feat(amethyst): in-app geohash location chat (Bitchat interop)

Adds a self-contained Android surface for Bitchat-interoperable public geohash chat, reachable from the geohash feed screen's new chat action: - GeohashChatScreen + GeohashChatViewModel: live subscription to the cell's ephemeral kind-20000/20001 events on the geographically-nearest relays, renders messages (nickname + teleport marker) with a live participant count, and sends kind-20000 messages signed with the device's per-geohash throwaway identity plus a small NIP-13 PoW. - GeohashChatDeviceSeed: device-level random seed (global encrypted storage) all per-geohash identities derive from, kept off any account so posting never reveals the user's npub. - Account.signWithAndSendPrivately; Route.GeohashChat + navigation wiring. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0172JoMccseEKenyWan6txWV
2026-10-06 03:38:23 +00:00 · 2026-07-15 16:17:54 +00:00
parent b6729bec00
commit 5a0f3c8ff1
8 changed files with 467 additions and 1 deletions
@@ -3291,6 +3291,23 @@ class Account(
        client.publish(event, relayList)
    }

+    /**
+     * Sign [template] with an arbitrary [signer] (e.g. a per-geohash ephemeral
+     * identity that is deliberately NOT this account's key) and publish to exactly
+     * [relayList]. Used by geohash location chat, where authorship inside a cell
+     * must not be linkable to the user's npub.
+     */
+    suspend fun <T : Event> signWithAndSendPrivately(
+        template: EventTemplate<T>,
+        signer: NostrSigner,
+        relayList: Set<NormalizedRelayUrl>,
+    ): T {
+        val event = signer.sign(template)
+        cache.justConsumeMyOwnEvent(event)
+        if (relayList.isNotEmpty()) client.publish(event, relayList)
+        return event
+    }
+
    suspend fun <T : Event> signAndSendPrivatelyOrBroadcast(
        template: EventTemplate<T>,
        relayList: (T) -> List<NormalizedRelayUrl>?,
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.geohash
+
+import androidx.core.content.edit
+import com.vitorpamplona.amethyst.Amethyst
+import com.vitorpamplona.quartz.experimental.bitchat.identity.GeohashKeyDerivation
+import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
+import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.utils.RandomInstance
+
+/**
+ * Device-level random seed that all per-geohash chat identities are derived
+ * from (see [GeohashKeyDerivation]). Kept out of any account: geohash channel
+ * identities are anonymous and must not be linkable to the user's npub, and one
+ * seed per device (shared across accounts) matches Bitchat's model.
+ *
+ * Stored in the app's global encrypted storage, generated once on first use.
+ * Callers must be off the main thread (encrypted storage enforces this).
+ */
+object GeohashChatDeviceSeed {
+    private const val PREF_KEY = "geohash_chat_device_seed"
+
+    @Volatile private var cached: ByteArray? = null
+
+    fun seed(): ByteArray {
+        cached?.let { return it }
+        synchronized(this) {
+            cached?.let { return it }
+            val prefs = Amethyst.instance.encryptedStorage()
+            val existing = prefs.getString(PREF_KEY, null)
+            val seed =
+                if (existing != null && existing.length == GeohashKeyDerivation.SEED_SIZE * 2) {
+                    existing.hexToByteArray()
+                } else {
+                    val fresh = RandomInstance.bytes(GeohashKeyDerivation.SEED_SIZE)
+                    prefs.edit { putString(PREF_KEY, fresh.toHexKey()) }
+                    fresh
+                }
+            cached = seed
+            return seed
+        }
+    }
+
+    /** The Nostr key pair this device uses inside [geohash]. */
+    fun keyPair(geohash: String) = GeohashKeyDerivation.deriveKeyPair(seed(), geohash)
+}
@@ -102,6 +102,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.CalendarsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.create.NewCalendarCollectionScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.create.NewCalendarEventScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.detail.CalendarEventDetailScreen
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.geohashChat.GeohashChatScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup.CreateGroupScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup.EditGroupInfoScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup.MarmotGroupChatScreen
@@ -625,6 +626,14 @@ fun BuildNavigation(
            )
        }

+        composableFromEndArgs<Route.GeohashChat> {
+            GeohashChatScreen(
+                geohash = it.geohash,
+                accountViewModel = accountViewModel,
+                nav = nav,
+            )
+        }
+
        composableFromEndArgs<Route.RelayGroup> {
            RelayGroupChatScreen(
                id = it.id,
@@ -641,6 +641,10 @@ sealed class Route {

    @Serializable object NewEphemeralChat : Route()

+    @Serializable data class GeohashChat(
+        val geohash: String,
+    ) : Route()
+
    @Serializable data class RelayGroup(
        val id: String,
        val relayUrl: String,
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.geohashChat
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.experimental.bitchat.geohash.GeohashChatEvent
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon as SymbolIcon
+
+/**
+ * A Bitchat-interoperable public geohash location chat: everyone physically (or
+ * "teleported") in the same geohash cell shares an ephemeral, relay-broadcast
+ * room. Messages are signed with a per-geohash throwaway identity, so posting
+ * here does not reveal the account's npub.
+ */
+@Composable
+fun GeohashChatScreen(
+    geohash: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val viewModel: GeohashChatViewModel = viewModel(key = "GeohashChat/$geohash")
+    viewModel.init(geohash, accountViewModel)
+
+    val messages by viewModel.messages.collectAsStateWithLifecycle()
+    val participants by viewModel.participants.collectAsStateWithLifecycle()
+    val relays by viewModel.relays.collectAsStateWithLifecycle()
+
+    var nickname by remember { mutableStateOf("") }
+    var draft by remember { mutableStateOf("") }
+    val listState = rememberLazyListState()
+
+    Column(Modifier.fillMaxSize().imePadding()) {
+        Column(Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 8.dp)) {
+            Text("#$geohash", style = MaterialTheme.typography.titleMedium, fontWeight = FontWeight.Bold)
+            Text(
+                "$participants here · ${relays.size} relays",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        }
+        HorizontalDivider()
+
+        LazyColumn(
+            state = listState,
+            reverseLayout = true,
+            modifier = Modifier.weight(1f).fillMaxWidth(),
+        ) {
+            items(messages.asReversed(), key = { it.id }) { message ->
+                GeohashMessageRow(message)
+            }
+        }
+
+        HorizontalDivider()
+        OutlinedTextField(
+            value = nickname,
+            onValueChange = { nickname = it },
+            singleLine = true,
+            label = { Text("Nickname (optional)") },
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 4.dp),
+        )
+        Row(
+            Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            OutlinedTextField(
+                value = draft,
+                onValueChange = { draft = it },
+                modifier = Modifier.weight(1f),
+                placeholder = { Text("Message #$geohash") },
+            )
+            IconButton(
+                enabled = draft.isNotBlank() && relays.isNotEmpty(),
+                onClick = {
+                    viewModel.sendMessage(draft, nickname)
+                    draft = ""
+                },
+            ) {
+                SymbolIcon(symbol = MaterialSymbols.AutoMirrored.Send, contentDescription = "Send")
+            }
+        }
+    }
+}
+
+@Composable
+private fun GeohashMessageRow(message: GeohashChatEvent) {
+    val name = message.nickname()?.takeIf { it.isNotBlank() } ?: message.pubKey.take(8)
+    Column(Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 4.dp)) {
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            Text(name, style = MaterialTheme.typography.labelLarge, fontWeight = FontWeight.SemiBold)
+            if (message.isTeleported()) {
+                Text(
+                    "  ✈",
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.primary,
+                )
+            }
+        }
+        Text(message.content, style = MaterialTheme.typography.bodyMedium)
+    }
+}
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.geohashChat
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.vitorpamplona.amethyst.Amethyst
+import com.vitorpamplona.amethyst.commons.service.georelay.GeoRelayCsvLoader
+import com.vitorpamplona.amethyst.commons.service.georelay.GeoRelayDirectory
+import com.vitorpamplona.amethyst.service.geohash.GeohashChatDeviceSeed
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.experimental.bitchat.geohash.GeohashChatEvent
+import com.vitorpamplona.quartz.experimental.bitchat.geohash.GeohashPresenceEvent
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.nip01Core.crypto.verify
+import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.SubscriptionListener
+import com.vitorpamplona.quartz.nip01Core.relay.client.single.newSubId
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
+import com.vitorpamplona.quartz.nip13Pow.miner.PoWMiner
+import com.vitorpamplona.quartz.utils.TimeUtils
+import kotlinx.coroutines.Dispatchers
+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 kotlinx.coroutines.withContext
+
+/**
+ * Drives a single Bitchat-interoperable geohash location chat.
+ *
+ * Ephemeral kind-20000 messages (and kind-20001 presence) for the cell are
+ * routed to the geographically-nearest relays ([GeoRelayDirectory]); because the
+ * events are ephemeral the relays broadcast but do not store them, so this holds
+ * a live subscription for as long as the screen is open. Outgoing messages are
+ * signed with the device's per-geohash throwaway identity and carry a small
+ * NIP-13 proof of work so relays that rate-limit geohash chat let them through.
+ *
+ * Follows the codebase convention of a no-arg ViewModel initialized once via
+ * [init] from the composable.
+ */
+class GeohashChatViewModel : ViewModel() {
+    lateinit var geohash: String
+        private set
+
+    private lateinit var accountViewModel: AccountViewModel
+
+    private val _messages = MutableStateFlow<List<GeohashChatEvent>>(emptyList())
+    val messages: StateFlow<List<GeohashChatEvent>> = _messages.asStateFlow()
+
+    private val _relays = MutableStateFlow<List<NormalizedRelayUrl>>(emptyList())
+    val relays: StateFlow<List<NormalizedRelayUrl>> = _relays.asStateFlow()
+
+    private val _participants = MutableStateFlow(0)
+    val participants: StateFlow<Int> = _participants.asStateFlow()
+
+    private val seen = HashSet<String>()
+    private val present = HashSet<String>()
+    private val subId = newSubId()
+    private var started = false
+    private var subscribed = false
+
+    fun init(
+        geohash: String,
+        accountViewModel: AccountViewModel,
+    ) {
+        if (started) return
+        started = true
+        this.geohash = geohash
+        this.accountViewModel = accountViewModel
+        viewModelScope.launch { start() }
+    }
+
+    private suspend fun start() {
+        val relays = resolveRelays()
+        _relays.value = relays
+        if (relays.isEmpty()) return
+
+        val since = TimeUtils.now() - INITIAL_LOOKBACK_SECS
+        val filter =
+            Filter(
+                kinds = listOf(GeohashChatEvent.KIND, GeohashPresenceEvent.KIND),
+                tags = mapOf("g" to listOf(geohash)),
+                since = since,
+                limit = 500,
+            )
+        val listener =
+            object : SubscriptionListener {
+                override fun onEvent(
+                    event: Event,
+                    isLive: Boolean,
+                    relay: NormalizedRelayUrl,
+                    forFilters: List<Filter>?,
+                ) {
+                    ingest(event)
+                }
+            }
+        accountViewModel.account.client.subscribe(subId, relays.associateWith { listOf(filter) }, listener)
+        subscribed = true
+    }
+
+    private fun ingest(event: Event) {
+        if (!event.verify()) return
+        if (event.geohashOrNull() != geohash) return
+        if (!seen.add(event.id)) return
+        when (event) {
+            is GeohashChatEvent -> {
+                if (present.add(event.pubKey)) _participants.value = present.size
+                _messages.update { current -> (current + event).sortedBy { it.createdAt } }
+            }
+
+            is GeohashPresenceEvent -> {
+                if (present.add(event.pubKey)) _participants.value = present.size
+            }
+        }
+    }
+
+    private fun Event.geohashOrNull(): String? =
+        when (this) {
+            is GeohashChatEvent -> geohash()
+            is GeohashPresenceEvent -> geohash()
+            else -> null
+        }
+
+    /** Build, mine a small PoW, sign with the per-geohash identity, and publish. */
+    fun sendMessage(
+        text: String,
+        nickname: String?,
+        teleported: Boolean = false,
+    ) {
+        val trimmed = text.trim()
+        if (trimmed.isEmpty()) return
+        val relays = _relays.value.toSet()
+        if (relays.isEmpty()) return
+
+        viewModelScope.launch {
+            val keyPair = withContext(Dispatchers.IO) { GeohashChatDeviceSeed.keyPair(geohash) }
+            val signer = NostrSignerInternal(keyPair)
+
+            var template = GeohashChatEvent.build(trimmed, geohash, nickname = nickname?.ifBlank { null }, teleported = teleported)
+            template =
+                withContext(Dispatchers.Default) {
+                    val deadline = System.nanoTime() + POW_TIMEOUT_NANOS
+                    runCatching {
+                        PoWMiner.mine(template, keyPair.pubKey.toHexKey(), POW_BITS, powThreads()) { System.nanoTime() < deadline }
+                    }.getOrDefault(template)
+                }
+
+            runCatching { accountViewModel.account.signWithAndSendPrivately(template, signer, relays) }
+        }
+    }
+
+    /** Announce presence in the cell (a bare kind-20001 heartbeat). */
+    fun announcePresence(nickname: String?) {
+        val relays = _relays.value.toSet()
+        if (relays.isEmpty()) return
+        viewModelScope.launch {
+            val keyPair = withContext(Dispatchers.IO) { GeohashChatDeviceSeed.keyPair(geohash) }
+            val signer = NostrSignerInternal(keyPair)
+            val template = GeohashPresenceEvent.build(geohash, nickname = nickname?.ifBlank { null })
+            runCatching { accountViewModel.account.signWithAndSendPrivately(template, signer, relays) }
+        }
+    }
+
+    private suspend fun resolveRelays(): List<NormalizedRelayUrl> {
+        if (!refreshed) {
+            runCatching {
+                GeoRelayCsvLoader { Amethyst.instance.okHttpClients.getHttpClient(false) }.refresh(sharedDirectory)
+            }
+            refreshed = sharedDirectory.size > GeoRelayDirectory.FALLBACK.size
+        }
+        return sharedDirectory.closestRelays(geohash)
+    }
+
+    override fun onCleared() {
+        if (subscribed) runCatching { accountViewModel.account.client.unsubscribe(subId) }
+        super.onCleared()
+    }
+
+    companion object {
+        private const val INITIAL_LOOKBACK_SECS = 60L * 60L
+        private const val POW_BITS = 8
+        private const val POW_TIMEOUT_NANOS = 2_000_000_000L
+
+        private fun powThreads(): Int = Runtime.getRuntime().availableProcessors().coerceAtLeast(1)
+
+        /** Process-wide directory, refreshed once from the live CSV then reused across channels. */
+        private val sharedDirectory = GeoRelayDirectory()
+
+        @Volatile private var refreshed = false
+    }
+}
@@ -21,6 +21,7 @@
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.geohash

 import android.annotation.SuppressLint
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
@@ -28,6 +29,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.font.FontWeight
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserIsFollowingGeohash
 import com.vitorpamplona.amethyst.ui.feeds.WatchLifecycleAndUpdateModel
 import com.vitorpamplona.amethyst.ui.layouts.DisappearingScaffold
@@ -42,6 +44,8 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.geohash.dal.GeoHashFeedView
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.geohash.datasource.GeoHashFilterAssemblerSubscription
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.profile.FollowButton
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.profile.UnfollowButton
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon as SymbolIcon

@Composable
 fun GeoHashScreen(
@@ -91,7 +95,7 @@ fun GeoHashScreen(
            TopBarExtensibleWithBackButton(
                title = {
                    DisplayGeoTagHeader(tag.geohash, Modifier.weight(1f))
-                    GeoHashActionOptions(tag.geohash, accountViewModel)
+                    GeoHashActionOptions(tag.geohash, accountViewModel, nav)
                },
                popBack = nav::popBack,
            )
@@ -130,7 +134,15 @@ fun DisplayGeoTagHeader(
 fun GeoHashActionOptions(
    tag: String,
    accountViewModel: AccountViewModel,
+    nav: INav,
 ) {
+    IconButton(onClick = { nav.nav(Route.GeohashChat(tag)) }) {
+        SymbolIcon(
+            symbol = MaterialSymbols.AutoMirrored.Chat,
+            contentDescription = stringRes(R.string.geohash_chat_open),
+        )
+    }
+
    val isFollowingTag by observeUserIsFollowingGeohash(tag, accountViewModel)

    if (isFollowingTag) {
@@ -4198,4 +4198,5 @@
    <string name="unable_to_create_a_lightning_invoice_before_sending_the_zap_element_pr_not_found_in_the_resulting_json_with_user">Unable to create a lightning invoice from %1$s: Element pr not found in the resulting JSON.</string>
    <string name="app_name_debug" translatable="false">Amy Debug</string>
    <string name="app_name_benchmark" translatable="false">Amy Benchmark</string>
+    <string name="geohash_chat_open">Open location chat</string>
 </resources>