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

@@ -0,0 +1,94 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api
+
+import com.runicgateway.app.data.api.dto.RustEventListDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardDto
+import com.runicgateway.app.data.api.dto.RustOnlineDto
+import com.runicgateway.app.data.api.dto.RustServerListDto
+import com.runicgateway.app.data.api.dto.RustServerResponse
+import com.runicgateway.app.data.api.dto.RustWipeListDto
+import retrofit2.http.GET
+import retrofit2.http.Path
+import retrofit2.http.Query
+
+/**
+ * `module-rust`'s public read path (PLAN.md §9 M14; `docs/modules/rust/PLAN.md`
+ * §17).
+ *
+ * **These paths are hardcoded, and that is the contract rather than a shortcut.**
+ * `MODULE_API.md` §2.9 forbids a client inferring a route from a capability, so
+ * the app cannot build `/<module id>/servers` from what `GET /public/modules`
+ * reports. A capability answers one question — *is the module there* — and these
+ * five addresses are knowledge the app has because someone read the module's
+ * router, exactly as the nine `/uo/` paths in [NavPaths] are.
+ *
+ * Its own interface, not a section of [PublicApi], for the reason [EventsApi] is
+ * its own: these exist only where the Rust module is installed, and a backend
+ * running a different game answers none of them.
+ */
+interface RustApi {
+
+    /**
+     * Every Rust server this site follows.
+     *
+     * Answers from the module's own tables and never from a live call to a game
+     * host, so it succeeds while every server in the fleet is off — a server
+     * nobody can reach comes back `online: false, stale: true` with everything it
+     * last said still attached. There is no failure case here for the game being
+     * down, only for the website being down.
+     */
+    @GET("api/v1/public/rust/servers")
+    suspend fun getServers(): RustServerListDto
+
+    /**
+     * One server, or a **404**.
+     *
+     * The only route under `/servers/{id}` that can say a server is not there:
+     * the four below answer an empty list for an id nobody configured, because an
+     * unknown server genuinely has no events and nobody online. A server an
+     * operator **disabled** answers the same 404 — switching one off is not
+     * switching it into a refusal.
+     */
+    @GET("api/v1/public/rust/servers/{id}")
+    suspend fun getServer(@Path("id") id: String): RustServerResponse
+
+    /**
+     * The feed, newest first.
+     *
+     * [kind] is comma-separated and [wipe] a wipe id; both are optional, and an
+     * **absent one must be absent rather than empty** — `?wipe=` asks for a wipe
+     * whose id is the empty string and answers nothing, with no error to notice.
+     * Retrofit drops a null `@Query` entirely, which is why these are nullable
+     * and never defaulted to `""`.
+     *
+     * The server serves a default-deny allowlist: moderation events, login
+     * attempts and anything carrying an IP address are stored and never returned
+     * here, whatever is asked for.
+     */
+    @GET("api/v1/public/rust/servers/{id}/events")
+    suspend fun getEvents(
+        @Path("id") id: String,
+        @Query("kind") kind: String? = null,
+        @Query("wipe") wipe: String? = null,
+        @Query("limit") limit: Int? = null,
+    ): RustEventListDto
+
+    /** Per wipe when [wipe] is given, all-time otherwise — the same rows summed. */
+    @GET("api/v1/public/rust/servers/{id}/leaderboard")
+    suspend fun getLeaderboard(
+        @Path("id") id: String,
+        @Query("wipe") wipe: String? = null,
+        @Query("sort") sort: String? = null,
+        @Query("limit") limit: Int? = null,
+    ): RustLeaderboardDto
+
+    /** Every wipe this server has had, newest first. */
+    @GET("api/v1/public/rust/servers/{id}/wipes")
+    suspend fun getWipes(@Path("id") id: String): RustWipeListDto
+
+    /** The presence board, which an unreachable server does not clear. */
+    @GET("api/v1/public/rust/servers/{id}/online")
+    suspend fun getOnline(@Path("id") id: String): RustOnlineDto
+}

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

@@ -0,0 +1,196 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api.dto
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonNull
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+
+/**
+ * DTOs for `module-rust`'s public read path (`docs/modules/rust/PLAN.md` §17,
+ * §18; M14).
+ *
+ * **Every one of these renders while the game is off**, which is the module's own
+ * promise and therefore this leg's: the website never calls a game server from a
+ * page, it answers from its own tables, and a server nobody can reach answers
+ * `online: false` with everything it last said still attached. Nothing here has
+ * an "unavailable" shape, because there is no such answer on this wire.
+ */
+
+/** `GET /public/rust/servers` — every server this site follows. */
+@Serializable
+data class RustServerListDto(
+    val servers: List<RustServerDto> = emptyList(),
+)
+
+/** `GET /public/rust/servers/{id}` — one of them, or a 404. */
+@Serializable
+data class RustServerResponse(
+    val server: RustServerDto = RustServerDto(),
+)
+
+/**
+ * One Rust server and what it last reported.
+ *
+ * **[online] and [stale] are not the same fact and the screen needs both.**
+ * `online` is what the last frame said; `stale` is whether anything has arrived
+ * recently enough to believe it. The server computes `online` as *"the row says
+ * up AND the row is fresh"*, so a stale row can never claim a server is up — but
+ * `stale` still has to come through, because a fresh row saying "down" and a row
+ * nobody has written in an hour are different things to say to a reader.
+ *
+ * **[lastSeenAt] is what a page means by "last reported", and [updatedAt] is
+ * not.** The module shipped a defect on exactly this in phase 3 and fixed it in
+ * phase 4: `updatedAt` moves on every poll including a FAILED one, so reading it
+ * as "last reported" made an offline server claim it had just checked in, every
+ * thirty seconds, for as long as it stayed down. Only a frame moves
+ * `lastSeenAt`. The app must not repeat the mistake one tier along.
+ */
+@Serializable
+data class RustServerDto(
+    val id: String = "",
+    val name: String = "",
+    val online: Boolean = false,
+    val players: Int = 0,
+    val maxPlayers: Int = 0,
+    val hostname: String? = null,
+    val level: String? = null,
+    val worldSize: Int? = null,
+    val seed: Long? = null,
+    /** The CURRENT wipe, from the state row rather than the newest ingested wipe. */
+    val wipeId: String? = null,
+    val wipedAt: String? = null,
+    /** When a frame last arrived. What "last reported" means. */
+    val lastSeenAt: String? = null,
+    /** When this module last wrote the row — a failed poll moves it too. */
+    val updatedAt: String? = null,
+    val stale: Boolean = false,
+)
+
+/** `GET /public/rust/servers/{id}/events` — the killfeed and everything else public. */
+@Serializable
+data class RustEventListDto(
+    val events: List<RustEventDto> = emptyList(),
+)
+
+/**
+ * One stored frame.
+ *
+ * **[frame] is deliberately untyped.** The module stores the whole frame the
+ * bridge plugin emitted and indexes only the columns it serves, so the fields
+ * differ per [kind] and a later protocol adds more. A sealed hierarchy here would
+ * have to be extended in this repo before a server running a newer plugin could
+ * say anything new, and the module's own rule is the opposite: an unknown kind
+ * renders as itself rather than being dropped. [RustFeed] is the one place that
+ * knows the field names.
+ *
+ * [t] is epoch milliseconds — the stamp the plugin put on the frame, not a
+ * database column, so it is a number here and an ISO string everywhere else on
+ * this wire.
+ */
+@Serializable
+data class RustEventDto(
+    val id: Long = 0,
+    val kind: String = "",
+    val t: Long = 0,
+    val wipeId: String? = null,
+    val steamId: String? = null,
+    val frame: JsonObject = JsonObject(emptyMap()),
+) {
+    /**
+     * One frame field as text, or null.
+     *
+     * **A JSON `null` answers null, not the four letters.** The plugin writes
+     * explicit nulls — `reason` on a clean disconnect, `weapon` on a fall — and a
+     * primitive's `content` is the string `"null"` for every one of them, which
+     * would put the word into a killfeed line. An empty string answers null too:
+     * the callers here all mean "is there something to show".
+     */
+    fun str(key: String): String? = primitive(key)?.content?.takeIf { it.isNotEmpty() }
+
+    /** One frame field as a number, or null when it is absent, null or not one. */
+    fun num(key: String): Double? = primitive(key)?.content?.toDoubleOrNull()
+
+    /** One frame field as a flag. Absent, null and anything non-boolean are all false. */
+    fun flag(key: String): Boolean = primitive(key)?.content == "true"
+
+    /** The raw element, for a caller that wants to decide for itself. */
+    fun raw(key: String): JsonElement? = frame[key]
+
+    private fun primitive(key: String): JsonPrimitive? =
+        (frame[key] as? JsonPrimitive)?.takeIf { it !is JsonNull }
+}
+
+/** `GET /public/rust/servers/{id}/leaderboard` — per wipe, or all-time. */
+@Serializable
+data class RustLeaderboardDto(
+    val leaderboard: List<RustLeaderboardRowDto> = emptyList(),
+)
+
+/**
+ * One player's standing.
+ *
+ * All-time is these same per-wipe rows summed rather than a second set of
+ * counters, so the two can never disagree — which is why a player who appears
+ * only in an older wipe **drops out** of the current one rather than reading
+ * zero. The screen must not fill that gap in with zeroes.
+ */
+@Serializable
+data class RustLeaderboardRowDto(
+    val steamId: String = "",
+    val name: String? = null,
+    val kills: Int = 0,
+    val deaths: Int = 0,
+    val npcKills: Int = 0,
+    val structures: Int = 0,
+    val playtimeSec: Long = 0,
+    val lastSeen: String? = null,
+)
+
+/** `GET /public/rust/servers/{id}/wipes` — every wipe this server has had, newest first. */
+@Serializable
+data class RustWipeListDto(
+    val wipes: List<RustWipeDto> = emptyList(),
+)
+
+/**
+ * One wipe.
+ *
+ * [wipeId] is derived by the bridge plugin from the save's creation time and
+ * stamped on every frame, so it is the same id the feed and the leaderboard are
+ * filtered by — which is what makes the per-wipe view navigable at all.
+ */
+@Serializable
+data class RustWipeDto(
+    val wipeId: String = "",
+    val saveCreatedAt: String? = null,
+    val firstSeen: String? = null,
+    val lastSeen: String? = null,
+)
+
+/** `GET /public/rust/servers/{id}/online` — who is on right now. */
+@Serializable
+data class RustOnlineDto(
+    val players: List<RustPresenceDto> = emptyList(),
+)
+
+/**
+ * One row of the presence board.
+ *
+ * Read from the board the bridge re-sends on every connect and every minute,
+ * rather than counted from connect and disconnect events — so it is right even
+ * after the website has missed one. **An unreachable server does not clear it**,
+ * deliberately: these rows are still the best answer anybody has. Presented bare
+ * they read as *who is on right now*, which is the one thing an offline server
+ * cannot be saying, so the screen has to say which it is.
+ */
+@Serializable
+data class RustPresenceDto(
+    val steamId: String = "",
+    val name: String? = null,
+    val sleeping: Boolean = false,
+    val connectedAt: String? = null,
+)

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

@@ -0,0 +1,84 @@
+/*
+ * 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.map
+import com.runicgateway.app.core.result.safeApiCall
+import com.runicgateway.app.data.api.RustApi
+import com.runicgateway.app.data.api.dto.RustEventDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardRowDto
+import com.runicgateway.app.data.api.dto.RustPresenceDto
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustWipeDto
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * The Rust module's public read path (PLAN.md §9 M14).
+ *
+ * Every read unwraps its envelope here rather than in a view model, so no screen
+ * holds a `…Dto` whose only job was to carry one list. Nothing is cached and
+ * nothing is merged: the module's tables are already the cache — the site's whole
+ * premise is that it answers from what a server last said rather than from the
+ * server — so a second copy in the app would only add a way for the two to
+ * disagree.
+ */
+@Singleton
+class RustRepository @Inject constructor(
+    private val api: RustApi,
+) {
+    /** Every server this site follows, with what each last reported. */
+    suspend fun servers(): ApiResult<List<RustServerDto>> =
+        safeApiCall { api.getServers() }.map { it.servers }
+
+    /** One server. A 404 here means no such server, or one an operator disabled. */
+    suspend fun server(id: String): ApiResult<RustServerDto> =
+        safeApiCall { api.getServer(id) }.map { it.server }
+
+    /**
+     * The feed.
+     *
+     * [kinds] is joined here rather than by a caller, so the query string this
+     * app sends exists in one place — and an **empty** list is sent as no `kind`
+     * parameter at all, which asks for the whole allowlist. Sending `kind=` would
+     * ask for a kind named the empty string.
+     */
+    suspend fun events(
+        id: String,
+        kinds: List<String> = emptyList(),
+        wipe: String? = null,
+        limit: Int? = null,
+    ): ApiResult<List<RustEventDto>> = safeApiCall {
+        api.getEvents(
+            id = id,
+            kind = kinds.takeIf { it.isNotEmpty() }?.joinToString(","),
+            wipe = wipe?.takeIf { it.isNotBlank() },
+            limit = limit,
+        )
+    }.map { it.events }
+
+    /** The leaderboard: per wipe when [wipe] is given, all-time otherwise. */
+    suspend fun leaderboard(
+        id: String,
+        wipe: String? = null,
+        sort: String? = null,
+        limit: Int? = null,
+    ): ApiResult<List<RustLeaderboardRowDto>> = safeApiCall {
+        api.getLeaderboard(
+            id = id,
+            wipe = wipe?.takeIf { it.isNotBlank() },
+            sort = sort?.takeIf { it.isNotBlank() },
+            limit = limit,
+        )
+    }.map { it.leaderboard }
+
+    /** Every wipe this server has had, newest first. */
+    suspend fun wipes(id: String): ApiResult<List<RustWipeDto>> =
+        safeApiCall { api.getWipes(id) }.map { it.wipes }
+
+    /** The presence board. Rows survive an unreachable server, by design. */
+    suspend fun online(id: String): ApiResult<List<RustPresenceDto>> =
+        safeApiCall { api.getOnline(id) }.map { it.players }
+}

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

@@ -159,6 +159,24 @@ object Capability {
      */
     const val SHARD = "shard"
 
+    /**
+     * The Rust module (`docs/modules/rust/PLAN.md` D16, phase 5).
+     *
+     * A second game module, and therefore a second string rather than a second
+     * meaning for [SHARD]: a Rust site is a **fleet of servers** with a list
+     * above them, where a shard is one place — the surfaces are not the same
+     * shape and a client cannot render one as the other.
+     *
+     * `module-rust` also declares `servers`, `killfeed`, `leaderboard`,
+     * `presence` and `wipes`, and this gates on none of them. Every one of those
+     * names a SURFACE, and core flattens all modules' capabilities into one list
+     * — so `servers` is a word another module could declare tomorrow, which would
+     * silently reveal these rows on a site that does not run Rust. `rust` is the
+     * string only that module can mean, which is the same job [SHARD] does for
+     * `module-uo`.
+     */
+    const val RUST = "rust"
+
     /** Core's event system (events Phase 14a). Never a module's. */
     const val EVENTS = "events"
 }

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

@@ -21,6 +21,7 @@ import com.runicgateway.app.data.api.AdminApi
 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.RustApi
 import com.runicgateway.app.data.api.SsoApi
 import dagger.Module
 import dagger.Provides
@@ -132,6 +133,19 @@ object NetworkModule {
     @Singleton
     fun provideEventsApi(retrofit: Retrofit): EventsApi = retrofit.create(EventsApi::class.java)
 
+    /**
+     * `module-rust`'s public read path (§9 M14).
+     *
+     * A MODULE's routes, unlike [provideEventsApi] beside it — they exist only on
+     * a backend where an operator installed the Rust module, and the drawer rows
+     * that lead to them are gated on its `rust` capability. Provided
+     * unconditionally all the same: a Retrofit interface costs nothing until
+     * something calls it, and there is nowhere at injection time to ask.
+     */
+    @Provides
+    @Singleton
+    fun provideRustApi(retrofit: Retrofit): RustApi = retrofit.create(RustApi::class.java)
+
     /** Opt-in push devices + subscriptions (§11, M7) — bearer-authed on the main client. */
     @Provides
     @Singleton

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

@@ -0,0 +1,110 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.rememberUpdatedState
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.lifecycle.repeatOnLifecycle
+import com.runicgateway.app.core.result.ApiResult
+import kotlinx.coroutines.delay
+
+/**
+ * Repeated reads of a surface that changes while somebody is looking at it
+ * (`docs/modules/rust/PLAN.md` D14, and D17 for this leg).
+ *
+ * ## Why a refresh is not a load
+ *
+ * The app has had exactly one shape for a read until now: set [UiState.Loading],
+ * ask, replace. That is right for opening a screen and wrong for a poll — a
+ * twenty-second refresh built on it would clear the killfeed, put a spinner where
+ * it was and re-fill it, three times a minute, for ever. The website hit the same
+ * wall one tier along: core's `useAsync` blanks its data on every dependency
+ * change, so `module-rust` bundles its own `usePolled`. This is that hook's other
+ * half.
+ *
+ * The rule both ends keep: **a refresh is invisible when it succeeds, and keeps
+ * the rows when it fails.** A site whose whole premise is "it renders while the
+ * game is off" must not blank itself the first time a request does.
+ */
+
+/** How often a live surface re-reads itself while somebody is looking at it (D17). */
+const val POLL_INTERVAL_MS = 20_000L
+
+/**
+ * What a poll produced: the state to render, and whether the last attempt failed.
+ *
+ * Two fields rather than a wider [UiState] because they are two facts and a
+ * screen renders them in different places — the rows in the list, the failure as
+ * a quiet line above it. Collapsing them would force the choice this exists to
+ * avoid: show the error and lose the rows, or keep the rows and say nothing.
+ */
+data class Polled<out T>(
+    val state: UiState<T> = UiState.Loading,
+    /** True when the most recent refresh failed **and there were rows to keep**. */
+    val refreshFailed: Boolean = false,
+)
+
+/**
+ * Fold a refresh into what is already on screen.
+ *
+ * Three cases, and the middle one is the whole point:
+ *
+ *  - **It answered.** The new data replaces the old and any previous failure
+ *    clears. This is the ordinary path and it is silent.
+ *  - **It failed, and there are rows.** The rows stay exactly as they are and the
+ *    failure is reported beside them. Nothing is blanked and nothing is retried
+ *    on the reader's behalf — the next tick is twenty seconds away.
+ *  - **It failed, and there is nothing yet.** There is nothing to protect, so it
+ *    becomes an ordinary error with a retry — which is what the first load
+ *    failing means.
+ *
+ * Pure, and takes the current state rather than reading one, so the rule is
+ * tested without a dispatcher, a view model or Compose.
+ */
+fun <T> refreshInto(current: UiState<T>, result: ApiResult<T>): Polled<T> = when {
+    result is ApiResult.Ok -> Polled(UiState.Success(result.data), refreshFailed = false)
+    current is UiState.Success -> Polled(current, refreshFailed = true)
+    else -> Polled(result.toUiState(), refreshFailed = false)
+}
+
+/**
+ * Run [block] now and every [intervalMs] for as long as this screen is resumed.
+ *
+ * `repeatOnLifecycle` is what makes this the phone's version of D14's Page
+ * Visibility gate, and it gets three behaviours from one line:
+ *
+ *  - **Nothing runs while the app is away.** The coroutine is cancelled at
+ *    `onPause`, so a backgrounded app makes no requests at all — not a slower
+ *    poll, none.
+ *  - **Coming back refreshes immediately.** The block is restarted from the top
+ *    at `onResume`, which calls [block] before the first [delay] — so the first
+ *    thing a returning reader sees is current, not up to twenty seconds old.
+ *  - **A dialog or the recents switcher pauses it**, because that is what RESUMED
+ *    means. The alternative, STARTED, keeps polling behind a partially
+ *    obscured screen, which is precisely the reader who is not reading.
+ *
+ * **Keyed on the lifecycle owner alone, and [block] is held through
+ * `rememberUpdatedState`.** Keying on the block would restart the loop on every
+ * recomposition, because a lambda is a new object each time; capturing it without
+ * `rememberUpdatedState` would freeze the *first* one, so a tab change or a
+ * newly chosen wipe would keep refreshing the question the reader has stopped
+ * asking. The loop is stable and what it calls is current.
+ */
+@Composable
+fun PollWhileResumed(intervalMs: Long = POLL_INTERVAL_MS, block: suspend () -> Unit) {
+    val lifecycleOwner = LocalLifecycleOwner.current
+    val current by rememberUpdatedState(block)
+    LaunchedEffect(lifecycleOwner) {
+        lifecycleOwner.lifecycle.repeatOnLifecycle(Lifecycle.State.RESUMED) {
+            while (true) {
+                current()
+                delay(intervalMs)
+            }
+        }
+    }
+}

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

@@ -57,6 +57,7 @@ import com.runicgateway.app.core.auth.Session
 import com.runicgateway.app.core.web.WebHandoff
 import com.runicgateway.app.data.api.dto.BrandDto
 import com.runicgateway.app.data.appearance.SiteAppearance
+import com.runicgateway.app.data.repository.Capability
 import com.runicgateway.app.ui.auth.AccountScreen
 import com.runicgateway.app.ui.auth.LoginScreen
 import com.runicgateway.app.ui.auth.RecoveryCodesScreen
@@ -101,6 +102,9 @@ import com.runicgateway.app.ui.shard.MarketScreen
 import com.runicgateway.app.ui.shard.MarketVendorScreen
 import com.runicgateway.app.ui.shard.RulesScreen
 import com.runicgateway.app.ui.shard.ShardBoard
+import com.runicgateway.app.ui.rust.RustBadgeViewModel
+import com.runicgateway.app.ui.rust.RustServerScreen
+import com.runicgateway.app.ui.rust.RustServersScreen
 import com.runicgateway.app.ui.shard.ShardScreen
 import com.runicgateway.app.ui.theme.LocalShardStructure
 import com.runicgateway.app.ui.wiki.WikiPageScreen
@@ -118,6 +122,9 @@ private val TOP_LEVEL_ROUTES = setOf(
     // gesture works on them. The event page and an arc are detail screens and are
     // deliberately absent — a back gesture there means "back", not "open the menu".
     Routes.EVENTS, Routes.MY_EVENTS,
+    // The Rust server list is a drawer row (M14); one server's page is a detail
+    // screen and is deliberately absent — a back gesture there means "back".
+    Routes.RUST,
     Routes.PLAYER_CHARACTERS, Routes.PLAYER_VENDORS, Routes.PLAYER_HOUSES,
     Routes.ADMIN_DASHBOARD, Routes.ADMIN_CONTENT, Routes.ADMIN_MODERATION, Routes.ADMIN_SUPPORT,
 )
@@ -140,6 +147,7 @@ fun RunicApp(
     onDeepLinkConsumed: () -> Unit = {},
     sessionViewModel: SessionViewModel = hiltViewModel(),
     inboxBadgeViewModel: InboxBadgeViewModel = hiltViewModel(),
+    rustBadgeViewModel: RustBadgeViewModel = hiltViewModel(),
 ) {
     val brand = appearance.brand
     val navController = rememberNavController()
@@ -163,6 +171,17 @@ fun RunicApp(
     }
 
     val unread by inboxBadgeViewModel.unread.collectAsStateWithLifecycle()
+    // How many people are on the Rust fleet, for the drawer row's badge — the
+    // phone's answer to D15's footer count (M14). Refreshed with the capability
+    // answer rather than on a timer: a badge is a glance, not a feed, and this is
+    // the only place that knows whether the module is installed at all. A host
+    // that has not answered yet asks nothing, so a cold start makes no request
+    // until it knows there is something to ask about.
+    val rustOnline by rustBadgeViewModel.online.collectAsStateWithLifecycle()
+    LaunchedEffect(capabilities) {
+        val caps = capabilities
+        if (caps != null) rustBadgeViewModel.refresh(Capability.RUST in caps)
+    }
     // The badge follows the session, so signing out clears it rather than leaving
     // the previous account's count on the drawer.
     LaunchedEffect(session) { inboxBadgeViewModel.refresh() }
@@ -267,10 +286,17 @@ fun RunicApp(
                                 colors = drawerItemColors,
                                 indented = true,
                                 unread = unread,
+                                rustOnline = rustOnline,
                             ) { openNode(child) }
                         }
                     } else {
-                        NavRow(node, currentRoute, drawerItemColors, unread = unread) { openNode(node) }
+                        NavRow(
+                            node = node,
+                            currentRoute = currentRoute,
+                            colors = drawerItemColors,
+                            unread = unread,
+                            rustOnline = rustOnline,
+                        ) { openNode(node) }
                     }
                 }
 
@@ -386,6 +412,7 @@ private fun NavRow(
     colors: NavigationDrawerItemColors,
     indented: Boolean = false,
     unread: Int = 0,
+    rustOnline: Int = 0,
     onClick: () -> Unit,
 ) {
     val route = when (node) {
@@ -405,6 +432,15 @@ private fun NavRow(
     // admin's own nav override pointing at it, since the badge belongs to the
     // destination, not to the bundled entry.
     val showsUnread = !handsOff && unread > 0 && route == Routes.NOTIFICATIONS
+    // The live player count rides on whichever row leads to the Rust list, for the
+    // same reason the unread count rides on whichever leads to the inbox — the
+    // number belongs to the destination, not to the bundled entry, so an admin's
+    // own nav override pointing there carries it too.
+    //
+    // **Zero renders nothing**, rather than a `0`: an empty fleet is not a
+    // notification, and a badge that read `0` on a site whose servers are simply
+    // quiet would be worse than no badge at all.
+    val showsRustOnline = !handsOff && rustOnline > 0 && route == Routes.RUST
 
     NavigationDrawerItem(
         label = { Text(label) },
@@ -432,6 +468,19 @@ private fun NavRow(
                     )
                 }
             }
+            showsRustOnline -> {
+                {
+                    // Named for a screen reader: "42" beside "Rust servers" reads
+                    // as a count to a sighted user and as a bare number to
+                    // everyone else.
+                    val spoken = stringResource(R.string.rust_online_badge, rustOnline)
+                    Text(
+                        text = rustOnline.toString(),
+                        style = MaterialTheme.typography.labelLarge,
+                        modifier = Modifier.semantics { contentDescription = spoken },
+                    )
+                }
+            }
             else -> null
         },
         colors = colors,
@@ -573,6 +622,17 @@ private fun RunicNavHost(
         ) { entry ->
             AtlasCreatureScreen(slug = entry.arguments?.getString(Routes.Args.SLUG).orEmpty())
         }
+        // The Rust module's two screens (M14). Not under `shard/`: a different game,
+        // a different shape — a fleet with a list above it rather than one place.
+        composable(Routes.RUST) {
+            RustServersScreen(onOpenServer = { id -> navController.navigate(Routes.rustServer(id)) })
+        }
+        composable(
+            route = Routes.RUST_SERVER,
+            arguments = listOf(navArgument(Routes.Args.SERVER_ID) { type = NavType.StringType }),
+        ) {
+            RustServerScreen(onBack = { navController.navigateTopLevel(Routes.RUST) })
+        }
         composable(Routes.WIKI) {
             WikiScreen(onOpenPage = { slug -> navController.navigate(Routes.wikiPage(slug)) })
         }

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

@@ -128,6 +128,17 @@ val APP_MENU: List<MenuEntry> = listOf(
         feature = ShardFeature.MARKET,
         capability = Capability.SHARD,
     ),
+    // The Rust module (M14). ONE row, because the module's whole public surface is
+    // one list and one page beneath it — `/rust` IS the server list, not a hub
+    // above one.
+    //
+    // **No `feature`, and that is not an omission.** The visibility framework is
+    // `module-uo`'s own (`shardVisibility`, six files under `module-uo/server/`
+    // and none under core's), and §2.7 forbids a module importing another's — so
+    // `module-rust` has no per-viewer visibility layer yet. Its phase 14 builds
+    // one; until then these routes are public to everyone the site is public to,
+    // and a `feature` here would be gating on a flag nothing publishes.
+    MenuEntry(Routes.RUST, R.string.menu_rust, capability = Capability.RUST),
     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),

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

@@ -70,6 +70,15 @@ import com.runicgateway.app.data.repository.ContentRepository.PostCategory
  * })
  * ```
  *
+ * and from `module-rust/client/src/entry.jsx`, which registers one (M14):
+ *
+ * ```jsx
+ * registry.registerNav(ID, {
+ *   area: 'public',
+ *   items: [{ label: 'Servers', to: '/rust' }],
+ * })
+ * ```
+ *
  * None of those nine declares an `order`, so `mergeFlat` appends them after core's
  * rows in registration order — which is the order they are listed in below.
  *
@@ -119,6 +128,16 @@ val WEBSITE_PUBLIC_NAV: List<WebNavPath> = listOf(
     WebNavPath("/uo/atlas", Routes.ATLAS),
     WebNavPath("/uo/leaderboards", Routes.SHARD_LEADERBOARDS),
     WebNavPath("/uo/market", Routes.SHARD_MARKET),
+    // module-rust's one row (M14). It registers `{ label: 'Servers', to: '/rust' }`
+    // and nothing else — `/rust` IS the server list, because core strips the
+    // trailing separator from a module route registered with `path: ''`.
+    //
+    // **Both modules can be installed on one backend**, and then the nav is core's
+    // eight plus ten. This table is a superset by design: a path here for a module
+    // an operator has NOT installed never appears in that backend's nav and so is
+    // never looked up, while a path missing from it makes a link that exists hand
+    // off to a browser.
+    WebNavPath("/rust", Routes.RUST),
 )
 
 /**
@@ -178,7 +197,12 @@ private val RESERVED_TOP_LEVEL = setOf(
     // Only ids the app knows about need listing: an unknown module's `/<id>` would
     // resolve to a CMS page that 404s, which is the same answer the browser gives
     // it, and core cannot enumerate them for us here anyway.
-    "uo",
+    //
+    // `rust` is here for the opposite reason to the rest: `/rust` DOES resolve, to
+    // the server list, and it does so through the nav table above — this set only
+    // stops the CMS-page fallback claiming it. Without the entry a site with the
+    // module absent would open a page-not-found screen instead of the browser.
+    "uo", "rust",
 )
 
 /**
@@ -209,6 +233,7 @@ private val RESERVED_TOP_LEVEL = setOf(
  * //   /uo/shard, /uo/shard/activity, /uo/champs, /uo/guilds, /uo/guilds/:id,
  * //   /uo/governors, /uo/houses, /uo/rules, /uo/leaderboards, /uo/market,
  * //   /uo/market/vendors/:serial, /uo/atlas, /uo/atlas/:slug
+ * //   /rust, /rust/servers/:id
  * // CMS pages: top-level /:slug, matched only after the named routes above
  * <Route path="/:slug" element={<CmsPage />} />
  * ```
@@ -231,6 +256,8 @@ private val RESERVED_TOP_LEVEL = setOf(
  * /uo/<shard surface>             → the mapped shard route (§6.2)
  * /uo/atlas/<slug>                → ATLAS_CREATURE
  * /uo/market/vendors/<serial>     → SHARD_MARKET_VENDOR
+ * /rust                           → RUST         (module-rust's server list)
+ * /rust/servers/<id>              → RUST_SERVER
  * /site/about                     → PAGE("about")
  * /<slug>                         → PAGE(slug), unless <slug> is reserved
  * anything else                   → null, i.e. the Custom Tab
@@ -295,6 +322,10 @@ fun resolveWebPath(path: String?): String? {
             Routes.atlasCreature(segments[2])
         segments[0] == MODULE_UO && segments.size == 4 && segments[1] == "market" &&
             segments[2] == "vendors" -> Routes.marketVendor(segments[3])
+        // module-rust's one page below the list. `/rust` itself is already
+        // answered by the nav table above, before this fallback is reached.
+        segments[0] == MODULE_RUST && segments.size == 3 && segments[1] == "servers" ->
+            Routes.rustServer(segments[2])
         else -> null
     }
 }
@@ -322,3 +353,6 @@ private fun runParam(query: String): String? {
  * module is countable. It is a literal on purpose — see the file header.
  */
 private const val MODULE_UO = "uo"
+
+/** The second game module's id (M14). A literal for the same reason. */
+private const val MODULE_RUST = "rust"

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

@@ -70,6 +70,22 @@ object Routes {
     const val EVENT_SERIES = "events/series/{slug}"
     const val MY_EVENTS = "account/events"
 
+    /**
+     * The Rust module's surface (§9 M14, `docs/modules/rust/PLAN.md` D12, D13).
+     *
+     * **[RUST] is the server list, not a hub above one.** The module registers its
+     * pages with `path: ''` and core strips the trailing separator, so `/rust` on
+     * the website *is* the list — there is no landing page between the drawer row
+     * and the servers, and adding one here would invent a screen the website does
+     * not have.
+     *
+     * **A different game, so a different route tree.** These are deliberately not
+     * folded into [SHARD]: one shard is a place, and a Rust site is a fleet. The
+     * two can be installed on the same backend, and then both trees exist at once.
+     */
+    const val RUST = "rust"
+    const val RUST_SERVER = "rust/servers/{serverId}"
+
     /** Public shard hub (§6.2). */
     const val SHARD = "shard"
 
@@ -121,6 +137,7 @@ object Routes {
         const val ID_OR_SLUG = "idOrSlug"
         const val SERIAL = "serial"
         const val RUN = "run"
+        const val SERVER_ID = "serverId"
     }
 
     fun page(slug: String) = "page/$slug"
@@ -140,6 +157,42 @@ object Routes {
     /** One player vendor's shop, by in-game (hex) serial. */
     fun marketVendor(serial: String) = "shard/market/$serial"
 
+    /**
+     * One Rust server's page.
+     *
+     * The id is a slug an operator chose, so it is encoded: nothing stops one
+     * carrying a character a path would otherwise eat, and a server nobody can
+     * open is a worse failure than a name nobody can read.
+     *
+     * **Encoded here rather than with `android.net.Uri`**, which is a stub in a
+     * JVM unit test and throws "not mocked" — this object is pure and every test
+     * that builds a route would have to become an instrumented one to keep it
+     * that way.
+     */
+    fun rustServer(id: String) = "rust/servers/${encodePathSegment(id)}"
+
+    /**
+     * Percent-encode one path segment, allowing only the unreserved set.
+     *
+     * Deliberately stricter than it needs to be: encoding a character that did
+     * not need it still round-trips, where missing one that did produces a route
+     * NavHost matches differently from the one that was built. UTF-8 first, so a
+     * non-ASCII name is encoded per byte rather than per character.
+     */
+    private fun encodePathSegment(value: String): String = buildString {
+        for (byte in value.toByteArray(Charsets.UTF_8)) {
+            val code = byte.toInt() and 0xFF
+            val char = code.toChar()
+            if (code < 128 && (char.isLetterOrDigit() || char in UNRESERVED)) {
+                append(char)
+            } else {
+                append('%').append(code.toString(16).uppercase().padStart(2, '0'))
+            }
+        }
+    }
+
+    private const val UNRESERVED = "-._~"
+
     /** One creature's atlas page, by slug. */
     fun atlasCreature(slug: String) = "atlas/$slug"
 

app/src/main/java/com/runicgateway/app/ui/rust/RustBadgeViewModel.kt

@@ -0,0 +1,88 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.runicgateway.app.core.result.ApiResult
+import com.runicgateway.app.data.repository.RustRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * The live player count on the drawer's Rust row — the phone's answer to D15
+ * (`docs/modules/rust/PLAN.md` §17.4).
+ *
+ * ## Why the drawer and not a footer
+ *
+ * D15 put "2 servers · 42 online" in core's `site.footer.status` slot, which
+ * exists because every page of the website renders the same footer. The app has
+ * no footer and no slot; what it has is a drawer row per surface and, already, a
+ * precedent for a number beside one — the inbox's unread badge, in the same
+ * `NavigationDrawerItem` badge slot, with the same screen-reader treatment. So
+ * the count rides there.
+ *
+ * **The number is players, not servers.** A badge is one integer, and of the two
+ * halves of D15's line the live one is how many people are on: a server count
+ * changes when an operator edits configuration, which is not news, and is visible
+ * on the page the row opens anyway.
+ *
+ * ## What keeps it honest
+ *
+ * The website's version renders nothing until it has an answer, nothing at all if
+ * the request fails, and never polls — because one request per page view is a
+ * cost and a timer in a footer on every page is a different kind of thing. All
+ * three rules hold here:
+ *
+ *  - **Zero renders nothing.** No badge, rather than a `0` — an empty server is
+ *    not a notification.
+ *  - **A failure leaves the last count** rather than dropping to zero. A moment
+ *    with no connectivity is not everybody logging off.
+ *  - **It refreshes on resume, with the unread badge**, and never on a timer. The
+ *    count is a glance, not a feed.
+ *
+ * It is asked for **only when the module is installed** — the caller gates on the
+ * `rust` capability — so a site running a different game makes no request at all.
+ */
+@HiltViewModel
+class RustBadgeViewModel @Inject constructor(
+    private val repository: RustRepository,
+) : ViewModel() {
+
+    private val _online = MutableStateFlow(0)
+
+    /** How many people are on across every server, or 0 when there is nothing to say. */
+    val online: StateFlow<Int> = _online.asStateFlow()
+
+    /**
+     * Ask, if the Rust module is there.
+     *
+     * [installed] is passed in rather than read here so this holds no opinion
+     * about capabilities: the drawer already knows, and a view model that
+     * re-derived it would be a second copy of a rule that lives in one place.
+     * Absent — the host has not answered yet — makes no request and keeps
+     * whatever is showing.
+     */
+    fun refresh(installed: Boolean) {
+        if (!installed) {
+            _online.value = 0
+            return
+        }
+
+        viewModelScope.launch {
+            when (val result = repository.servers()) {
+                // A server that is stale or unreachable already answers `online:
+                // false` with `players: 0`, so summing the whole list needs no
+                // second staleness rule here.
+                is ApiResult.Ok -> _online.value = result.data.sumOf { it.players }
+                // Keep the last number. See the class doc.
+                else -> Unit
+            }
+        }
+    }
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustFeed.kt

@@ -0,0 +1,199 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import com.runicgateway.app.data.api.dto.RustEventDto
+
+/**
+ * One stored frame as one line of a feed — the Kotlin half of `module-rust`'s
+ * `client/src/lib/feed.js` (PLAN.md §9 M14).
+ *
+ * `GET /public/rust/servers/{id}/events` answers rows shaped
+ * `{ id, kind, t, wipeId, steamId, frame }`, where `frame` is the whole frame the
+ * bridge plugin emitted. Everything a killfeed line needs is in there, under the
+ * names the plugin wrote, and **this file is the one place in the app that knows
+ * them**.
+ *
+ * ## It returns parts, not a sentence
+ *
+ * A row wants the names emphasised and the detail muted, and a function returning
+ * `"Alice killed Bob"` would force the screen to re-parse its own output to style
+ * it. Parts also make this testable without Compose, which is the only way this
+ * leg has real coverage of what a feed row says.
+ *
+ * ## The rule for an unknown kind
+ *
+ * **It renders as itself.** A later protocol adds kinds and an operator's module
+ * may be older than their game host, so a feed that dropped what it did not
+ * recognise would be a screen quietly saying less than the truth. The server's
+ * allowlist has already decided the row may be seen; what is left here is
+ * presentation, and the honest presentation of a kind we have no words for is its
+ * own name.
+ */
+
+/** The row's category, for the small colour a screen gives it — never for meaning. */
+enum class FeedTone { KILL, DEATH, JOIN, LEAVE, CHAT, SERVER, OTHER }
+
+/**
+ * One row, ready to render.
+ *
+ * [actor] and [subject] are names and are emphasised; [verb] and [detail] are
+ * prose. Any of them may be null or empty.
+ *
+ * [join] is what goes between the actor and the verb, and it exists for exactly
+ * one case: chat. "Brannock see you in september" is not a sentence anybody
+ * writes, and putting the colon in the message would put presentation inside text
+ * a player typed.
+ */
+data class FeedLine(
+    val tone: FeedTone,
+    val actor: String? = null,
+    val join: String = " ",
+    val verb: String = "",
+    val subject: String? = null,
+    val detail: String = "",
+)
+
+/** One filter the feed offers, and the kinds it asks the API for. */
+data class FeedFilter(val id: String, val label: String, val kinds: List<String>)
+
+/**
+ * Kinds this feed asks for.
+ *
+ * `player.tally` is public and deliberately **not** here: it is an aggregate the
+ * plugin flushes every sixty seconds per active player, so a feed including it
+ * would be mostly wood counts. It is the leaderboard's input, and the leaderboard
+ * is where it shows up.
+ */
+val FEED_KINDS: List<String> = listOf(
+    "player.death",
+    "player.connected",
+    "player.disconnected",
+    "player.respawned",
+    "player.chat",
+    "server.wipe",
+    "server.initialized",
+    "server.shutdown",
+)
+
+/** The filters the feed offers. The first is the default and asks for everything. */
+val FEED_FILTERS: List<FeedFilter> = listOf(
+    FeedFilter("all", "Everything", FEED_KINDS),
+    FeedFilter("kills", "Kills", listOf("player.death")),
+    FeedFilter("chat", "Chat", listOf("player.chat")),
+    FeedFilter(
+        "sessions",
+        "Comings and goings",
+        listOf("player.connected", "player.disconnected", "player.respawned"),
+    ),
+    FeedFilter("server", "Server", listOf("server.wipe", "server.initialized", "server.shutdown")),
+)
+
+/** The kinds a filter id asks for; an id nobody offers falls back to everything. */
+fun kindsFor(filterId: String): List<String> =
+    (FEED_FILTERS.firstOrNull { it.id == filterId } ?: FEED_FILTERS.first()).kinds
+
+/** One row as the parts a screen renders. */
+fun describe(row: RustEventDto): FeedLine {
+    val name = row.str("name")
+
+    return when (row.kind) {
+        "player.death" -> death(row, name)
+
+        "player.connected" ->
+            FeedLine(FeedTone.JOIN, actor = name, verb = "connected")
+
+        "player.disconnected" -> FeedLine(
+            tone = FeedTone.LEAVE,
+            actor = name,
+            verb = "disconnected",
+            // Two optional halves, and the session is the interesting one. The
+            // plugin OMITS `sessionSec` for a player who was already on when it
+            // loaded, so an absent value means "unknown" and never zero — which is
+            // why this reads the parsed number rather than trusting a default.
+            detail = listOfNotNull(
+                row.str("reason"),
+                row.num("sessionSec")?.takeIf { it > 0 }?.let { "after ${playtime(it.toLong())}" },
+            ).joinToString(" · "),
+        )
+
+        "player.respawned" ->
+            FeedLine(FeedTone.JOIN, actor = name, verb = "respawned")
+
+        "player.chat" -> FeedLine(
+            tone = FeedTone.CHAT,
+            actor = name,
+            join = ": ",
+            // The message is the row, so it goes in `verb` where a screen renders
+            // it unemphasised — and it is the one field on this wire whose bytes a
+            // player chooses. Compose renders it as text and never as markup;
+            // nothing here may ever stop doing that.
+            verb = row.str("message").orEmpty(),
+            detail = row.str("channel")?.takeIf { it != "Global" }.orEmpty(),
+        )
+
+        "server.wipe" -> FeedLine(
+            tone = FeedTone.SERVER,
+            verb = "The map was wiped",
+            detail = row.str("wipeId")?.let { "new wipe $it" }.orEmpty(),
+        )
+
+        "server.initialized" -> FeedLine(FeedTone.SERVER, verb = "The server came up")
+
+        "server.shutdown" -> FeedLine(FeedTone.SERVER, verb = "The server went down")
+
+        else -> FeedLine(
+            tone = FeedTone.OTHER,
+            actor = name,
+            verb = row.kind.takeIf { it.isNotBlank() } ?: "unknown",
+        )
+    }
+}
+
+/**
+ * A death, which is four different sentences.
+ *
+ * The plugin distinguishes `player`, `self`, `npc` and `environment` precisely so
+ * a reader does not have to guess from an absent field, and collapsing any two of
+ * them loses something. A killfeed reporting a fall as a kill by nobody is the
+ * failure this avoids.
+ */
+private fun death(row: RustEventDto, name: String?): FeedLine {
+    val where = listOfNotNull(
+        row.str("weapon")?.let { "with ${prefabName(it)}" },
+        row.num("distance")?.let { "${Math.round(it)}m" },
+        row.str("grid"),
+        if (row.flag("sleeping")) "while sleeping" else null,
+    ).joinToString(" · ")
+
+    return when (row.str("attackerType")) {
+        "player" -> FeedLine(
+            tone = FeedTone.KILL,
+            actor = row.str("attackerName"),
+            verb = "killed",
+            subject = name,
+            detail = where,
+        )
+
+        "self" -> FeedLine(
+            tone = FeedTone.DEATH,
+            actor = name,
+            verb = "died by their own hand",
+            detail = where,
+        )
+
+        "npc" -> FeedLine(
+            tone = FeedTone.DEATH,
+            actor = prefabName(row.str("attackerName")).ifBlank { "Something" },
+            verb = "killed",
+            subject = name,
+            detail = where,
+        )
+
+        // `environment` and anything else: falling, drowning, the world. The
+        // plugin legitimately has no attacker on this path, so an ABSENT type is
+        // this case rather than a missing field to complain about.
+        else -> FeedLine(tone = FeedTone.DEATH, actor = name, verb = "died", detail = where)
+    }
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustFormat.kt

@@ -0,0 +1,154 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import com.runicgateway.app.core.time.parseWireInstant
+import java.time.Instant
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+import java.time.format.FormatStyle
+import java.util.Locale
+
+/**
+ * Formatting for the Rust screens — pure, no Compose, no Android (PLAN.md §9
+ * M14).
+ *
+ * The Kotlin half of `module-rust`'s `client/src/lib/format.js`, and it is a
+ * deliberate second implementation rather than something shared: the two clients
+ * have different formatting libraries under them (`Intl` there, `java.time`
+ * here), and the thing worth keeping identical is the **rules**, not the code.
+ * Those rules are restated here beside each function so a reader can check them
+ * against the website without opening it.
+ *
+ * Everything takes `now` as a parameter, so a boundary is testable rather than a
+ * property of the machine the test runs on.
+ */
+
+/**
+ * The stamp on a feed row.
+ *
+ * **Today's rows get a time; everything older gets a date as well.** The feed can
+ * be filtered to a past wipe, and a row from six weeks ago rendered as `14:03`
+ * reads as this afternoon — which is exactly what the website's own page walk
+ * found, three events from August all apparently a few minutes old. The boundary
+ * is the **calendar day**, not a duration, because that is what a reader means by
+ * "what time was that".
+ */
+fun feedClock(
+    value: String?,
+    epochMillis: Long? = null,
+    now: Instant = Instant.now(),
+    zone: ZoneId = ZoneId.systemDefault(),
+    locale: Locale = Locale.getDefault(),
+): String {
+    val at = epochMillis?.takeIf { it > 0 }?.let(Instant::ofEpochMilli) ?: parseWireInstant(value) ?: return ""
+
+    val time = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT)
+        .withLocale(locale)
+        .format(at.atZone(zone))
+
+    val sameDay = at.atZone(zone).toLocalDate() == now.atZone(zone).toLocalDate()
+    if (sameDay) return time
+
+    val date = DateTimeFormatter.ofPattern("d MMM", locale).format(at.atZone(zone))
+    return "$date $time"
+}
+
+/** A date, for a wipe: the thing people actually compare wipes by. */
+fun wipeDay(
+    value: String?,
+    zone: ZoneId = ZoneId.systemDefault(),
+    locale: Locale = Locale.getDefault(),
+): String? {
+    val at = parseWireInstant(value) ?: return null
+    return DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM)
+        .withLocale(locale)
+        .format(at.atZone(zone))
+}
+
+/**
+ * "3 minutes ago", for a "last reported" line.
+ *
+ * Returns null rather than a word for an absent stamp, so the caller decides what
+ * "never" looks like in its own layout — on this surface a server that has never
+ * reported is a real and ordinary state, not a missing value to apologise for.
+ */
+fun rustAgo(value: String?, now: Instant = Instant.now()): String? {
+    val at = parseWireInstant(value) ?: return null
+    val seconds = java.time.Duration.between(at, now).seconds
+
+    // Under a minute in either direction, say the thing rather than "in 0 seconds".
+    if (kotlin.math.abs(seconds) < 45) return "just now"
+
+    val future = seconds < 0
+    val magnitude = kotlin.math.abs(seconds)
+    val (unit, size) = AGO_UNITS.first { magnitude >= it.second }
+    val amount = Math.round(magnitude.toDouble() / size)
+    val plural = if (amount == 1L) unit else "${unit}s"
+
+    return if (future) "in $amount $plural" else "$amount $plural ago"
+}
+
+private val AGO_UNITS = listOf(
+    "year" to 31_536_000L,
+    "month" to 2_592_000L,
+    "week" to 604_800L,
+    "day" to 86_400L,
+    "hour" to 3_600L,
+    "minute" to 60L,
+    "second" to 1L,
+)
+
+/**
+ * A session or a playtime, as `4h 12m`.
+ *
+ * Seconds are dropped above a minute and kept below it: a two-hour session
+ * reported to the second is noise, and a forty-second one reported as "0m" is
+ * wrong.
+ */
+fun playtime(seconds: Long?): String {
+    val total = seconds ?: return "—"
+    if (total <= 0) return "—"
+    if (total < 60) return "${total}s"
+
+    val hours = total / 3600
+    val minutes = Math.round((total % 3600) / 60.0)
+
+    return when {
+        hours == 0L -> "${minutes}m"
+        minutes == 0L -> "${hours}h"
+        else -> "${hours}h ${minutes}m"
+    }
+}
+
+/**
+ * A prefab short name as something readable — `patrolhelicopter` stays itself,
+ * `rifle.ak` becomes `rifle ak`.
+ *
+ * Deliberately a light touch rather than a lookup table: a table mapping every
+ * Rust prefab to a pretty name is a second copy of the game's item list that goes
+ * stale every wipe, and the short name is what a Rust player reads on their own
+ * server console anyway.
+ */
+fun prefabName(name: String?): String {
+    if (name.isNullOrBlank()) return ""
+    return name.replace(Regex("[_.]+"), " ").trim()
+}
+
+/** A steam id, shortened for a table cell, without pretending it is a name. */
+fun shortSteamId(steamId: String?): String {
+    val id = steamId.orEmpty()
+    return if (id.length > 10) "…${id.takeLast(6)}" else id
+}
+
+/**
+ * What to call a player who has no name yet.
+ *
+ * The presence board and the leaderboard both carry a nullable `name`: the plugin
+ * knows a steam id before it knows anything else. Showing a shortened id is
+ * honest — it is not a name and does not look like one — where "Unknown" would
+ * lose the only identifier there is.
+ */
+fun playerLabel(name: String?, steamId: String?): String =
+    name?.takeIf { it.isNotBlank() } ?: shortSteamId(steamId)

app/src/main/java/com/runicgateway/app/ui/rust/RustServerScreen.kt

@@ -0,0 +1,535 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ScrollableTabRow
+import androidx.compose.material3.Tab
+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.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+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.RustEventDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardRowDto
+import com.runicgateway.app.data.api.dto.RustPresenceDto
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustWipeDto
+import com.runicgateway.app.ui.ErrorKind
+import com.runicgateway.app.ui.PollWhileResumed
+import com.runicgateway.app.ui.Polled
+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.PillTone
+import com.runicgateway.app.ui.components.SectionLabel
+import com.runicgateway.app.ui.components.ShardCard
+import com.runicgateway.app.ui.components.StatusPill
+
+/**
+ * One Rust server: the feed, the leaderboard, who is on, and the wipes (D13).
+ *
+ * **One screen with tabs, not four destinations** — the same call the website
+ * makes, and more obviously right on a phone: the four panels are four questions
+ * about one thing, and a reader moving between them is not navigating.
+ *
+ * The phase criterion lives here. With the server unreachable this still renders
+ * its map, size, seed, wipe date, killfeed, leaderboards, last known presence
+ * board and wipe history, because every one of those is read from the website's
+ * own tables rather than from the game.
+ */
+@Composable
+fun RustServerScreen(
+    onBack: () -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: RustServerViewModel = hiltViewModel(),
+) {
+    val ui by viewModel.state.collectAsStateWithLifecycle()
+
+    PollWhileResumed { viewModel.refresh() }
+
+    when (val s = ui.server.state) {
+        is UiState.Loading -> LoadingView(modifier)
+
+        // **A mistyped address is not a fault and must not be dressed as one.**
+        // The website's first version put its generic error panel under this
+        // heading, so an unknown id read "No such server / Something went wrong"
+        // and sent a reader looking for an outage. A 404 is its own answer; the
+        // error panel is kept for a request that failed for a reason nobody can
+        // see. A server an operator disabled answers the same 404 — switching one
+        // off is not switching it into a refusal.
+        is UiState.Error -> if (s.kind == ErrorKind.NOT_FOUND) {
+            MissingServer(onBack, modifier)
+        } else {
+            ErrorView(s.kind, onRetry = viewModel::load, modifier = modifier)
+        }
+
+        is UiState.Success -> ServerDetail(s.data, ui, viewModel, modifier)
+    }
+}
+
+@Composable
+private fun MissingServer(onBack: () -> Unit, modifier: Modifier = Modifier) {
+    Column(
+        modifier = modifier.fillMaxSize().padding(24.dp),
+        verticalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        Text(stringResource(R.string.rust_no_such_server), style = MaterialTheme.typography.titleLarge)
+        Text(
+            text = stringResource(R.string.rust_no_such_server_detail),
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Text(
+            text = stringResource(R.string.rust_back_to_servers),
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.clickable(onClick = onBack).padding(top = 8.dp),
+        )
+    }
+}
+
+@Composable
+private fun ServerDetail(
+    server: RustServerDto,
+    ui: RustServerUi,
+    viewModel: RustServerViewModel,
+    modifier: Modifier = Modifier,
+) {
+    Column(modifier.fillMaxSize()) {
+        ServerHeader(server, ui.selectedWipe, viewModel::selectWipe, ui.wipes)
+
+        val tabs = RustTab.entries
+        ScrollableTabRow(selectedTabIndex = tabs.indexOf(ui.tab), edgePadding = 16.dp) {
+            tabs.forEach { tab ->
+                Tab(
+                    selected = tab == ui.tab,
+                    onClick = { viewModel.selectTab(tab) },
+                    text = { Text(stringResource(tabLabel(tab))) },
+                )
+            }
+        }
+
+        when (ui.tab) {
+            RustTab.FEED -> FeedPanel(ui.feed, ui.filterId, viewModel::selectFilter, viewModel::retryFeed)
+            RustTab.LEADERBOARD -> LeaderboardPanel(
+                ui.leaderboard,
+                ui.sort,
+                viewModel::selectSort,
+                viewModel::retryLeaderboard,
+            )
+            RustTab.ONLINE -> OnlinePanel(ui.online, server.online, viewModel::retryOnline)
+            RustTab.WIPES -> WipesPanel(
+                ui.wipes,
+                server.wipeId,
+                ui.selectedWipe,
+                viewModel::openWipe,
+                viewModel::retryWipes,
+            )
+        }
+    }
+}
+
+private fun tabLabel(tab: RustTab): Int = when (tab) {
+    RustTab.FEED -> R.string.rust_tab_feed
+    RustTab.LEADERBOARD -> R.string.rust_tab_leaderboard
+    RustTab.ONLINE -> R.string.rust_tab_online
+    RustTab.WIPES -> R.string.rust_tab_wipes
+}
+
+@Composable
+private fun ServerHeader(
+    server: RustServerDto,
+    selectedWipe: String?,
+    onSelectWipe: (String?) -> Unit,
+    wipes: UiState<List<RustWipeDto>>,
+) {
+    Column(Modifier.padding(horizontal = 16.dp, vertical = 12.dp)) {
+        Text(server.name.ifBlank { server.id }, style = MaterialTheme.typography.headlineSmall)
+
+        describeWorld(server)?.let {
+            Text(
+                text = it,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 4.dp),
+            )
+        }
+
+        Row(
+            modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+            horizontalArrangement = Arrangement.spacedBy(12.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            if (server.online) {
+                StatusPill(
+                    text = stringResource(R.string.rust_online_count, server.players, server.maxPlayers),
+                    tone = PillTone.Success,
+                )
+            } else {
+                StatusPill(text = stringResource(R.string.rust_offline), tone = PillTone.Neutral)
+            }
+            Text(
+                text = lastReported(server),
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        }
+
+        // The wipe picker sits above the tabs because it filters two of them. It
+        // is absent until the wipe list has loaded — offering a filter with one
+        // option would look like a server that has only ever had one wipe.
+        val available = (wipes as? UiState.Success)?.data.orEmpty()
+        if (available.isNotEmpty()) {
+            WipeFilter(available, server.wipeId, selectedWipe, onSelectWipe)
+        }
+    }
+}
+
+@Composable
+private fun WipeFilter(
+    wipes: List<RustWipeDto>,
+    currentWipeId: String?,
+    selected: String?,
+    onSelect: (String?) -> Unit,
+) {
+    Row(
+        modifier = Modifier.fillMaxWidth().horizontalScroll(rememberScrollState()).padding(top = 10.dp),
+        horizontalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        // **Null is all time, and it is the default.** It is a real choice rather
+        // than an absent filter: all-time is the per-wipe rows summed, which is
+        // the answer to "who plays here", where a wipe is the answer to "who is
+        // winning now".
+        FilterChip(
+            selected = selected == null,
+            onClick = { onSelect(null) },
+            label = { Text(stringResource(R.string.rust_all_time)) },
+        )
+        wipes.forEach { wipe ->
+            val label = wipeDay(wipe.saveCreatedAt ?: wipe.firstSeen) ?: wipe.wipeId
+            FilterChip(
+                selected = selected == wipe.wipeId,
+                onClick = { onSelect(wipe.wipeId) },
+                label = {
+                    Text(
+                        if (wipe.wipeId == currentWipeId) {
+                            stringResource(R.string.rust_wipe_current, label)
+                        } else {
+                            label
+                        },
+                    )
+                },
+            )
+        }
+    }
+}
+
+// ── Feed ──────────────────────────────────────────────────────────────────
+
+@Composable
+private fun FeedPanel(
+    feed: Polled<List<RustEventDto>>,
+    filterId: String,
+    onFilter: (String) -> Unit,
+    onRetry: () -> Unit,
+) {
+    Column(Modifier.fillMaxSize()) {
+        Row(
+            modifier = Modifier.fillMaxWidth().horizontalScroll(rememberScrollState())
+                .padding(horizontal = 16.dp, vertical = 8.dp),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            FEED_FILTERS.forEach { filter ->
+                FilterChip(
+                    selected = filter.id == filterId,
+                    onClick = { onFilter(filter.id) },
+                    label = { Text(filter.label) },
+                )
+            }
+        }
+
+        when (val s = feed.state) {
+            is UiState.Loading -> LoadingView()
+            is UiState.Error -> ErrorView(s.kind, onRetry = onRetry)
+            is UiState.Success -> if (s.data.isEmpty()) {
+                EmptyView(stringResource(R.string.rust_feed_empty))
+            } else {
+                LazyColumn(
+                    contentPadding = PaddingValues(horizontal = 16.dp, vertical = 8.dp),
+                    verticalArrangement = Arrangement.spacedBy(10.dp),
+                ) {
+                    if (feed.refreshFailed) {
+                        item { RefreshFailedLine() }
+                    }
+                    items(s.data, key = { it.id }) { FeedRow(it) }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun FeedRow(row: RustEventDto) {
+    val line = describe(row)
+
+    Row(verticalAlignment = Alignment.Top) {
+        // The stamp carries a date for anything not from today — a row from six
+        // weeks ago rendered as a bare time reads as this afternoon, which is
+        // exactly what happens the moment the feed is filtered to a past wipe.
+        Text(
+            text = feedClock(value = null, epochMillis = row.t),
+            style = MaterialTheme.typography.labelSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(end = 10.dp, top = 2.dp),
+        )
+        Column {
+            Row {
+                line.actor?.let {
+                    Text(it, style = MaterialTheme.typography.bodyMedium, fontWeight = FontWeight.SemiBold)
+                    Text(line.join, style = MaterialTheme.typography.bodyMedium)
+                }
+                // The chat message lands here, and it is the one field on this
+                // wire whose bytes a player chooses. Compose renders it as text
+                // and never as markup; nothing here may ever stop doing that.
+                Text(line.verb, style = MaterialTheme.typography.bodyMedium)
+                line.subject?.let {
+                    Text(" ", style = MaterialTheme.typography.bodyMedium)
+                    Text(it, style = MaterialTheme.typography.bodyMedium, fontWeight = FontWeight.SemiBold)
+                }
+            }
+            if (line.detail.isNotBlank()) {
+                Text(
+                    text = line.detail,
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+    }
+}
+
+// ── Leaderboard ───────────────────────────────────────────────────────────
+
+/**
+ * The columns, and which of them the API can sort by.
+ *
+ * `structures` has no sort on the wire and therefore no tap here — a header that
+ * sorts by something other than what it says is worse than one that does not
+ * sort.
+ */
+private data class RustColumn(val labelRes: Int, val sort: String?, val value: (RustLeaderboardRowDto) -> String)
+
+private val RUST_COLUMNS = listOf(
+    RustColumn(R.string.rust_col_kills, RustSort.KILLS) { it.kills.toString() },
+    RustColumn(R.string.rust_col_deaths, RustSort.DEATHS) { it.deaths.toString() },
+    RustColumn(R.string.rust_col_npc_kills, RustSort.NPC_KILLS) { it.npcKills.toString() },
+    RustColumn(R.string.rust_col_structures, null) { it.structures.toString() },
+    RustColumn(R.string.rust_col_played, RustSort.PLAYTIME) { playtime(it.playtimeSec) },
+)
+
+@Composable
+private fun LeaderboardPanel(
+    state: UiState<List<RustLeaderboardRowDto>>,
+    sort: String,
+    onSort: (String) -> Unit,
+    onRetry: () -> Unit,
+) {
+    when (state) {
+        is UiState.Loading -> LoadingView()
+        is UiState.Error -> ErrorView(state.kind, onRetry = onRetry)
+        is UiState.Success -> if (state.data.isEmpty()) {
+            // **Empty is a real answer here and is not "no data".** All-time is
+            // the per-wipe rows summed, so a player who appears only in an older
+            // wipe drops out of the current one rather than reading zero — an
+            // empty board for a wipe means nobody scored on that map.
+            EmptyView(stringResource(R.string.rust_leaderboard_empty))
+        } else {
+            LazyColumn(
+                contentPadding = PaddingValues(16.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                item {
+                    Row(Modifier.fillMaxWidth()) {
+                        SectionLabel(stringResource(R.string.rust_col_player), Modifier.weight(1f))
+                        RUST_COLUMNS.forEach { column ->
+                            SectionLabel(
+                                text = stringResource(column.labelRes),
+                                modifier = Modifier
+                                    .weight(1f)
+                                    .then(
+                                        if (column.sort != null) {
+                                            Modifier.clickable { onSort(column.sort) }
+                                        } else {
+                                            Modifier
+                                        },
+                                    ),
+                            )
+                        }
+                    }
+                }
+                items(state.data, key = { it.steamId }) { row ->
+                    Row(Modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
+                        Text(
+                            text = playerLabel(row.name, row.steamId),
+                            style = MaterialTheme.typography.bodyMedium,
+                            modifier = Modifier.weight(1f),
+                        )
+                        RUST_COLUMNS.forEach { column ->
+                            Text(
+                                text = column.value(row),
+                                style = MaterialTheme.typography.bodySmall,
+                                color = if (column.sort == sort) {
+                                    MaterialTheme.colorScheme.primary
+                                } else {
+                                    MaterialTheme.colorScheme.onSurfaceVariant
+                                },
+                                modifier = Modifier.weight(1f),
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+// ── Online ────────────────────────────────────────────────────────────────
+
+@Composable
+private fun OnlinePanel(
+    online: Polled<List<RustPresenceDto>>,
+    serverOnline: Boolean,
+    onRetry: () -> Unit,
+) {
+    when (val s = online.state) {
+        is UiState.Loading -> LoadingView()
+        is UiState.Error -> ErrorView(s.kind, onRetry = onRetry)
+        is UiState.Success -> if (s.data.isEmpty()) {
+            EmptyView(
+                stringResource(
+                    if (serverOnline) R.string.rust_nobody_on else R.string.rust_presence_offline,
+                ),
+            )
+        } else {
+            LazyColumn(
+                contentPadding = PaddingValues(16.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                // **The board is the last one that ARRIVED, and an unreachable
+                // server does not clear it** — deliberately, because these rows
+                // are still the best answer anybody has. Presented bare they read
+                // as "these people are on right now", which is the one thing an
+                // offline server cannot be saying. So the panel says which it is.
+                item {
+                    Text(
+                        text = stringResource(
+                            if (serverOnline) R.string.rust_presence_live else R.string.rust_presence_last_known,
+                        ),
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+                if (online.refreshFailed) {
+                    item { RefreshFailedLine() }
+                }
+                items(s.data, key = { it.steamId }) { player ->
+                    ShardCard(Modifier.fillMaxWidth()) {
+                        Row(Modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
+                            Text(
+                                text = playerLabel(player.name, player.steamId),
+                                style = MaterialTheme.typography.bodyMedium,
+                                modifier = Modifier.weight(1f),
+                            )
+                            if (player.sleeping) {
+                                StatusPill(
+                                    text = stringResource(R.string.rust_sleeping),
+                                    tone = PillTone.Neutral,
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+// ── Wipes ─────────────────────────────────────────────────────────────────
+
+@Composable
+private fun WipesPanel(
+    state: UiState<List<RustWipeDto>>,
+    currentWipeId: String?,
+    selected: String?,
+    onOpenWipe: (String) -> Unit,
+    onRetry: () -> Unit,
+) {
+    when (state) {
+        is UiState.Loading -> LoadingView()
+        is UiState.Error -> ErrorView(state.kind, onRetry = onRetry)
+        is UiState.Success -> if (state.data.isEmpty()) {
+            EmptyView(stringResource(R.string.rust_wipes_empty))
+        } else {
+            LazyColumn(
+                contentPadding = PaddingValues(16.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                items(state.data, key = { it.wipeId }) { wipe ->
+                    ShardCard(
+                        Modifier.fillMaxWidth().clickable { onOpenWipe(wipe.wipeId) },
+                    ) {
+                        Row(Modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
+                            Text(
+                                text = wipeDay(wipe.saveCreatedAt ?: wipe.firstSeen) ?: wipe.wipeId,
+                                style = MaterialTheme.typography.bodyMedium,
+                                modifier = Modifier.weight(1f),
+                            )
+                            if (wipe.wipeId == currentWipeId) {
+                                StatusPill(
+                                    text = stringResource(R.string.rust_wipe_this_one),
+                                    tone = PillTone.Success,
+                                )
+                            } else if (wipe.wipeId == selected) {
+                                StatusPill(
+                                    text = stringResource(R.string.rust_wipe_selected),
+                                    tone = PillTone.Info,
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun RefreshFailedLine() {
+    Text(
+        text = stringResource(R.string.rust_refresh_failed),
+        style = MaterialTheme.typography.bodySmall,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+    )
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustServerViewModel.kt

@@ -0,0 +1,268 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.lifecycle.SavedStateHandle
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.runicgateway.app.data.api.dto.RustEventDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardRowDto
+import com.runicgateway.app.data.api.dto.RustPresenceDto
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustWipeDto
+import com.runicgateway.app.data.repository.RustRepository
+import com.runicgateway.app.ui.Polled
+import com.runicgateway.app.ui.UiState
+import com.runicgateway.app.ui.navigation.Routes
+import com.runicgateway.app.ui.refreshInto
+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
+
+/** The four sections of a server's page (D13). */
+enum class RustTab { FEED, LEADERBOARD, ONLINE, WIPES }
+
+/** What a leaderboard column sorts by — the API's own vocabulary, not the app's. */
+object RustSort {
+    const val KILLS = "kills"
+    const val DEATHS = "deaths"
+    const val NPC_KILLS = "npcKills"
+    const val PLAYTIME = "playtime"
+}
+
+/**
+ * Everything one server's page is showing.
+ *
+ * One state object rather than eight flows: every panel on the page is about the
+ * same server and the same selected wipe, and a screen that collected them
+ * separately could render a leaderboard for one wipe beside a feed for another
+ * for a frame.
+ */
+data class RustServerUi(
+    val serverId: String = "",
+    val server: Polled<RustServerDto> = Polled(),
+    val tab: RustTab = RustTab.FEED,
+    val filterId: String = "all",
+    val sort: String = RustSort.KILLS,
+    /** The wipe every panel is filtered to. **Null is all time**, not "unknown". */
+    val selectedWipe: String? = null,
+    val feed: Polled<List<RustEventDto>> = Polled(),
+    val online: Polled<List<RustPresenceDto>> = Polled(),
+    val leaderboard: UiState<List<RustLeaderboardRowDto>> = UiState.Loading,
+    val wipes: UiState<List<RustWipeDto>> = UiState.Loading,
+)
+
+/**
+ * One Rust server (PLAN.md §9 M14; `docs/modules/rust/PLAN.md` D13, D14).
+ *
+ * ## What polls and what does not
+ *
+ * D14, and it is a statement about the questions rather than about cost: the
+ * **feed**, **who is on** and the **server's own line** change while somebody is
+ * looking at the page, and the **leaderboard** and the **wipe list** do not in
+ * any way a reader would want to watch. A leaderboard that re-sorted itself under
+ * a finger every twenty seconds would be worse than a stale one.
+ *
+ * Only the **visible** live panel is polled. The website can afford to mount the
+ * one tab it is showing; here the tabs are one screen, so the refresh asks what
+ * the reader is actually looking at.
+ *
+ * ## Changing the question versus asking it again
+ *
+ * A poll is the same question asked again, so it keeps what is on screen
+ * ([refreshInto]). Changing the filter, the sort or the wipe is a **different
+ * question**, so the panel blanks and loads — what is there is an answer to
+ * something the reader has stopped asking, and leaving it up while the new one
+ * arrives would show a killfeed for last wipe under a heading naming this one.
+ */
+@HiltViewModel
+class RustServerViewModel @Inject constructor(
+    private val repository: RustRepository,
+    savedStateHandle: SavedStateHandle,
+) : ViewModel() {
+
+    private val serverId: String = savedStateHandle[Routes.Args.SERVER_ID] ?: ""
+
+    private val _state = MutableStateFlow(RustServerUi(serverId = serverId))
+    val state: StateFlow<RustServerUi> = _state.asStateFlow()
+
+    init {
+        load()
+    }
+
+    /** A first load or a retry of the whole page. */
+    fun load() {
+        _state.update { it.copy(server = Polled(UiState.Loading), feed = Polled(UiState.Loading)) }
+        viewModelScope.launch {
+            askServer()
+            askFeed()
+        }
+    }
+
+    /**
+     * The poll tick.
+     *
+     * The server line always, and then whichever live panel is on screen. A tab
+     * showing the leaderboard or the wipes does no extra work — the reader is
+     * looking at something that does not move.
+     */
+    fun refresh() {
+        viewModelScope.launch {
+            askServer()
+            when (_state.value.tab) {
+                RustTab.FEED -> askFeed()
+                RustTab.ONLINE -> askOnline()
+                RustTab.LEADERBOARD, RustTab.WIPES -> Unit
+            }
+        }
+    }
+
+    /**
+     * Open a tab, loading its panel the first time it is opened.
+     *
+     * The two that do not poll are loaded exactly once per question: re-asking on
+     * every tab switch would put a spinner over a leaderboard the reader has
+     * already read, for an answer that cannot have changed while they were three
+     * taps away.
+     */
+    fun selectTab(tab: RustTab) {
+        val already = _state.value
+        _state.update { it.copy(tab = tab) }
+
+        viewModelScope.launch {
+            when (tab) {
+                RustTab.FEED -> if (already.feed.state !is UiState.Success) askFeed()
+                RustTab.ONLINE -> if (already.online.state !is UiState.Success) askOnline()
+                RustTab.LEADERBOARD -> if (already.leaderboard !is UiState.Success) askLeaderboard()
+                RustTab.WIPES -> if (already.wipes !is UiState.Success) askWipes()
+            }
+        }
+    }
+
+    /** A different question for the feed: blank it and ask. */
+    fun selectFilter(filterId: String) {
+        if (filterId == _state.value.filterId) return
+        _state.update { it.copy(filterId = filterId, feed = Polled(UiState.Loading)) }
+        viewModelScope.launch { askFeed() }
+    }
+
+    /** A different question for the leaderboard: blank it and ask. */
+    fun selectSort(sort: String) {
+        if (sort == _state.value.sort) return
+        _state.update { it.copy(sort = sort, leaderboard = UiState.Loading) }
+        viewModelScope.launch { askLeaderboard() }
+    }
+
+    /**
+     * Pick a wipe, or all time with null.
+     *
+     * It is the one selection that changes **two** panels, so both are blanked —
+     * and only the loaded ones are re-asked, so choosing a wipe from the Wipes tab
+     * does not fetch a leaderboard nobody has opened.
+     */
+    fun selectWipe(wipeId: String?) {
+        if (wipeId == _state.value.selectedWipe) return
+
+        val hadLeaderboard = _state.value.leaderboard is UiState.Success
+        _state.update {
+            it.copy(
+                selectedWipe = wipeId,
+                feed = Polled(UiState.Loading),
+                leaderboard = if (hadLeaderboard) UiState.Loading else it.leaderboard,
+            )
+        }
+
+        viewModelScope.launch {
+            askFeed()
+            if (hadLeaderboard) askLeaderboard()
+        }
+    }
+
+    /**
+     * Pick a wipe from the Wipes tab, which is a navigation as much as a filter.
+     *
+     * The question it asks is "what happened during that map", and the answer is
+     * the feed — so it lands there rather than leaving the reader on a list of
+     * dates with nothing visibly changed.
+     */
+    fun openWipe(wipeId: String) {
+        selectWipe(wipeId)
+        selectTab(RustTab.FEED)
+    }
+
+    /**
+     * Retry one panel after its own load failed.
+     *
+     * Four entry points rather than one, because a failed leaderboard is not a
+     * reason to re-read the feed the reader can already see — and [load] is the
+     * whole page, which is right for a failed *server* read and heavy-handed for
+     * anything else.
+     */
+    fun retryFeed() {
+        _state.update { it.copy(feed = Polled(UiState.Loading)) }
+        viewModelScope.launch { askFeed() }
+    }
+
+    fun retryLeaderboard() {
+        _state.update { it.copy(leaderboard = UiState.Loading) }
+        viewModelScope.launch { askLeaderboard() }
+    }
+
+    fun retryOnline() {
+        _state.update { it.copy(online = Polled(UiState.Loading)) }
+        viewModelScope.launch { askOnline() }
+    }
+
+    fun retryWipes() {
+        _state.update { it.copy(wipes = UiState.Loading) }
+        viewModelScope.launch { askWipes() }
+    }
+
+    private suspend fun askServer() {
+        val result = repository.server(serverId)
+        _state.update { it.copy(server = refreshInto(it.server.state, result)) }
+    }
+
+    private suspend fun askFeed() {
+        val current = _state.value
+        val result = repository.events(
+            id = serverId,
+            kinds = kindsFor(current.filterId),
+            wipe = current.selectedWipe,
+            limit = FEED_LIMIT,
+        )
+        _state.update { it.copy(feed = refreshInto(it.feed.state, result)) }
+    }
+
+    private suspend fun askOnline() {
+        val result = repository.online(serverId)
+        _state.update { it.copy(online = refreshInto(it.online.state, result)) }
+    }
+
+    private suspend fun askLeaderboard() {
+        val current = _state.value
+        val result = repository.leaderboard(
+            id = serverId,
+            wipe = current.selectedWipe,
+            sort = current.sort,
+            limit = LEADERBOARD_LIMIT,
+        )
+        _state.update { it.copy(leaderboard = result.toUiState()) }
+    }
+
+    private suspend fun askWipes() {
+        _state.update { it.copy(wipes = repository.wipes(serverId).toUiState()) }
+    }
+
+    private companion object {
+        /** Matches the website's feed page size; the server caps at 200 regardless. */
+        const val FEED_LIMIT = 100
+        const val LEADERBOARD_LIMIT = 50
+    }
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustServersScreen.kt

@@ -0,0 +1,185 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.MaterialTheme
+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.res.stringResource
+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.RustServerDto
+import com.runicgateway.app.ui.PollWhileResumed
+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.PillTone
+import com.runicgateway.app.ui.components.ShardCard
+import com.runicgateway.app.ui.components.StatusPill
+
+/**
+ * Every Rust server this site follows — the module's landing page (D8, D12).
+ *
+ * **The phase criterion is this screen with every server off.** Nothing here is a
+ * live call to a game host: the website answers from its own tables, so a fleet
+ * that has been down for a week renders a week of last-known state rather than an
+ * error. The one thing that can fail is the website itself.
+ */
+@Composable
+fun RustServersScreen(
+    onOpenServer: (String) -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: RustServersViewModel = hiltViewModel(),
+) {
+    val polled by viewModel.state.collectAsStateWithLifecycle()
+
+    PollWhileResumed { viewModel.refresh() }
+
+    when (val s = polled.state) {
+        is UiState.Loading -> LoadingView(modifier)
+        is UiState.Error -> ErrorView(s.kind, onRetry = viewModel::load, modifier = modifier)
+        is UiState.Success -> {
+            if (s.data.isEmpty()) {
+                EmptyView(stringResource(R.string.rust_servers_empty), modifier)
+            } else {
+                ServerList(s.data, polled.refreshFailed, onOpenServer, modifier)
+            }
+        }
+    }
+}
+
+@Composable
+private fun ServerList(
+    servers: List<RustServerDto>,
+    refreshFailed: Boolean,
+    onOpenServer: (String) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    LazyColumn(
+        modifier = modifier.fillMaxSize(),
+        contentPadding = PaddingValues(16.dp),
+        verticalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        // A failed refresh says so and changes nothing else. The rows below it are
+        // the last good answer and stay exactly as they were — blanking them is
+        // the one thing a site whose premise is "it renders while the game is off"
+        // must not do when a request fails.
+        if (refreshFailed) {
+            item {
+                Text(
+                    text = stringResource(R.string.rust_refresh_failed),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
+        items(servers, key = { it.id }) { server ->
+            ServerRow(server) { onOpenServer(server.id) }
+        }
+    }
+}
+
+@Composable
+private fun ServerRow(server: RustServerDto, onOpen: () -> Unit) {
+    ShardCard(modifier = Modifier.fillMaxWidth().clickable(onClick = onOpen)) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = server.name.ifBlank { server.id },
+                style = MaterialTheme.typography.titleMedium,
+                modifier = Modifier.weight(1f),
+            )
+            // `online` already has staleness folded into it server-side — a row
+            // nobody has written recently cannot claim a server is up — so this
+            // renders the field rather than second-guessing it.
+            if (server.online) {
+                StatusPill(
+                    text = stringResource(
+                        R.string.rust_online_count,
+                        server.players,
+                        server.maxPlayers,
+                    ),
+                    tone = PillTone.Success,
+                )
+            } else {
+                StatusPill(text = stringResource(R.string.rust_offline), tone = PillTone.Neutral)
+            }
+        }
+
+        val world = describeWorld(server)
+        if (world != null) {
+            Text(
+                text = world,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 4.dp),
+            )
+        }
+
+        Text(
+            text = lastReported(server),
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(top = 2.dp),
+        )
+    }
+}
+
+/**
+ * The world line — the things a Rust player asks first.
+ *
+ * Null when the server has never described itself, so the caller leaves the line
+ * out rather than printing an empty one. A server configured this morning that
+ * has not connected yet is in exactly that state, and it is not an error.
+ */
+@Composable
+internal fun describeWorld(server: RustServerDto): String? {
+    val parts = listOfNotNull(
+        server.level,
+        server.worldSize?.let { stringResource(R.string.rust_world_size, it) },
+        server.seed?.let { stringResource(R.string.rust_world_seed, it) },
+        wipeDay(server.wipedAt)?.let { stringResource(R.string.rust_wiped_on, it) },
+    )
+    return parts.takeIf { it.isNotEmpty() }?.joinToString(" · ")
+}
+
+/**
+ * "last reported 3 minutes ago".
+ *
+ * **Reads `lastSeenAt` and never `updatedAt`.** The module shipped that exact
+ * confusion and fixed it in phase 4: `updatedAt` moves on every poll including a
+ * failed one, so an offline server claimed it had just checked in, every thirty
+ * seconds, for as long as it stayed down. Only a frame moves `lastSeenAt`.
+ */
+@Composable
+internal fun lastReported(server: RustServerDto): String {
+    val ago = rustAgo(server.lastSeenAt)
+        ?: return stringResource(R.string.rust_never_reported)
+
+    return if (server.stale) {
+        stringResource(R.string.rust_last_reported_stale, ago)
+    } else {
+        stringResource(R.string.rust_last_reported, ago)
+    }
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustServersViewModel.kt

@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.repository.RustRepository
+import com.runicgateway.app.ui.Polled
+import com.runicgateway.app.ui.UiState
+import com.runicgateway.app.ui.refreshInto
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * The Rust server list — the module's landing page, one tier along (PLAN.md §9
+ * M14; `docs/modules/rust/PLAN.md` D12).
+ *
+ * **`toUiState`, not `toShardUiState`.** These routes carry no `requireFeature`
+ * gate, so a `404` here is a genuinely missing thing and never an admin's
+ * visibility switch. Offering "this shard doesn't publish it" for one would name
+ * a cause that does not exist on this surface.
+ *
+ * [refresh] is what the screen's poll calls and [load] is what a retry calls, and
+ * the difference is the whole of [refreshInto]: a refresh keeps the rows when it
+ * fails, a load is allowed to blank them because there is nothing on screen to
+ * protect.
+ */
+@HiltViewModel
+class RustServersViewModel @Inject constructor(
+    private val repository: RustRepository,
+) : ViewModel() {
+
+    private val _state = MutableStateFlow(Polled<List<RustServerDto>>())
+    val state: StateFlow<Polled<List<RustServerDto>>> = _state.asStateFlow()
+
+    /** A first load or a retry: show the spinner, then replace whatever comes back. */
+    fun load() {
+        _state.value = Polled(UiState.Loading)
+        viewModelScope.launch { ask() }
+    }
+
+    /** A poll: silent on success, and it keeps the rows on failure. */
+    fun refresh() {
+        viewModelScope.launch { ask() }
+    }
+
+    private suspend fun ask() {
+        _state.value = refreshInto(_state.value.state, repository.servers())
+    }
+}

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

@@ -44,6 +44,7 @@
     <string name="menu_events">Events</string>
     <string name="menu_wiki">Wiki</string>
     <string name="menu_shard">Shard</string>
+    <string name="menu_rust">Rust servers</string>
     <string name="menu_rules">Rules</string>
     <string name="menu_atlas">Atlas</string>
     <string name="menu_leaderboards">Leaderboards</string>
@@ -566,4 +567,42 @@
     <string name="events_score">Score %1$s</string>
     <string name="events_show_more">Show more</string>
     <string name="events_loading">Loading…</string>
+
+    <!-- Rust module (M14, docs/modules/rust/PLAN.md §18) -->
+    <string name="rust_servers_empty">No Rust servers are configured on this site yet.</string>
+    <string name="rust_offline">Offline</string>
+    <string name="rust_online_count">%1$d / %2$d online</string>
+    <string name="rust_never_reported">has never reported</string>
+    <string name="rust_last_reported">last reported %1$s</string>
+    <string name="rust_last_reported_stale">last reported %1$s — out of date, so it is shown as offline</string>
+    <string name="rust_world_size">size %1$d</string>
+    <string name="rust_world_seed">seed %1$d</string>
+    <string name="rust_wiped_on">wiped %1$s</string>
+    <string name="rust_refresh_failed">Could not refresh just now. This is the last thing the site heard.</string>
+    <string name="rust_no_such_server">No such server</string>
+    <string name="rust_no_such_server_detail">This address does not name a server this site follows.</string>
+    <string name="rust_back_to_servers">Back to the server list</string>
+    <string name="rust_tab_feed">Feed</string>
+    <string name="rust_tab_leaderboard">Leaderboard</string>
+    <string name="rust_tab_online">Online</string>
+    <string name="rust_tab_wipes">Wipes</string>
+    <string name="rust_all_time">All time</string>
+    <string name="rust_wipe_current">%1$s (this wipe)</string>
+    <string name="rust_wipe_this_one">Current</string>
+    <string name="rust_wipe_selected">Showing</string>
+    <string name="rust_feed_empty">Nothing has happened on this server yet — or not during the wipe you are looking at.</string>
+    <string name="rust_leaderboard_empty">Nobody has scored here yet.</string>
+    <string name="rust_wipes_empty">This server has not reported a wipe yet.</string>
+    <string name="rust_nobody_on">The server is up and the island is empty. Somebody has to be first.</string>
+    <string name="rust_presence_offline">Presence is the one thing on this page that cannot be answered from the record — it is who is connected now, and nothing is.</string>
+    <string name="rust_presence_live">On the server right now.</string>
+    <string name="rust_presence_last_known">The last board this server sent. It is offline, so this is who was on then — not who is on now.</string>
+    <string name="rust_sleeping">Sleeping</string>
+    <string name="rust_col_player">Player</string>
+    <string name="rust_col_kills">Kills</string>
+    <string name="rust_col_deaths">Deaths</string>
+    <string name="rust_col_npc_kills">NPC</string>
+    <string name="rust_col_structures">Built</string>
+    <string name="rust_col_played">Played</string>
+    <string name="rust_online_badge">%1$d players online</string>
 </resources>

app/src/test/java/com/runicgateway/app/data/api/fake/FakeRustApi.kt

@@ -0,0 +1,97 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.data.api.fake
+
+import com.runicgateway.app.data.api.RustApi
+import com.runicgateway.app.data.api.dto.RustEventListDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardDto
+import com.runicgateway.app.data.api.dto.RustOnlineDto
+import com.runicgateway.app.data.api.dto.RustServerListDto
+import com.runicgateway.app.data.api.dto.RustServerResponse
+import com.runicgateway.app.data.api.dto.RustWipeListDto
+
+/**
+ * A configurable fake of [RustApi] (M14). Set the `var` a call should answer
+ * with; set [error] to make every call throw.
+ *
+ * **The `last…` fields are what the tests that matter assert on.** The module's
+ * own API has one rule nothing about a successful response can show: an absent
+ * query parameter must be **absent** rather than empty, because `?wipe=` asks for
+ * a wipe whose id is the empty string and answers nothing, with no error to
+ * notice. Recording what was asked is the only way to see that from here.
+ */
+class FakeRustApi : RustApi {
+
+    var error: Throwable? = null
+
+    var servers: RustServerListDto = RustServerListDto()
+    var server: RustServerResponse = RustServerResponse()
+    var events: RustEventListDto = RustEventListDto()
+    var leaderboard: RustLeaderboardDto = RustLeaderboardDto()
+    var wipes: RustWipeListDto = RustWipeListDto()
+    var online: RustOnlineDto = RustOnlineDto()
+
+    var serversCalls: Int = 0
+    var eventCalls: Int = 0
+    var leaderboardCalls: Int = 0
+    var onlineCalls: Int = 0
+    var wipeCalls: Int = 0
+
+    /** The `kind` the last feed read carried — null means it sent none at all. */
+    var lastKind: String? = null
+
+    /** The `wipe` the last feed read carried; null means all wipes. */
+    var lastFeedWipe: String? = null
+    var lastLeaderboardWipe: String? = null
+    var lastSort: String? = null
+    var lastId: String? = null
+
+    private fun <T> reply(value: T): T {
+        error?.let { throw it }
+        return value
+    }
+
+    override suspend fun getServers(): RustServerListDto {
+        serversCalls++
+        return reply(servers)
+    }
+
+    override suspend fun getServer(id: String): RustServerResponse {
+        lastId = id
+        return reply(server)
+    }
+
+    override suspend fun getEvents(id: String, kind: String?, wipe: String?, limit: Int?): RustEventListDto {
+        eventCalls++
+        lastId = id
+        lastKind = kind
+        lastFeedWipe = wipe
+        return reply(events)
+    }
+
+    override suspend fun getLeaderboard(
+        id: String,
+        wipe: String?,
+        sort: String?,
+        limit: Int?,
+    ): RustLeaderboardDto {
+        leaderboardCalls++
+        lastId = id
+        lastLeaderboardWipe = wipe
+        lastSort = sort
+        return reply(leaderboard)
+    }
+
+    override suspend fun getWipes(id: String): RustWipeListDto {
+        wipeCalls++
+        lastId = id
+        return reply(wipes)
+    }
+
+    override suspend fun getOnline(id: String): RustOnlineDto {
+        onlineCalls++
+        lastId = id
+        return reply(online)
+    }
+}

app/src/test/java/com/runicgateway/app/ui/PollingTest.kt

@@ -0,0 +1,81 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui
+
+import com.runicgateway.app.core.result.ApiResult
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The rule a poll lives on (M14, `docs/modules/rust/PLAN.md` D14).
+ *
+ * **A refresh is invisible when it succeeds and keeps the rows when it fails.**
+ * The site's whole premise is that it renders while the game is off, and an app
+ * that blanked itself the first time a request failed would break that one tier
+ * along from where it was built.
+ */
+class PollingTest {
+
+    @Test
+    fun `a successful refresh replaces the data and clears a previous failure`() {
+        val after = refreshInto(UiState.Success(listOf("old")), ApiResult.Ok(listOf("new")))
+
+        assertEquals(UiState.Success(listOf("new")), after.state)
+        assertFalse(after.refreshFailed)
+    }
+
+    @Test
+    fun `a failed refresh keeps the rows and reports the failure`() {
+        // The case this whole file exists for. Nothing is blanked, nothing is
+        // retried on the reader's behalf, and the failure is a fact the screen can
+        // render beside rows that are still the best answer anybody has.
+        val before = UiState.Success(listOf("old"))
+        val after = refreshInto(before, ApiResult.NetworkError(RuntimeException("offline")))
+
+        assertEquals(before, after.state)
+        assertTrue(after.refreshFailed)
+    }
+
+    @Test
+    fun `a failure with nothing on screen is an ordinary error`() {
+        // There is nothing to protect, so this is a first load that failed — and a
+        // screen that reported "could not refresh" over a blank page would be
+        // hiding the retry the reader needs.
+        val after = refreshInto(UiState.Loading, ApiResult.HttpError(500, "boom"))
+
+        assertTrue(after.state is UiState.Error)
+        assertFalse(after.refreshFailed)
+    }
+
+    @Test
+    fun `a 404 on a first load keeps its own kind`() {
+        val after = refreshInto(UiState.Loading, ApiResult.HttpError(404, "gone"))
+
+        assertEquals(UiState.Error(ErrorKind.NOT_FOUND, 404), after.state)
+    }
+
+    @Test
+    fun `a successful refresh over an error recovers`() {
+        val after = refreshInto(
+            UiState.Error(ErrorKind.NETWORK),
+            ApiResult.Ok(listOf("back")),
+        )
+
+        assertEquals(UiState.Success(listOf("back")), after.state)
+        assertFalse(after.refreshFailed)
+    }
+
+    @Test
+    fun `an empty answer is a success, not a failure to keep the old rows through`() {
+        // An empty list is an ANSWER — the feed filtered to a wipe nothing happened
+        // in, a fleet with nobody on it. Treating it as "nothing came back" and
+        // keeping stale rows would make an emptied board impossible to observe.
+        val after = refreshInto(UiState.Success(listOf("old")), ApiResult.Ok(emptyList<String>()))
+
+        assertEquals(UiState.Success(emptyList<String>()), after.state)
+        assertFalse(after.refreshFailed)
+    }
+}

app/src/test/java/com/runicgateway/app/ui/navigation/NavOverridesTest.kt

@@ -52,11 +52,17 @@ class NavOverridesTest {
      * showing through** (M13): About is core's last nav row at index 7 and the
      * module's nine append after it at 8-16. Under the stale sixteen-row table
      * About was index 15 and came last, which is what these assertions used to say.
+     *
+     * **The Rust row is last, at 17** (M14). These tests carry no capability
+     * answer, which fails open, so both game modules' rows appear here — a state
+     * no real backend is in and exactly the one this merge has to be correct for,
+     * since the sort key is the website's number line and not what happens to be
+     * installed.
      */
     private val mergedPublic = listOf(
         Routes.HOME, Routes.NEWS, Routes.EVENTS, Routes.WIKI, Routes.page("about"),
         Routes.SHARD, Routes.SHARD_RULES, Routes.ATLAS, Routes.SHARD_LEADERBOARDS,
-        Routes.SHARD_MARKET,
+        Routes.SHARD_MARKET, Routes.RUST,
     )
 
     /** How many rows that block holds, so the take/drop below say why. */
@@ -154,13 +160,14 @@ class NavOverridesTest {
     // ── Order ────────────────────────────────────────────────────────────
 
     @Test fun anExplicitOrderMovesTheRowWithinThePublicBlock() {
-        // The website's own indices: About is 7, and Market — the last row of all,
+        // The website's own indices: About is 7, Market is 16, and the Rust row —
-        // now that the module's nine append after core's eight — is 16. Dragging
+        // the last of all, now that a second game module's row appends after the
-        // About to the top and Home past the end writes exactly this.
+        // first's nine — is 17. Dragging About to the top and Home past the end
+        // writes exactly this.
         val routes = routes(
             nav(
                 "/site/about" to entry(order = 0),
-                "/" to entry(order = 17),
+                "/" to entry(order = 18),
             ),
         )
 
@@ -168,7 +175,7 @@ class NavOverridesTest {
             listOf(
                 Routes.page("about"), Routes.NEWS, Routes.EVENTS, Routes.WIKI, Routes.SHARD,
                 Routes.SHARD_RULES, Routes.ATLAS, Routes.SHARD_LEADERBOARDS, Routes.SHARD_MARKET,
-                Routes.HOME,
+                Routes.RUST, Routes.HOME,
             ),
             routes.take(publicBlock),
         )

app/src/test/java/com/runicgateway/app/ui/navigation/NavPathsTest.kt

@@ -19,12 +19,12 @@ import org.junit.Test
 class NavPathsTest {
 
     @Test fun everyWebsiteNavPathIsMapped() {
-        // Core's eight rows plus module-uo's nine, both quoted in NavPaths.kt. If
+        // Core's eight rows, module-uo's nine and module-rust's one, all quoted in
-        // either side adds one, this is the test that says so — a path with no
+        // NavPaths.kt. If any of the three adds one, this is the test that says so
-        // mapping is silently unresolvable in phase 6's link handling, which is
+        // — a path with no mapping is silently unresolvable in phase 6's link
-        // exactly how the nine shard rows went stale for a month after the
+        // handling, which is exactly how the nine shard rows went stale for a month
-        // module-system cutover moved them from /site/ to /uo/ (M13).
+        // after the module-system cutover moved them from /site/ to /uo/ (M13).
-        assertEquals(17, WEBSITE_PUBLIC_NAV.size)
+        assertEquals(18, WEBSITE_PUBLIC_NAV.size)
         assertEquals(WEBSITE_PUBLIC_NAV.size, WEB_PATH_TO_ROUTE.size)
     }
 
@@ -61,9 +61,15 @@ class NavPathsTest {
     }
 
     @Test fun theDrawerRowsAreTheIntersectionWithAppMenu() {
-        // Ten of the seventeen have a drawer row. The other seven are mapped but not
+        // Eleven of the eighteen have a drawer row. The other seven are mapped but
-        // surfaced — three news category tabs and the four Shard hub boards — and
+        // not surfaced — three news category tabs and the four Shard hub boards —
-        // an override for one of them is ignored rather than obeyed (§6.2).
+        // and an override for one of them is ignored rather than obeyed (§6.2).
+        //
+        // **Both game modules appear here, and no backend serves both lists.** The
+        // table is a superset on purpose: a path for a module an operator has not
+        // installed never appears in that backend's nav and is never looked up,
+        // while a path MISSING from it makes a link that does exist hand off to a
+        // browser.
         val coded = APP_MENU.map { it.route }.toSet()
         val surfaced = WEBSITE_PUBLIC_NAV.filter { it.route in coded }.map { it.path }
 
@@ -71,6 +77,7 @@ class NavPathsTest {
             listOf(
                 "/", "/site/news", "/site/events", "/wiki", "/site/about",
                 "/uo/shard", "/uo/rules", "/uo/atlas", "/uo/leaderboards", "/uo/market",
+                "/rust",
             ),
             surfaced,
         )

app/src/test/java/com/runicgateway/app/ui/navigation/NavTreeTest.kt

@@ -166,10 +166,12 @@ class NavTreeTest {
 
         val shape = tree(row).shape()
 
-        // Nine public rows are left at the top level (Wiki moved into the section),
+        // Ten public rows are left at the top level (Wiki moved into the section),
-        // then the section, then the app's own rows.
+        // then the section, then the app's own rows. The tenth is the Rust row:
-        assertEquals("section:lore", shape[9])
+        // these tests carry no capability answer, which fails open, so both game
-        assertEquals(Routes.CONTACT, shape[10])
+        // modules' rows are present — see NavOverridesTest's `mergedPublic`.
+        assertEquals("section:lore", shape[10])
+        assertEquals(Routes.CONTACT, shape[11])
     }
 
     @Test fun aSectionsOrderPlacesItAmongTheCodedRows() {
@@ -324,9 +326,9 @@ class NavTreeTest {
         val shape = tree(row).shape()
 
         assertEquals(listOf("link:a", "link:b"), shape.filter { it.startsWith("link:") })
-        // Market, not About: the module's nine rows append after core's eight on the
+        // The Rust row, not About: both modules' rows append after core's eight on
-        // website's number line, so Market is the last coded row rather than About.
+        // the website's number line, and Rust's is last at 17.
-        assertEquals(Routes.SHARD_MARKET, shape[shape.indexOf("link:a") - 1])
+        assertEquals(Routes.RUST, shape[shape.indexOf("link:a") - 1])
     }
 
     @Test fun aLinksOrderPlacesItAmongTheCodedRows() {

app/src/test/java/com/runicgateway/app/ui/navigation/RustNavigationTest.kt

@@ -0,0 +1,112 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.navigation
+
+import com.runicgateway.app.core.auth.Session
+import com.runicgateway.app.data.repository.Capability
+import com.runicgateway.app.data.repository.SiteCapabilities
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The Rust row, its routes, and the two ways a Rust link can reach the app
+ * (M14, `docs/modules/rust/PLAN.md` §18).
+ *
+ * The question this file really asks is the phase criterion's other half: **a UO
+ * site is unchanged.** Two game modules can be installed on one backend, and
+ * neither one's rows may appear on a site running only the other.
+ */
+class RustNavigationTest {
+
+    private fun serving(vararg caps: String) =
+        SiteCapabilities(core = emptySet(), modules = caps.toSet())
+
+    private fun routesFor(capabilities: SiteCapabilities?) =
+        visibleEntries(APP_MENU, Session.SignedOut, features = null, capabilities = capabilities)
+            .map { it.route }
+
+    @Test fun aRustSiteShowsTheRustRowAndNoShardRows() {
+        val routes = routesFor(serving(Capability.RUST))
+
+        assertTrue(Routes.RUST in routes)
+        assertFalse("a Rust site has no shard", Routes.SHARD in routes)
+        assertFalse(Routes.ATLAS in routes)
+    }
+
+    @Test fun aUoSiteIsExactlyAsItWas() {
+        // The other half of the criterion. Adding a second game module must not
+        // put a row on a site that does not run it.
+        val routes = routesFor(serving(Capability.SHARD))
+
+        assertFalse("a UO site has no Rust row", Routes.RUST in routes)
+        assertTrue(Routes.SHARD in routes)
+    }
+
+    @Test fun bothModulesInstalledShowsBothTrees() {
+        val routes = routesFor(serving(Capability.SHARD, Capability.RUST))
+
+        assertTrue(Routes.SHARD in routes)
+        assertTrue(Routes.RUST in routes)
+    }
+
+    @Test fun theSurfaceCapabilitiesDoNotRevealTheRow() {
+        // `module-rust` declares `servers`, `killfeed`, `leaderboard`, `presence`
+        // and `wipes` as well, and the app gates on NONE of them — every one names
+        // a surface, and core flattens all modules' capabilities into one list, so
+        // another module declaring `servers` would otherwise reveal these screens
+        // on a site with no Rust at all.
+        val routes = routesFor(serving("servers", "killfeed", "leaderboard", "presence", "wipes"))
+
+        assertFalse(Routes.RUST in routes)
+    }
+
+    @Test fun aHostThatHasNeverAnsweredStillShowsEverything() {
+        // Fail-open on an UNKNOWN answer, which is not the same as an empty one.
+        // The server gates every call regardless, so the cost of guessing wrong is
+        // a link that briefly 404s.
+        assertTrue(Routes.RUST in routesFor(null))
+    }
+
+    @Test fun aServerIdIsEncodedIntoItsRoute() {
+        assertEquals("rust/servers/main", Routes.rustServer("main"))
+        assertEquals("rust/servers/eu-main", Routes.rustServer("eu-main"))
+        // An operator names these, and nothing stops one carrying a character a
+        // path would otherwise eat.
+        assertEquals("rust/servers/a%2Fb", Routes.rustServer("a/b"))
+        assertEquals("rust/servers/two%20words", Routes.rustServer("two words"))
+    }
+
+    @Test fun theWebsiteNavRowOpensNatively() {
+        // `module-rust` registers exactly one nav item, `{ label: 'Servers', to:
+        // '/rust' }`. Without this mapping an admin's nav override on that row —
+        // or an added link to it — hands off to a browser instead.
+        assertEquals(Routes.RUST, appRouteForWebPath("/rust"))
+        assertEquals(Routes.RUST, appRouteForWebPath("/rust/"))
+    }
+
+    @Test fun anAddedLinkToOneServerResolves() {
+        assertEquals(Routes.rustServer("main"), resolveWebPath("/rust/servers/main"))
+    }
+
+    @Test fun theRustPrefixIsNotMistakenForACmsPage() {
+        // The site serves CMS pages from a top-level `/<slug>`, and `/rust` would
+        // otherwise fall into that rule and open a page-not-found screen. It is
+        // reserved so the nav table above answers it — and so that a site WITHOUT
+        // the module hands off to the browser, which gives the same answer the web
+        // would.
+        assertEquals(Routes.RUST, resolveWebPath("/rust"))
+        assertNull("a deeper unknown Rust path hands off", resolveWebPath("/rust/servers/main/extra"))
+    }
+
+    @Test fun aRustPathWithAQueryHandsOff() {
+        // The website keeps tab, filter, wipe and sort in the URL; the app keeps
+        // them in a view model. Resolving `?tab=wipes` natively would silently drop
+        // what the admin wrote, so it goes to the browser, which honors it.
+        assertNull(resolveWebPath("/rust?tab=wipes"))
+        assertNull(resolveWebPath("/rust/servers/main?wipe=w1"))
+    }
+}

app/src/test/java/com/runicgateway/app/ui/rust/RustBadgeViewModelTest.kt

@@ -0,0 +1,80 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustServerListDto
+import com.runicgateway.app.data.api.fake.FakeRustApi
+import com.runicgateway.app.data.repository.RustRepository
+import com.runicgateway.app.util.MainDispatcherRule
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+import java.io.IOException
+
+/** The drawer row's live count — the phone's answer to D15 (M14). */
+class RustBadgeViewModelTest {
+
+    @get:Rule
+    val dispatcherRule = MainDispatcherRule()
+
+    private val api = FakeRustApi()
+    private fun viewModel() = RustBadgeViewModel(RustRepository(api))
+
+    @Test
+    fun `it sums the people on every server`() {
+        api.servers = RustServerListDto(
+            listOf(
+                RustServerDto(id = "a", online = true, players = 12),
+                RustServerDto(id = "b", online = true, players = 30),
+            ),
+        )
+
+        val vm = viewModel()
+        vm.refresh(installed = true)
+
+        assertEquals(42, vm.online.value)
+    }
+
+    @Test
+    fun `a site without the module is never asked`() {
+        // The gate is the caller's — the drawer already knows, from the capability
+        // answer. A site running a different game makes no request at all.
+        val vm = viewModel()
+        vm.refresh(installed = false)
+
+        assertEquals(0, api.serversCalls)
+        assertEquals(0, vm.online.value)
+    }
+
+    @Test
+    fun `an unreachable server contributes nothing on its own`() {
+        // A stale or offline row already answers `online: false` with `players: 0`
+        // server-side, so there is no second staleness rule to keep in step here.
+        api.servers = RustServerListDto(
+            listOf(
+                RustServerDto(id = "a", online = true, players = 5),
+                RustServerDto(id = "b", online = false, players = 0, stale = true),
+            ),
+        )
+
+        val vm = viewModel()
+        vm.refresh(installed = true)
+
+        assertEquals(5, vm.online.value)
+    }
+
+    @Test
+    fun `a failed read keeps the last number rather than dropping to zero`() {
+        // A moment with no connectivity is not everybody logging off.
+        api.servers = RustServerListDto(listOf(RustServerDto(id = "a", online = true, players = 7)))
+        val vm = viewModel()
+        vm.refresh(installed = true)
+
+        api.error = IOException("offline")
+        vm.refresh(installed = true)
+
+        assertEquals(7, vm.online.value)
+    }
+}

app/src/test/java/com/runicgateway/app/ui/rust/RustDtoTest.kt

@@ -0,0 +1,105 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import com.runicgateway.app.data.api.dto.RustEventDto
+import com.runicgateway.app.data.api.dto.RustServerListDto
+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 what the module actually answers with (M14).
+ *
+ * The JSON here is copied from `module-rust`'s own shape functions rather than
+ * invented, because the only thing worth testing about a DTO is whether it agrees
+ * with the other end.
+ */
+class RustDtoTest {
+
+    private val json = Json { ignoreUnknownKeys = true }
+
+    @Test
+    fun `an unreachable server decodes with everything it last said`() {
+        // The phase criterion in one object: `online: false`, `stale: true`, and
+        // every descriptive field still populated. This is what makes a page that
+        // renders while the game is off possible at all.
+        val list = json.decodeFromString<RustServerListDto>(
+            """
+            {"servers":[{
+              "id":"main","name":"Main","online":false,"players":0,"maxPlayers":100,
+              "hostname":"Main | Vanilla","level":"Procedural Map","worldSize":4000,
+              "seed":1934567,"wipeId":"w-2026-09-04","wipedAt":"2026-09-04T18:00:00.000Z",
+              "lastSeenAt":"2026-09-14T10:12:00.000Z","updatedAt":"2026-09-16T13:59:30.000Z",
+              "stale":true
+            }]}
+            """.trimIndent(),
+        )
+
+        val server = list.servers.single()
+        assertFalse(server.online)
+        assertTrue(server.stale)
+        assertEquals("Procedural Map", server.level)
+        assertEquals(4000, server.worldSize)
+        // The two timestamps are two facts and both survive the wire.
+        assertEquals("2026-09-14T10:12:00.000Z", server.lastSeenAt)
+        assertEquals("2026-09-16T13:59:30.000Z", server.updatedAt)
+    }
+
+    @Test
+    fun `a server that has never connected decodes with nulls, not zeroes`() {
+        val list = json.decodeFromString<RustServerListDto>(
+            """{"servers":[{"id":"new","name":"New","online":false,"players":0,"maxPlayers":0,
+               "hostname":null,"level":null,"worldSize":null,"seed":null,"wipeId":null,
+               "wipedAt":null,"lastSeenAt":null,"updatedAt":null,"stale":true}]}""",
+        )
+
+        val server = list.servers.single()
+        assertNull(server.level)
+        assertNull(server.worldSize)
+        assertNull(server.lastSeenAt)
+    }
+
+    @Test
+    fun `an unknown field does not break decoding`() {
+        // Protocol 2 is not the last one. A later plugin adds fields to a frame's
+        // envelope and an older app must keep reading the rest.
+        val list = json.decodeFromString<RustServerListDto>(
+            """{"servers":[{"id":"main","name":"Main","somethingNew":{"a":1}}],"alsoNew":7}""",
+        )
+
+        assertEquals("main", list.servers.single().id)
+    }
+
+    @Test
+    fun `a frame keeps whatever the plugin wrote`() {
+        val event = json.decodeFromString<RustEventDto>(
+            """{"id":9,"kind":"player.death","t":1789574400000,"wipeId":"w1","steamId":"765",
+               "frame":{"name":"Bob","attackerType":"player","attackerName":"Alice","distance":42.4}}""",
+        )
+
+        assertEquals("player.death", event.kind)
+        assertEquals(1789574400000L, event.t)
+        assertEquals("Alice", event.str("attackerName"))
+        assertEquals(42.4, event.num("distance")!!, 0.001)
+        assertNull("an absent field is null, not empty", event.str("weapon"))
+        assertFalse(event.flag("sleeping"))
+    }
+
+    @Test
+    fun `a frame with no fields at all still decodes`() {
+        // `server.initialized` carries an envelope and nothing else, and the model
+        // answers an EMPTY frame for a stored row whose JSON will not parse —
+        // deliberately, so one bad row does not fail a whole page.
+        val event = json.decodeFromString<RustEventDto>(
+            """{"id":1,"kind":"server.initialized","t":1,"frame":{}}""",
+        )
+
+        assertNull(event.str("name"))
+        assertEquals(FeedTone.SERVER, describe(event).tone)
+    }
+}

app/src/test/java/com/runicgateway/app/ui/rust/RustFeedTest.kt

@@ -0,0 +1,140 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import com.runicgateway.app.data.api.dto.RustEventDto
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonObject
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * What a feed row says (M14).
+ *
+ * The frames here are the shapes the bridge plugin actually emits, written as
+ * JSON rather than built with a DTO constructor — the whole point of the untyped
+ * `frame` is that the app reads names off the wire, and a test that bypassed the
+ * parse would prove nothing about the names.
+ */
+class RustFeedTest {
+
+    private fun row(kind: String, frame: String = "{}", t: Long = 1_000): RustEventDto =
+        RustEventDto(id = 1, kind = kind, t = t, frame = Json.parseToJsonElement(frame) as JsonObject)
+
+    @Test
+    fun `a player kill names the killer, the victim and the weapon`() {
+        val line = describe(
+            row(
+                "player.death",
+                """{"name":"Bob","attackerType":"player","attackerName":"Alice","weapon":"rifle.ak","distance":42.4}""",
+            ),
+        )
+
+        assertEquals(FeedTone.KILL, line.tone)
+        assertEquals("Alice", line.actor)
+        assertEquals("killed", line.verb)
+        assertEquals("Bob", line.subject)
+        assertTrue(line.detail.contains("with rifle ak"))
+        assertTrue(line.detail.contains("42m"))
+    }
+
+    @Test
+    fun `a fall is a death by nobody, not a kill`() {
+        // The failure this distinction exists to avoid: `HitInfo` is legitimately
+        // null when the world kills somebody, so an ABSENT attacker type is the
+        // environment case rather than a missing field. Reporting it as a kill by
+        // nobody is the bug.
+        val line = describe(row("player.death", """{"name":"Bob"}"""))
+
+        assertEquals(FeedTone.DEATH, line.tone)
+        assertEquals("Bob", line.actor)
+        assertEquals("died", line.verb)
+        assertNull(line.subject)
+    }
+
+    @Test
+    fun `an NPC kill reads the prefab as words`() {
+        val line = describe(
+            row("player.death", """{"name":"Bob","attackerType":"npc","attackerName":"patrolhelicopter"}"""),
+        )
+
+        assertEquals("patrolhelicopter", line.actor)
+        assertEquals("Bob", line.subject)
+    }
+
+    @Test
+    fun `a suicide names one person once`() {
+        val line = describe(row("player.death", """{"name":"Bob","attackerType":"self"}"""))
+
+        assertEquals("Bob", line.actor)
+        assertNull(line.subject)
+    }
+
+    @Test
+    fun `chat puts the colon in the join, never in the message`() {
+        val line = describe(row("player.chat", """{"name":"Bob","message":"see you in september"}"""))
+
+        assertEquals(": ", line.join)
+        assertEquals("see you in september", line.verb)
+    }
+
+    @Test
+    fun `a disconnect with no session reports only the reason`() {
+        // The plugin OMITS `sessionSec` for a player who was already connected when
+        // it loaded, so an absent value means "unknown" and must not become "after
+        // 0s" — which is what a DTO default of zero would produce if it were read
+        // without this guard.
+        val line = describe(row("player.disconnected", """{"name":"Bob","reason":"Disconnected"}"""))
+
+        assertEquals("Disconnected", line.detail)
+    }
+
+    @Test
+    fun `a JSON null field does not become the word null`() {
+        // A primitive's `content` is literally "null" for a JSON null, and the
+        // plugin writes explicit nulls — so a naive read puts the four letters
+        // into a killfeed line.
+        val line = describe(row("player.disconnected", """{"name":"Bob","reason":null,"sessionSec":null}"""))
+
+        assertEquals("", line.detail)
+    }
+
+    @Test
+    fun `an unknown kind renders as itself rather than vanishing`() {
+        // A later protocol adds kinds and an operator's module may be older than
+        // their game host. The server's allowlist has already decided the row may
+        // be seen; dropping it here would be the screen quietly saying less than
+        // the truth.
+        val line = describe(row("player.teleported", """{"name":"Bob"}"""))
+
+        assertEquals(FeedTone.OTHER, line.tone)
+        assertEquals("player.teleported", line.verb)
+        assertEquals("Bob", line.actor)
+    }
+
+    @Test
+    fun `the tally kind is not in the feed's own list`() {
+        // It is an aggregate the plugin flushes every sixty seconds per active
+        // player, so a feed carrying it would be mostly wood counts. It is the
+        // leaderboard's input.
+        assertTrue("player.tally" !in FEED_KINDS)
+    }
+
+    @Test
+    fun `every filter asks for kinds the feed knows`() {
+        for (filter in FEED_FILTERS) {
+            assertTrue(
+                "${filter.id} asks for a kind the feed does not list",
+                FEED_KINDS.containsAll(filter.kinds),
+            )
+        }
+    }
+
+    @Test
+    fun `an unknown filter id falls back to everything`() {
+        assertEquals(FEED_KINDS, kindsFor("nonsense"))
+    }
+}

app/src/test/java/com/runicgateway/app/ui/rust/RustFormatTest.kt

@@ -0,0 +1,134 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.time.Instant
+import java.time.ZoneId
+import java.util.Locale
+
+/** Formatting rules the Rust screens depend on (M14). */
+class RustFormatTest {
+
+    private val utc = ZoneId.of("UTC")
+    private val uk = Locale.UK
+    private val now = Instant.parse("2026-09-16T14:00:00Z")
+
+    @Test
+    fun `a row from today is a bare time`() {
+        val stamp = Instant.parse("2026-09-16T09:05:00Z").toEpochMilli()
+        val text = feedClock(value = null, epochMillis = stamp, now = now, zone = utc, locale = uk)
+
+        assertTrue(text, ':' in text)
+        assertTrue("today's row should carry no date: $text", "Sep" !in text)
+    }
+
+    @Test
+    fun `a row from another day carries its date`() {
+        // The defect this rule exists for: the feed can be filtered to a past
+        // wipe, and three events from six weeks ago all rendered as `02:03 PM`
+        // read as this afternoon. The boundary is the CALENDAR day, not a
+        // duration, because that is what a reader means by "what time was that".
+        val stamp = Instant.parse("2026-08-05T09:05:00Z").toEpochMilli()
+        val text = feedClock(value = null, epochMillis = stamp, now = now, zone = utc, locale = uk)
+
+        assertTrue("an older row should carry a date: $text", "Aug" in text)
+    }
+
+    @Test
+    fun `yesterday is another day even when it is minutes ago`() {
+        val justBeforeMidnight = Instant.parse("2026-09-15T23:58:00Z").toEpochMilli()
+        val shortlyAfter = Instant.parse("2026-09-16T00:02:00Z")
+        val text = feedClock(
+            value = null,
+            epochMillis = justBeforeMidnight,
+            now = shortlyAfter,
+            zone = utc,
+            locale = uk,
+        )
+
+        assertTrue("four minutes ago but a different day: $text", "Sep" in text)
+    }
+
+    @Test
+    fun `an unparseable stamp is empty rather than a guess`() {
+        assertEquals("", feedClock(value = null, epochMillis = null, now = now, zone = utc, locale = uk))
+        assertEquals("", feedClock(value = "not a date", now = now, zone = utc, locale = uk))
+    }
+
+    @Test
+    fun `a zoneless DATETIME is read as UTC`() {
+        // Express serializes a Date to ISO with a `Z`, but these values start life
+        // as MariaDB DATETIME columns and one read back as a string reaches the
+        // wire with no zone at all. Reading it as local time silently shifts every
+        // timestamp by the device's offset — a bug that looks right on the machine
+        // it was written on.
+        val text = feedClock(
+            value = "2026-08-05 09:05:00",
+            now = now,
+            zone = utc,
+            locale = uk,
+        )
+
+        assertTrue(text, "Aug" in text)
+        assertTrue(text, "09:05" in text)
+    }
+
+    @Test
+    fun `a server that has never reported has no ago line at all`() {
+        // Null rather than the word "never", so the caller decides what that looks
+        // like — on this surface a server that has never reported is a real and
+        // ordinary state, not a missing value to apologise for.
+        assertNull(rustAgo(null, now))
+        assertNull(rustAgo("", now))
+    }
+
+    @Test
+    fun `under a minute says just now rather than in zero seconds`() {
+        assertEquals("just now", rustAgo("2026-09-16T13:59:40Z", now))
+    }
+
+    @Test
+    fun `ago picks the largest unit that fits`() {
+        assertEquals("3 minutes ago", rustAgo("2026-09-16T13:57:00Z", now))
+        assertEquals("2 hours ago", rustAgo("2026-09-16T12:00:00Z", now))
+        assertEquals("1 day ago", rustAgo("2026-09-15T14:00:00Z", now))
+    }
+
+    @Test
+    fun `playtime drops seconds above a minute and keeps them below`() {
+        assertEquals("—", playtime(null))
+        assertEquals("—", playtime(0))
+        assertEquals("40s", playtime(40))
+        assertEquals("12m", playtime(12 * 60))
+        assertEquals("4h 12m", playtime(4 * 3600 + 12 * 60))
+        assertEquals("2h", playtime(2 * 3600))
+    }
+
+    @Test
+    fun `a prefab reads as words without a lookup table`() {
+        assertEquals("rifle ak", prefabName("rifle.ak"))
+        assertEquals("patrolhelicopter", prefabName("patrolhelicopter"))
+        assertEquals("", prefabName(null))
+    }
+
+    @Test
+    fun `a nameless player shows a shortened id, not the word unknown`() {
+        // A steam id is not a name and does not look like one, which is the point:
+        // the plugin knows an id before it knows anything else, and "Unknown" would
+        // lose the only identifier there is.
+        assertEquals("…345678", playerLabel(null, "76561198012345678"))
+        assertEquals("Bob", playerLabel("Bob", "76561198012345678"))
+        assertEquals("…345678", playerLabel("  ", "76561198012345678"))
+    }
+
+    @Test
+    fun `a short id is left whole`() {
+        assertEquals("1234", shortSteamId("1234"))
+        assertEquals("", shortSteamId(null))
+    }
+}

app/src/test/java/com/runicgateway/app/ui/rust/RustServerViewModelTest.kt

@@ -0,0 +1,193 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.rust
+
+import androidx.lifecycle.SavedStateHandle
+import com.runicgateway.app.data.api.dto.RustLeaderboardDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardRowDto
+import com.runicgateway.app.data.api.dto.RustOnlineDto
+import com.runicgateway.app.data.api.dto.RustPresenceDto
+import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustServerResponse
+import com.runicgateway.app.data.api.dto.RustWipeDto
+import com.runicgateway.app.data.api.dto.RustWipeListDto
+import com.runicgateway.app.data.api.fake.FakeRustApi
+import com.runicgateway.app.data.repository.RustRepository
+import com.runicgateway.app.ui.UiState
+import com.runicgateway.app.util.MainDispatcherRule
+import okhttp3.ResponseBody.Companion.toResponseBody
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import retrofit2.HttpException
+import retrofit2.Response
+import java.io.IOException
+
+/** One server's page: what it asks for, and when (M14). */
+class RustServerViewModelTest {
+
+    @get:Rule
+    val dispatcherRule = MainDispatcherRule()
+
+    private val api = FakeRustApi()
+    private val repository = RustRepository(api)
+
+    private fun viewModel(id: String = "main") = RustServerViewModel(
+        repository,
+        SavedStateHandle(mapOf("serverId" to id)),
+    )
+
+    @Test
+    fun `it opens on the feed and asks for nothing else`() {
+        api.server = RustServerResponse(RustServerDto(id = "main", name = "Main"))
+
+        val vm = viewModel()
+
+        assertEquals(RustTab.FEED, vm.state.value.tab)
+        assertEquals(1, api.eventCalls)
+        assertEquals(0, api.leaderboardCalls)
+        assertEquals(0, api.onlineCalls)
+        assertEquals(0, api.wipeCalls)
+    }
+
+    @Test
+    fun `all time sends no wipe parameter at all`() {
+        // `?wipe=` asks for a wipe whose id is the empty string and answers
+        // nothing, with no error to notice. An absent parameter must be ABSENT.
+        viewModel()
+
+        assertNull(api.lastFeedWipe)
+    }
+
+    @Test
+    fun `everything sends the whole kind list, and kills sends one`() {
+        val vm = viewModel()
+        assertEquals(FEED_KINDS.joinToString(","), api.lastKind)
+
+        vm.selectFilter("kills")
+        assertEquals("player.death", api.lastKind)
+    }
+
+    @Test
+    fun `a tab is loaded once, not on every visit`() {
+        // Re-asking on every tab switch would put a spinner over a leaderboard the
+        // reader has already read, for an answer that cannot have changed while
+        // they were three taps away.
+        api.leaderboard = RustLeaderboardDto(listOf(RustLeaderboardRowDto(steamId = "1", kills = 3)))
+        val vm = viewModel()
+
+        vm.selectTab(RustTab.LEADERBOARD)
+        vm.selectTab(RustTab.FEED)
+        vm.selectTab(RustTab.LEADERBOARD)
+
+        assertEquals(1, api.leaderboardCalls)
+    }
+
+    @Test
+    fun `the poll asks only for the panel on screen`() {
+        api.online = RustOnlineDto(listOf(RustPresenceDto(steamId = "1")))
+        val vm = viewModel()
+        val feedBefore = api.eventCalls
+
+        vm.selectTab(RustTab.ONLINE)
+        val onlineBefore = api.onlineCalls
+        vm.refresh()
+
+        assertEquals("the feed is not on screen", feedBefore, api.eventCalls)
+        assertEquals(onlineBefore + 1, api.onlineCalls)
+    }
+
+    @Test
+    fun `a poll on a still panel asks for nothing but the server line`() {
+        api.wipes = RustWipeListDto(listOf(RustWipeDto(wipeId = "w1")))
+        val vm = viewModel()
+
+        vm.selectTab(RustTab.WIPES)
+        val wipesBefore = api.wipeCalls
+        val feedBefore = api.eventCalls
+        vm.refresh()
+
+        assertEquals(wipesBefore, api.wipeCalls)
+        assertEquals(feedBefore, api.eventCalls)
+    }
+
+    @Test
+    fun `choosing a wipe re-asks the feed and, if it is loaded, the leaderboard`() {
+        api.leaderboard = RustLeaderboardDto(listOf(RustLeaderboardRowDto(steamId = "1")))
+        val vm = viewModel()
+
+        vm.selectWipe("wipe-1")
+        assertEquals("wipe-1", api.lastFeedWipe)
+        // Nobody has opened the leaderboard, so nothing was fetched for it.
+        assertEquals(0, api.leaderboardCalls)
+
+        vm.selectTab(RustTab.LEADERBOARD)
+        vm.selectWipe("wipe-2")
+        assertEquals("wipe-2", api.lastLeaderboardWipe)
+        assertEquals("wipe-2", api.lastFeedWipe)
+    }
+
+    @Test
+    fun `picking the same wipe twice asks nothing`() {
+        val vm = viewModel()
+        vm.selectWipe("wipe-1")
+        val calls = api.eventCalls
+
+        vm.selectWipe("wipe-1")
+
+        assertEquals(calls, api.eventCalls)
+    }
+
+    @Test
+    fun `opening a wipe from the wipes tab lands on the feed`() {
+        // Picking a wipe there is a navigation as much as a filter: the question is
+        // "what happened during that map", and the answer is the feed.
+        val vm = viewModel()
+        vm.selectTab(RustTab.WIPES)
+
+        vm.openWipe("wipe-1")
+
+        assertEquals(RustTab.FEED, vm.state.value.tab)
+        assertEquals("wipe-1", vm.state.value.selectedWipe)
+    }
+
+    @Test
+    fun `a 404 on the server read is its own state, not a generic error`() {
+        // A mistyped address is not a fault. The screen reads NOT_FOUND and says
+        // "no such server" rather than dressing it as an outage.
+        api.error = HttpException(Response.error<Any>(404, "".toResponseBody(null)))
+
+        val vm = viewModel("typo")
+
+        val state = vm.state.value.server.state
+        assertTrue(state is UiState.Error)
+        assertEquals(404, (state as UiState.Error).httpStatus)
+    }
+
+    @Test
+    fun `a failed poll keeps the server line that was there`() {
+        api.server = RustServerResponse(RustServerDto(id = "main", name = "Main"))
+        val vm = viewModel()
+
+        api.error = IOException("offline")
+        vm.refresh()
+
+        val state = vm.state.value.server.state
+        assertTrue(state is UiState.Success)
+        assertEquals("Main", (state as UiState.Success).data.name)
+        assertTrue(vm.state.value.server.refreshFailed)
+    }
+
+    @Test
+    fun `sorting sends the API's own vocabulary`() {
+        val vm = viewModel()
+        vm.selectTab(RustTab.LEADERBOARD)
+
+        vm.selectSort(RustSort.PLAYTIME)
+
+        assertEquals("playtime", api.lastSort)
+    }
+}