean = false,
+    val requiresLinkedAccount: Boolean = false,
+)
+
+/** `GET /auth/me/notifications/streams` — the catalog. */
+@Serializable
+data class NotificationStreamsDto(
+    val streams: List<NotificationStreamDto> = emptyList(),
+)
+
+/**
+ * `GET/PUT /auth/me/notifications/subscriptions` — the user's opted-in stream ids.
+ * PUT replaces the full set; unknown ids are dropped server-side and the stored set
+ * echoed back.
+ */
+@Serializable
+data class NotificationSubscriptionsDto(
+    val streams: List<String> = emptyList(),
+)

app/src/main/java/com/runicgateway/app/data/api/dto/PublicDto.kt

@@ -55,6 +55,17 @@ data class RegistrationFlagsDto(
     val sso: Boolean = false,
 )
 
+/**
+ * Push-notification relay config (M7). [ntfyUrl] is the client-facing ntfy base
+ * URL the app's embedded distributor registers its device topic against; null (or
+ * absent, on an older backend) means push isn't configured for this shard and the
+ * Notifications screen shows it as unavailable.
+ */
+@Serializable
+data class PushConfigDto(
+    val ntfyUrl: String? = null,
+)
+
 /**
  * `GET /public/settings` — whitelisted settings + branding. Only the keys the
  * app consumes are modeled; other whitelisted keys are ignored.
@@ -67,4 +78,6 @@ data class SettingsDto(
     val registration: RegistrationFlagsDto = RegistrationFlagsDto(),
     val gameAccountSignup: Boolean = false,
     val brand: BrandDto = BrandDto(),
+    /** Push relay config (M7); default (null ntfyUrl) on a backend that predates it. */
+    val push: PushConfigDto = PushConfigDto(),
 )

app/src/main/java/com/runicgateway/app/data/api/dto/SsoDto.kt

@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api.dto
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Wire shapes for the Mobile SSO Authorization Bridge (PLAN.md §4.2, M9). The
+ * success payload of `/auth/mobile/sso/exchange` is the shared [MobileTokenResponse]
+ * (same pair as `/auth/mobile/login`) — this file only adds the two shapes unique
+ * to the bridge. Every DTO ignores unknown keys (NetworkModule's lenient Json), so
+ * additive backend fields stay safe (§8).
+ */
+
+/**
+ * One entry of `GET /auth/providers` — public discovery, never secrets. [icon] is
+ * the provider kind (`google` | `discord` | `oidc` | `oauth2`); the app renders a
+ * button per provider from this list rather than hardcoding a set. [loginUrl] is
+ * the *website* start path (unused by the app, which builds its own
+ * `/auth/mobile/sso/start` URL); kept so the shape matches the backend exactly.
+ */
+@Serializable
+data class SsoProviderDto(
+    val id: String,
+    val name: String,
+    val icon: String? = null,
+    val loginUrl: String? = null,
+    val priority: Int? = null,
+)
+
+/**
+ * `POST /auth/mobile/sso/exchange` body — the one-time authorization code from the
+ * callback deep link plus the PKCE verifier stashed at `/start` (Layer B). Wire
+ * name is snake_case to match the backend's `{ code, code_verifier }`.
+ */
+@Serializable
+data class MobileSsoExchangeRequest(
+    val code: String,
+    @SerialName("code_verifier") val codeVerifier: String,
+)

app/src/main/java/com/runicgateway/app/data/repository/AuthRepository.kt

@@ -4,10 +4,13 @@
 package com.runicgateway.app.data.repository
 
 import com.runicgateway.app.core.auth.SessionManager
+import com.runicgateway.app.core.push.PushManager
 import com.runicgateway.app.data.api.AuthApi
+import com.runicgateway.app.data.api.SsoApi
 import com.runicgateway.app.data.api.dto.MobileLoginRequest
 import com.runicgateway.app.data.api.dto.MobileLogoutRequest
 import com.runicgateway.app.data.api.dto.MobileTokenResponse
+import com.runicgateway.app.data.api.dto.SsoProviderDto
 import com.runicgateway.app.data.api.dto.TotpRequiredError
 import kotlinx.coroutines.CancellationException
 import kotlinx.serialization.json.Json
@@ -25,10 +28,25 @@ import javax.inject.Singleton
 @Singleton
 class AuthRepository @Inject constructor(
     private val authApi: AuthApi,
+    private val ssoApi: SsoApi,
     private val sessionManager: SessionManager,
+    private val pushManager: PushManager,
     private val json: Json,
 ) {
 
+    /**
+     * The shard's enabled SSO providers for the native login buttons (§4.2). Public
+     * discovery, never secrets. Returns an empty list on any failure — the login
+     * screen then keeps the website hand-off fallback rather than showing nothing.
+     */
+    suspend fun ssoProviders(): List<SsoProviderDto> = try {
+        ssoApi.providers()
+    } catch (e: CancellationException) {
+        throw e
+    } catch (_: Exception) {
+        emptyList()
+    }
+
     /** Outcome of a login attempt (§4.1). */
     sealed interface LoginResult {
         data object Success : LoginResult
@@ -75,6 +93,16 @@ class AuthRepository @Inject constructor(
      * network call fails, so the user is always signed out locally.
      */
     suspend fun logout(allDevices: Boolean = false) {
+        // Deregister this device's push endpoint while the bearer is still valid, so
+        // no orphan device row is left behind (§11). Keeps the opt-in intent so push
+        // resumes on the next sign-in; best-effort, never blocks the logout.
+        try {
+            pushManager.deregisterDevice()
+        } catch (e: CancellationException) {
+            throw e
+        } catch (_: Exception) {
+            // Ignore — local session teardown proceeds regardless.
+        }
         val refreshToken = sessionManager.currentRefreshToken()
         try {
             authApi.logout(MobileLogoutRequest(refreshToken = refreshToken, all = allDevices))

app/src/main/java/com/runicgateway/app/data/repository/ConnectionRepository.kt

@@ -26,6 +26,7 @@ class ConnectionRepository @Inject constructor(
     private val prefs: ServerPreferences,
     private val baseUrlHolder: BaseUrlHolder,
     private val sessionManager: SessionManager,
+    private val pushManager: com.runicgateway.app.core.push.PushManager,
     private val config: com.runicgateway.app.core.AppConfig,
 ) {
 
@@ -96,6 +97,14 @@ class ConnectionRepository @Inject constructor(
      * signed-out state against the new host.
      */
     suspend fun disconnect() {
+        // Deregister the push endpoint on the current (old) host while still authed,
+        // then clear the shard's ntfy URL — the new host advertises its own (§11).
+        try {
+            pushManager.deregisterDevice()
+        } catch (_: Exception) {
+            // Best-effort; the reset proceeds regardless.
+        }
+        pushManager.setNtfyUrl(null)
         sessionManager.onSignedOut()
         prefs.clear()
         baseUrlHolder.set(null)

app/src/main/java/com/runicgateway/app/data/repository/NotificationsRepository.kt

@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.repository
+
+import com.runicgateway.app.core.result.ApiResult
+import com.runicgateway.app.core.result.safeApiCall
+import com.runicgateway.app.data.api.NotificationsApi
+import com.runicgateway.app.data.api.dto.NotificationStreamsDto
+import com.runicgateway.app.data.api.dto.NotificationSubscriptionsDto
+import com.runicgateway.app.data.api.dto.PushDeviceDto
+import com.runicgateway.app.data.api.dto.RegisterDeviceRequest
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Device registration + per-user stream subscriptions over the opt-in push surface
+ * (PLAN.md §11, M7 Part 2). Every call returns a typed [ApiResult] so the screen
+ * and the [com.runicgateway.app.core.push.PushManager] degrade gracefully — a `400`
+ * (endpoint off the shard's allow-set) or a down backend never throws (§7).
+ */
+@Singleton
+class NotificationsRepository @Inject constructor(
+    private val api: NotificationsApi,
+) {
+    suspend fun registerDevice(endpoint: String, platform: String?): ApiResult<PushDeviceDto> =
+        safeApiCall { api.registerDevice(RegisterDeviceRequest(endpoint = endpoint, platform = platform)) }
+
+    suspend fun listDevices(): ApiResult<List<PushDeviceDto>> = safeApiCall { api.listDevices() }
+
+    suspend fun deleteDevice(id: Long): ApiResult<Unit> = safeApiCall { api.deleteDevice(id) }
+
+    suspend fun streams(): ApiResult<NotificationStreamsDto> = safeApiCall { api.streams() }
+
+    suspend fun subscriptions(): ApiResult<NotificationSubscriptionsDto> =
+        safeApiCall { api.subscriptions() }
+
+    suspend fun setSubscriptions(streams: List<String>): ApiResult<NotificationSubscriptionsDto> =
+        safeApiCall { api.putSubscriptions(NotificationSubscriptionsDto(streams)) }
+}

app/src/main/java/com/runicgateway/app/di/NetworkModule.kt

@@ -14,8 +14,10 @@ import com.runicgateway.app.core.net.UserAgentInterceptor
 import com.runicgateway.app.data.api.AuthApi
 import com.runicgateway.app.data.api.AuthRefreshApi
 import com.runicgateway.app.data.api.MeApi
+import com.runicgateway.app.data.api.NotificationsApi
 import com.runicgateway.app.data.api.PlayerShardApi
 import com.runicgateway.app.data.api.PublicApi
+import com.runicgateway.app.data.api.SsoApi
 import dagger.Module
 import dagger.Provides
 import dagger.hilt.InstallIn
@@ -95,6 +97,11 @@ object NetworkModule {
     @Singleton
     fun provideAuthApi(retrofit: Retrofit): AuthApi = retrofit.create(AuthApi::class.java)
 
+    /** Native SSO discovery + code exchange (§4.2, M9) — on the main client. */
+    @Provides
+    @Singleton
+    fun provideSsoApi(retrofit: Retrofit): SsoApi = retrofit.create(SsoApi::class.java)
+
     /** Role-agnostic self-service (§6.4) — bearer-authed on the main client. */
     @Provides
     @Singleton
@@ -106,6 +113,12 @@ object NetworkModule {
     fun providePlayerShardApi(retrofit: Retrofit): PlayerShardApi =
         retrofit.create(PlayerShardApi::class.java)
 
+    /** Opt-in push devices + subscriptions (§11, M7) — bearer-authed on the main client. */
+    @Provides
+    @Singleton
+    fun provideNotificationsApi(retrofit: Retrofit): NotificationsApi =
+        retrofit.create(NotificationsApi::class.java)
+
     /**
      * Token refresh runs on its own **bare** client — UA + host retargeting only,
      * no auth interceptor and no authenticator — so a refresh can never recurse

app/src/main/java/com/runicgateway/app/ui/AppViewModel.kt

@@ -6,6 +6,7 @@ package com.runicgateway.app.ui
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.runicgateway.app.core.net.BaseUrlHolder
+import com.runicgateway.app.core.push.PushManager
 import com.runicgateway.app.core.result.ApiResult
 import com.runicgateway.app.data.api.dto.BrandDto
 import com.runicgateway.app.data.repository.ConnectionRepository
@@ -27,6 +28,7 @@ class AppViewModel @Inject constructor(
     private val connectionRepository: ConnectionRepository,
     private val settingsRepository: SettingsRepository,
     private val baseUrlHolder: BaseUrlHolder,
+    private val pushManager: PushManager,
 ) : ViewModel() {
 
     sealed interface AppState {
@@ -66,8 +68,16 @@ class AppViewModel @Inject constructor(
         }
     }
 
-    private suspend fun loadBrand(): BrandDto? =
-        (settingsRepository.getSettings() as? ApiResult.Ok)?.data?.brand
+    /**
+     * Load public settings for branding and feed the shard's push relay URL into the
+     * [PushManager] (§11) — its arrival is what lets push re-register after a restart
+     * or sign-in. Returns the brand block (null if settings couldn't be loaded).
+     */
+    private suspend fun loadBrand(): BrandDto? {
+        val settings = (settingsRepository.getSettings() as? ApiResult.Ok)?.data
+        pushManager.setNtfyUrl(settings?.push?.ntfyUrl)
+        return settings?.brand
+    }
 
     /**
      * Resolve a possibly site-relative asset path (branding logos, post images)

app/src/main/java/com/runicgateway/app/ui/RunicApp.kt

@@ -56,6 +56,7 @@ import com.runicgateway.app.ui.navigation.Routes
 import com.runicgateway.app.ui.navigation.visibleEntries
 import com.runicgateway.app.ui.news.NewsScreen
 import com.runicgateway.app.ui.news.PostScreen
+import com.runicgateway.app.ui.notifications.NotificationsScreen
 import com.runicgateway.app.ui.page.PageScreen
 import com.runicgateway.app.ui.player.CharacterSheetScreen
 import com.runicgateway.app.ui.player.CharactersScreen
@@ -75,6 +76,7 @@ import kotlinx.coroutines.launch
 /** Destinations that show the drawer (hamburger); others show a back arrow. */
 private val TOP_LEVEL_ROUTES = setOf(
     Routes.HOME, Routes.NEWS, Routes.WIKI, Routes.SHARD, Routes.CONTACT, Routes.PAGE, Routes.ACCOUNT,
+    Routes.NOTIFICATIONS,
     Routes.PLAYER_CHARACTERS, Routes.PLAYER_VENDORS, Routes.PLAYER_HOUSES,
 )
 
@@ -91,6 +93,8 @@ fun RunicApp(
     brand: BrandDto?,
     onChangeServer: () -> Unit,
     modifier: Modifier = Modifier,
+    deepLinkStream: String? = null,
+    onDeepLinkConsumed: () -> Unit = {},
     sessionViewModel: SessionViewModel = hiltViewModel(),
 ) {
     val navController = rememberNavController()
@@ -105,6 +109,16 @@ fun RunicApp(
         onPauseOrDispose { }
     }
 
+    // A tapped push notification deep-links to its stream's screen (§11, item 7).
+    LaunchedEffect(deepLinkStream) {
+        val stream = deepLinkStream ?: return@LaunchedEffect
+        navController.navigate(Routes.forStream(stream)) {
+            popUpTo(Routes.HOME) { saveState = true }
+            launchSingleTop = true
+        }
+        onDeepLinkConsumed()
+    }
+
     val backStackEntry by navController.currentBackStackEntryAsState()
     val currentRoute = backStackEntry?.destination?.route
     val isTopLevel = currentRoute in TOP_LEVEL_ROUTES
@@ -309,6 +323,14 @@ private fun RunicNavHost(
                 }
             }
         }
+        composable(Routes.NOTIFICATIONS) {
+            // Signed-in only; a sign-out (or demotion) sends the user home rather than
+            // leaving stale settings up. The backend gates every call regardless (§5).
+            when (session) {
+                is Session.SignedIn -> NotificationsScreen()
+                Session.SignedOut -> LaunchedEffect(Unit) { navController.navigateTopLevel(Routes.HOME) }
+            }
+        }
 
         // ── Player game data (§6.3) — reached from the player-only menu groups.
         // The server enforces the player gate on every call; these screens simply

app/src/main/java/com/runicgateway/app/ui/auth/LoginScreen.kt

@@ -16,6 +16,7 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
@@ -56,6 +57,13 @@ fun LoginScreen(
         if (state.signedIn) onSignedIn()
     }
 
+    // Open a freshly-minted SSO /start URL in a Custom Tab, exactly once (§4.2).
+    LaunchedEffect(state.ssoLaunchUrl) {
+        val url = state.ssoLaunchUrl ?: return@LaunchedEffect
+        WebHandoff.open(context, url)
+        viewModel.onSsoLaunchConsumed()
+    }
+
     Column(
         modifier = modifier
             .fillMaxSize()
@@ -155,6 +163,29 @@ fun LoginScreen(
             }
         }
 
+        // ── Native SSO (§4.2, M9): a button per enabled provider that opens the
+        // Custom-Tab bridge and returns the user signed in. Falls back to the
+        // website login hand-off when the shard exposes no providers.
+        if (state.ssoProviders.isNotEmpty()) {
+            state.ssoProviders.forEach { provider ->
+                OutlinedButton(
+                    onClick = { viewModel.onSsoProviderClick(provider) },
+                    enabled = !state.submitting,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(top = 12.dp),
+                ) {
+                    Text(stringResource(R.string.login_sso_provider, provider.name))
+                }
+            }
+        } else {
+            viewModel.ssoLoginUrl?.let { url ->
+                TextButton(onClick = { WebHandoff.open(context, url) }) {
+                    Text(stringResource(R.string.login_sso))
+                }
+            }
+        }
+
         // ── Website hand-offs (§4.2): open the site's own pages in a Custom Tab ──
         viewModel.registerUrl?.let { url ->
             TextButton(
@@ -167,11 +198,6 @@ fun LoginScreen(
                 Text(stringResource(R.string.login_forgot))
             }
         }
-        viewModel.ssoLoginUrl?.let { url ->
-            TextButton(onClick = { WebHandoff.open(context, url) }) {
-                Text(stringResource(R.string.login_sso))
-            }
-        }
     }
 }
 
@@ -181,4 +207,5 @@ private fun loginErrorRes(error: LoginError): Int = when (error) {
     LoginError.RATE_LIMITED -> R.string.login_error_rate_limited
     LoginError.SERVER -> R.string.login_error_server
     LoginError.NETWORK -> R.string.login_error_network
+    LoginError.SSO -> R.string.login_error_sso
 }

app/src/main/java/com/runicgateway/app/ui/auth/LoginViewModel.kt

@@ -5,7 +5,9 @@ package com.runicgateway.app.ui.auth
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.runicgateway.app.core.auth.sso.SsoAuthManager
 import com.runicgateway.app.core.web.WebsiteUrls
+import com.runicgateway.app.data.api.dto.SsoProviderDto
 import com.runicgateway.app.data.repository.AuthRepository
 import com.runicgateway.app.data.repository.AuthRepository.LoginResult
 import dagger.hilt.android.lifecycle.HiltViewModel
@@ -25,11 +27,12 @@ import javax.inject.Inject
 @HiltViewModel
 class LoginViewModel @Inject constructor(
     private val authRepository: AuthRepository,
+    private val ssoAuthManager: SsoAuthManager,
     private val websiteUrls: WebsiteUrls,
 ) : ViewModel() {
 
     /** The transient error surfaced under the form after a failed attempt. */
-    enum class LoginError { INVALID_CREDENTIALS, BAD_CODE, RATE_LIMITED, SERVER, NETWORK }
+    enum class LoginError { INVALID_CREDENTIALS, BAD_CODE, RATE_LIMITED, SERVER, NETWORK, SSO }
 
     data class UiState(
         val username: String = "",
@@ -40,11 +43,40 @@ class LoginViewModel @Inject constructor(
         val submitting: Boolean = false,
         val error: LoginError? = null,
         val signedIn: Boolean = false,
+        /** The shard's enabled SSO providers (§4.2); empty → website hand-off fallback. */
+        val ssoProviders: List<SsoProviderDto> = emptyList(),
+        /** A `/auth/mobile/sso/start` URL the screen should open in a Custom Tab, once. */
+        val ssoLaunchUrl: String? = null,
     )
 
     private val _state = MutableStateFlow(UiState())
     val state: StateFlow<UiState> = _state.asStateFlow()
 
+    init {
+        // Discover the native SSO providers to render buttons for (§4.2).
+        viewModelScope.launch {
+            val providers = authRepository.ssoProviders()
+            if (providers.isNotEmpty()) _state.update { it.copy(ssoProviders = providers) }
+        }
+        // Consume the SSO bridge outcome: a returned callback completes here even if
+        // this ViewModel was recreated while the Custom Tab was foreground (§4.2).
+        viewModelScope.launch {
+            ssoAuthManager.outcome.collect { outcome ->
+                when (outcome) {
+                    SsoAuthManager.Outcome.Success -> {
+                        ssoAuthManager.consumeOutcome()
+                        _state.update { it.copy(submitting = false, signedIn = true) }
+                    }
+                    is SsoAuthManager.Outcome.Failed -> {
+                        ssoAuthManager.consumeOutcome()
+                        _state.update { it.copy(submitting = false, error = mapSsoError(outcome.reason)) }
+                    }
+                    SsoAuthManager.Outcome.Idle -> Unit
+                }
+            }
+        }
+    }
+
     fun onUsernameChange(value: String) = _state.update { it.copy(username = value, error = null) }
     fun onPasswordChange(value: String) = _state.update { it.copy(password = value, error = null) }
     fun onCodeChange(value: String) =
@@ -52,8 +84,33 @@ class LoginViewModel @Inject constructor(
 
     val registerUrl: String? get() = websiteUrls.register()
     val forgotPasswordUrl: String? get() = websiteUrls.forgotPassword()
+
+    /** Website login hand-off — the fallback when native SSO discovery is empty (§4.2). */
     val ssoLoginUrl: String? get() = websiteUrls.login()
 
+    /**
+     * Begin a native SSO flow for [provider]: mint PKCE + state and surface the
+     * `/start` URL for the screen to open in a Custom Tab. No-op (leaves a SERVER
+     * error) if the base URL isn't set yet — the website fallback still shows.
+     */
+    fun onSsoProviderClick(provider: SsoProviderDto) {
+        if (_state.value.submitting) return
+        val url = ssoAuthManager.buildStartUrl(provider.id)
+        if (url == null) {
+            _state.update { it.copy(error = LoginError.SSO) }
+            return
+        }
+        _state.update { it.copy(error = null, ssoLaunchUrl = url) }
+    }
+
+    /** The screen has opened the Custom Tab; clear so it isn't re-launched on recompose. */
+    fun onSsoLaunchConsumed() = _state.update { it.copy(ssoLaunchUrl = null) }
+
+    private fun mapSsoError(reason: SsoAuthManager.Failure): LoginError = when (reason) {
+        SsoAuthManager.Failure.NETWORK -> LoginError.NETWORK
+        else -> LoginError.SSO
+    }
+
     fun submit() {
         val s = _state.value
         if (s.submitting) return

app/src/main/java/com/runicgateway/app/ui/navigation/Menu.kt

@@ -44,6 +44,7 @@ val APP_MENU: List<MenuEntry> = listOf(
     MenuEntry(Routes.page("about"), R.string.menu_about),
     MenuEntry(Routes.CONTACT, R.string.menu_contact),
     MenuEntry(Routes.ACCOUNT, R.string.menu_account, MenuAccess.SIGNED_IN),
+    MenuEntry(Routes.NOTIFICATIONS, R.string.menu_notifications, MenuAccess.SIGNED_IN),
     MenuEntry(Routes.PLAYER_CHARACTERS, R.string.menu_my_characters, MenuAccess.PLAYER),
     MenuEntry(Routes.PLAYER_VENDORS, R.string.menu_my_vendors, MenuAccess.PLAYER),
     MenuEntry(Routes.PLAYER_HOUSES, R.string.menu_my_houses, MenuAccess.PLAYER),

app/src/main/java/com/runicgateway/app/ui/navigation/Routes.kt

@@ -18,6 +18,9 @@ object Routes {
     const val LOGIN = "login"
     const val ACCOUNT = "account"
 
+    /** Opt-in push notification settings (§11, signed-in). */
+    const val NOTIFICATIONS = "notifications"
+
     /** Public shard hub (§6.2). */
     const val SHARD = "shard"
 
@@ -57,4 +60,23 @@ object Routes {
 
     /** The character-sheet route for an in-game serial (e.g. "0x24C"). */
     fun playerChar(serial: String) = "player/char/$serial"
+
+    /**
+     * The in-app destination a tapped push notification deep-links to (§11, M7
+     * Part 2 work item 7). Maps a stream id to the screen that shows its content;
+     * unknown streams land on Home. Personal streams route to the player groups
+     * (a signed-out/demoted tap is caught by [com.runicgateway.app.ui.PlayerGate]).
+     */
+    fun forStream(streamId: String): String = when (streamId) {
+        com.runicgateway.app.core.push.PushStreams.NEWS_POST -> NEWS
+        com.runicgateway.app.core.push.PushStreams.SERVER_STATUS,
+        com.runicgateway.app.core.push.PushStreams.CHAMP_START,
+        com.runicgateway.app.core.push.PushStreams.IDOC_WARNING,
+        com.runicgateway.app.core.push.PushStreams.GOVERNOR_ELECTION,
+        -> SHARD
+        com.runicgateway.app.core.push.PushStreams.VENDOR_SALE -> PLAYER_VENDORS
+        com.runicgateway.app.core.push.PushStreams.HOUSE_IDOC -> PLAYER_HOUSES
+        com.runicgateway.app.core.push.PushStreams.ACCOUNT_LOGIN -> ACCOUNT
+        else -> HOME
+    }
 }

app/src/main/java/com/runicgateway/app/ui/notifications/NotificationsScreen.kt

@@ -0,0 +1,182 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.notifications
+
+import android.Manifest
+import android.os.Build
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.runicgateway.app.R
+import com.runicgateway.app.data.api.dto.NotificationStreamDto
+import com.runicgateway.app.ui.UiState
+import com.runicgateway.app.ui.components.EmptyView
+import com.runicgateway.app.ui.components.ErrorView
+import com.runicgateway.app.ui.components.LoadingView
+import com.runicgateway.app.ui.components.SectionLabel
+
+/**
+ * The Notifications settings screen (PLAN.md §11, M7 Part 2 work item 6): the
+ * subscribable catalog with per-stream toggles. Personal streams are greyed until a
+ * game account is linked; turning a stream on requests the POST_NOTIFICATIONS
+ * permission (API 33+) and registers the device, turning them all off unregisters it.
+ */
+@Composable
+fun NotificationsScreen(
+    modifier: Modifier = Modifier,
+    viewModel: NotificationsViewModel = hiltViewModel(),
+) {
+    val state by viewModel.state.collectAsStateWithLifecycle()
+    val context = LocalContext.current
+
+    // Ask once for POST_NOTIFICATIONS when the user first enables a stream (API 33+).
+    val permissionLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.RequestPermission(),
+    ) { /* granted or not, the subscription is already saved server-side */ }
+
+    fun ensureNotificationPermission() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            permissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
+        }
+    }
+
+    Column(
+        modifier = modifier
+            .fillMaxSize()
+            .verticalScroll(rememberScrollState())
+            .padding(16.dp),
+    ) {
+        Text(
+            text = stringResource(R.string.notifications_title),
+            style = MaterialTheme.typography.titleLarge,
+        )
+        Spacer(Modifier.height(4.dp))
+        Text(
+            text = stringResource(R.string.notifications_subtitle),
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Spacer(Modifier.height(16.dp))
+
+        if (!state.supported) {
+            EmptyView(message = stringResource(R.string.notifications_unsupported))
+            return@Column
+        }
+
+        state.feedback?.let { fb ->
+            Text(
+                text = stringResource(fb.messageRes),
+                style = MaterialTheme.typography.bodyMedium,
+                color = if (fb.ok) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.error,
+                modifier = Modifier.padding(bottom = 12.dp),
+            )
+        }
+
+        when (val catalog = state.catalog) {
+            is UiState.Loading -> LoadingView()
+            is UiState.Error -> ErrorView(kind = catalog.kind, onRetry = viewModel::load)
+            is UiState.Success -> StreamList(
+                streams = catalog.data,
+                subscribed = state.subscribed,
+                hasLinkedAccount = state.hasLinkedAccount,
+                busy = state.busy,
+                onToggle = { stream, on ->
+                    if (on) ensureNotificationPermission()
+                    viewModel.setSubscribed(stream, on)
+                },
+            )
+        }
+    }
+}
+
+@Composable
+private fun StreamList(
+    streams: List<NotificationStreamDto>,
+    subscribed: Set<String>,
+    hasLinkedAccount: Boolean,
+    busy: Boolean,
+    onToggle: (NotificationStreamDto, Boolean) -> Unit,
+) {
+    if (streams.isEmpty()) {
+        EmptyView(message = stringResource(R.string.notifications_empty))
+        return
+    }
+    val (personal, general) = streams.partition { it.personal }
+
+    if (general.isNotEmpty()) {
+        SectionLabel(stringResource(R.string.notifications_section_general))
+        Spacer(Modifier.height(8.dp))
+        general.forEach { stream ->
+            StreamRow(stream, subscribed.contains(stream.id), enabled = !busy, hint = null) { on ->
+                onToggle(stream, on)
+            }
+            HorizontalDivider()
+        }
+        Spacer(Modifier.height(20.dp))
+    }
+
+    if (personal.isNotEmpty()) {
+        SectionLabel(stringResource(R.string.notifications_section_personal))
+        Spacer(Modifier.height(8.dp))
+        personal.forEach { stream ->
+            val selectable = streamSelectable(stream, hasLinkedAccount)
+            val hint = if (!selectable) stringResource(R.string.notifications_requires_link) else null
+            StreamRow(stream, subscribed.contains(stream.id) && selectable, enabled = !busy && selectable, hint = hint) { on ->
+                onToggle(stream, on)
+            }
+            HorizontalDivider()
+        }
+    }
+}
+
+@Composable
+private fun StreamRow(
+    stream: NotificationStreamDto,
+    checked: Boolean,
+    enabled: Boolean,
+    hint: String?,
+    onToggle: (Boolean) -> Unit,
+) {
+    Row(
+        modifier = Modifier.fillMaxWidth().padding(vertical = 12.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Column(modifier = Modifier.weight(1f).padding(end = 12.dp)) {
+            Text(
+                text = stream.label,
+                style = MaterialTheme.typography.bodyLarge,
+                color = if (enabled) MaterialTheme.colorScheme.onSurface else MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            Text(
+                text = hint ?: stream.description,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                fontStyle = if (hint != null) FontStyle.Italic else FontStyle.Normal,
+            )
+        }
+        Switch(checked = checked, onCheckedChange = onToggle, enabled = enabled)
+    }
+}

app/src/main/java/com/runicgateway/app/ui/notifications/NotificationsViewModel.kt

@@ -0,0 +1,135 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.notifications
+
+import androidx.annotation.StringRes
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.runicgateway.app.R
+import com.runicgateway.app.core.push.PushManager
+import com.runicgateway.app.core.result.ApiResult
+import com.runicgateway.app.data.api.dto.NotificationStreamDto
+import com.runicgateway.app.data.repository.NotificationsRepository
+import com.runicgateway.app.data.repository.PlayerShardRepository
+import com.runicgateway.app.ui.UiState
+import com.runicgateway.app.ui.toUiState
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * Drives the Notifications settings screen (PLAN.md §11, M7 Part 2 work item 6):
+ * the stream catalog with per-stream toggles bound to
+ * `GET/PUT /auth/me/notifications/subscriptions`. A **personal** stream is greyed
+ * until the user has a linked game account (§11), and turning the opt-in set
+ * non-empty/empty drives the [PushManager] to register/unregister the device.
+ */
+@HiltViewModel
+class NotificationsViewModel @Inject constructor(
+    private val notifications: NotificationsRepository,
+    private val playerShard: PlayerShardRepository,
+    private val pushManager: PushManager,
+) : ViewModel() {
+
+    data class Feedback(val ok: Boolean, @param:StringRes val messageRes: Int)
+
+    data class State(
+        val catalog: UiState<List<NotificationStreamDto>> = UiState.Loading,
+        val subscribed: Set<String> = emptySet(),
+        /** Whether the user has ≥1 linked game account — personal streams need it. */
+        val hasLinkedAccount: Boolean = false,
+        /** Whether this shard advertises a push relay at all (else the screen says so). */
+        val supported: Boolean = true,
+        val busy: Boolean = false,
+        val feedback: Feedback? = null,
+    )
+
+    private val _state = MutableStateFlow(State())
+    val state: StateFlow<State> = _state.asStateFlow()
+
+    init {
+        viewModelScope.launch {
+            pushManager.supported.collect { supported -> _state.update { it.copy(supported = supported) } }
+        }
+        load()
+    }
+
+    fun load() {
+        _state.update { it.copy(catalog = UiState.Loading) }
+        viewModelScope.launch {
+            val catalog = notifications.streams().let { result ->
+                when (result) {
+                    is ApiResult.Ok -> ApiResult.Ok(result.data.streams)
+                    is ApiResult.HttpError -> result
+                    is ApiResult.NetworkError -> result
+                }
+            }
+            _state.update { it.copy(catalog = catalog.toUiState()) }
+
+            when (val subs = notifications.subscriptions()) {
+                is ApiResult.Ok -> _state.update { it.copy(subscribed = subs.data.streams.toSet()) }
+                else -> Unit
+            }
+            // A linked game account gates the personal streams; failure → treat as none.
+            val linked = (playerShard.accounts() as? ApiResult.Ok)?.data?.isNotEmpty() == true
+            _state.update { it.copy(hasLinkedAccount = linked) }
+        }
+    }
+
+    fun clearFeedback() = _state.update { it.copy(feedback = null) }
+
+    /** Toggle [stream]; refuses a personal stream with no linked account. */
+    fun setSubscribed(stream: NotificationStreamDto, on: Boolean) {
+        val s = _state.value
+        if (s.busy) return
+        if (on && !streamSelectable(stream, s.hasLinkedAccount)) return
+        val next = if (on) s.subscribed + stream.id else s.subscribed - stream.id
+
+        _state.update { it.copy(busy = true, feedback = null) }
+        viewModelScope.launch {
+            when (val result = notifications.setSubscriptions(next.toList())) {
+                is ApiResult.Ok -> {
+                    val stored = result.data.streams.toSet()
+                    _state.update { it.copy(subscribed = stored) }
+                    reconcilePush(stored)
+                }
+                is ApiResult.NetworkError -> finish(false, R.string.error_network)
+                is ApiResult.HttpError -> finish(false, R.string.notifications_save_error)
+            }
+        }
+    }
+
+    /**
+     * Register or unregister the device to match the opted-in set (PLAN.md §11:
+     * register when signed-in + subscribed, unregister when the set empties).
+     */
+    private suspend fun reconcilePush(subscribed: Set<String>) {
+        if (subscribed.isEmpty()) {
+            pushManager.disable()
+            finish(true, R.string.notifications_all_off)
+            return
+        }
+        when (val res = pushManager.enable()) {
+            is PushManager.PushResult.Enabled -> finish(true, R.string.notifications_saved)
+            is PushManager.PushResult.Unsupported -> finish(false, R.string.notifications_unsupported)
+            is PushManager.PushResult.NotSignedIn -> finish(false, R.string.notifications_save_error)
+            is PushManager.PushResult.Failed ->
+                finish(false, if (res.status == 400) R.string.notifications_relay_error else R.string.notifications_save_error)
+        }
+    }
+
+    private fun finish(ok: Boolean, @StringRes messageRes: Int) =
+        _state.update { it.copy(busy = false, feedback = Feedback(ok, messageRes)) }
+}
+
+/**
+ * Whether a stream's toggle is selectable for a user: a personal stream needs a
+ * linked game account (PLAN.md §11). Pure so the gating is unit-tested without Compose.
+ */
+fun streamSelectable(stream: NotificationStreamDto, hasLinkedAccount: Boolean): Boolean =
+    !stream.requiresLinkedAccount || hasLinkedAccount

app/src/main/res/values/strings.xml

@@ -61,11 +61,14 @@
     <string name="login_register">Create an account</string>
     <string name="login_forgot">Forgot your password?</string>
     <string name="login_sso">Sign in with Google or Discord (on the website)</string>
+    <!-- %1$s is the provider name, e.g. "Google" or "Discord" (native SSO, M9). -->
+    <string name="login_sso_provider">Sign in with %1$s</string>
     <string name="login_error_credentials">Incorrect username or password.</string>
     <string name="login_error_code">That code didn\'t match. Try the current code.</string>
     <string name="login_error_rate_limited">Too many attempts. Please try again shortly.</string>
     <string name="login_error_server">Something went wrong. Please try again.</string>
     <string name="login_error_network">Can\'t reach the site. Check your connection and try again.</string>
+    <string name="login_error_sso">Couldn\'t complete that sign-in. Please try again.</string>
 
     <!-- ── Auth: account (§5, §6.3) ────────────────────────────────────── -->
     <string name="account_title">My account</string>
@@ -257,4 +260,37 @@
     <string name="houses_empty">No houses are in danger right now.</string>
     <string name="houses_fallback_name">A house</string>
     <string name="houses_idoc_badge">IDOC</string>
+
+    <!-- ── Push notifications (§11, M7 Part 2) ─────────────────────────── -->
+    <string name="menu_notifications">Notifications</string>
+    <string name="notifications_title">Notifications</string>
+    <string name="notifications_subtitle">Choose what this shard notifies you about. Nothing is sent unless you turn it on.</string>
+    <string name="notifications_section_general">General</string>
+    <string name="notifications_section_personal">Your game account</string>
+    <string name="notifications_requires_link">Link a game account to enable this.</string>
+    <string name="notifications_empty">This shard offers no notification streams yet.</string>
+    <string name="notifications_unsupported">This shard hasn\'t set up push notifications yet.</string>
+    <string name="notifications_saved">Notification settings saved.</string>
+    <string name="notifications_all_off">Notifications turned off.</string>
+    <string name="notifications_save_error">Couldn\'t save your notification settings. Try again.</string>
+    <string name="notifications_relay_error">This shard\'s push relay isn\'t reachable right now.</string>
+
+    <!-- Notification channels + the ongoing foreground-service notification. -->
+    <string name="push_channel_messages">Shard notifications</string>
+    <string name="push_channel_messages_desc">Alerts you opted into from this shard.</string>
+    <string name="push_channel_service">Background connection</string>
+    <string name="push_channel_service_desc">Keeps the connection open to deliver notifications.</string>
+    <string name="push_service_title">Notifications active</string>
+    <string name="push_service_text">Listening for shard notifications.</string>
+
+    <!-- Per-stream notification titles (content-free tickle → generic title, §11). -->
+    <string name="push_stream_news_post">New post</string>
+    <string name="push_stream_server_status">Shard status changed</string>
+    <string name="push_stream_idoc_warning">A house is falling (IDOC)</string>
+    <string name="push_stream_champ_start">Champion spawn started</string>
+    <string name="push_stream_governor_election">New governor elected</string>
+    <string name="push_stream_vendor_sale">Your vendor made a sale</string>
+    <string name="push_stream_house_idoc">Your house entered IDOC</string>
+    <string name="push_stream_account_login">Login to your account</string>
+    <string name="push_stream_generic">New notification</string>
 </resources>

app/src/test/java/com/runicgateway/app/core/auth/sso/PkceTest.kt

@@ -0,0 +1,49 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.auth.sso
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * PKCE Layer B primitives (PLAN.md §4.2). The challenge encoding must match the
+ * backend byte-for-byte (`base64url(SHA-256(verifier))`, no padding) or `/exchange`
+ * rejects every code — so it is pinned against the RFC 7636 test vector.
+ */
+class PkceTest {
+
+    // RFC 4648 §5 URL-safe base64 alphabet, no padding.
+    private val base64UrlNoPad = Regex("^[A-Za-z0-9_-]+$")
+
+    @Test fun `challenge matches the RFC 7636 vector`() {
+        // RFC 7636 Appendix B.
+        val verifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
+        assertEquals("E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM", Pkce.challengeOf(verifier))
+    }
+
+    @Test fun `verifier is url-safe base64 without padding`() {
+        val verifier = Pkce.newVerifier()
+        assertTrue("verifier charset: $verifier", base64UrlNoPad.matches(verifier))
+        // 32 random bytes → 43 base64 chars (no padding), inside RFC 7636's 43–128.
+        assertEquals(43, verifier.length)
+    }
+
+    @Test fun `challenge is url-safe base64 without padding`() {
+        val challenge = Pkce.challengeOf(Pkce.newVerifier())
+        assertTrue("challenge charset: $challenge", base64UrlNoPad.matches(challenge))
+        // SHA-256 (32 bytes) → 43 base64 chars, no '=' padding.
+        assertEquals(43, challenge.length)
+    }
+
+    @Test fun `verifiers and states are unique per call`() {
+        assertNotEquals(Pkce.newVerifier(), Pkce.newVerifier())
+        assertNotEquals(Pkce.newState(), Pkce.newState())
+    }
+
+    @Test fun `state is url-safe base64 without padding`() {
+        assertTrue(base64UrlNoPad.matches(Pkce.newState()))
+    }
+}

app/src/test/java/com/runicgateway/app/core/auth/sso/SsoAuthManagerTest.kt

@@ -0,0 +1,223 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.auth.sso
+
+import com.runicgateway.app.core.auth.Session
+import com.runicgateway.app.core.auth.SessionManager
+import com.runicgateway.app.core.auth.StoredSession
+import com.runicgateway.app.core.auth.TokenStore
+import com.runicgateway.app.core.net.BaseUrlHolder
+import com.runicgateway.app.data.api.SsoApi
+import com.runicgateway.app.data.api.dto.MobileSsoExchangeRequest
+import com.runicgateway.app.data.api.dto.MobileTokenResponse
+import com.runicgateway.app.data.api.dto.SafeUserDto
+import com.runicgateway.app.data.api.dto.SsoProviderDto
+import kotlinx.coroutines.test.runTest
+import okhttp3.HttpUrl.Companion.toHttpUrl
+import okhttp3.MediaType.Companion.toMediaTypeOrNull
+import okhttp3.ResponseBody.Companion.toResponseBody
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import retrofit2.Response
+
+/**
+ * The native SSO bridge orchestration (PLAN.md §4.2, M9): start-URL building, the
+ * CSRF/state guard, the code→token exchange, and that a success drives the *same*
+ * [SessionManager] the password login uses. Runs over a fake [SsoApi] + a real
+ * [SessionManager] on a fake [TokenStore]; no Android framework types are touched.
+ */
+class SsoAuthManagerTest {
+
+    private class FakeTokenStore(var stored: StoredSession? = null) : TokenStore {
+        override fun load(): StoredSession? = stored
+        override fun save(session: StoredSession) { stored = session }
+        override fun clear() { stored = null }
+    }
+
+    /** Records the exchange it was called with and returns a scripted response. */
+    private class FakeSsoApi(
+        private val exchangeResult: () -> Response<MobileTokenResponse>,
+    ) : SsoApi {
+        var exchangeCalls = 0
+        var lastRequest: MobileSsoExchangeRequest? = null
+
+        override suspend fun providers(): List<SsoProviderDto> = emptyList()
+
+        override suspend fun exchange(body: MobileSsoExchangeRequest): Response<MobileTokenResponse> {
+            exchangeCalls++
+            lastRequest = body
+            return exchangeResult()
+        }
+    }
+
+    private fun tokenPair() = MobileTokenResponse(
+        accessToken = "access-A",
+        refreshToken = "refresh-A",
+        expiresIn = "15m",
+        user = SafeUserDto(id = 7, username = "alice", role = "player"),
+    )
+
+    private fun error(code: Int): Response<MobileTokenResponse> =
+        Response.error(code, "".toResponseBody("application/json".toMediaTypeOrNull()))
+
+    private fun managerWith(
+        api: SsoApi,
+        session: SessionManager,
+        base: String? = "https://shard.example.com/",
+    ): SsoAuthManager {
+        val holder = BaseUrlHolder()
+        if (base != null) holder.set(base.toHttpUrl())
+        return SsoAuthManager(api, session, holder)
+    }
+
+    /** Build a start URL and pull the generated `state` back out of it. */
+    private fun startAndState(mgr: SsoAuthManager, provider: String = "google"): String {
+        val url = mgr.buildStartUrl(SsoProviderDto(id = provider, name = "Google").id)!!
+        return url.toHttpUrl().queryParameter("state")!!
+    }
+
+    @Test fun `buildStartUrl carries provider, challenge, state and the fixed redirect`() {
+        val mgr = managerWith(FakeSsoApi { tokenPair().let { Response.success(it) } }, SessionManager(FakeTokenStore()))
+        val url = mgr.buildStartUrl("google")!!
+        val http = url.toHttpUrl()
+
+        assertTrue(url.startsWith("https://shard.example.com/api/v1/auth/mobile/sso/start"))
+        assertEquals("google", http.queryParameter("provider"))
+        assertEquals(SsoAuthManager.REDIRECT_URI, http.queryParameter("redirect_uri"))
+        assertTrue(!http.queryParameter("code_challenge").isNullOrBlank())
+        assertTrue(!http.queryParameter("state").isNullOrBlank())
+    }
+
+    @Test fun `buildStartUrl returns null when no base url is set`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()), base = null)
+        assertNull(mgr.buildStartUrl("google"))
+    }
+
+    @Test fun `successful callback exchanges and signs in`() = runTest {
+        val api = FakeSsoApi { Response.success(tokenPair()) }
+        val session = SessionManager(FakeTokenStore())
+        val mgr = managerWith(api, session)
+
+        val state = startAndState(mgr)
+        mgr.complete(state = state, code = "auth-code-1", error = null)
+
+        assertEquals(1, api.exchangeCalls)
+        assertEquals("auth-code-1", api.lastRequest?.code)
+        assertTrue(session.state.value is Session.SignedIn)
+        assertEquals("access-A", session.currentAccessToken())
+        assertEquals(SsoAuthManager.Outcome.Success, mgr.outcome.value)
+    }
+
+    @Test fun `state mismatch fails without exchanging`() = runTest {
+        val api = FakeSsoApi { Response.success(tokenPair()) }
+        val session = SessionManager(FakeTokenStore())
+        val mgr = managerWith(api, session)
+
+        startAndState(mgr) // establishes a pending with a different state
+        mgr.complete(state = "not-the-state", code = "auth-code-1", error = null)
+
+        assertEquals(0, api.exchangeCalls)
+        assertTrue(session.state.value is Session.SignedOut)
+        assertEquals(SsoAuthManager.Outcome.Failed(SsoAuthManager.Failure.STATE_MISMATCH), mgr.outcome.value)
+    }
+
+    @Test fun `missing pending flow (process death) fails closed`() = runTest {
+        val api = FakeSsoApi { Response.success(tokenPair()) }
+        val mgr = managerWith(api, SessionManager(FakeTokenStore()))
+
+        // No buildStartUrl → nothing stashed; a callback can't be trusted.
+        mgr.complete(state = "anything", code = "auth-code-1", error = null)
+
+        assertEquals(0, api.exchangeCalls)
+        assertEquals(SsoAuthManager.Outcome.Failed(SsoAuthManager.Failure.STATE_MISMATCH), mgr.outcome.value)
+    }
+
+    @Test fun `error callback maps to a declined sign-in and does not exchange`() = runTest {
+        val api = FakeSsoApi { Response.success(tokenPair()) }
+        val mgr = managerWith(api, SessionManager(FakeTokenStore()))
+
+        val state = startAndState(mgr)
+        mgr.complete(state = state, code = null, error = "access_denied")
+
+        assertEquals(0, api.exchangeCalls)
+        assertEquals(SsoAuthManager.Outcome.Failed(SsoAuthManager.Failure.DENIED), mgr.outcome.value)
+    }
+
+    @Test fun `401 exchange maps to expired code`() = runTest {
+        val api = FakeSsoApi { error(401) }
+        val session = SessionManager(FakeTokenStore())
+        val mgr = managerWith(api, session)
+
+        val state = startAndState(mgr)
+        mgr.complete(state = state, code = "stale-code", error = null)
+
+        assertEquals(1, api.exchangeCalls)
+        assertTrue(session.state.value is Session.SignedOut)
+        assertEquals(SsoAuthManager.Outcome.Failed(SsoAuthManager.Failure.EXPIRED_CODE), mgr.outcome.value)
+    }
+
+    @Test fun `a second delivery of the same callback finds no pending`() = runTest {
+        val api = FakeSsoApi { Response.success(tokenPair()) }
+        val mgr = managerWith(api, SessionManager(FakeTokenStore()))
+
+        val state = startAndState(mgr)
+        mgr.complete(state = state, code = "auth-code-1", error = null)
+        mgr.complete(state = state, code = "auth-code-1", error = null) // replay
+
+        // Only the first delivery exchanged; the replay fails the state guard.
+        assertEquals(1, api.exchangeCalls)
+        assertEquals(SsoAuthManager.Outcome.Failed(SsoAuthManager.Failure.STATE_MISMATCH), mgr.outcome.value)
+    }
+
+    @Test fun `matchesCallback only accepts the fixed scheme host and path`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()))
+        assertTrue(mgr.matchesCallback("runicgateway", "auth", "/callback"))
+        assertTrue(!mgr.matchesCallback("https", "auth", "/callback"))
+        assertTrue(!mgr.matchesCallback("runicgateway", "auth", "/other"))
+        assertTrue(!mgr.matchesCallback("runicgateway", "evil", "/callback"))
+    }
+
+    // ── App Links (docs/android/APP_LINKS.md) ────────────────────────────────
+
+    @Test fun `matchesAppLinkCallback accepts only https, the app-link path, and the paired host`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()))
+        // Paired to shard.example.com (managerWith default base).
+        assertTrue(mgr.matchesAppLinkCallback("https", "shard.example.com", "/mobile/callback"))
+        // Host-trust: a foreign host is refused even over https + right path.
+        assertTrue(!mgr.matchesAppLinkCallback("https", "evil.example.com", "/mobile/callback"))
+        // Wrong scheme / wrong path.
+        assertTrue(!mgr.matchesAppLinkCallback("http", "shard.example.com", "/mobile/callback"))
+        assertTrue(!mgr.matchesAppLinkCallback("https", "shard.example.com", "/callback"))
+        // Host match is case-insensitive.
+        assertTrue(mgr.matchesAppLinkCallback("https", "SHARD.EXAMPLE.COM", "/mobile/callback"))
+    }
+
+    @Test fun `matchesAppLinkCallback is false before a shard is paired`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()), base = null)
+        assertTrue(!mgr.matchesAppLinkCallback("https", "shard.example.com", "/mobile/callback"))
+    }
+
+    @Test fun `buildStartUrl requests the custom scheme when no app-link host is baked`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()))
+        // Generic build: appLinkHost defaults to BuildConfig.APP_LINK_HOST ("" in tests).
+        val redirect = mgr.buildStartUrl("google")!!.toHttpUrl().queryParameter("redirect_uri")
+        assertEquals(SsoAuthManager.REDIRECT_URI, redirect)
+    }
+
+    @Test fun `buildStartUrl requests the https app-link callback when the baked host matches the paired host`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()))
+        mgr.appLinkHost = "shard.example.com" // white-label build baked this shard's host
+        val redirect = mgr.buildStartUrl("google")!!.toHttpUrl().queryParameter("redirect_uri")
+        assertEquals("https://shard.example.com/mobile/callback", redirect)
+    }
+
+    @Test fun `buildStartUrl falls back to the custom scheme when the baked host does not match the paired shard`() {
+        val mgr = managerWith(FakeSsoApi { Response.success(tokenPair()) }, SessionManager(FakeTokenStore()))
+        mgr.appLinkHost = "other-shard.example.com" // built for a different shard than the paired one
+        val redirect = mgr.buildStartUrl("google")!!.toHttpUrl().queryParameter("redirect_uri")
+        assertEquals(SsoAuthManager.REDIRECT_URI, redirect)
+    }
+}

app/src/test/java/com/runicgateway/app/core/push/NtfyTopicTest.kt

@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Tests for the app's own ntfy topic + endpoint URL building (PLAN.md §11, work
+ * item 1) — the heart of the embedded-distributor design.
+ */
+class NtfyTopicTest {
+
+    @Test fun generatesUnguessableTopicsInTheAllowedCharset() {
+        val a = NtfyTopic.generate()
+        val b = NtfyTopic.generate()
+        assertNotEquals(a, b)
+        assertTrue("prefixed", a.startsWith("up"))
+        assertTrue("length", a.length >= 24)
+        assertTrue("charset", a.all { it.isLetterOrDigit() })
+    }
+
+    @Test fun buildsEndpointAndSseUrls() {
+        assertEquals("https://ntfy.tld/up7", NtfyTopic.endpointUrl("https://ntfy.tld", "up7"))
+        assertEquals("https://ntfy.tld/up7/sse", NtfyTopic.sseUrl("https://ntfy.tld", "up7"))
+    }
+
+    @Test fun toleratesTrailingSlashOnBase() {
+        assertEquals("https://ntfy.tld/up7", NtfyTopic.endpointUrl("https://ntfy.tld/", "up7"))
+    }
+
+    @Test fun nullOrBlankInputsYieldNull() {
+        assertNull(NtfyTopic.endpointUrl(null, "up7"))
+        assertNull(NtfyTopic.endpointUrl("", "up7"))
+        assertNull(NtfyTopic.endpointUrl("https://ntfy.tld", " "))
+        assertNull(NtfyTopic.sseUrl(null, "up7"))
+    }
+}

app/src/test/java/com/runicgateway/app/core/push/PushTickleTest.kt

@@ -0,0 +1,52 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.core.push
+
+import kotlinx.serialization.json.Json
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+/**
+ * Parsing tests for the content-free push tickle over ntfy's SSE envelope
+ * (PLAN.md §11). A `message` frame yields `{ stream, ref }`; lifecycle frames and
+ * malformed bodies are dropped (never thrown, §7).
+ */
+class PushTickleTest {
+
+    private val json = Json { ignoreUnknownKeys = true }
+
+    @Test fun parsesMessageFrame() {
+        // ntfy wraps our POSTed body in { event:"message", message:"<our json>" }.
+        val data = """{"id":"x","time":1,"event":"message","topic":"up1","message":"{\"stream\":\"vendor.sale\",\"ref\":\"0x40001\"}"}"""
+        val tickle = parseNtfyTickle(json, data)
+        assertEquals(PushTickle("vendor.sale", "0x40001"), tickle)
+    }
+
+    @Test fun parsesMessageWithoutRef() {
+        val data = """{"event":"message","message":"{\"stream\":\"server.status\"}"}"""
+        val tickle = parseNtfyTickle(json, data)
+        assertEquals("server.status", tickle?.stream)
+        assertNull(tickle?.ref)
+    }
+
+    @Test fun dropsOpenAndKeepaliveFrames() {
+        assertNull(parseNtfyTickle(json, """{"event":"open","topic":"up1"}"""))
+        assertNull(parseNtfyTickle(json, """{"event":"keepalive","topic":"up1"}"""))
+    }
+
+    @Test fun dropsMalformedOrEmpty() {
+        assertNull(parseNtfyTickle(json, ""))
+        assertNull(parseNtfyTickle(json, ": keepalive comment"))
+        assertNull(parseNtfyTickle(json, "not json"))
+        // A message whose inner body isn't our shape → no stream → dropped.
+        assertNull(parseNtfyTickle(json, """{"event":"message","message":"{}"}"""))
+        assertNull(parseNtfyTickle(json, """{"event":"message","message":"garbage"}"""))
+    }
+
+    @Test fun decodeTickleRejectsBlankStream() {
+        assertNull(decodeTickle(json, """{"stream":"","ref":"x"}"""))
+        assertEquals(PushTickle("news.post"), decodeTickle(json, """{"stream":"news.post"}"""))
+    }
+}

app/src/test/java/com/runicgateway/app/data/api/dto/NotificationsDtoTest.kt

@@ -0,0 +1,75 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api.dto
+
+import kotlinx.serialization.json.Json
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Decoding tests for the opt-in push DTOs (PLAN.md §11, M7 Part 2). Shapes come
+ * from the merged backend (`notifications.controller` / `pushDevices.model`);
+ * unknown keys are ignored (additive fields, §8).
+ */
+class NotificationsDtoTest {
+
+    private val json = Json {
+        ignoreUnknownKeys = true
+        explicitNulls = false
+        coerceInputValues = true
+    }
+
+    @Test fun pushDeviceDecodes() {
+        val dto = json.decodeFromString<PushDeviceDto>(
+            """{"id":9,"transport":"unifiedpush","endpoint":"https://ntfy.example.com/up123",
+               "platform":"android","createdAt":"2026-07-20T00:00:00Z","lastSeenAt":null}""",
+        )
+        assertEquals(9L, dto.id)
+        assertEquals("unifiedpush", dto.transport)
+        assertEquals("https://ntfy.example.com/up123", dto.endpoint)
+        assertEquals("android", dto.platform)
+        assertNull(dto.lastSeenAt)
+    }
+
+    @Test fun streamCatalogDecodesPersonalFlags() {
+        val dto = json.decodeFromString<NotificationStreamsDto>(
+            """{"streams":[
+                 {"id":"news.post","label":"News posts","description":"New posts.","personal":false,"requiresLinkedAccount":false},
+                 {"id":"vendor.sale","label":"Your vendor sold","description":"A sale.","personal":true,"requiresLinkedAccount":true}
+               ]}""",
+        )
+        assertEquals(2, dto.streams.size)
+        val news = dto.streams.first { it.id == "news.post" }
+        assertFalse(news.personal)
+        assertFalse(news.requiresLinkedAccount)
+        val vendor = dto.streams.first { it.id == "vendor.sale" }
+        assertTrue(vendor.personal)
+        assertTrue(vendor.requiresLinkedAccount)
+    }
+
+    @Test fun subscriptionsDecode() {
+        val dto = json.decodeFromString<NotificationSubscriptionsDto>(
+            """{"streams":["news.post","champ.start"]}""",
+        )
+        assertEquals(listOf("news.post", "champ.start"), dto.streams)
+    }
+
+    @Test fun settingsPushBlockDecodes() {
+        val dto = json.decodeFromString<SettingsDto>(
+            """{"site_title":"Shard","brand":{"name":"Shard"},"push":{"ntfyUrl":"https://ntfy.shard.tld"}}""",
+        )
+        assertEquals("https://ntfy.shard.tld", dto.push.ntfyUrl)
+    }
+
+    @Test fun settingsPushDefaultsNullOnOlderBackend() {
+        // A backend predating M7 omits `push` entirely — the app must still decode.
+        val dto = json.decodeFromString<SettingsDto>(
+            """{"site_title":"Shard","brand":{"name":"Shard"}}""",
+        )
+        assertNull(dto.push.ntfyUrl)
+    }
+}

app/src/test/java/com/runicgateway/app/ui/notifications/NotificationRoutingTest.kt

@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.notifications
+
+import com.runicgateway.app.core.push.PushStreams
+import com.runicgateway.app.data.api.dto.NotificationStreamDto
+import com.runicgateway.app.ui.navigation.Routes
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Tests the pure push helpers: the stream → deep-link route map (PLAN.md §11 work
+ * item 7) and the personal-stream gating (a personal stream needs a linked account).
+ */
+class NotificationRoutingTest {
+
+    @Test fun deepLinkRoutesMapEachStreamToItsScreen() {
+        assertEquals(Routes.NEWS, Routes.forStream(PushStreams.NEWS_POST))
+        assertEquals(Routes.SHARD, Routes.forStream(PushStreams.SERVER_STATUS))
+        assertEquals(Routes.SHARD, Routes.forStream(PushStreams.CHAMP_START))
+        assertEquals(Routes.SHARD, Routes.forStream(PushStreams.IDOC_WARNING))
+        assertEquals(Routes.SHARD, Routes.forStream(PushStreams.GOVERNOR_ELECTION))
+        assertEquals(Routes.PLAYER_VENDORS, Routes.forStream(PushStreams.VENDOR_SALE))
+        assertEquals(Routes.PLAYER_HOUSES, Routes.forStream(PushStreams.HOUSE_IDOC))
+        assertEquals(Routes.ACCOUNT, Routes.forStream(PushStreams.ACCOUNT_LOGIN))
+    }
+
+    @Test fun unknownStreamFallsBackToHome() {
+        assertEquals(Routes.HOME, Routes.forStream("something.new"))
+    }
+
+    @Test fun personalStreamNeedsLinkedAccount() {
+        val personal = NotificationStreamDto(id = "vendor.sale", personal = true, requiresLinkedAccount = true)
+        assertFalse(streamSelectable(personal, hasLinkedAccount = false))
+        assertTrue(streamSelectable(personal, hasLinkedAccount = true))
+    }
+
+    @Test fun generalStreamIsAlwaysSelectable() {
+        val general = NotificationStreamDto(id = "news.post", personal = false, requiresLinkedAccount = false)
+        assertTrue(streamSelectable(general, hasLinkedAccount = false))
+    }
+}