feat: attachment support — display, upload, and send files in chat

- Parse and render message attachments from loaded conversations (images
  inline via OkHttp + in-memory cache, other kinds as icon chips)
- Wire up the + button with Android file picker (ActivityResultContracts)
- Upload files to /api/v1/upload with progress tracking and preview chips
- Send attachments with chat requests and persist them in saved messages
- Markdown: horizontal rules, blockquotes, links, code block copy button

app/src/main/java/dev/kaizen/app/chat/ChatComponents.kt

@@ -46,6 +46,7 @@ import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
@@ -64,6 +65,7 @@ import androidx.compose.ui.text.font.FontStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import dev.kaizen.app.net.Attachment
 import dev.kaizen.app.ui.theme.Amber
 import dev.kaizen.app.ui.theme.AmberDeep
 import dev.kaizen.app.ui.theme.OnAmber
@@ -71,6 +73,27 @@ import java.time.LocalDateTime
 import java.time.format.DateTimeFormatter
 import java.util.Locale
 import kotlin.OptIn
+import android.graphics.BitmapFactory
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.material.icons.rounded.AudioFile
+import androidx.compose.material.icons.rounded.Close
+import androidx.compose.material.icons.rounded.Code
+import androidx.compose.material.icons.rounded.Image
+import androidx.compose.material.icons.automirrored.rounded.InsertDriveFile
+import androidx.compose.material.icons.rounded.PictureAsPdf
+import androidx.compose.material.icons.rounded.VideoFile
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.text.style.TextOverflow
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import java.util.concurrent.TimeUnit
 
 @Composable
 fun KaizenHeader(modifier: Modifier = Modifier) {
@@ -283,38 +306,45 @@ fun MessageRow(message: Message) {
     val cs = MaterialTheme.colorScheme
     val isDark = isSystemInDarkTheme()
 
+    val hasAttachments = message.attachments.isNotEmpty()
+
     if (message.role == Role.User) {
         Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.End) {
             val shape = RoundedCornerShape(20.dp, 20.dp, 6.dp, 20.dp)
 
-            // Specular highlighting and gradient matching the oklch brand colors
             val borderBrush = remember {
-                Brush.verticalGradient(
-                    listOf(
-                        Amber.copy(alpha = 0.45f),
-                        AmberDeep.copy(alpha = 0.15f)
-                    )
-                )
+                Brush.verticalGradient(listOf(Amber.copy(alpha = 0.45f), AmberDeep.copy(alpha = 0.15f)))
             }
             val bgBrush = remember {
-                Brush.verticalGradient(
-                    listOf(
-                        Amber.copy(alpha = 0.18f),
-                        AmberDeep.copy(alpha = 0.08f)
-                    )
-                )
+                Brush.verticalGradient(listOf(Amber.copy(alpha = 0.18f), AmberDeep.copy(alpha = 0.08f)))
             }
 
             Box(
                 Modifier
                     .widthIn(max = 300.dp)
-                    .shadow(elevation = 3.dp, shape = shape, clip = false) // Raised amber glass bubble!
+                    .shadow(elevation = 3.dp, shape = shape, clip = false)
                     .clip(shape)
                     .background(bgBrush)
-                    .border(1.2.dp, borderBrush, shape)
-                    .padding(horizontal = 16.dp, vertical = 11.dp),
+                    .border(1.2.dp, borderBrush, shape),
             ) {
-                Text(message.content, color = cs.onBackground, fontSize = 16.sp, lineHeight = 22.sp)
+                Column {
+                    if (hasAttachments) {
+                        AttachmentGrid(message.attachments, Modifier.padding(6.dp))
+                    }
+                    if (message.content.isNotBlank()) {
+                        Text(
+                            message.content,
+                            color = cs.onBackground,
+                            fontSize = 16.sp,
+                            lineHeight = 22.sp,
+                            modifier = Modifier.padding(
+                                start = 16.dp, end = 16.dp,
+                                top = if (hasAttachments) 4.dp else 11.dp,
+                                bottom = 11.dp,
+                            ),
+                        )
+                    }
+                }
             }
         }
     } else {
@@ -322,13 +352,16 @@ fun MessageRow(message: Message) {
             KaizenOrb(28.dp, streaming = message.streaming)
             Spacer(Modifier.width(10.dp))
             Box(Modifier.weight(1f).padding(top = 3.dp)) {
-                if (message.thinking) {
-                    TypingDots()
-                } else {
-                    MarkdownText(
-                        text = message.content,
-                        streaming = message.streaming,
-                    )
+                Column {
+                    if (hasAttachments) {
+                        AttachmentGrid(message.attachments)
+                        if (message.content.isNotBlank() || message.thinking) Spacer(Modifier.height(8.dp))
+                    }
+                    if (message.thinking) {
+                        TypingDots()
+                    } else {
+                        MarkdownText(text = message.content, streaming = message.streaming)
+                    }
                 }
             }
         }
@@ -361,12 +394,26 @@ private fun TypingDots() {
     }
 }
 
+/** A file pending upload or already uploaded, shown as a preview chip above the input. */
+data class PendingFile(
+    val id: String = java.util.UUID.randomUUID().toString(),
+    val name: String,
+    val mimeType: String,
+    val bytes: ByteArray,
+    val uploaded: Attachment? = null,
+    val error: String? = null,
+    val uploading: Boolean = true,
+)
+
 @Composable
 fun ChatInput(
     value: String,
     onValueChange: (String) -> Unit,
     onSend: () -> Unit,
     enabled: Boolean,
+    pendingFiles: List<PendingFile> = emptyList(),
+    onAddClick: () -> Unit = {},
+    onRemoveFile: (String) -> Unit = {},
     modifier: Modifier = Modifier,
 ) {
     val cs = MaterialTheme.colorScheme
@@ -408,40 +455,63 @@ fun ChatInput(
         }
     }
 
-    Row(
+    Column(
         modifier
             .fillMaxWidth()
             .padding(horizontal = 12.dp)
-            .shadow(elevation = 8.dp, shape = RoundedCornerShape(28.dp), clip = false) // Luxurious floating ambient shadow!
+            .shadow(elevation = 8.dp, shape = RoundedCornerShape(28.dp), clip = false)
             .clip(RoundedCornerShape(28.dp))
             .background(glassBg)
-            .border(1.2.dp, glassBorder, RoundedCornerShape(28.dp))
-            .padding(horizontal = 8.dp, vertical = 8.dp),
-        verticalAlignment = Alignment.CenterVertically,
+            .border(1.2.dp, glassBorder, RoundedCornerShape(28.dp)),
     ) {
-        GhostIconButton(Icons.Rounded.Add, "Anhang")
-        Box(
-            Modifier
-                .weight(1f)
-                .heightIn(min = 36.dp)
-                .padding(horizontal = 4.dp),
-            contentAlignment = Alignment.CenterStart
-        ) {
-            if (value.isEmpty()) {
-                Text("Nachricht eingeben …", color = cs.onSurfaceVariant, fontSize = 16.sp)
+        if (pendingFiles.isNotEmpty()) {
+            Row(
+                Modifier
+                    .fillMaxWidth()
+                    .horizontalScroll(rememberScrollState())
+                    .padding(start = 12.dp, end = 12.dp, top = 8.dp),
+                horizontalArrangement = Arrangement.spacedBy(6.dp),
+            ) {
+                pendingFiles.forEach { pf ->
+                    PendingFileChip(pf, onRemove = { onRemoveFile(pf.id) })
+                }
             }
-            BasicTextField(
-                value = value,
-                onValueChange = onValueChange,
-                textStyle = TextStyle(color = cs.onBackground, fontSize = 16.sp, lineHeight = 22.sp),
-                cursorBrush = SolidColor(Amber),
-                maxLines = 6,
-                modifier = Modifier.fillMaxWidth(),
-            )
         }
-        GhostIconButton(Icons.Rounded.Call, "Anruf")
-        Spacer(Modifier.width(4.dp))
-        SendButton(enabled = enabled && value.isNotBlank(), onClick = onSend)
+        Row(
+            Modifier.padding(horizontal = 8.dp, vertical = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Box(
+                Modifier.size(40.dp).clip(CircleShape).clickable(onClick = onAddClick),
+                contentAlignment = Alignment.Center,
+            ) {
+                Icon(Icons.Rounded.Add, "Anhang", tint = cs.onSurfaceVariant, modifier = Modifier.size(22.dp))
+            }
+            Box(
+                Modifier
+                    .weight(1f)
+                    .heightIn(min = 36.dp)
+                    .padding(horizontal = 4.dp),
+                contentAlignment = Alignment.CenterStart
+            ) {
+                if (value.isEmpty()) {
+                    Text("Nachricht eingeben …", color = cs.onSurfaceVariant, fontSize = 16.sp)
+                }
+                BasicTextField(
+                    value = value,
+                    onValueChange = onValueChange,
+                    textStyle = TextStyle(color = cs.onBackground, fontSize = 16.sp, lineHeight = 22.sp),
+                    cursorBrush = SolidColor(Amber),
+                    maxLines = 6,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            }
+            GhostIconButton(Icons.Rounded.Call, "Anruf")
+            Spacer(Modifier.width(4.dp))
+            val canSend = enabled && (value.isNotBlank() || pendingFiles.any { it.uploaded != null })
+                    && pendingFiles.none { it.uploading }
+            SendButton(enabled = canSend, onClick = onSend)
+        }
     }
 }
 
@@ -453,6 +523,83 @@ private fun GhostIconButton(icon: ImageVector, contentDescription: String) {
     }
 }
 
+@Composable
+private fun PendingFileChip(pf: PendingFile, onRemove: () -> Unit) {
+    val cs = MaterialTheme.colorScheme
+    val isDark = isSystemInDarkTheme()
+    val bg = if (isDark) Color.White.copy(alpha = 0.08f) else Color.Black.copy(alpha = 0.06f)
+    val isImage = pf.mimeType.startsWith("image/")
+
+    Box(
+        Modifier
+            .size(64.dp)
+            .clip(RoundedCornerShape(10.dp))
+            .background(bg),
+        contentAlignment = Alignment.Center,
+    ) {
+        if (isImage && pf.uploaded != null) {
+            NetworkImage(
+                url = pf.uploaded.url,
+                contentDescription = pf.name,
+                modifier = Modifier.fillMaxSize().clip(RoundedCornerShape(10.dp)),
+            )
+        } else {
+            val icon = when {
+                pf.mimeType.startsWith("image/") -> Icons.Rounded.Image
+                pf.mimeType.startsWith("video/") -> Icons.Rounded.VideoFile
+                pf.mimeType.startsWith("audio/") -> Icons.Rounded.AudioFile
+                pf.mimeType == "application/pdf" -> Icons.Rounded.PictureAsPdf
+                else -> Icons.AutoMirrored.Rounded.InsertDriveFile
+            }
+            Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                Icon(icon, null, tint = cs.onSurfaceVariant, modifier = Modifier.size(20.dp))
+                Text(
+                    pf.name,
+                    color = cs.onSurfaceVariant,
+                    fontSize = 9.sp,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    modifier = Modifier.padding(horizontal = 4.dp),
+                )
+            }
+        }
+        if (pf.uploading) {
+            Box(
+                Modifier.fillMaxSize()
+                    .background(Color.Black.copy(alpha = 0.4f)),
+                contentAlignment = Alignment.Center,
+            ) {
+                androidx.compose.material3.CircularProgressIndicator(
+                    modifier = Modifier.size(20.dp),
+                    strokeWidth = 2.dp,
+                    color = Color.White,
+                )
+            }
+        }
+        if (pf.error != null) {
+            Box(
+                Modifier.fillMaxSize()
+                    .background(Color(0xFFDC2626).copy(alpha = 0.3f)),
+                contentAlignment = Alignment.Center,
+            ) {
+                Icon(Icons.Rounded.Close, "Fehler", tint = Color.White, modifier = Modifier.size(18.dp))
+            }
+        }
+        Box(
+            Modifier
+                .align(Alignment.TopEnd)
+                .padding(2.dp)
+                .size(18.dp)
+                .clip(CircleShape)
+                .background(Color.Black.copy(alpha = 0.5f))
+                .clickable(onClick = onRemove),
+            contentAlignment = Alignment.Center,
+        ) {
+            Icon(Icons.Rounded.Close, "Entfernen", tint = Color.White, modifier = Modifier.size(12.dp))
+        }
+    }
+}
+
 @Composable
 private fun SendButton(enabled: Boolean, onClick: () -> Unit) {
     val cs = MaterialTheme.colorScheme
@@ -478,6 +625,117 @@ private fun SendButton(enabled: Boolean, onClick: () -> Unit) {
     }
 }
 
+// ── Attachment rendering ────────────────────────────────────────────────────
+
+private object NetworkImageCache {
+    private val cache = object : LinkedHashMap<String, ImageBitmap>(32, 0.75f, true) {
+        override fun removeEldestEntry(eldest: MutableMap.MutableEntry<String, ImageBitmap>?) = size > 50
+    }
+    private val client = OkHttpClient.Builder()
+        .connectTimeout(15, TimeUnit.SECONDS)
+        .readTimeout(30, TimeUnit.SECONDS)
+        .build()
+
+    suspend fun load(url: String): ImageBitmap? = withContext(Dispatchers.IO) {
+        synchronized(cache) { cache[url] }?.let { return@withContext it }
+        try {
+            val req = Request.Builder().url(url).build()
+            client.newCall(req).execute().use { resp ->
+                if (!resp.isSuccessful) return@withContext null
+                val bytes = resp.body!!.bytes()
+                val probe = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+                BitmapFactory.decodeByteArray(bytes, 0, bytes.size, probe)
+                val scale = maxOf(1, maxOf(probe.outWidth, probe.outHeight) / 1536)
+                val opts = BitmapFactory.Options().apply { inSampleSize = scale }
+                val bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.size, opts)
+                    ?: return@withContext null
+                bmp.asImageBitmap().also { synchronized(cache) { cache[url] = it } }
+            }
+        } catch (_: Exception) { null }
+    }
+}
+
+@Composable
+private fun NetworkImage(
+    url: String,
+    contentDescription: String?,
+    modifier: Modifier = Modifier,
+    contentScale: ContentScale = ContentScale.Crop,
+) {
+    var bitmap by remember(url) { mutableStateOf<ImageBitmap?>(null) }
+    LaunchedEffect(url) { bitmap = NetworkImageCache.load(url) }
+
+    val bmp = bitmap
+    if (bmp != null) {
+        Image(
+            bitmap = bmp,
+            contentDescription = contentDescription,
+            modifier = modifier,
+            contentScale = contentScale,
+        )
+    } else {
+        Box(
+            modifier
+                .fillMaxWidth()
+                .height(160.dp)
+                .clip(RoundedCornerShape(10.dp))
+                .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.3f)),
+        )
+    }
+}
+
+@Composable
+fun AttachmentGrid(attachments: List<Attachment>, modifier: Modifier = Modifier) {
+    if (attachments.isEmpty()) return
+    val images = attachments.filter { it.kind == "image" }
+    val others = attachments.filter { it.kind != "image" }
+
+    Column(modifier, verticalArrangement = Arrangement.spacedBy(6.dp)) {
+        images.forEach { att ->
+            NetworkImage(
+                url = att.url,
+                contentDescription = att.name,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .heightIn(max = 280.dp)
+                    .clip(RoundedCornerShape(10.dp)),
+            )
+        }
+        others.forEach { att -> FileChip(att) }
+    }
+}
+
+@Composable
+private fun FileChip(attachment: Attachment) {
+    val cs = MaterialTheme.colorScheme
+    val isDark = isSystemInDarkTheme()
+    val bg = if (isDark) Color.White.copy(alpha = 0.08f) else Color.Black.copy(alpha = 0.06f)
+    val icon = when (attachment.kind) {
+        "pdf" -> Icons.Rounded.PictureAsPdf
+        "audio" -> Icons.Rounded.AudioFile
+        "video" -> Icons.Rounded.VideoFile
+        "code" -> Icons.Rounded.Code
+        else -> Icons.AutoMirrored.Rounded.InsertDriveFile
+    }
+    Row(
+        Modifier
+            .clip(RoundedCornerShape(8.dp))
+            .background(bg)
+            .padding(horizontal = 10.dp, vertical = 6.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Icon(icon, null, tint = cs.onSurfaceVariant, modifier = Modifier.size(16.dp))
+        Spacer(Modifier.width(6.dp))
+        Text(
+            attachment.name,
+            color = cs.onSurfaceVariant,
+            fontSize = 13.sp,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}
+
 /** Crisp upward arrow drawn with strokes (sharper than a glyph). */
 @Composable
 private fun SendArrow(color: Color) {

app/src/main/java/dev/kaizen/app/chat/ChatModels.kt

@@ -9,6 +9,7 @@ import androidx.compose.material.icons.rounded.Movie
 import androidx.compose.material.icons.rounded.MusicNote
 import androidx.compose.material.icons.rounded.Tune
 import androidx.compose.ui.graphics.vector.ImageVector
+import dev.kaizen.app.net.Attachment
 
 enum class Role { User, Assistant }
 
@@ -18,9 +19,8 @@ data class Message(
     val content: String,
     val streaming: Boolean = false,
     val thinking: Boolean = false,
-    // Stable server-side id (UUID) used for persistence + parentId chaining. Generated
-    // on creation; overwritten with the DB id when loading an existing conversation.
     val wireId: String = java.util.UUID.randomUUID().toString(),
+    val attachments: List<Attachment> = emptyList(),
 )
 
 // Empty-state suggestion pills (mirrors the web hero)

app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt

@@ -54,6 +54,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import dev.kaizen.app.haptics.rememberHaptics
+import dev.kaizen.app.net.Attachment
 import dev.kaizen.app.net.ChatHttpException
 import dev.kaizen.app.net.ChatSpeed
 import dev.kaizen.app.net.ConversationSummary
@@ -65,6 +66,9 @@ import dev.kaizen.app.net.SessionViewModel
 import dev.kaizen.app.net.WireMessage
 import dev.kaizen.app.settings.SettingsScreen
 import dev.kaizen.app.settings.SettingsViewModel
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.ui.platform.LocalContext
 import androidx.lifecycle.compose.LifecycleResumeEffect
 import kotlinx.coroutines.async
 import kotlinx.coroutines.launch
@@ -110,6 +114,33 @@ fun ChatScreen(
 
     var loadError by remember { mutableStateOf<String?>(null) }
 
+    // Pending file attachments — uploaded immediately on pick, cleared on send.
+    val pendingFiles = remember { mutableStateListOf<PendingFile>() }
+    val context = LocalContext.current
+
+    val filePicker = rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) { uri ->
+        uri ?: return@rememberLauncherForActivityResult
+        val cfg = session.config ?: return@rememberLauncherForActivityResult
+        val cr = context.contentResolver
+        val mimeType = cr.getType(uri) ?: "application/octet-stream"
+        val fileName = uri.lastPathSegment?.substringAfterLast('/') ?: "file"
+        val bytes = cr.openInputStream(uri)?.use { it.readBytes() } ?: return@rememberLauncherForActivityResult
+        val pf = PendingFile(name = fileName, mimeType = mimeType, bytes = bytes)
+        pendingFiles.add(pf)
+        scope.launch {
+            when (val r = KaizenApi.uploadFile(cfg.baseUrl, cfg.token, fileName, mimeType, bytes)) {
+                is FetchResult.Ok -> {
+                    val idx = pendingFiles.indexOfFirst { it.id == pf.id }
+                    if (idx >= 0) pendingFiles[idx] = pendingFiles[idx].copy(uploaded = r.data, uploading = false)
+                }
+                is FetchResult.Fail -> {
+                    val idx = pendingFiles.indexOfFirst { it.id == pf.id }
+                    if (idx >= 0) pendingFiles[idx] = pendingFiles[idx].copy(error = r.reason, uploading = false)
+                }
+            }
+        }
+    }
+
     LaunchedEffect(session.config?.baseUrl, session.config?.token) {
         val cfg = session.config ?: return@LaunchedEffect
         loadError = null
@@ -169,6 +200,7 @@ fun ChatScreen(
                         role = if (m.role == "assistant") Role.Assistant else Role.User,
                         content = m.content,
                         wireId = m.id,
+                        attachments = m.attachments,
                     ),
                 )
             }
@@ -178,21 +210,23 @@ fun ChatScreen(
 
     fun send(text: String) {
         val trimmed = text.trim()
-        if (trimmed.isEmpty() || isStreaming) return
+        val uploadedAtts = pendingFiles.mapNotNull { it.uploaded }
+        if (trimmed.isEmpty() && uploadedAtts.isEmpty()) return
+        if (isStreaming) return
         val cfg = session.config ?: return
         haptics.click()
-        // parentId chains the linear history: the user msg hangs off the last message.
+
         val userParentId = messages.lastOrNull()?.wireId
-        val userMsg = Message(nextId++, Role.User, trimmed)
+        val userMsg = Message(nextId++, Role.User, trimmed, attachments = uploadedAtts)
         messages.add(userMsg)
         input = ""
+        pendingFiles.clear()
         val assistantId = nextId++
         val assistantWireId = java.util.UUID.randomUUID().toString()
         messages.add(Message(assistantId, Role.Assistant, "", streaming = true, thinking = true, wireId = assistantWireId))
         isStreaming = true
         val wasNewConversation = conversationId == null
 
-        // Wire history = the visible conversation minus the streaming placeholder.
         val history = messages
             .filter { it.id != assistantId }
             .map { WireMessage(if (it.role == Role.User) "user" else "assistant", it.content) }
@@ -201,14 +235,14 @@ fun ChatScreen(
             haptics.thinkingStart()
             var sawContent = false
             try {
-                // Launch conversation creation in parallel — the chat stream does not
-                // need a conversation id, only the post-stream persistence does. This
-                // eliminates a full network RTT from the TTFT on new chats.
                 val convIdDeferred = if (conversationId == null) {
                     async { KaizenApi.createConversation(cfg.baseUrl, cfg.token) }
                 } else null
 
-                KaizenApi.chat(cfg.baseUrl, cfg.token, cfg.model, history, cfg.speed).collect { visible ->
+                KaizenApi.chat(
+                    cfg.baseUrl, cfg.token, cfg.model, history, cfg.speed,
+                    attachments = uploadedAtts.takeIf { it.isNotEmpty() },
+                ).collect { visible ->
                     val idx = messages.indexOfLast { it.id == assistantId }
                     if (idx < 0) return@collect
                     if (!sawContent && visible.isNotEmpty()) {
@@ -224,15 +258,17 @@ fun ChatScreen(
                 val finalContent = if (idx >= 0) messages[idx].content else ""
                 if (idx >= 0) messages[idx] = messages[idx].copy(streaming = false, thinking = false)
 
-                // Await the conversation id — the create ran in parallel with the stream
                 val convId = convIdDeferred?.await()?.also { conversationId = it } ?: conversationId
 
-                // Persist the exchange (best-effort); auto-title + sidebar refresh on a new conversation.
                 if (convId != null && finalContent.isNotEmpty()) {
                     val saved = KaizenApi.saveMessages(
                         cfg.baseUrl, cfg.token, convId,
                         listOf(
-                            SaveMessage(id = userMsg.wireId, parentId = userParentId, role = "user", content = trimmed),
+                            SaveMessage(
+                                id = userMsg.wireId, parentId = userParentId,
+                                role = "user", content = trimmed,
+                                attachments = uploadedAtts.takeIf { it.isNotEmpty() },
+                            ),
                             SaveMessage(id = assistantWireId, parentId = userMsg.wireId, role = "assistant", content = finalContent, model = cfg.model),
                         ),
                     )
@@ -425,6 +461,9 @@ fun ChatScreen(
                                 onValueChange = { input = it },
                                 onSend = { send(input) },
                                 enabled = !isStreaming,
+                                pendingFiles = pendingFiles,
+                                onAddClick = { filePicker.launch("*/*") },
+                                onRemoveFile = { id -> pendingFiles.removeAll { it.id == id } },
                             )
                             Spacer(Modifier.height(16.dp)) // Completely clears keyboard edges on all screens
                         }

app/src/main/java/dev/kaizen/app/chat/Markdown.kt

@@ -2,25 +2,40 @@ package dev.kaizen.app.chat
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.horizontalScroll
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.IntrinsicSize
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.rounded.Check
+import androidx.compose.material.icons.rounded.ContentCopy
+import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 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.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalClipboard
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.SpanStyle
 import androidx.compose.ui.text.buildAnnotatedString
@@ -28,8 +43,12 @@ import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.text.font.FontStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import dev.kaizen.app.haptics.rememberHaptics
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 
 private sealed interface MdBlock {
     data class Paragraph(val text: String) : MdBlock
@@ -37,6 +56,8 @@ private sealed interface MdBlock {
     data class CodeFence(val lang: String, val code: String) : MdBlock
     data class ListBlock(val items: List<ListItem>) : MdBlock
     data class Item(val text: String, val ordered: Boolean, val index: Int) : MdBlock
+    data object HorizontalRule : MdBlock
+    data class Blockquote(val text: String) : MdBlock
 }
 
 private data class ListItem(val text: String, val ordered: Boolean, val index: Int)
@@ -48,6 +69,29 @@ private fun parseBlocks(src: String): List<MdBlock> {
     while (i < lines.size) {
         val line = lines[i]
 
+        // Horizontal rule: ---, ***, ___ (3+ of same char, optionally spaced)
+        if (Regex("^\\s*([-*_])\\s*\\1\\s*\\1[\\s\\-*_]*$").matches(line)) {
+            blocks.add(MdBlock.HorizontalRule)
+            i++
+            continue
+        }
+
+        // Blockquote: > ...
+        val bqMatch = Regex("^\\s*>\\s?(.*)").matchEntire(line)
+        if (bqMatch != null) {
+            val bqLines = mutableListOf(bqMatch.groupValues[1])
+            i++
+            while (i < lines.size) {
+                val m = Regex("^\\s*>\\s?(.*)").matchEntire(lines[i])
+                if (m != null) {
+                    bqLines.add(m.groupValues[1])
+                    i++
+                } else break
+            }
+            blocks.add(MdBlock.Blockquote(bqLines.joinToString("\n")))
+            continue
+        }
+
         // Code fence
         if (line.trimStart().startsWith("```")) {
             val lang = line.trimStart().removePrefix("```").trim()
@@ -117,6 +161,8 @@ private fun parseBlocks(src: String): List<MdBlock> {
                 || Regex("^#{1,3}\\s+").containsMatchIn(next)
                 || Regex("^\\s*[-*+]\\s+").containsMatchIn(next)
                 || Regex("^\\s*\\d+[.)]\\s+").containsMatchIn(next)
+                || Regex("^\\s*([-*_])\\s*\\1\\s*\\1[\\s\\-*_]*$").matches(next)
+                || Regex("^\\s*>\\s?").containsMatchIn(next)
             ) break
             paraLines.add(next)
             i++
@@ -126,11 +172,26 @@ private fun parseBlocks(src: String): List<MdBlock> {
     return blocks
 }
 
-private fun inlineMarkdown(text: String, baseColor: Color, codeColor: Color, codeBg: Color): AnnotatedString {
+private fun inlineMarkdown(text: String, baseColor: Color, codeColor: Color, codeBg: Color, linkColor: Color = Color(0xFF3B82F6)): AnnotatedString {
     return buildAnnotatedString {
         var pos = 0
         val src = text
         while (pos < src.length) {
+            // Link: [text](url)
+            if (src[pos] == '[') {
+                val closeBracket = src.indexOf(']', pos + 1)
+                if (closeBracket > pos && closeBracket + 1 < src.length && src[closeBracket + 1] == '(') {
+                    val closeParen = src.indexOf(')', closeBracket + 2)
+                    if (closeParen > closeBracket) {
+                        val linkText = src.substring(pos + 1, closeBracket)
+                        withStyle(SpanStyle(color = linkColor, fontWeight = FontWeight.Medium)) {
+                            append(linkText)
+                        }
+                        pos = closeParen + 1
+                        continue
+                    }
+                }
+            }
             // Inline code: `...`
             if (src[pos] == '`' && pos + 1 < src.length) {
                 val end = src.indexOf('`', pos + 1)
@@ -324,20 +385,27 @@ fun MarkdownText(text: String, streaming: Boolean = false, modifier: Modifier =
                             .border(1.dp, codeBorder, RoundedCornerShape(10.dp))
                     ) {
                         Column {
-                            if (block.lang.isNotBlank()) {
+                            // Header row: lang badge + copy button
+                            Row(
+                                Modifier
+                                    .fillMaxWidth()
+                                    .padding(start = 12.dp, end = 6.dp, top = 6.dp),
+                                verticalAlignment = Alignment.CenterVertically,
+                            ) {
                                 Text(
-                                    block.lang,
+                                    if (block.lang.isNotBlank()) block.lang else "code",
                                     color = langBadgeColor,
                                     fontSize = 11.sp,
                                     fontWeight = FontWeight.Medium,
-                                    modifier = Modifier.padding(start = 12.dp, top = 8.dp),
                                 )
+                                Spacer(Modifier.weight(1f))
+                                CopyButton(block.code)
                             }
                             Box(
                                 Modifier
                                     .fillMaxWidth()
                                     .horizontalScroll(rememberScrollState())
-                                    .padding(horizontal = 12.dp, vertical = if (block.lang.isNotBlank()) 6.dp else 10.dp)
+                                    .padding(horizontal = 12.dp, vertical = 6.dp)
                             ) {
                                 Text(
                                     text = highlightCode(block.code + if (isLast) cursor else "", block.lang, isDark),
@@ -375,6 +443,45 @@ fun MarkdownText(text: String, streaming: Boolean = false, modifier: Modifier =
                     Spacer(Modifier.height(4.dp))
                 }
 
+                is MdBlock.HorizontalRule -> {
+                    if (idx > 0) Spacer(Modifier.height(8.dp))
+                    Box(
+                        Modifier
+                            .fillMaxWidth()
+                            .height(1.dp)
+                            .background(cs.onSurfaceVariant.copy(alpha = 0.25f))
+                    )
+                    Spacer(Modifier.height(8.dp))
+                }
+
+                is MdBlock.Blockquote -> {
+                    if (idx > 0) Spacer(Modifier.height(6.dp))
+                    Row(
+                        Modifier
+                            .fillMaxWidth()
+                            .height(IntrinsicSize.Min)
+                            .padding(start = 2.dp)
+                    ) {
+                        Box(
+                            Modifier
+                                .width(3.dp)
+                                .fillMaxHeight()
+                                .clip(RoundedCornerShape(1.5.dp))
+                                .background(cs.primary.copy(alpha = 0.5f))
+                        )
+                        Spacer(Modifier.width(10.dp))
+                        Text(
+                            text = inlineMarkdown(block.text + if (isLast) cursor else "", cs.onSurfaceVariant, inlineCodeColor, inlineCodeBg),
+                            color = cs.onSurfaceVariant,
+                            fontSize = 15.sp,
+                            lineHeight = 22.sp,
+                            fontStyle = FontStyle.Italic,
+                            modifier = Modifier.weight(1f),
+                        )
+                    }
+                    Spacer(Modifier.height(6.dp))
+                }
+
                 is MdBlock.Paragraph -> {
                     if (idx > 0) Spacer(Modifier.height(6.dp))
                     Text(
@@ -390,3 +497,39 @@ fun MarkdownText(text: String, streaming: Boolean = false, modifier: Modifier =
         }
     }
 }
+
+@Composable
+private fun CopyButton(code: String) {
+    val clipboard = LocalClipboard.current
+    val haptics = rememberHaptics()
+    val scope = rememberCoroutineScope()
+    var copied by remember { mutableStateOf(false) }
+    val cs = MaterialTheme.colorScheme
+
+    Box(
+        Modifier
+            .size(28.dp)
+            .clip(CircleShape)
+            .clickable {
+                haptics.tick()
+                copied = true
+                scope.launch {
+                    clipboard.setClipEntry(
+                        androidx.compose.ui.platform.ClipEntry(
+                            android.content.ClipData.newPlainText("code", code)
+                        )
+                    )
+                    delay(1500)
+                    copied = false
+                }
+            },
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            imageVector = if (copied) Icons.Rounded.Check else Icons.Rounded.ContentCopy,
+            contentDescription = "Kopieren",
+            tint = if (copied) Color(0xFF22C55E) else cs.onSurfaceVariant.copy(alpha = 0.5f),
+            modifier = Modifier.size(14.dp),
+        )
+    }
+}

app/src/main/java/dev/kaizen/app/net/KaizenApi.kt

@@ -10,6 +10,7 @@ import kotlinx.serialization.decodeFromString
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.MultipartBody
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
@@ -29,6 +30,7 @@ import java.util.concurrent.TimeUnit
     val messages: List<WireMessage>,
     val reasoningEffort: String? = null,
     val preferThroughput: Boolean? = null,
+    val attachments: List<Attachment>? = null,
 )
 
 /** One entry from GET /api/v1/models — the picker's row. `provider == "vertex"` drives the hoster badge. */
@@ -55,12 +57,24 @@ data class ConversationSummary(
 @Serializable private data class CreateConvoRequest(val title: String? = null)
 @Serializable private data class CreatedConversation(val id: String)
 
+/** Attachment on a persisted message (image, audio, video, pdf, document, code). */
+@Serializable
+data class Attachment(
+    val url: String,
+    val kind: String = "",
+    val name: String = "",
+    val mimeType: String = "",
+    val size: Long? = null,
+    val fileId: String? = null,
+)
+
 /** One persisted message from GET /api/v1/conversations/[id]. */
 @Serializable
 data class StoredMessage(
     val id: String,
     val role: String,
     val content: String = "",
+    val attachments: List<Attachment> = emptyList(),
 )
 
 @Serializable private data class ConversationDetail(val messages: List<StoredMessage> = emptyList())
@@ -74,6 +88,7 @@ data class SaveMessage(
     val content: String,
     val kind: String = "chat",
     val model: String? = null,
+    val attachments: List<Attachment>? = null,
 )
 
 @Serializable private data class SaveMessagesRequest(val messages: List<SaveMessage>)
@@ -314,6 +329,7 @@ object KaizenApi {
         model: String,
         messages: List<WireMessage>,
         speed: ChatSpeed = ChatSpeed.Normal,
+        attachments: List<Attachment>? = null,
     ): Flow<String> = flow {
         val payload = json.encodeToString(
             ChatRequest(
@@ -321,6 +337,7 @@ object KaizenApi {
                 messages = messages,
                 reasoningEffort = speed.reasoningEffort,
                 preferThroughput = if (speed.preferThroughput) true else null,
+                attachments = attachments?.takeIf { it.isNotEmpty() },
             ),
         ).toRequestBody(jsonMedia)
         val req = Request.Builder()
@@ -354,6 +371,46 @@ object KaizenApi {
      * handshake (~150-300ms on mobile) from the first real request after app
      * start or background resume.
      */
+    /** POST /api/v1/upload — multipart file upload, returns the created Attachment. */
+    suspend fun uploadFile(
+        baseUrl: String,
+        token: String,
+        fileName: String,
+        mimeType: String,
+        bytes: ByteArray,
+    ): FetchResult<Attachment> = withContext(Dispatchers.IO) {
+        val body = MultipartBody.Builder()
+            .setType(MultipartBody.FORM)
+            .addFormDataPart(
+                "file", fileName,
+                bytes.toRequestBody(mimeType.toMediaType()),
+            )
+            .build()
+        val req = Request.Builder()
+            .url("$baseUrl/api/v1/upload")
+            .post(body)
+            .header("Authorization", "Bearer $token")
+            .build()
+        try {
+            client.newCall(req).execute().use { resp ->
+                if (!resp.isSuccessful) {
+                    val reason = "upload: HTTP ${resp.code}" + when (resp.code) {
+                        401 -> " (Token ungültig)"
+                        413 -> " (Datei zu groß)"
+                        else -> ""
+                    }
+                    Log.w(TAG, "uploadFile: HTTP ${resp.code}")
+                    return@use FetchResult.Fail(reason)
+                }
+                val raw = resp.body!!.string()
+                FetchResult.Ok(json.decodeFromString<Attachment>(raw))
+            }
+        } catch (e: Exception) {
+            Log.w(TAG, "uploadFile: ${e.javaClass.simpleName}: ${e.message}")
+            FetchResult.Fail(diagnoseFetchError("upload", e))
+        }
+    }
+
     suspend fun prewarm(baseUrl: String) = withContext(Dispatchers.IO) {
         try {
             val req = Request.Builder().url("$baseUrl/api/v1/meta").build()