diff --git a/packages/server/src/background-processes/manager.ts b/packages/server/src/background-processes/manager.ts
index 18d79e7f..6864f180 100644
--- a/packages/server/src/background-processes/manager.ts
+++ b/packages/server/src/background-processes/manager.ts
@@ -11,6 +11,7 @@ const ROOT_DIR = ".codenomad/background_processes"
 const INDEX_FILE = "index.json"
 const OUTPUT_FILE = "output.txt"
 const STOP_TIMEOUT_MS = 2000
+const EXIT_WAIT_TIMEOUT_MS = 5000
 const MAX_OUTPUT_BYTES = 20 * 1024
 const OUTPUT_PUBLISH_INTERVAL_MS = 1000
 
@@ -21,6 +22,7 @@ interface ManagerDeps {
 }
 
 interface RunningProcess {
+  id: string
   child: ChildProcess
   outputPath: string
   exitPromise: Promise<void>
@@ -61,9 +63,15 @@ export class BackgroundProcessManager {
     const child = spawn("bash", ["-c", command], {
       cwd: workspace.path,
       stdio: ["ignore", "pipe", "pipe"],
+      detached: process.platform !== "win32",
+    })
+
+    child.on("exit", () => {
+      this.killProcessTree(child, "SIGTERM")
     })
 
     const record: BackgroundProcess = {
+
       id,
       workspaceId,
       title,
@@ -91,7 +99,7 @@ export class BackgroundProcessManager {
       })
     })
 
-    this.running.set(id, { child, outputPath, exitPromise, workspaceId })
+    this.running.set(id, { id, child, outputPath, exitPromise, workspaceId })
 
     let lastPublishAt = 0
     const maybePublishSize = () => {
@@ -128,7 +136,7 @@ export class BackgroundProcessManager {
 
     const running = this.running.get(processId)
     if (running?.child && !running.child.killed) {
-      running.child.kill("SIGTERM")
+      this.killProcessTree(running.child, "SIGTERM")
       await this.waitForExit(running)
     }
 
@@ -149,7 +157,7 @@ export class BackgroundProcessManager {
 
     const running = this.running.get(processId)
     if (running?.child && !running.child.killed) {
-      running.child.kill("SIGTERM")
+      this.killProcessTree(running.child, "SIGTERM")
       await this.waitForExit(running)
     }
 
@@ -255,26 +263,64 @@ export class BackgroundProcessManager {
   private async cleanupWorkspace(workspaceId: string) {
     for (const [, running] of this.running.entries()) {
       if (running.workspaceId !== workspaceId) continue
-      running.child.kill("SIGTERM")
+      this.killProcessTree(running.child, "SIGTERM")
       await this.waitForExit(running)
     }
+
     await this.removeWorkspaceDir(workspaceId)
   }
 
+  private killProcessTree(child: ChildProcess, signal: NodeJS.Signals) {
+    const pid = child.pid
+    if (!pid) return
+
+    if (process.platform !== "win32") {
+      try {
+        process.kill(-pid, signal)
+        return
+      } catch {
+        // Fall back to killing the direct child.
+      }
+    }
+
+    try {
+      child.kill(signal)
+    } catch {
+      // ignore
+    }
+  }
+
   private async waitForExit(running: RunningProcess) {
-    let resolved = false
-    const timeout = setTimeout(() => {
-      if (!resolved) {
-        running.child.kill("SIGKILL")
+    let exited = false
+    const exitPromise = running.exitPromise.finally(() => {
+      exited = true
+    })
+
+    const killTimeout = setTimeout(() => {
+      if (!exited) {
+        this.killProcessTree(running.child, "SIGKILL")
       }
     }, STOP_TIMEOUT_MS)
 
-    await running.exitPromise.finally(() => {
-      resolved = true
-      clearTimeout(timeout)
-    })
+    try {
+      await Promise.race([
+        exitPromise,
+        new Promise<void>((resolve) => {
+          setTimeout(resolve, EXIT_WAIT_TIMEOUT_MS)
+        }),
+      ])
+
+      if (!exited) {
+        this.killProcessTree(running.child, "SIGKILL")
+        this.running.delete(running.id)
+        this.deps.logger.warn({ pid: running.child.pid }, "Timed out waiting for background process to exit")
+      }
+    } finally {
+      clearTimeout(killTimeout)
+    }
   }
 
+
   private statusFromExit(code: number | null): BackgroundProcessStatus {
     if (code === null) return "stopped"
     if (code === 0) return "stopped"
diff --git a/packages/ui/src/components/alert-dialog.tsx b/packages/ui/src/components/alert-dialog.tsx
index 7dc7b73f..fce38bad 100644
--- a/packages/ui/src/components/alert-dialog.tsx
+++ b/packages/ui/src/components/alert-dialog.tsx
@@ -1,5 +1,5 @@
 import { Dialog } from "@kobalte/core/dialog"
-import { Component, Show, createEffect } from "solid-js"
+import { Component, Show, createEffect, createSignal } from "solid-js"
 import { alertDialogState, dismissAlertDialog } from "../stores/alerts"
 import type { AlertVariant, AlertDialogState } from "../stores/alerts"
 
@@ -27,8 +27,9 @@ const variantAccent: Record<AlertVariant, { badgeBg: string; badgeBorder: string
   },
 }
 
-function dismiss(confirmed: boolean, payload?: AlertDialogState | null) {
+function dismiss(confirmed: boolean, payload?: AlertDialogState | null, promptValue?: string) {
   const current = payload ?? alertDialogState()
+
   if (current?.type === "confirm") {
     if (confirmed) {
       current.onConfirm?.()
@@ -36,7 +37,23 @@ function dismiss(confirmed: boolean, payload?: AlertDialogState | null) {
       current.onCancel?.()
     }
     current.resolve?.(confirmed)
-  } else if (confirmed) {
+    dismissAlertDialog()
+    return
+  }
+
+  if (current?.type === "prompt") {
+    if (confirmed) {
+      current.onConfirm?.()
+      current.resolvePrompt?.(promptValue ?? "")
+    } else {
+      current.onCancel?.()
+      current.resolvePrompt?.(null)
+    }
+    dismissAlertDialog()
+    return
+  }
+
+  if (confirmed) {
     current?.onConfirm?.()
   }
   dismissAlertDialog()
@@ -60,9 +77,12 @@ const AlertDialog: Component = () => {
         const accent = variantAccent[variant]
         const title = payload.title || accent.fallbackTitle
         const isConfirm = payload.type === "confirm"
-        const confirmLabel = payload.confirmLabel || (isConfirm ? "Confirm" : "OK")
+        const isPrompt = payload.type === "prompt"
+        const confirmLabel = payload.confirmLabel || (isConfirm ? "Confirm" : isPrompt ? "Run" : "OK")
         const cancelLabel = payload.cancelLabel || "Cancel"
 
+        const [inputValue, setInputValue] = createSignal(payload.inputDefaultValue ?? "")
+
         return (
           <Dialog
             open
@@ -98,27 +118,47 @@ const AlertDialog: Component = () => {
                     </div>
                   </div>
 
-                  <div class="mt-6 flex justify-end gap-3">
-                    {isConfirm && (
-                      <button
-                        type="button"
-                        class="button-secondary"
-                        onClick={() => dismiss(false, payload)}
-                      >
-                        {cancelLabel}
-                      </button>
-                    )}
-                    <button
-                      type="button"
-                      class="button-primary"
-                      ref={(el) => {
-                        primaryButtonRef = el
-                      }}
-                      onClick={() => dismiss(true, payload)}
-                    >
-                      {confirmLabel}
-                    </button>
-                  </div>
+                   <Show when={isPrompt}>
+                     <div class="mt-4">
+                       <label class="text-xs font-medium text-muted uppercase tracking-wide">
+                         {payload.inputLabel || "Arguments"}
+                       </label>
+                       <input
+                         class="modal-search-input mt-2"
+                         value={inputValue()}
+                         placeholder={payload.inputPlaceholder || ""}
+                         onInput={(e) => setInputValue(e.currentTarget.value)}
+                         onKeyDown={(e) => {
+                           if (e.key === "Enter") {
+                             e.preventDefault()
+                             dismiss(true, payload, inputValue())
+                           }
+                         }}
+                       />
+                     </div>
+                   </Show>
+
+                   <div class="mt-6 flex justify-end gap-3">
+                     {(isConfirm || isPrompt) && (
+                       <button
+                         type="button"
+                         class="button-secondary"
+                         onClick={() => dismiss(false, payload)}
+                       >
+                         {cancelLabel}
+                       </button>
+                     )}
+                     <button
+                       type="button"
+                       class="button-primary"
+                       ref={(el) => {
+                         primaryButtonRef = el
+                       }}
+                       onClick={() => dismiss(true, payload, inputValue())}
+                     >
+                       {confirmLabel}
+                     </button>
+                   </div>
                 </Dialog.Content>
               </div>
             </Dialog.Portal>
diff --git a/packages/ui/src/components/instance/instance-shell2.tsx b/packages/ui/src/components/instance/instance-shell2.tsx
index 6931ef8f..0579e149 100644
--- a/packages/ui/src/components/instance/instance-shell2.tsx
+++ b/packages/ui/src/components/instance/instance-shell2.tsx
@@ -39,8 +39,7 @@ import {
 import { keyboardRegistry, type KeyboardShortcut } from "../../lib/keyboard-registry"
 import { messageStoreBus } from "../../stores/message-v2/bus"
 import { clearSessionRenderCache } from "../message-block"
-import { buildCustomCommandEntries } from "../../lib/command-utils"
-import { getCommands as getInstanceCommands } from "../../stores/commands"
+
 import { isOpen as isCommandPaletteOpen, hideCommandPalette, showCommandPalette } from "../../stores/command-palette"
 import SessionList from "../session-list"
 import KeyboardHint from "../keyboard-hint"
@@ -376,9 +375,7 @@ const InstanceShell2: Component<InstanceShellProps> = (props) => {
     }
   }
 
-  const customCommands = createMemo(() => buildCustomCommandEntries(props.instance.id, getInstanceCommands(props.instance.id)))
-
-  const instancePaletteCommands = createMemo(() => [...props.paletteCommands(), ...customCommands()])
+  const instancePaletteCommands = createMemo(() => props.paletteCommands())
   const paletteOpen = createMemo(() => isCommandPaletteOpen(props.instance.id))
 
   const keyboardShortcuts = createMemo(() =>
diff --git a/packages/ui/src/components/message-timeline.tsx b/packages/ui/src/components/message-timeline.tsx
index df3f28f3..a16f4b8e 100644
--- a/packages/ui/src/components/message-timeline.tsx
+++ b/packages/ui/src/components/message-timeline.tsx
@@ -5,7 +5,7 @@ import type { ClientPart } from "../types/message"
 import type { MessageRecord } from "../stores/message-v2/types"
 import { buildRecordDisplayData } from "../stores/message-v2/record-display-cache"
 import { getToolIcon } from "./tool-call/utils"
-import { User as UserIcon, Bot as BotIcon, FoldVertical } from "lucide-solid"
+import { User as UserIcon, Bot as BotIcon, FoldVertical, ShieldAlert } from "lucide-solid"
 
 export type TimelineSegmentType = "user" | "assistant" | "tool" | "compaction"
 
@@ -17,6 +17,7 @@ export interface TimelineSegment {
   tooltip: string
   shortLabel?: string
   variant?: "auto" | "manual"
+  toolPartIds?: string[]
 }
 
 interface MessageTimelineProps {
@@ -47,6 +48,7 @@ interface PendingSegment {
   toolTitles: string[]
   toolTypeLabels: string[]
   toolIcons: string[]
+  toolPartIds: string[]
   hasPrimaryText: boolean
 }
 
@@ -179,6 +181,7 @@ export function buildTimelineSegments(instanceId: string, record: MessageRecord)
       label,
       tooltip,
       shortLabel,
+      toolPartIds: isToolSegment ? pending.toolPartIds : undefined,
     })
     segmentIndex += 1
     pending = null
@@ -187,7 +190,7 @@ export function buildTimelineSegments(instanceId: string, record: MessageRecord)
   const ensureSegment = (type: TimelineSegmentType): PendingSegment => {
     if (!pending || pending.type !== type) {
       flushPending()
-      pending = { type, texts: [], reasoningTexts: [], toolTitles: [], toolTypeLabels: [], toolIcons: [], hasPrimaryText: type !== "assistant" }
+      pending = { type, texts: [], reasoningTexts: [], toolTitles: [], toolTypeLabels: [], toolIcons: [], toolPartIds: [], hasPrimaryText: type !== "assistant" }
     }
     return pending!
   }
@@ -204,6 +207,9 @@ export function buildTimelineSegments(instanceId: string, record: MessageRecord)
       target.toolTitles.push(getToolTitle(toolPart))
       target.toolTypeLabels.push(getToolTypeLabel(toolPart))
       target.toolIcons.push(getToolIcon(typeof toolPart.tool === "string" ? toolPart.tool : "tool"))
+      if (typeof toolPart.id === "string" && toolPart.id.length > 0) {
+        target.toolPartIds.push(toolPart.id)
+      }
       continue
     }
 
@@ -359,9 +365,25 @@ const MessageTimeline: Component<MessageTimelineProps> = (props) => {
         {(segment) => {
           onCleanup(() => buttonRefs.delete(segment.id))
           const isActive = () => props.activeMessageId === segment.messageId
-          const isHidden = () => segment.type === "tool" && !(showTools() || isActive())
+
+          const hasActivePermission = () => {
+            if (segment.type !== "tool") return false
+            const partIds = segment.toolPartIds ?? []
+            if (partIds.length === 0) return false
+            for (const partId of partIds) {
+              const permissionState = store().getPermissionState(segment.messageId, partId)
+              if (permissionState?.active) return true
+            }
+            return false
+          }
+
+          const isHidden = () => segment.type === "tool" && !(showTools() || isActive() || hasActivePermission())
+
            const shortLabelContent = () => {
              if (segment.type === "tool") {
+               if (hasActivePermission()) {
+                 return <ShieldAlert class="message-timeline-icon" aria-hidden="true" />
+               }
                return segment.shortLabel ?? getToolIcon("tool")
              }
              if (segment.type === "compaction") {
@@ -378,7 +400,7 @@ const MessageTimeline: Component<MessageTimelineProps> = (props) => {
                ref={(el) => registerButtonRef(segment.id, el)}
                type="button"
                data-variant={segment.variant}
-               class={`message-timeline-segment message-timeline-${segment.type} ${segment.type === "compaction" ? `message-timeline-compaction-${segment.variant ?? "manual"}` : ""} ${isActive() ? "message-timeline-segment-active" : ""} ${isHidden() ? "message-timeline-segment-hidden" : ""}`}
+               class={`message-timeline-segment message-timeline-${segment.type} ${hasActivePermission() ? "message-timeline-segment-permission" : ""} ${segment.type === "compaction" ? `message-timeline-compaction-${segment.variant ?? "manual"}` : ""} ${isActive() ? "message-timeline-segment-active" : ""} ${isHidden() ? "message-timeline-segment-hidden" : ""}`}
 
               aria-current={isActive() ? "true" : undefined}
               aria-hidden={isHidden() ? "true" : undefined}
diff --git a/packages/ui/src/components/prompt-input.tsx b/packages/ui/src/components/prompt-input.tsx
index f0f621a1..e214e9ae 100644
--- a/packages/ui/src/components/prompt-input.tsx
+++ b/packages/ui/src/components/prompt-input.tsx
@@ -9,7 +9,8 @@ import type { Attachment } from "../types/attachment"
 import type { Agent } from "../types/session"
 import Kbd from "./kbd"
 import { getActiveInstance } from "../stores/instances"
-import { agents, getSessionDraftPrompt, setSessionDraftPrompt, clearSessionDraftPrompt } from "../stores/sessions"
+import { agents, getSessionDraftPrompt, setSessionDraftPrompt, clearSessionDraftPrompt, executeCustomCommand } from "../stores/sessions"
+import { getCommands } from "../stores/commands"
 import { showAlertDialog } from "../stores/alerts"
 import { getLogger } from "../lib/logger"
 const log = getLogger("actions")
@@ -36,6 +37,7 @@ export default function PromptInput(props: PromptInputProps) {
   const [historyDraft, setHistoryDraft] = createSignal<string | null>(null)
   const [, setIsFocused] = createSignal(false)
   const [showPicker, setShowPicker] = createSignal(false)
+  const [pickerMode, setPickerMode] = createSignal<"mention" | "command">("mention")
   const [searchQuery, setSearchQuery] = createSignal("")
   const [atPosition, setAtPosition] = createSignal<number | null>(null)
   const [isDragging, setIsDragging] = createSignal(false)
@@ -560,14 +562,28 @@ export default function PromptInput(props: PromptInputProps) {
     const currentAttachments = attachments()
     if (props.disabled || (!text && currentAttachments.length === 0)) return
 
-    const resolvedPrompt = resolvePastedPlaceholders(text, currentAttachments)
     const isShellMode = mode() === "shell"
 
+    // Slash command routing (match OpenCode TUI): only run if the command exists.
+    const isSlashCandidate = !isShellMode && text.startsWith("/")
+    const firstSpace = isSlashCandidate ? text.indexOf(" ") : -1
+    const commandToken = isSlashCandidate ? (firstSpace === -1 ? text : text.slice(0, firstSpace)) : ""
+    const commandName = isSlashCandidate ? commandToken.slice(1) : ""
+    const commandArgs = isSlashCandidate ? (firstSpace === -1 ? "" : text.slice(firstSpace + 1).trimStart()) : ""
+
+    const isKnownSlashCommand =
+      isSlashCandidate &&
+      commandName.length > 0 &&
+      getCommands(props.instanceId).some((cmd) => cmd.name === commandName)
+
+    const resolvedPrompt = isKnownSlashCommand ? text : resolvePastedPlaceholders(text, currentAttachments)
+    const historyEntry = resolvedPrompt
+
     const refreshHistory = async () => {
       try {
-        await addToHistory(props.instanceFolder, resolvedPrompt)
+        await addToHistory(props.instanceFolder, historyEntry)
         setHistory((prev) => {
-          const next = [resolvedPrompt, ...prev]
+          const next = [historyEntry, ...prev]
           if (next.length > HISTORY_LIMIT) {
             next.length = HISTORY_LIMIT
           }
@@ -580,12 +596,25 @@ export default function PromptInput(props: PromptInputProps) {
     }
 
     clearPrompt()
-    clearAttachments(props.instanceId, props.sessionId)
-    setIgnoredAtPositions(new Set<number>())
-    setPasteCount(0)
-    setImageCount(0)
+
+    // Ignore attachments for slash commands, but keep them for next prompt.
+    if (!isKnownSlashCommand) {
+      clearAttachments(props.instanceId, props.sessionId)
+      setPasteCount(0)
+      setImageCount(0)
+      setIgnoredAtPositions(new Set<number>())
+    } else {
+      syncAttachmentCounters("", currentAttachments)
+      setIgnoredAtPositions(new Set<number>())
+    }
+
     setHistoryDraft(null)
 
+    if (isKnownSlashCommand) {
+      // Record attempted slash commands even if execution fails.
+      void refreshHistory()
+    }
+ 
     try {
       if (isShellMode) {
         if (props.onRunShell) {
@@ -593,10 +622,14 @@ export default function PromptInput(props: PromptInputProps) {
         } else {
           await props.onSend(resolvedPrompt, [])
         }
+      } else if (isKnownSlashCommand) {
+        await executeCustomCommand(props.instanceId, props.sessionId, commandName, commandArgs)
       } else {
         await props.onSend(resolvedPrompt, currentAttachments)
       }
-      void refreshHistory()
+      if (!isKnownSlashCommand) {
+        void refreshHistory()
+      }
     } catch (error) {
       log.error("Failed to send message:", error)
       showAlertDialog("Failed to send message", {
@@ -677,11 +710,27 @@ export default function PromptInput(props: PromptInputProps) {
     setHistoryDraft(null)
 
     const cursorPos = target.selectionStart
+
+    // Slash command picker (only when editing the command token: "/<query>")
+    if (value.startsWith("/") && cursorPos >= 1) {
+      const firstWhitespaceIndex = value.slice(1).search(/\s/)
+      const tokenEnd = firstWhitespaceIndex === -1 ? value.length : firstWhitespaceIndex + 1
+
+      if (cursorPos <= tokenEnd) {
+        setPickerMode("command")
+        setAtPosition(0)
+        setSearchQuery(value.substring(1, cursorPos))
+        setShowPicker(true)
+        return
+      }
+    }
+
     const textBeforeCursor = value.substring(0, cursorPos)
     const lastAtIndex = textBeforeCursor.lastIndexOf("@")
 
     const previousAtPosition = atPosition()
 
+
     if (lastAtIndex === -1) {
       setIgnoredAtPositions(new Set<number>())
     } else if (previousAtPosition !== null && lastAtIndex !== previousAtPosition) {
@@ -698,6 +747,7 @@ export default function PromptInput(props: PromptInputProps) {
 
       if (!hasSpace && cursorPos === lastAtIndex + textAfterAt.length + 1) {
         if (!ignoredAtPositions().has(lastAtIndex)) {
+          setPickerMode("mention")
           setAtPosition(lastAtIndex)
           setSearchQuery(textAfterAt)
           setShowPicker(true)
@@ -716,9 +766,30 @@ export default function PromptInput(props: PromptInputProps) {
       | {
           type: "file"
           file: { path: string; relativePath?: string; isGitFile: boolean; isDirectory?: boolean }
-        },
+        }
+      | { type: "command"; command: { name: string; description?: string } },
   ) {
-    if (item.type === "agent") {
+    if (item.type === "command") {
+      const name = item.command.name
+      const currentPrompt = prompt()
+
+      const afterSlash = currentPrompt.slice(1)
+      const firstWhitespaceIndex = afterSlash.search(/\s/)
+      const tokenEnd = firstWhitespaceIndex === -1 ? currentPrompt.length : firstWhitespaceIndex + 1
+
+      const before = ""
+      const after = currentPrompt.substring(tokenEnd)
+      const newPrompt = before + `/${name} ` + after
+      setPrompt(newPrompt)
+
+      setTimeout(() => {
+        if (textareaRef) {
+          const newCursorPos = `/${name} `.length
+          textareaRef.setSelectionRange(newCursorPos, newCursorPos)
+          textareaRef.focus()
+        }
+      }, 0)
+    } else if (item.type === "agent") {
       const agentName = item.agent.name
       const existingAttachments = attachments()
       const alreadyAttached = existingAttachments.some(
@@ -822,7 +893,7 @@ export default function PromptInput(props: PromptInputProps) {
 
   function handlePickerClose() {
     const pos = atPosition()
-    if (pos !== null) {
+    if (pickerMode() === "mention" && pos !== null) {
       setIgnoredAtPositions((prev) => new Set(prev).add(pos))
     }
     setShowPicker(false)
@@ -959,6 +1030,7 @@ export default function PromptInput(props: PromptInputProps) {
   }
  
   const shellHint = () => (mode() === "shell" ? { key: "Esc", text: "to exit shell mode" } : { key: "!", text: "for shell mode" })
+  const commandHint = () => ({ key: "/", text: "for commands" })
 
   const shouldShowOverlay = () => prompt().length === 0
 
@@ -981,9 +1053,11 @@ export default function PromptInput(props: PromptInputProps) {
         <Show when={showPicker() && instance()}>
           <UnifiedPicker
             open={showPicker()}
+            mode={pickerMode()}
             onClose={handlePickerClose}
             onSelect={handlePickerSelect}
             agents={instanceAgents()}
+            commands={getCommands(props.instanceId)}
             instanceClient={instance()!.client}
             searchQuery={searchQuery()}
             textareaRef={textareaRef}
@@ -1149,6 +1223,11 @@ export default function PromptInput(props: PromptInputProps) {
                       <span class="prompt-overlay-text">
                         • <Kbd>{shellHint().key}</Kbd> {shellHint().text}
                       </span>
+                      <Show when={mode() !== "shell"}>
+                        <span class="prompt-overlay-text">
+                          • <Kbd>{commandHint().key}</Kbd> {commandHint().text}
+                        </span>
+                      </Show>
                       <Show when={mode() === "shell"}>
                         <span class="prompt-overlay-shell-active">Shell mode active</span>
                       </Show>
diff --git a/packages/ui/src/components/unified-picker.tsx b/packages/ui/src/components/unified-picker.tsx
index d12e9899..fab200c9 100644
--- a/packages/ui/src/components/unified-picker.tsx
+++ b/packages/ui/src/components/unified-picker.tsx
@@ -1,5 +1,6 @@
-import { Component, createSignal, createEffect, For, Show, onCleanup } from "solid-js"
+import { Component, createSignal, createEffect, createMemo, For, Show, onCleanup } from "solid-js"
 import type { Agent } from "../types/session"
+import type { Command as SDKCommand } from "@opencode-ai/sdk/v2"
 import type { OpencodeClient } from "@opencode-ai/sdk/v2/client"
 import { serverApi } from "../lib/api-client"
 import { getLogger } from "../lib/logger"
@@ -67,13 +68,18 @@ function mapEntriesToFileItems(entries: { path: string; type: "file" | "director
   })
 }
 
-type PickerItem = { type: "agent"; agent: Agent } | { type: "file"; file: FileItem }
+type PickerItem =
+  | { type: "agent"; agent: Agent }
+  | { type: "file"; file: FileItem }
+  | { type: "command"; command: SDKCommand }
 
 interface UnifiedPickerProps {
   open: boolean
+  mode?: "mention" | "command"
   onSelect: (item: PickerItem) => void
   onClose: () => void
   agents: Agent[]
+  commands?: SDKCommand[]
   instanceClient: OpencodeClient | null
   searchQuery: string
   textareaRef?: HTMLTextAreaElement
@@ -81,6 +87,8 @@ interface UnifiedPickerProps {
 }
 
 const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
+  const mode = () => props.mode ?? "mention"
+
   const [files, setFiles] = createSignal<FileItem[]>([])
   const [filteredAgents, setFilteredAgents] = createSignal<Agent[]>([])
   const [selectedIndex, setSelectedIndex] = createSignal(0)
@@ -246,6 +254,11 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
       return
     }
 
+    if (mode() !== "mention") {
+      // Command mode doesn't use file snapshots.
+      return
+    }
+
     const workspaceChanged = lastWorkspaceId !== props.workspaceId
     const queryChanged = lastQuery !== props.searchQuery
 
@@ -262,6 +275,7 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
 
   createEffect(() => {
     if (!props.open) return
+    if (mode() !== "mention") return
 
     const query = props.searchQuery.toLowerCase()
     const filtered = query
@@ -275,8 +289,25 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
     setFilteredAgents(filtered)
   })
 
+  const filteredCommands = createMemo(() => {
+    if (mode() !== "command") return []
+    const q = props.searchQuery.trim().toLowerCase()
+    const source = props.commands ?? []
+    if (!q) return source
+    return source.filter((cmd) => {
+      const nameMatch = cmd.name.toLowerCase().includes(q)
+      const descMatch = (cmd.description ?? "").toLowerCase().includes(q)
+      return nameMatch || descMatch
+    })
+  })
+
   const allItems = (): PickerItem[] => {
     const items: PickerItem[] = []
+    if (mode() === "command") {
+      filteredCommands().forEach((command) => items.push({ type: "command", command }))
+      return items
+    }
+
     filteredAgents().forEach((agent) => items.push({ type: "agent", agent }))
     files().forEach((file) => items.push({ type: "file", file }))
     return items
@@ -329,9 +360,10 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
     }
   })
 
+  const commandCount = () => filteredCommands().length
   const agentCount = () => filteredAgents().length
   const fileCount = () => files().length
-  const isLoading = () => loadingState() !== "idle"
+  const isLoading = () => mode() === "mention" && loadingState() !== "idle"
   const loadingMessage = () => {
     if (loadingState() === "search") {
       return "Searching..."
@@ -351,7 +383,9 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
       >
         <div class="dropdown-header">
           <div class="dropdown-header-title">
-            Select Agent or File
+            <Show when={mode() === "command"} fallback={"Select Agent or File"}>
+              Select Command
+            </Show>
             <Show when={isLoading()}>
               <span class="ml-2">{loadingMessage()}</span>
             </Show>
@@ -359,11 +393,41 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
         </div>
 
         <div ref={scrollContainerRef} class="dropdown-content max-h-60">
-          <Show when={agentCount() === 0 && fileCount() === 0}>
+          <Show when={(mode() === "command" ? commandCount() === 0 : agentCount() === 0 && fileCount() === 0)}>
             <div class="dropdown-empty">No results found</div>
           </Show>
 
-          <Show when={agentCount() > 0}>
+          <Show when={mode() === "command" && commandCount() > 0}>
+            <div class="dropdown-section-header">COMMANDS</div>
+            <For each={filteredCommands()}>
+              {(command) => {
+                const itemIndex = allItems().findIndex((item) => item.type === "command" && item.command.name === command.name)
+                return (
+                  <div
+                    class={`dropdown-item ${itemIndex === selectedIndex() ? "dropdown-item-highlight" : ""}`}
+                    data-picker-selected={itemIndex === selectedIndex()}
+                    onClick={() => handleSelect({ type: "command", command })}
+                  >
+                    <div class="flex items-start gap-2">
+                      <svg class="dropdown-icon-accent h-4 w-4 mt-0.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16" />
+                      </svg>
+                      <div class="flex-1">
+                        <div class="text-sm font-medium">/{command.name}</div>
+                        <Show when={command.description}>
+                          <div class="mt-0.5 text-xs" style="color: var(--text-muted)">
+                            {(command.description ?? "").length > 80 ? (command.description ?? "").slice(0, 80) + "..." : command.description}
+                          </div>
+                        </Show>
+                      </div>
+                    </div>
+                  </div>
+                )
+              }}
+            </For>
+          </Show>
+
+          <Show when={mode() === "mention" && agentCount() > 0}>
             <div class="dropdown-section-header">
               AGENTS
             </div>
@@ -418,7 +482,7 @@ const UnifiedPicker: Component<UnifiedPickerProps> = (props) => {
             </For>
           </Show>
 
-          <Show when={fileCount() > 0}>
+          <Show when={mode() === "mention" && fileCount() > 0}>
             <div class="dropdown-section-header">
               FILES
             </div>
diff --git a/packages/ui/src/lib/command-utils.ts b/packages/ui/src/lib/command-utils.ts
index 992586d5..7152d5a3 100644
--- a/packages/ui/src/lib/command-utils.ts
+++ b/packages/ui/src/lib/command-utils.ts
@@ -1,6 +1,6 @@
 import type { Command } from "./commands"
 import type { Command as SDKCommand } from "@opencode-ai/sdk"
-import { showAlertDialog } from "../stores/alerts"
+import { showAlertDialog, showPromptDialog } from "../stores/alerts"
 import { activeSessionId, executeCustomCommand } from "../stores/sessions"
 import { getLogger } from "./logger"
 
@@ -11,15 +11,29 @@ export function commandRequiresArguments(template?: string): boolean {
   return /\$(?:\d+|ARGUMENTS)/.test(template)
 }
 
-export function promptForCommandArguments(command: SDKCommand): string | null {
+export async function promptForCommandArguments(command: SDKCommand): Promise<string | null> {
   if (!commandRequiresArguments(command.template)) {
     return ""
   }
-  const input = window.prompt(`Arguments for /${command.name}`, "")
-  if (input === null) {
+
+  try {
+    return await showPromptDialog(`Arguments for /${command.name}`, {
+      title: "Custom command",
+      variant: "info",
+      inputLabel: "Arguments",
+      inputPlaceholder: "e.g. foo bar",
+      inputDefaultValue: "",
+      confirmLabel: "Run",
+      cancelLabel: "Cancel",
+    })
+  } catch (error) {
+    log.error("Failed to prompt for command arguments", error)
+    showAlertDialog("Failed to open arguments prompt.", {
+      title: "Command arguments",
+      variant: "error",
+    })
     return null
   }
-  return input
 }
 
 function formatCommandLabel(name: string): string {
@@ -43,11 +57,11 @@ export function buildCustomCommandEntries(instanceId: string, commands: SDKComma
         })
         return
       }
-      const args = promptForCommandArguments(cmd)
-      if (args === null) {
-        return
-      }
       try {
+        const args = await promptForCommandArguments(cmd)
+        if (args === null) {
+          return
+        }
         await executeCustomCommand(instanceId, sessionId, cmd.name, args)
       } catch (error) {
         log.error("Failed to run custom command", error)
diff --git a/packages/ui/src/stores/alerts.ts b/packages/ui/src/stores/alerts.ts
index a3c7775b..720e0208 100644
--- a/packages/ui/src/stores/alerts.ts
+++ b/packages/ui/src/stores/alerts.ts
@@ -3,7 +3,7 @@ import { createSignal } from "solid-js"
 export type AlertVariant = "info" | "warning" | "error"
 
 export type AlertDialogState = {
-  type?: "alert" | "confirm"
+  type?: "alert" | "confirm" | "prompt"
   title?: string
   message: string
   detail?: string
@@ -12,7 +12,17 @@ export type AlertDialogState = {
   cancelLabel?: string
   onConfirm?: () => void
   onCancel?: () => void
+
+  // prompt-only
+  inputLabel?: string
+  inputPlaceholder?: string
+  inputDefaultValue?: string
+
+  // confirm-only
   resolve?: (value: boolean) => void
+
+  // prompt-only
+  resolvePrompt?: (value: string | null) => void
 }
 
 const [alertDialogState, setAlertDialogState] = createSignal<AlertDialogState | null>(null)
@@ -39,6 +49,23 @@ export function showConfirmDialog(message: string, options?: Omit<AlertDialogSta
   })
 }
 
+export function showPromptDialog(
+  message: string,
+  options?: Omit<AlertDialogState, "message" | "type" | "resolve" | "resolvePrompt">,
+): Promise<string | null> {
+  const activeElement = typeof document !== "undefined" ? (document.activeElement as HTMLElement | null) : null
+  activeElement?.blur()
+
+  return new Promise<string | null>((resolvePrompt) => {
+    setAlertDialogState({
+      type: "prompt",
+      message,
+      ...options,
+      resolvePrompt,
+    })
+  })
+}
+
 export function dismissAlertDialog() {
   setAlertDialogState(null)
 }
diff --git a/packages/ui/src/styles/messaging/message-timeline.css b/packages/ui/src/styles/messaging/message-timeline.css
index a639a9e5..4d8fda6a 100644
--- a/packages/ui/src/styles/messaging/message-timeline.css
+++ b/packages/ui/src/styles/messaging/message-timeline.css
@@ -146,6 +146,30 @@
   background-color: var(--surface-secondary);
 }
 
+.message-timeline-segment.message-timeline-segment-permission {
+  border-color: var(--session-status-permission-fg);
+  background-color: var(--session-status-permission-bg);
+  color: var(--session-status-permission-fg);
+}
+
+.message-timeline-segment.message-timeline-segment-permission:hover,
+.message-timeline-segment.message-timeline-segment-permission:focus-visible {
+  background-color: var(--session-status-permission-bg);
+  color: var(--session-status-permission-fg);
+  border-color: var(--session-status-permission-fg);
+  transform: translateY(-1px);
+}
+
+.message-timeline-segment-active.message-timeline-segment-permission,
+.message-timeline-segment-active.message-timeline-segment-permission:hover,
+.message-timeline-segment-active.message-timeline-segment-permission:focus-visible {
+  background-color: var(--session-status-permission-bg) !important;
+  border-color: var(--session-status-permission-fg) !important;
+  color: var(--session-status-permission-fg) !important;
+  transform: none;
+  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.35);
+}
+
 .message-timeline-compaction-auto {
   border-color: var(--session-status-compacting-fg);
   background-color: var(--surface-secondary);