diff --git a/packages/opencode/src/cli/cmd/tui/app.tsx b/packages/opencode/src/cli/cmd/tui/app.tsx
index 93d1fc19ae2b..c855d254857b 100644
--- a/packages/opencode/src/cli/cmd/tui/app.tsx
+++ b/packages/opencode/src/cli/cmd/tui/app.tsx
@@ -59,6 +59,7 @@ import { TuiConfigProvider, useTuiConfig } from "./context/tui-config"
 import { TuiConfig } from "@/config/tui"
 import { createTuiApi, TuiPluginRuntime, type RouteMap } from "./plugin"
 import { FormatError, FormatUnknownError } from "@/cli/error"
+import { Notification } from "@/notification"
 
 async function getTerminalBackgroundColor(): Promise<"dark" | "light"> {
   // can't set raw mode if not a TTY
@@ -816,6 +817,15 @@ function App(props: { onSnapshot?: () => Promise<string[]> }) {
     }
   })
 
+  sdk.event.on("session.idle", async (evt) => {
+    if (tuiConfig.notifications === false) return
+    const focused = await Notification.terminalIsFocused().catch(() => false)
+    if (focused) return
+
+    const sessionID = evt.properties.sessionID
+    Notification.show("opencode", `${sessionID} completed`).catch(() => {})
+  })
+
   sdk.event.on("session.error", (evt) => {
     const error = evt.properties.error
     if (error && typeof error === "object" && error.name === "MessageAbortedError") return
@@ -826,6 +836,12 @@ function App(props: { onSnapshot?: () => Promise<string[]> }) {
       message,
       duration: 5000,
     })
+
+    void Notification.terminalIsFocused().then((focused) => {
+      if (focused) return
+      if (tuiConfig.notifications === false) return
+      Notification.show("opencode", `Error: ${message}`)
+    })
   })
 
   sdk.event.on("installation.update-available", async (evt) => {
diff --git a/packages/opencode/src/cli/cmd/tui/ui/toast.tsx b/packages/opencode/src/cli/cmd/tui/ui/toast.tsx
index 36095580fb08..fdaaaba6c0db 100644
--- a/packages/opencode/src/cli/cmd/tui/ui/toast.tsx
+++ b/packages/opencode/src/cli/cmd/tui/ui/toast.tsx
@@ -1,19 +1,35 @@
-import { createContext, useContext, type ParentProps, Show } from "solid-js"
+import { createContext, useContext, type ParentProps, Show, createMemo } from "solid-js"
 import { createStore } from "solid-js/store"
 import { useTheme } from "@tui/context/theme"
 import { useTerminalDimensions } from "@opentui/solid"
-import { SplitBorder } from "../component/border"
 import { TextAttributes } from "@opentui/core"
 import z from "zod"
 import { TuiEvent } from "../event"
 
 export type ToastOptions = z.infer<typeof TuiEvent.ToastShow.properties>
 
+const VARIANT_ICONS: Record<string, string> = {
+  error: "✗",
+  success: "✓",
+  info: "ℹ",
+  warning: "⚠",
+}
+
 export function Toast() {
   const toast = useToast()
   const { theme } = useTheme()
   const dimensions = useTerminalDimensions()
 
+  const icon = createMemo(() => {
+    if (!toast.currentToast) return ""
+    return VARIANT_ICONS[toast.currentToast.variant] ?? "●"
+  })
+
+  const iconColor = createMemo(() => {
+    if (!toast.currentToast) return theme.text
+    return theme[toast.currentToast.variant] ?? theme.text
+  })
+
   return (
     <Show when={toast.currentToast}>
       {(current) => (
@@ -30,14 +46,18 @@ export function Toast() {
           paddingBottom={1}
           backgroundColor={theme.backgroundPanel}
           borderColor={theme[current().variant]}
-          border={["left", "right"]}
-          customBorderChars={SplitBorder.customBorderChars}
+          border={["top", "bottom", "left", "right"]}
         >
-          <Show when={current().title}>
-            <text attributes={TextAttributes.BOLD} marginBottom={1} fg={theme.text}>
-              {current().title}
+          <box flexDirection="row" gap={1} marginBottom={1}>
+            <text fg={iconColor()} attributes={TextAttributes.BOLD}>
+              {icon()}
             </text>
-          </Show>
+            <Show when={current().title}>
+              <text attributes={TextAttributes.BOLD} fg={theme.text}>
+                {current().title}
+              </text>
+            </Show>
+          </box>
           <text fg={theme.text} wrapMode="word" width="100%">
             {current().message}
           </text>
@@ -64,7 +84,7 @@ function init() {
         setStore("currentToast", null)
       }, duration).unref()
     },
-    error: (err: any) => {
+    error: (err: unknown) => {
       if (err instanceof Error)
         return toast.show({
           variant: "error",
diff --git a/packages/opencode/src/config/tui-schema.ts b/packages/opencode/src/config/tui-schema.ts
index b126d3c96a42..05ab851a4f3d 100644
--- a/packages/opencode/src/config/tui-schema.ts
+++ b/packages/opencode/src/config/tui-schema.ts
@@ -22,6 +22,11 @@ export const TuiOptions = z.object({
     .enum(["auto", "stacked"])
     .optional()
     .describe("Control diff rendering style: 'auto' adapts to terminal width, 'stacked' always shows single column"),
+  notifications: z
+    .boolean()
+    .default(true)
+    .optional()
+    .describe("Show system notifications when sessions complete or error. Requires terminal focus-loss detection."),
 })
 
 export const TuiInfo = z
diff --git a/packages/opencode/src/notification/index.ts b/packages/opencode/src/notification/index.ts
new file mode 100644
index 000000000000..bb17373d47ca
--- /dev/null
+++ b/packages/opencode/src/notification/index.ts
@@ -0,0 +1,95 @@
+import { platform } from "os"
+import { Process } from "@/util/process"
+import { which } from "@/util/which"
+
+const TERMINAL_APPS = [
+  "terminal",
+  "iterm",
+  "iterm2",
+  "warp",
+  "alacritty",
+  "kitty",
+  "ghostty",
+  "wezterm",
+  "hyper",
+  "tabby",
+  "wave",
+  "tmux",
+  "zellij",
+  "vscode",
+  "code",
+]
+
+function escapeForOsascript(s: string): string {
+  return s.replace(/\\/g, "\\\\").replace(/"/g, '\\"')
+}
+
+export namespace Notification {
+  export async function terminalIsFocused(): Promise<boolean> {
+    if (platform() !== "darwin") return false
+
+    const result = await Process.text(
+      [
+        "osascript",
+        "-e",
+        'tell application "System Events" to get name of first application process whose frontmost is true',
+      ],
+      { nothrow: true },
+    )
+    const frontmost = result.text.trim().toLowerCase()
+    return TERMINAL_APPS.some((app) => frontmost.includes(app))
+  }
+
+  export async function show(title: string, message: string): Promise<void> {
+    const os = platform()
+
+    if (os === "darwin") {
+      const escaped = escapeForOsascript(message)
+      const titleEscaped = escapeForOsascript(title)
+      await Process.run(
+        [
+          "osascript",
+          "-e",
+          `tell application "Terminal" to display notification "${escaped}" with title "${titleEscaped}"`,
+        ],
+        { nothrow: true },
+      )
+      return
+    }
+
+    if (os === "linux") {
+      if (which("notify-send")) {
+        await Process.run(["notify-send", "--app-name=opencode", title, message], { nothrow: true })
+        return
+      }
+      if (which("notify")) {
+        await Process.run(["notify", title, message], { nothrow: true })
+        return
+      }
+      return
+    }
+
+    if (os === "win32") {
+      const script = [
+        "[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] | Out-Null",
+        "[Windows.Data.Xml.Dom.XmlDocument, Windows.Data.Xml.Dom.XmlDocument, ContentType = WindowsRuntime] | Out-Null",
+        `$template = "<toast><visual><binding template='ToastText02'><text id='1'>${escapeXml(title)}</text><text id='2'>${escapeXml(message)}</text></binding></visual></toast>"`,
+        "$xml = New-Object Windows.Data.Xml.Dom.XmlDocument",
+        "$xml.LoadXml($template)",
+        "$toast = [Windows.UI.Notifications.ToastNotification]::new($xml)",
+        '[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier("opencode").Show($toast)',
+      ].join("; ")
+      await Process.run(["powershell.exe", "-NonInteractive", "-NoProfile", "-Command", script], { nothrow: true })
+      return
+    }
+  }
+}
+
+function escapeXml(s: string): string {
+  return s
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&apos;")
+}
diff --git a/packages/web/src/content/docs/ar/plugins.mdx b/packages/web/src/content/docs/ar/plugins.mdx
index d7c025bbc319..10de0789b0aa 100644
--- a/packages/web/src/content/docs/ar/plugins.mdx
+++ b/packages/web/src/content/docs/ar/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/bs/plugins.mdx b/packages/web/src/content/docs/bs/plugins.mdx
index 7e046cb83dfd..475fafd6e609 100644
--- a/packages/web/src/content/docs/bs/plugins.mdx
+++ b/packages/web/src/content/docs/bs/plugins.mdx
@@ -216,7 +216,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/da/plugins.mdx b/packages/web/src/content/docs/da/plugins.mdx
index 908c6e111130..b99e45de746c 100644
--- a/packages/web/src/content/docs/da/plugins.mdx
+++ b/packages/web/src/content/docs/da/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/de/plugins.mdx b/packages/web/src/content/docs/de/plugins.mdx
index 57fcdbba6e85..4520d77547b4 100644
--- a/packages/web/src/content/docs/de/plugins.mdx
+++ b/packages/web/src/content/docs/de/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/es/plugins.mdx b/packages/web/src/content/docs/es/plugins.mdx
index dc4418072516..2993b701c407 100644
--- a/packages/web/src/content/docs/es/plugins.mdx
+++ b/packages/web/src/content/docs/es/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/fr/plugins.mdx b/packages/web/src/content/docs/fr/plugins.mdx
index 48cdc4d116d6..2068f0c14920 100644
--- a/packages/web/src/content/docs/fr/plugins.mdx
+++ b/packages/web/src/content/docs/fr/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/it/plugins.mdx b/packages/web/src/content/docs/it/plugins.mdx
index 3fc22a78c565..90716588099c 100644
--- a/packages/web/src/content/docs/it/plugins.mdx
+++ b/packages/web/src/content/docs/it/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/ja/plugins.mdx b/packages/web/src/content/docs/ja/plugins.mdx
index 06a0dca9adf9..058777a612e5 100644
--- a/packages/web/src/content/docs/ja/plugins.mdx
+++ b/packages/web/src/content/docs/ja/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/ko/plugins.mdx b/packages/web/src/content/docs/ko/plugins.mdx
index f20eb90c46cb..6ad660c4d9ad 100644
--- a/packages/web/src/content/docs/ko/plugins.mdx
+++ b/packages/web/src/content/docs/ko/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/nb/plugins.mdx b/packages/web/src/content/docs/nb/plugins.mdx
index 27d23ec63a83..42fd1903baee 100644
--- a/packages/web/src/content/docs/nb/plugins.mdx
+++ b/packages/web/src/content/docs/nb/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/pl/plugins.mdx b/packages/web/src/content/docs/pl/plugins.mdx
index 510c8a22e4c3..2ea2494bf244 100644
--- a/packages/web/src/content/docs/pl/plugins.mdx
+++ b/packages/web/src/content/docs/pl/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/pt-br/plugins.mdx b/packages/web/src/content/docs/pt-br/plugins.mdx
index 54c5b1ffaca8..096c13907bb4 100644
--- a/packages/web/src/content/docs/pt-br/plugins.mdx
+++ b/packages/web/src/content/docs/pt-br/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/ru/plugins.mdx b/packages/web/src/content/docs/ru/plugins.mdx
index 1d7ffb339be9..910a4c571a1e 100644
--- a/packages/web/src/content/docs/ru/plugins.mdx
+++ b/packages/web/src/content/docs/ru/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/th/plugins.mdx b/packages/web/src/content/docs/th/plugins.mdx
index e672715a4efe..0073ed26a2ad 100644
--- a/packages/web/src/content/docs/th/plugins.mdx
+++ b/packages/web/src/content/docs/th/plugins.mdx
@@ -225,7 +225,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/tr/plugins.mdx b/packages/web/src/content/docs/tr/plugins.mdx
index 4926f5f70e55..bf7233fffafa 100644
--- a/packages/web/src/content/docs/tr/plugins.mdx
+++ b/packages/web/src/content/docs/tr/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/zh-cn/plugins.mdx b/packages/web/src/content/docs/zh-cn/plugins.mdx
index e8a8bd70cbc3..c106f87cce38 100644
--- a/packages/web/src/content/docs/zh-cn/plugins.mdx
+++ b/packages/web/src/content/docs/zh-cn/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }
diff --git a/packages/web/src/content/docs/zh-tw/plugins.mdx b/packages/web/src/content/docs/zh-tw/plugins.mdx
index 8163c291e002..8444dea117fd 100644
--- a/packages/web/src/content/docs/zh-tw/plugins.mdx
+++ b/packages/web/src/content/docs/zh-tw/plugins.mdx
@@ -224,7 +224,7 @@ export const NotificationPlugin = async ({ project, client, $, directory, worktr
     event: async ({ event }) => {
       // Send notification on session completion
       if (event.type === "session.idle") {
-        await $`osascript -e 'display notification "Session completed!" with title "opencode"'`
+        await $`osascript -e 'tell application "Terminal" to display notification "Session completed!" with title "opencode"'`
       }
     },
   }