diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 958bfe1..2a1cca8 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -33,6 +33,7 @@ ETTerms 是一個給工程師 / 韌體 / 硬體驗證人員用的**單一視窗
 | PDU 控制（選用） | **SnmpSharpNet** | 沿用 MyTeraTerm PDU 控制（`pductrl` / `pduconnect`） |
 | 日誌 | 自製 **AppLogger**（從 MyTeraTerm 移植） | 檔案 + Debug 雙輸出 |
 | AI / MCP 整合（選用） | **stdio MCP server**（官方 C# SDK `ModelContextProtocol`） | 兩個獨立 server：`ETTerms.SerialMcp`（不自己開 port，經本機 named pipe 橋接 GUI 持有的 serial session）與 `ETTerms.PduMcp`（直接打 SNMP 控制 PDU 插座，不需 GUI）；把收發 / 電源控制暴露成 AI 可呼叫工具（Kiro CLI / Claude CLI），見 [AI / MCP Integration](#ai--mcp-integrationserial-mcp--pdu-mcp-server) |
+| 內建 AI Assistant（Phase 10 規劃中） | **Microsoft.Extensions.AI**（OpenAI 相容 client + function calling） | GUI 內建 agent 聊天分頁，in-process 直呼 serial / PDU 工具（不經 MCP）；**BYO endpoint**——Provider 預設空白，發佈版不含任何私人端點，API key 存 Credential Manager |
 | 打包 | `dotnet publish` + （選用）Inno Setup / MSIX | 單機安裝，current-user |
 
 > **與舊版 MyTeraTerm 的關鍵差異：** 舊版是把真正的 `ttermpro.exe`（TeraTerm）嵌進 Panel，靠 **com0com 虛擬 COM 對**攔截 serial 來跑腳本。ETTerms 改走**全原生**：SSH.NET 做 SSH、`System.IO.Ports` 做 serial、自繪 VT100 控制項做終端機畫面，**不再依賴外部 TeraTerm exe，也不再需要 com0com**。腳本引擎從「驅動 com0com bridge」改成「驅動原生 `ISessionChannel`」。
@@ -161,6 +162,11 @@ ETTerms/
         │   └── Pdu/
         │       └── PduController.cs#   SnmpSharpNet PDU 控制 (pductrl / pduconnect)
         │
+        ├── Ai/                     # ── 內建 AI Assistant（Phase 10, v0.6.0）──
+        │   ├── OpenAiChatClient.cs #   極簡 OpenAI 相容 /chat/completions（HttpClient, 非串流；BYO endpoint）
+        │   ├── AgentHost.cs        #   手寫 agent loop（tool_calls → 執行 → 餵回 → 迴圈，上限 8 輪）
+        │   └── AiTools.cs          #   工具集：serial（經 SerialBridge, [AI] echo）+ PDU（PduCore）；破壞性動作經 ConfirmAsync 彈框
+        │
         └── Infrastructure/
             ├── AppLogger.cs        #   日誌 (port 自 MyTeraTerm)
             ├── AppSettings.cs      #   使用者偏好 (JSON, %LocalAppData%\ETTerms\settings.json)
@@ -468,6 +474,37 @@ Kiro/Claude CLI ── 啟動子行程 ETTerms.PduMcp（stdio / JSON-RPC）
 
 > 所有工具回傳統一的 `{ "ok": bool, "result"/"error": ... }` JSON。SNMP community 目前沿用 GUI 版的 `"private"`。
 
+### 內建 AI Assistant（Phase 10 — ✅ 已完成 v0.6.0）
+
+> 讓 ETTerms **自己就是 agent host**——不經 Claude / Kiro,在 GUI 內建 AI 聊天**分頁**,用自然語言驅動 serial 與 PDU（「接上 COM3,送 help 看回應」「連上 PDU,把 outlet 3 重開」一句話完成）。**AI 分頁是 Workspace 的一種 pane**（工具列 `✨ AI Chat` 開啟）,可用 Layout（1×2 / 2×2…）與 serial 分頁**並排同時使用**——像 Claude Code / Kiro 那樣一邊聊、一邊看終端機。
+
+**設計原則：BYO Endpoint（使用者自帶 LLM 端點）**
+
+- Provider 設定（**Base URL / API Key / Model**）預設**全空白**;未設定時 AI 面板顯示「未設定 AI Provider」且功能完全停用——**發佈出去的 ETTerms 不內含任何端點,對一般使用者就是一個沒有 AI 的終端機**。
+- API Key 只存 **Windows Credential Manager**（`ETTerms/AiApiKey`,沿用 `CredentialVault`）;Base URL / Model 存 settings.json（本機、非 repo）。
+- 介面走 **OpenAI 相容 `/v1/chat/completions` + function calling**,任何供應商皆可接：本機 Ollama（`http://localhost:11434/v1`）、自架 LiteLLM gateway、公司內部 gateway、OpenAI 等。模型需支援 function calling。
+- 🚫 **鐵則：任何私人端點 URL / API key 不得出現在程式碼、預設值、文件範例、repo、publish 產物。** 文件範例一律用 `localhost` 或占位符。
+
+**架構（in-process function calling,不經 MCP）**
+
+```
+AiChatView（Workspace 的一種 pane，與 SessionPage 並排；工具列 ✨ AI Chat 開啟）
+  └─ AgentHost（Ai/AgentHost.cs）：維護對話歷史 + 手寫 agent loop（最多 8 輪工具）
+      ├─ OpenAiChatClient（Ai/OpenAiChatClient.cs）：極簡 OpenAI 相容 /chat/completions（非串流）→ 使用者設定的 Base URL
+      └─ AiTools（Ai/AiTools.cs）：in-process 直呼,不經子行程 / pipe
+          ├─ serial_list / attach / write / read    → SerialBridge 同一套路徑（[AI] 標色照舊；read 端自行累積 RX）
+          └─ pdu_connect / status / set_port / power_cycle → ETTerms.PduCore（本 session 內 IP→controller 登錄）
+```
+
+**為何內建 agent 不經 MCP：** MCP 解決的是「跨行程 / 跨信任邊界」（Claude / Kiro 是別人的 process,所以需要 stdio JSON-RPC + named pipe 橋接）;內建 agent 與工具在**同一個 process**,直呼即可,插一層「子行程 + 序列化 + pipe」繞一圈回自己記憶體裡的物件,只增加故障面。既有的 SerialMcp / PduMcp **不受影響**,繼續服務外部 AI CLI（Settings → AI MCP）。日後若要開放「使用者掛第三方 MCP server」（ETTerms 作為 **MCP host**）,把 MCP client 列出的工具 schema concat 進 `AiTools.GetSchemas()` 的清單即可,agent loop 不需改動。
+
+**安全設計：**
+- 破壞性 PDU 動作（`pdu_set_port` off / `pdu_power_cycle`）一律 **C# 端彈確認框**（`AiTools.ConfirmAsync` → GUI MessageBox,預設按鈕 No；不信 LLM 自律）。
+- 所有 AI 工具呼叫寫 **AppLogger** 留跡（`[AI tool] <name> <args>`）。
+- Serial TX 沿 Phase 9 慣例以 `[AI]` 標色 echo（`SerialBridgeEndpoint.Write`）,使用者全程看得到 AI 打了什麼。
+
+**實作選型：** 手寫 `OpenAiChatClient`（HttpClient + System.Text.Json,非串流）+ 手寫 agent loop,**不引入 `Microsoft.Extensions.AI`**——依賴最小、對任意 OpenAI 相容 gateway 相容性自己掌控、無額外 NuGet 演進風險。工具 schema 為手組 JSON（OpenAI function-calling 格式）。
+
 ---
 
 ## Key Constraints & Business Rules
@@ -482,6 +519,7 @@ Kiro/Claude CLI ── 啟動子行程 ETTerms.PduMcp（stdio / JSON-RPC）
 8. **GUI 先行：** Phase 1–2 必須先讓視窗外殼 + 分頁 + 假連線可見可操作，再接真實 channel。
 9. **不依賴外部 exe：** 不嵌 TeraTerm、不需 com0com；全原生 .NET 元件。
 10. **UI 不可被 channel I/O 阻塞：** channel 讀寫在背景，UI 更新一律 `Invoke` 回 UI thread。
+11. **AI Provider 預設空白（BYO endpoint）：** 內建 AI（Phase 10）未設定端點時完全停用;**任何私人端點 / 金鑰不得進程式碼、預設值、文件範例、publish 產物**。API key 只存 Windows Credential Manager。
 
 ---
 
@@ -490,6 +528,7 @@ Kiro/Claude CLI ── 啟動子行程 ETTerms.PduMcp（stdio / JSON-RPC）
 - **密碼儲存：** 一律使用 **Windows Credential Manager**（透過 `CredentialVault.cs`）。SQLite 內只存索引 `CredentialKey`，無明碼。SSH private key passphrase 同理。
 - **SSH host key 驗證：** 首次連線顯示 host key 指紋供使用者確認（trust-on-first-use），記錄已信任的指紋，之後比對；指紋不符要警告。
 - **私鑰檔保護：** private key 路徑存設定，但不複製 key 內容進 repo / SQLite。
+- **AI Provider（Phase 10）：** Base URL / Model 存本機 settings.json、API key 只存 Credential Manager（`ETTerms/AiApiKey`）;**無任何預設端點**——發佈產物內不含開發者私人伺服器資訊,文件範例一律 `localhost` / 占位符。AI 工具呼叫全程 AppLogger 留跡,破壞性 PDU 動作需 GUI 確認。
 - **輸入處理：** 終端機輸入直接透傳給遠端，不做 shell 注入解讀（本來就是終端機）；但 UI 載入腳本檔時要防路徑穿越 / 過大檔。
 - **日誌不含密碼：** `AppLogger` 與 `logopen` 輸出不可寫入密碼 / passphrase；連線資訊只記主機 / port，不記 credential。
 - **無 `secret/` 資料夾：** ETTerms 無伺服端祕密 / DB 密碼 / compile-time secret，連線密碼一律走 Windows Credential Manager，因此不設 `secret/` 集中目錄，也不需要 publish 類腳本。若日後做 Release 程式碼簽章，簽章 `.pfx` 請放在 repo 外並以環境變數 / CI secret 傳入。
@@ -704,6 +743,19 @@ Rename-Item (Join-Path $proot "ETTerms.exe") "ETTerms v$ver.exe"
 - [x] 註冊說明（`kiro-cli mcp add` / agent.json `mcpServers`）寫入 [docs/serial-mcp-guide.md](docs/serial-mcp-guide.md)，含「需先在 GUI 開好 port」前提
 **驗收條件：** ✅ GUI 開一條 Serial（COM3）→ 另一分頁 PowerShell 跑 kiro → AI 經 MCP `serial_attach` COM3 → `serial_write` 送指令、`serial_read` 讀回應，**整個過程在 GUI Tab1 即時可見（AI 的 TX 有 `[AI]` 標色）**；全程只有 GUI 開該 port。
 
+### Phase 10 — 內建 AI Assistant（BYO endpoint agent）（工作量：M）✅ 已完成（v0.6.0）
+**目標：** 不依賴 Claude / Kiro，GUI 內建 AI 聊天檢視，自然語言驅動 serial + PDU；**發佈版不含任何私人端點**（設計見 [內建 AI Assistant](#內建-ai-assistantphase-10--✅-已完成-v060)）。
+**包含：**
+- [x] `AppSettings` 加 `AiBaseUrl` / `AiModel` / `AiSystemPrompt`（預設空白）；API key 存 `CredentialVault`（`ETTerms/AiApiKey`）
+- [x] `App/SettingsView.cs` 加 **AI Assistant** 分頁：Base URL / Model / API Key（密碼框）/ 系統提示詞，Save 寫 settings + Credential Manager；空白＝停用
+- [x] `App/AiChatView.cs`：聊天 UI（乾淨逐字稿：user 靠右 accent、AI 靠左、工具灰字、thinking 收進 Send 按鈕）+ 底部控制列（輸入框 Fill + 右下角模型下拉 / Send）；`RefreshProvider()` 開分頁時依設定重建 client。**作為 Workspace pane**：`WorkspaceView` 工具列 `✨ AI Chat` → `OpenAiPane()`，`Session` 抽象化容納 `SessionPage` 或 `AiChatView`（`Content` 屬性），可與 serial 用 Layout 並排；AI 分頁無 Group / Log / Script（自動 skip）。**模型下拉**打端點 `/v1/models` 列出可選模型、即時切換並記住（Settings 不再設 model,只留 Base URL / Key / 系統提示詞）
+- [x] `Ai/OpenAiChatClient.cs`：極簡 OpenAI 相容 chat-completions（HttpClient，非串流）
+- [x] `Ai/AgentHost.cs`：手寫 agent loop（tool_calls → 執行 → role=tool 餵回 → 迴圈，上限 8 輪）
+- [x] `Ai/AiTools.cs`：serial（list/attach/write/read，經 `SerialBridge`，`[AI]` echo 沿用）+ PDU（connect/status/set_port/power_cycle，`ETTerms.PduCore`）；破壞性動作經 `ConfirmAsync` 彈框；每筆呼叫寫 AppLogger
+- [x] AI 入口在 `WorkspaceView` 工具列（`✨ AI Chat` 按鈕），開成可並排的 pane（非獨立 rail view）——這樣才能與 serial 分頁同時使用
+- [ ] （延伸，未做）MCP host：讓使用者掛自己的第三方 MCP server（schema concat 進 `AiTools.GetSchemas()`）
+**驗收條件：** ✅ 建置 0 錯誤；未設定 Provider 時 AI 面板停用並提示；`src` grep 無任何私人端點 / key（範例一律 localhost / 假 IP）。實機端到端（接 OpenAI 相容端點跑 serial/PDU 一句話流程、PDU 確認框、`[AI]` 標色、AppLogger 紀錄）待使用者驗收。
+
 ---
 
 ## Future Extensions
@@ -712,6 +764,7 @@ Rename-Item (Join-Path $proot "ETTerms.exe") "ETTerms v$ver.exe"
 
 - ~~**AI / MCP 整合**~~（✅ 已於 [Phase 9](#development-phases) 實作：Serial MCP Server，讓 AI agent 直接操作 serial；未來可再擴充 SSH / Shell MCP 工具）
 - ~~**SFTP 檔案瀏覽**~~（✅ 已於 Phase 8 實作：sidebar SFTP 分頁）
+- **AI Chat 氣泡版（WebView2）**（v0.7.0 候選）：目前 AI 分頁走 RichTextBox「乾淨逐字稿」風（與終端機一致、務實）；若要真正的聊天氣泡（圓角、限寬、user 右 AI 左）+ Markdown / 程式碼區塊高亮 + 工具呼叫可摺疊卡片,正解是改用 WebView2 + HTML/CSS 渲染。代價：引入 WebView2 依賴、portable 版變大。列為獨立升級,不在 RichTextBox 上硬做氣泡。
 - **Telnet** session 類型（補一個 `TelnetChannel : ISessionChannel`）
 - **RDP / VNC** 分頁（KKTerm 用 mstscax.dll；ETTerms 可後期評估）
 - **tmux 自動 attach**（SSH 斷線後自動回貼，仿 KKTerm）
diff --git a/CLAUDE.md b/CLAUDE.md
index 564f75f..be15db9 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,9 @@ ETTerms 是一個 **C# .NET 8 WinForms** 的原生 Windows 終端機工作台，
 
 **開發策略：GUI 先行** — 先把視窗外殼 + 分頁 + 連線清單做出來，再逐步補 Serial → SSH → VT100 → 腳本引擎 → Settings/About → PDU/Shell/SFTP。
 
-**進度：** Phase 1–5 ✅、Phase 6 ✅（TTL 引擎 + Group 同步，SSH 待驗收）、Phase 7 ✅（Settings/About）、Phase 8 ✅（PDU + Shell/ConPTY + SFTP + Settings 擴充）、Phase 9 ✅（Serial MCP server：**GUI 持有 COM port，MCP 經本機 named pipe 橋接**，AI 收發的資料即時以 `[AI]` 標色顯示在 GUI）。打包待指示。
+**進度：** Phase 1–5 ✅、Phase 6 ✅（TTL 引擎 + Group 同步，SSH 待驗收）、Phase 7 ✅（Settings/About）、Phase 8 ✅（PDU + Shell/ConPTY + SFTP + Settings 擴充）、Phase 9 ✅（Serial MCP server：**GUI 持有 COM port，MCP 經本機 named pipe 橋接**，AI 收發的資料即時以 `[AI]` 標色顯示在 GUI）、**Phase 10 ✅（v0.6.0）內建 AI Assistant**（見下）。打包待指示。
+
+**v0.6.0：** **內建 AI Assistant（Phase 10）** — 不經 Claude / Kiro，GUI 內建 ✨ AI 聊天**分頁**，自然語言驅動 serial + PDU。**AI 是 Workspace 的一種 pane**（工具列 `✨ AI Chat` 開啟，`WorkspaceView.Session` 抽象化為可容納 `SessionPage` 或 `AiChatView` 的 `Content`），可用 Layout 與 serial 分頁**並排同時用**（像 Claude/Kiro）；AI 分頁無 Group/Log/Script。**UI 走乾淨逐字稿風**（user 靠右 accent、AI 靠左、工具灰字、thinking 收進 Send 按鈕不洗版；與終端機美學一致，非氣泡——真氣泡+Markdown 的 WebView2 版列 v0.7.0）。**模型下拉**（右下角）打端點 `/v1/models` 列可選模型、即時切換並記住；**Settings 只留 Base URL / API Key / 系統提示詞,不再設 model**（`configured` 只看 Base URL）。**BYO endpoint**：`Settings → AI Assistant` 填 Base URL / Model / API Key（任意 OpenAI 相容 gateway：本機 Ollama、LiteLLM、公司 gateway、OpenAI…），**預設全空白＝功能停用**；🚫 **發佈版不含任何私人端點**，API key 存 Windows Credential Manager（`ETTerms/AiApiKey`）、Base URL/Model 存 settings.json，程式碼範例一律 `localhost`/假 IP。**架構（in-process，不經 MCP）**：`Ai/OpenAiChatClient`（極簡 OpenAI 相容 `/chat/completions`，HttpClient 非串流）+ `Ai/AgentHost`（手寫 agent loop，tool_calls→執行→role=tool 餵回→迴圈上限 8 輪）+ `Ai/AiTools`（serial list/attach/write/read 經 `SerialBridge`——與 MCP 同一路徑、AI 的 TX 照樣 `[AI]` 標色顯示在終端機；PDU connect/status/set_port/power_cycle 經 `ETTerms.PduCore`）。**安全**：破壞性 PDU 動作（關插座 / power-cycle）一律 `AiTools.ConfirmAsync` → GUI MessageBox（預設 No）確認，AI 不能自己斷電；每筆工具呼叫寫 AppLogger（`[AI tool] …`）。**刻意不引入 `Microsoft.Extensions.AI`**（手寫 client+loop，依賴最小、對任意 gateway 相容性自己掌控）。既有 SerialMcp/PduMcp（Settings → AI MCP）**不受影響**，繼續服務外部 AI CLI；兩者是「內建 agent（in-process）vs 外部 AI（MCP 跨行程）」的分工。新增 `src/ETTerms/Ai/`（3 檔）+ `App/AiChatView.cs`，`ActivityRail` 加 `Ai` view，`SettingsView` 加 AI Assistant 分頁，`AppSettings` 加 `AiBaseUrl/AiModel/AiSystemPrompt`。
 
 **v0.5.0：** 搜尋 / 關鍵字警示 / TTL 大擴充。**(1) Ctrl+F scrollback 搜尋** — `TerminalView` 內建搜尋列（Enter 往上找、Shift+Enter 往下、F3/Esc），全部命中黃底、目前命中橘底；命中以「絕對行號 = `ScreenBuffer.DroppedLines` + abs」錨定，環形緩衝丟舊行不漂移。**(2) 關鍵字高亮 + 分頁警示** — `AppSettings.KeywordRules`（`KeywordRule{Text,Enabled}` + 全域開關），Settings 新 **Highlight** 分頁可增刪/勾選；`TerminalView` 每次重繪只掃可見行標紅底（不分大小寫），`Feed` 路徑用獨立 Decoder+去 ANSI 偵測觸發 `KeywordAlert`（每關鍵字 2s 冷卻）→ `SessionPage` → `WorkspaceView` 把**非 active 分頁**的圓點標紅、切過去自動清除。**(3) TTL 對齊 TeraTerm** — 新 `TtlExpression` 運算式解析器（括號/邏輯/比較/十六進位 `0x`/`$`，失敗退回 legacy 規則相容舊腳本）；新增控制流 `goto/call(行內執行，迴圈內可用)/return/for-next/do-loop/until-enduntil/break/continue/end/exit/include/mpause`、等待 `waitln/waitregex/recvln/wait 多字串(TeraTerm 語意：逾時 result=0 繼續)/mtimeout`、字串 `strlen/strcompare/strconcat/strcopy/strinsert/strremove/strmatch/strscan/strreplace/strtrim/strsplit/strjoin/tolower/toupper/str2int/int2str/code2str/str2code/sprintf(→inputstr)/expandenv`、檔案 `fileopen/filereadln(result=1 是 EOF)/filewrite(ln)/fileclose/filecreate/filedelete/filesearch/basename/dirname/makepath/foldercreate/folderdelete/foldersearch/getdir/setdir`、雜項 `beep/getdate/gettime(strftime 子集)/getenv/setenv/random/exec/getver/getttdir/uptime/ifdefined/clipb2var/var2clipb/inputbox/yesnobox/crc32/checksum8/16/32/dispstr`、serial 專用 `sendbreak/setbaud/setdtr/setrts/sendfile`（`SerialChannel` 新增對應方法）；單行 `if <expr> <statement>` 支援；`Preprocess` 引號內 `;` 不再被當註解；系統變數 `inputstr/matchstr/groupmatchstr1-9`；`_vars` 改大小寫不敏感；**單字串 `wait` 保留 ETTerms settle+逾時中止語意（勿改）**，多字串才是 TeraTerm 語意。`SessionPage` 把 `runner.Output`（trace：`[wait]`/`>>`/錯誤）以灰色 echo 進終端機，**可由 Settings → Terminal 的 `ShowScriptTrace` 開關關閉**；`dispstr` 走獨立的 `Display` 事件一律顯示。灰色訊息只進畫面 buffer——不進 ⏺ Log 側錄、不進 AI bridge、不送裝置（機台原始 log 乾淨）。指令表＋範例：[docs/ttl-script-reference.md](docs/ttl-script-reference.md)（前段 ETTerms 獨有、後段與 TeraTerm 共有）。
 
@@ -37,6 +39,7 @@ ETTerms 是一個 **C# .NET 8 WinForms** 的原生 Windows 終端機工作台，
 - **連線儲存：** SQLite（`Microsoft.Data.Sqlite`）
 - **密碼儲存：** Windows Credential Manager（不落地明碼）
 - **PDU：** SnmpSharpNet（iPoMan II/III via SNMP）
+- **內建 AI Assistant（v0.6.0）：** 手寫 OpenAI 相容 client（HttpClient）+ agent loop，in-process 直呼 serial/PDU 工具；BYO endpoint（Provider 預設空白，發佈版不含端點）。`src/ETTerms/Ai/`。
 - **AI / MCP（選用）：** 兩個 stdio MCP server（官方 C# SDK `ModelContextProtocol`）。`ETTerms.SerialMcp`：**不自己開 COM port**，經本機 named pipe 接上 GUI 持有的 serial session，AI 的 TX/RX 同步顯示在 GUI。`ETTerms.PduMcp`（v0.3.0）：**直接打 SNMP** 控制 PDU 插座，非獨佔故不需 GUI 在跑。皆暴露給 Kiro CLI / Claude CLI
 - **設定持久化：** JSON → `%LocalAppData%\ETTerms\settings.json`
 
@@ -83,6 +86,7 @@ kiro-cli mcp add --name serial --command dotnet --args "run --project src\ETTerm
 ## 注意事項 / 禁止事項
 
 - 🚫 **密碼絕不寫進 SQLite / 程式碼 / log**，一律走 Windows Credential Manager。
+- 🚫 **內建 AI（Phase 10）採 BYO endpoint**：Provider（Base URL / API Key / Model）**預設空白**＝功能停用；**開發者私人的 LLM 端點 / API key 絕不寫進程式碼、預設值、文件範例、publish 產物**——只存在開發者本機的 settings.json / Credential Manager。文件與 UI 範例一律用 `http://localhost:11434/v1` 或占位符。發佈前驗收：publish 資料夾 grep 不到任何私人 IP / 網域 / key。
 - 🚫 **不嵌 TeraTerm、不依賴 com0com** —— ETTerms 走全原生（這是與舊版 MyTeraTerm 的關鍵差異）。
 - 🚫 不要把 `For_AI/` 內容 commit 進 git。
 - ⚠️ Serial COM port 同時只能被一個 session 開啟，開啟前檢查可用性。
@@ -95,7 +99,7 @@ kiro-cli mcp add --name serial --command dotnet --args "run --project src\ETTerm
 
 ## 資料夾用途
 
-- **`src/ETTerms/`** — 主應用程式（WinForms 視窗外殼 + 連線 / 終端機 / 腳本引擎）。
+- **`src/ETTerms/`** — 主應用程式（WinForms 視窗外殼 + 連線 / 終端機 / 腳本引擎）。內含 **`Ai/`**（v0.6.0 內建 AI Assistant：`OpenAiChatClient` + `AgentHost` + `AiTools`）與 `App/AiChatView.cs`。
 - **`src/ETTerms.SerialMcp/`** — ✅ stdio MCP server（給 AI agent 收發 serial）。獨立行程，但**不直接開 COM port**：經本機 named pipe 連到 GUI 的 `SerialBridgeServer`，由 GUI 代為讀寫實體 port；net8.0 console + `ModelContextProtocol` SDK。
 - **`src/ETTerms.PduMcp/`** — ✅ stdio MCP server（給 AI agent 控制 SNMP PDU，v0.3.0）。獨立行程，**直接打 SNMP**，不經 GUI、GUI 不開著也能用；net8.0 console + `ModelContextProtocol`，PDU 邏輯用 `ETTerms.PduCore`。
 - **`src/ETTerms.PduCore/`** — ✅ PDU SNMP 控制共用庫（v0.4.0）。GUI 與 PduMcp 共用的唯一 `PduController`（先前兩份複製已移除）；診斷 log 走建構子注入委派（GUI→AppLogger、MCP→stderr）；含批次查詢 `GetAllPortsStatus()`。
diff --git a/docs/release-notes/v0.5.0.md b/docs/release-notes/v0.5.0.md
new file mode 100644
index 0000000..a401385
--- /dev/null
+++ b/docs/release-notes/v0.5.0.md
@@ -0,0 +1,53 @@
+# v0.5.0 — Terminal search, keyword alerts & a major TTL scripting upgrade
+
+## ✨ New features
+
+**Find text in your scroll-back (Ctrl+F)**
+* Press **Ctrl+F** to open a search bar right inside the terminal and find any text in the
+  scroll-back history — **Enter** jumps to the previous match, **Shift+Enter** to the next,
+  **F3** repeats, **Esc** closes.
+* Every match is highlighted in **yellow**, the current one in **orange**, and matches stay
+  anchored to the right line even as old output scrolls off the top of the buffer.
+
+**Keyword highlighting + per-tab alerts**
+* Define your own keyword list under **Settings → Highlight** (add, remove, and enable/disable
+  each one). Matching text is highlighted on screen wherever it appears, case-insensitive.
+* When a keyword shows up on a tab you're **not** currently looking at, that tab's dot turns
+  **red** so you notice it — switching to the tab clears the alert. Great for watching several
+  sessions at once for an error string.
+
+**A much bigger, TeraTerm-compatible TTL scripting language**
+* The TTL engine now understands a large set of **TeraTerm-compatible commands**, so many
+  existing TeraTerm macros run with little or no change.
+* New control flow — `for`/`next`, `do`/`loop`, `while`/`until`, `call`, `goto`, `break`,
+  `continue`, `include` — plus a real expression parser (parentheses, logical & comparison
+  operators, hex `0x` / `$`), and dozens of new string, file/folder and utility commands
+  (`sprintf`, `strsplit`, `filereadln`, `getdate`, `random`, `crc32`, `inputbox`, `yesnobox`, …).
+* New **serial-specific** script commands: `sendbreak`, `setbaud`, `setdtr`, `setrts`, `sendfile`.
+* Note: a single-string `wait` keeps ETTerms' existing settle-and-timeout behavior; multi-string
+  `wait` follows TeraTerm semantics (times out and continues with `result=0`).
+
+**See — or hide — what your scripts are doing**
+* Scripts now echo their progress (waits, sends, errors) in **grey** directly in the terminal,
+  and you can switch this off under **Settings → Terminal** (**Show script trace**).
+* The trace is display-only: it never reaches your session log, the AI bridge, or the device,
+  so your captured machine logs stay clean.
+
+## 📦 Downloads
+
+Two builds are produced:
+
+| Build | Needs .NET 8 Desktop Runtime? | Notes |
+|-------|-------------------------------|-------|
+| **Standard** (`ETTerms_v0.5.0`) | ✅ Yes | Smaller; for machines that already have the runtime |
+| **Portable** (`ETTerms_v0.5.0_portable`) | ❌ No | Runtime bundled — unzip and run, no install / admin needed |
+
+Run `ETTerms v0.5.0.exe`.
+
+## 🔗 Links
+* TTL reference:
+  [docs/ttl-script-reference.md](https://github.com/ETWen/ETTerms/blob/main/docs/ttl-script-reference.md)
+* PDU MCP & Serial MCP setup guide:
+  [docs/serial-mcp-guide.md](https://github.com/ETWen/ETTerms/blob/main/docs/serial-mcp-guide.md)
+
+**Full changelog:** [v0.4.0...v0.5.0](https://github.com/ETWen/ETTerms/compare/v0.4.0...v0.5.0)
diff --git a/docs/release-notes/v0.6.0.md b/docs/release-notes/v0.6.0.md
new file mode 100644
index 0000000..f6012af
--- /dev/null
+++ b/docs/release-notes/v0.6.0.md
@@ -0,0 +1,37 @@
+# v0.6.0 — Talk to your serial port & PDU: a built-in AI Assistant
+
+## ✨ New features
+
+**Built-in AI Assistant — drive serial & PDU in plain language**
+* New **✨ AI Chat** button in the workspace toolbar opens an AI pane. Ask things like *"list the open serial sessions"*, *"attach to COM3, send `help` and show me the reply"*, or *"connect to the PDU and power-cycle outlet 3"* — the assistant calls the right tools for you.
+* Whatever the AI sends to a serial port shows up in that terminal tagged `[AI]`, so you always see exactly what it did — no hidden actions.
+* Runs entirely against your own machines: it talks to the serial session ETTerms already has open, and to the PDU over SNMP.
+
+**Sits right next to your terminal — like Claude Code / Kiro**
+* The AI Chat is a normal workspace pane, so you can use Layout (1×2, 2×2…) to put it side-by-side with a live Serial session — chat on one side, watch the device output on the other.
+* Clean transcript layout that matches the terminal: your messages align right, the AI's replies read left, and tool activity stays as quiet gray notes. "Thinking" is folded into the Send button instead of spamming the log.
+
+**Bring your own AI endpoint (nothing baked in)**
+* Point it at any OpenAI-compatible endpoint — a local Ollama, a LiteLLM gateway, your company's gateway, or OpenAI. Set the Base URL and API key once in **Settings → AI Assistant**; leave it blank and the assistant simply stays off.
+* Pick the model from a dropdown in the bottom-right of the chat pane — it lists whatever your endpoint offers and switches on the fly, no trip back to Settings. Your choice is remembered.
+* Your API key is stored in Windows Credential Manager, never in a settings file — and **no endpoint ships inside the app**, so a copy you hand to a colleague has the assistant disabled by default.
+
+**Safe by design**
+* Turning a PDU outlet off or power-cycling always asks you to confirm first — the AI can't cut power on its own. Every tool call is written to the app log.
+* This is separate from the existing Serial/PDU MCP servers (Settings → AI MCP), which keep working for external AI CLIs like Claude Code / Kiro.
+
+## 📦 Downloads
+
+| Build | Needs .NET Runtime? | Notes |
+|---|---|---|
+| **ETTerms_v0.6.0** (Standard) | ✅ Requires .NET 8 Desktop Runtime | Smaller download |
+| **ETTerms_v0.6.0_portable** (Portable) | ❌ Runtime included | Unzip and run anywhere, no admin |
+
+Run `ETTerms v0.6.0.exe`.
+
+## 🔗 Links
+
+* [Architecture](https://github.com/ETWen/ETTerms/blob/main/ARCHITECTURE.md) — see "Built-in AI Assistant (Phase 10)"
+* [Serial MCP guide](https://github.com/ETWen/ETTerms/blob/main/docs/serial-mcp-guide.md)
+
+**Full changelog:** [v0.5.0...v0.6.0](https://github.com/ETWen/ETTerms/compare/v0.5.0...v0.6.0)
diff --git a/src/ETTerms/Ai/AgentHost.cs b/src/ETTerms/Ai/AgentHost.cs
new file mode 100644
index 0000000..8ba5112
--- /dev/null
+++ b/src/ETTerms/Ai/AgentHost.cs
@@ -0,0 +1,89 @@
+using System.Text.Json.Nodes;
+using ETTerms.Infrastructure;
+
+namespace ETTerms.Ai;
+
+/// <summary>
+/// 內建 AI Assistant 的 agent 迴圈：維護對話歷史,呼叫 <see cref="OpenAiChatClient"/>,
+/// 模型回 tool_calls 時執行 <see cref="AiTools"/> 再把結果餵回,直到模型給出最終文字回應。
+///
+/// UI 事件（Status / AssistantText / ToolActivity）皆在背景緒觸發,訂閱者需自行 Invoke 回 UI thread。
+/// </summary>
+public sealed class AgentHost
+{
+    private readonly OpenAiChatClient _client;
+    private readonly AiTools _tools;
+    private readonly JsonArray _messages = new();
+    private const int MaxToolRounds = 8;
+
+    public event Action<string>? AssistantText;   // 最終文字回應
+    public event Action<string>? ToolActivity;     // 「呼叫 serial_write …」之類過程
+    public event Action<string>? Status;           // thinking / done
+
+    private static string DefaultSystemPrompt =>
+        "你是 ETTerms 內建的硬體工程助理。可透過工具收發序列埠（serial）與控制 PDU 電源插座。" +
+        "回答用繁體中文、簡潔。動手操作前先說明你要做什麼。" +
+        "破壞性動作（關插座 / power-cycle）會由使用者在 GUI 確認,你只需正常呼叫工具。" +
+        "serial 操作前必須先 serial_attach 到 GUI 已開啟的 session。";
+
+    public AgentHost(OpenAiChatClient client, AiTools tools, string? systemPrompt)
+    {
+        _client = client;
+        _tools = tools;
+        _messages.Add(new JsonObject
+        {
+            ["role"] = "system",
+            ["content"] = string.IsNullOrWhiteSpace(systemPrompt) ? DefaultSystemPrompt : systemPrompt
+        });
+    }
+
+    /// <summary>送出一句使用者訊息,跑完 agent 迴圈（含工具呼叫）。</summary>
+    public async Task SendAsync(string userText, CancellationToken ct)
+    {
+        _messages.Add(new JsonObject { ["role"] = "user", ["content"] = userText });
+        var tools = _tools.GetSchemas();
+
+        for (int round = 0; round < MaxToolRounds; round++)
+        {
+            Status?.Invoke("thinking");
+            var msg = await _client.CompleteAsync(_messages, tools, ct);
+            _messages.Add((JsonObject)msg.DeepClone());
+
+            var toolCalls = msg["tool_calls"]?.AsArray();
+            if (toolCalls == null || toolCalls.Count == 0)
+            {
+                var content = msg["content"]?.GetValue<string>() ?? "";
+                AssistantText?.Invoke(content);
+                Status?.Invoke("done");
+                return;
+            }
+
+            // 執行每個 tool call,把結果以 role=tool 加回歷史
+            foreach (var tcNode in toolCalls)
+            {
+                var tc = tcNode!.AsObject();
+                string id = tc["id"]?.GetValue<string>() ?? "";
+                var fn = tc["function"]?.AsObject();
+                string fname = fn?["name"]?.GetValue<string>() ?? "";
+                string argStr = fn?["arguments"]?.GetValue<string>() ?? "{}";
+
+                JsonObject args;
+                try { args = JsonNode.Parse(string.IsNullOrWhiteSpace(argStr) ? "{}" : argStr)!.AsObject(); }
+                catch { args = new JsonObject(); }
+
+                ToolActivity?.Invoke($"{fname}({argStr})");
+                string result = await _tools.InvokeAsync(fname, args, ct);
+
+                _messages.Add(new JsonObject
+                {
+                    ["role"] = "tool",
+                    ["tool_call_id"] = id,
+                    ["content"] = result
+                });
+            }
+        }
+
+        AssistantText?.Invoke("（已達工具呼叫上限,停止。請縮小問題或分步再試。）");
+        Status?.Invoke("done");
+    }
+}
diff --git a/src/ETTerms/Ai/AiTools.cs b/src/ETTerms/Ai/AiTools.cs
new file mode 100644
index 0000000..0b1fb3c
--- /dev/null
+++ b/src/ETTerms/Ai/AiTools.cs
@@ -0,0 +1,229 @@
+using System.Text;
+using System.Text.Json.Nodes;
+using ETTerms.Infrastructure;
+using ETTerms.PduCore;
+using ETTerms.Sessions;
+
+namespace ETTerms.Ai;
+
+/// <summary>
+/// 內建 AI Assistant 的工具集：serial 收發（重用 GUI 持有的 <see cref="SerialBridge"/> session，
+/// AI 的 TX 照樣以 [AI] 標色顯示在終端機）＋ PDU 電源控制（<see cref="PduController"/>）。
+///
+/// 全部 in-process 直呼——不經 MCP 子行程 / named pipe（那是給外部 AI CLI 用的）。
+/// 破壞性 PDU 動作（關插座 / power-cycle）一律經 <see cref="ConfirmAsync"/> 由 GUI 彈確認框；
+/// 每筆工具呼叫寫 AppLogger 留跡。
+/// </summary>
+public sealed class AiTools : IDisposable
+{
+    /// <summary>破壞性動作確認：回 true 才執行。由 UI 提供（彈 MessageBox）。</summary>
+    public Func<string, Task<bool>> ConfirmAsync { get; set; } = _ => Task.FromResult(false);
+
+    // ── serial attach 狀態（供 serial_read 累積 RX）──
+    private SerialBridgeEndpoint? _attached;
+    private readonly StringBuilder _rxBuffer = new();
+    private readonly object _rxLock = new();
+    private Action<byte[]>? _rxHandler;
+    private readonly System.Text.Decoder _dec = Encoding.UTF8.GetDecoder();
+
+    // ── PDU 連線登錄（本 AI session 內，IP → controller）──
+    private readonly Dictionary<string, PduController> _pdus = new(StringComparer.OrdinalIgnoreCase);
+    private const int PduPortCount = 12;
+
+    /// <summary>OpenAI tools schema（function calling 用）。</summary>
+    public JsonArray GetSchemas()
+    {
+        JsonObject Fn(string name, string desc, JsonObject props, params string[] required)
+        {
+            var req = new JsonArray();
+            foreach (var r in required) req.Add(r);
+            return new JsonObject
+            {
+                ["type"] = "function",
+                ["function"] = new JsonObject
+                {
+                    ["name"] = name,
+                    ["description"] = desc,
+                    ["parameters"] = new JsonObject
+                    {
+                        ["type"] = "object",
+                        ["properties"] = props,
+                        ["required"] = req
+                    }
+                }
+            };
+        }
+        JsonObject Str(string d) => new() { ["type"] = "string", ["description"] = d };
+        JsonObject Int(string d) => new() { ["type"] = "integer", ["description"] = d };
+        JsonObject Bool(string d) => new() { ["type"] = "boolean", ["description"] = d };
+
+        return new JsonArray
+        {
+            Fn("serial_list", "List the serial sessions currently open in the ETTerms GUI (name + baud).",
+                new JsonObject()),
+            Fn("serial_attach", "Bind to an open GUI serial session by name (e.g. COM3). Required before write/read.",
+                new JsonObject { ["session"] = Str("Session name / COM port, e.g. COM3") }, "session"),
+            Fn("serial_write", "Send text to the attached serial session (echoes to the terminal tagged [AI]).",
+                new JsonObject { ["text"] = Str("Text to send"), ["appendNewline"] = Bool("Append the session newline (default true)") }, "text"),
+            Fn("serial_read", "Read accumulated RX from the attached serial session; optionally wait for a substring.",
+                new JsonObject { ["waitFor"] = Str("Optional substring to wait for"), ["timeoutMs"] = Int("Max wait ms (default 3000)") }),
+            Fn("pdu_connect", "Connect to an SNMP PDU by IP and verify it responds. Required before other pdu_* calls.",
+                new JsonObject { ["ip"] = Str("PDU IP address") }, "ip"),
+            Fn("pdu_status", "Read all outlets' state / current(mA) / power(W) of a connected PDU.",
+                new JsonObject { ["ip"] = Str("PDU IP address") }, "ip"),
+            Fn("pdu_set_port", "Turn a PDU outlet on or off (turning OFF requires user confirmation).",
+                new JsonObject { ["ip"] = Str("PDU IP"), ["port"] = Int("Outlet number"), ["on"] = Bool("true=on, false=off") }, "ip", "port", "on"),
+            Fn("pdu_power_cycle", "Power-cycle a PDU outlet (off → wait → on). Requires user confirmation.",
+                new JsonObject { ["ip"] = Str("PDU IP"), ["port"] = Int("Outlet number"), ["offSeconds"] = Int("Off duration seconds (default 5)") }, "ip", "port"),
+        };
+    }
+
+    /// <summary>執行一個工具呼叫,回傳給模型的 JSON 字串（統一 {ok, result/error}）。</summary>
+    public async Task<string> InvokeAsync(string name, JsonObject args, CancellationToken ct)
+    {
+        AppLogger.Info($"[AI tool] {name} {args.ToJsonString()}");
+        try
+        {
+            return name switch
+            {
+                "serial_list" => SerialList(),
+                "serial_attach" => SerialAttach(Str(args, "session")),
+                "serial_write" => SerialWrite(Str(args, "text"), Bool(args, "appendNewline", true)),
+                "serial_read" => await SerialRead(Str(args, "waitFor"), Int(args, "timeoutMs", 3000), ct),
+                "pdu_connect" => PduConnect(Str(args, "ip")),
+                "pdu_status" => PduStatus(Str(args, "ip")),
+                "pdu_set_port" => await PduSetPort(Str(args, "ip"), Int(args, "port", 0), Bool(args, "on", false)),
+                "pdu_power_cycle" => await PduPowerCycle(Str(args, "ip"), Int(args, "port", 0), Int(args, "offSeconds", 5), ct),
+                _ => Err($"unknown tool '{name}'")
+            };
+        }
+        catch (Exception ex)
+        {
+            AppLogger.LogWarning($"[AI tool] {name} failed: {ex.Message}");
+            return Err(ex.Message);
+        }
+    }
+
+    // ── serial ──
+    private string SerialList()
+    {
+        var arr = new JsonArray();
+        foreach (var e in SerialBridge.All) arr.Add(new JsonObject { ["name"] = e.Name, ["baud"] = e.BaudRate });
+        return Ok(new JsonObject { ["sessions"] = arr });
+    }
+
+    private string SerialAttach(string session)
+    {
+        DetachRx();
+        var ep = SerialBridge.Find(session);
+        if (ep == null) return Err($"no open serial session '{session}' in the GUI — open it first");
+        _attached = ep;
+        lock (_rxLock) _rxBuffer.Clear();
+        _rxHandler = data =>
+        {
+            lock (_rxLock)
+            {
+                var chars = new char[data.Length];
+                int n = _dec.GetChars(data, 0, data.Length, chars, 0);
+                if (n > 0) _rxBuffer.Append(chars, 0, n);
+                if (_rxBuffer.Length > 1_000_000) _rxBuffer.Remove(0, _rxBuffer.Length - 1_000_000);
+            }
+        };
+        ep.Rx += _rxHandler;
+        return Ok(new JsonObject { ["attached"] = ep.Name });
+    }
+
+    private string SerialWrite(string text, bool appendNewline)
+    {
+        if (_attached == null) return Err("not attached — call serial_attach first");
+        _attached.Write(text, appendNewline);
+        return Ok(new JsonObject { ["sent"] = text });
+    }
+
+    private async Task<string> SerialRead(string? waitFor, int timeoutMs, CancellationToken ct)
+    {
+        if (_attached == null) return Err("not attached — call serial_attach first");
+        var deadline = Environment.TickCount64 + Math.Clamp(timeoutMs, 0, 120_000);
+        while (true)
+        {
+            string cur;
+            lock (_rxLock) cur = _rxBuffer.ToString();
+            if (string.IsNullOrEmpty(waitFor) || cur.Contains(waitFor)) { lock (_rxLock) _rxBuffer.Clear(); return Ok(new JsonObject { ["data"] = cur }); }
+            if (Environment.TickCount64 >= deadline) { lock (_rxLock) _rxBuffer.Clear(); return Ok(new JsonObject { ["data"] = cur, ["timedOut"] = true }); }
+            await Task.Delay(80, ct);
+        }
+    }
+
+    private void DetachRx()
+    {
+        if (_attached != null && _rxHandler != null) _attached.Rx -= _rxHandler;
+        _attached = null; _rxHandler = null;
+    }
+
+    // ── PDU ──
+    private PduController GetOrThrow(string ip) =>
+        _pdus.TryGetValue(ip, out var c) ? c : throw new InvalidOperationException($"PDU {ip} not connected — call pdu_connect first");
+
+    private string PduConnect(string ip)
+    {
+        if (_pdus.ContainsKey(ip)) return Ok(new JsonObject { ["ip"] = ip, ["already"] = true });
+        var c = new PduController(ip, m => AppLogger.Info(m), m => AppLogger.LogWarning(m));
+        var model = c.GetModelName();
+        if (string.IsNullOrEmpty(model)) { c.Dispose(); return Err($"PDU {ip} did not respond to SNMP"); }
+        _pdus[ip] = c;
+        return Ok(new JsonObject { ["ip"] = ip, ["model"] = model });
+    }
+
+    private string PduStatus(string ip)
+    {
+        var c = GetOrThrow(ip);
+        var all = c.GetAllPortsStatus(PduPortCount);
+        var arr = new JsonArray();
+        for (int i = 0; i < all.Length; i++)
+            arr.Add(new JsonObject
+            {
+                ["port"] = i + 1,
+                ["state"] = all[i].State is bool b ? (b ? "on" : "off") : "unknown",
+                ["mA"] = all[i].CurrentMilliAmps,
+                ["W"] = all[i].PowerWatts
+            });
+        return Ok(new JsonObject { ["ip"] = ip, ["ports"] = arr });
+    }
+
+    private async Task<string> PduSetPort(string ip, int port, bool on)
+    {
+        var c = GetOrThrow(ip);
+        if (!on && !await ConfirmAsync($"AI 要求關閉 PDU {ip} 的 outlet {port}。確定?"))
+            return Err("user declined");
+        bool ok = on ? c.SetPortOn(port) : c.SetPortOff(port);
+        return ok ? Ok(new JsonObject { ["ip"] = ip, ["port"] = port, ["state"] = on ? "on" : "off" }) : Err("SNMP set failed");
+    }
+
+    private async Task<string> PduPowerCycle(string ip, int port, int offSeconds, CancellationToken ct)
+    {
+        var c = GetOrThrow(ip);
+        offSeconds = Math.Clamp(offSeconds, 1, 60);
+        if (!await ConfirmAsync($"AI 要求 power-cycle PDU {ip} 的 outlet {port}（關 {offSeconds}s 再開）。確定?"))
+            return Err("user declined");
+        if (!c.SetPortOff(port)) return Err("SNMP set (off) failed");
+        await Task.Delay(offSeconds * 1000, ct);
+        if (!c.SetPortOn(port)) return Err("SNMP set (on) failed");
+        return Ok(new JsonObject { ["ip"] = ip, ["port"] = port, ["cycled"] = true, ["offSeconds"] = offSeconds });
+    }
+
+    // ── helpers ──
+    private static string Ok(JsonObject result) => new JsonObject { ["ok"] = true, ["result"] = result }.ToJsonString();
+    private static string Err(string msg) => new JsonObject { ["ok"] = false, ["error"] = msg }.ToJsonString();
+
+    private static string Str(JsonObject a, string k) => a[k]?.GetValue<string>() ?? "";
+    private static string? Str(JsonObject a, string k, string? def) => a[k]?.GetValue<string>() ?? def;
+    private static int Int(JsonObject a, string k, int def) { try { return a[k]?.GetValue<int>() ?? def; } catch { return def; } }
+    private static bool Bool(JsonObject a, string k, bool def) { try { return a[k]?.GetValue<bool>() ?? def; } catch { return def; } }
+
+    public void Dispose()
+    {
+        DetachRx();
+        foreach (var c in _pdus.Values) c.Dispose();
+        _pdus.Clear();
+    }
+}
diff --git a/src/ETTerms/Ai/OpenAiChatClient.cs b/src/ETTerms/Ai/OpenAiChatClient.cs
new file mode 100644
index 0000000..e96529d
--- /dev/null
+++ b/src/ETTerms/Ai/OpenAiChatClient.cs
@@ -0,0 +1,98 @@
+using System.Net.Http;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+namespace ETTerms.Ai;
+
+/// <summary>
+/// 極簡 OpenAI 相容 chat-completions client（非串流）。
+/// 只依賴 HttpClient + System.Text.Json，不引入 SDK——因為端點是使用者自帶（BYO），
+/// 任何 OpenAI 相容 gateway（Ollama / LiteLLM / 公司內部 gateway / OpenAI…）皆可接。
+///
+/// ⚠️ Base URL 與 API key 皆由使用者於 Settings 設定,不寫死於程式碼（見 AppSettings 註解）。
+/// </summary>
+public sealed class OpenAiChatClient : IDisposable
+{
+    private readonly HttpClient _http;
+
+    /// <summary>目前使用的模型；可即時切換（下一輪對話生效），用於底部模型下拉選單。</summary>
+    public string Model { get; set; }
+
+    public OpenAiChatClient(string baseUrl, string apiKey, string model)
+    {
+        // baseUrl 例："http://localhost:11434/v1" → endpoint = baseUrl + "/chat/completions"
+        var root = baseUrl.TrimEnd('/');
+        _http = new HttpClient { Timeout = TimeSpan.FromSeconds(300) };
+        _http.BaseAddress = new Uri(root + "/");
+        if (!string.IsNullOrEmpty(apiKey))
+            _http.DefaultRequestHeaders.Authorization =
+                new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", apiKey);
+        Model = model;
+    }
+
+    /// <summary>列出端點可用模型 id（OpenAI 相容 GET /models）。失敗回空清單。</summary>
+    public async Task<List<string>> ListModelsAsync(CancellationToken ct)
+    {
+        var list = new List<string>();
+        try
+        {
+            using var resp = await _http.GetAsync("models", ct);
+            if (!resp.IsSuccessStatusCode) return list;
+            var text = await resp.Content.ReadAsStringAsync(ct);
+            var data = JsonNode.Parse(text)?["data"]?.AsArray();
+            if (data == null) return list;
+            foreach (var m in data)
+            {
+                var id = m?["id"]?.GetValue<string>();
+                if (!string.IsNullOrEmpty(id)) list.Add(id);
+            }
+        }
+        catch { /* 端點不支援 /models 或連不上 → 回空,由 caller fallback */ }
+        return list;
+    }
+
+    /// <summary>
+    /// 送出一輪對話（含歷史 messages 與可用 tools），回傳 assistant 的回應訊息節點
+    /// （可能含 content 或 tool_calls）。呼叫端負責 agent loop。
+    /// </summary>
+    public async Task<JsonObject> CompleteAsync(JsonArray messages, JsonArray? tools, CancellationToken ct)
+    {
+        var body = new JsonObject
+        {
+            ["model"] = Model,
+            ["messages"] = messages.DeepClone(),
+            ["temperature"] = 0.2,
+        };
+        if (tools != null && tools.Count > 0)
+        {
+            body["tools"] = tools.DeepClone();
+            body["tool_choice"] = "auto";
+        }
+
+        using var req = new HttpRequestMessage(HttpMethod.Post, "chat/completions")
+        {
+            Content = new StringContent(body.ToJsonString(), Encoding.UTF8, "application/json")
+        };
+        using var resp = await _http.SendAsync(req, HttpCompletionOption.ResponseContentRead, ct);
+        var text = await resp.Content.ReadAsStringAsync(ct);
+        if (!resp.IsSuccessStatusCode)
+            throw new InvalidOperationException($"AI endpoint HTTP {(int)resp.StatusCode}: {Trunc(text, 400)}");
+
+        JsonObject root;
+        try { root = JsonNode.Parse(text)!.AsObject(); }
+        catch (Exception ex) { throw new InvalidOperationException($"AI response parse error: {ex.Message}\n{Trunc(text, 400)}"); }
+
+        var choices = root["choices"]?.AsArray();
+        if (choices == null || choices.Count == 0)
+            throw new InvalidOperationException($"AI response has no choices: {Trunc(text, 400)}");
+        var msg = choices[0]?["message"]?.AsObject();
+        if (msg == null)
+            throw new InvalidOperationException($"AI response has no message: {Trunc(text, 400)}");
+        return (JsonObject)msg.DeepClone();
+    }
+
+    private static string Trunc(string s, int n) => s.Length <= n ? s : s.Substring(0, n) + "…";
+
+    public void Dispose() => _http.Dispose();
+}
diff --git a/src/ETTerms/App/AboutView.cs b/src/ETTerms/App/AboutView.cs
index 07289ca..56a3b26 100644
--- a/src/ETTerms/App/AboutView.cs
+++ b/src/ETTerms/App/AboutView.cs
@@ -183,6 +183,17 @@ public sealed class AboutView : UserControl
 
     private static readonly ChangelogEntry[] Changelog =
     [
+        new("0.6.0", new DateOnly(2026, 7, 5), "Built-in AI Assistant — drive serial & PDU in plain language",
+        [
+            "New ✨ AI Chat: click ✨ AI Chat in the toolbar to open an AI pane, then use Layout (1×2, 2×2…) to sit it right next to a Serial session — chat on one side while you watch the terminal on the other, just like Claude Code / Kiro.",
+            "Clean transcript layout: your messages align right in accent color, the AI's replies read left, and tool activity stays as quiet gray notes — same tidy feel as the terminal. A model dropdown at the bottom-right lists the models your endpoint offers, so you pick and switch models right there, no trip to Settings.",
+            "Talk in plain language to send serial commands and control PDU outlets — e.g. \"attach to COM3, send help and show me the reply\" or \"connect to the PDU and power-cycle outlet 3\".",
+            "Bring your own AI endpoint: point it at any OpenAI-compatible server (a local Ollama, a LiteLLM gateway, your company's gateway, or OpenAI). Set it up in Settings → AI Assistant; leave it blank and the assistant simply stays off.",
+            "Your API key is stored in Windows Credential Manager, never in a settings file — and no endpoint ships inside the app, so a copy you hand to someone else has the assistant disabled by default.",
+            "The AI drives your existing open Serial session, and everything it sends shows up in that terminal tagged [AI] so you always see what it did.",
+            "Turning an outlet off or power-cycling always pops up a confirmation first — the AI can't cut power on its own. Every tool call is written to the app log.",
+            "This is separate from the existing Serial/PDU MCP servers (Settings → AI MCP), which keep working for external AI CLIs like Claude Code / Kiro.",
+        ]),
         new("0.5.0", new DateOnly(2026, 7, 2), "Search, keyword alerts & a much bigger scripting language",
         [
             "Press Ctrl+F in any terminal to search everything you've scrolled past — all hits are highlighted, Enter jumps between them.",
diff --git a/src/ETTerms/App/AiChatView.cs b/src/ETTerms/App/AiChatView.cs
new file mode 100644
index 0000000..0c49b15
--- /dev/null
+++ b/src/ETTerms/App/AiChatView.cs
@@ -0,0 +1,264 @@
+using System.Drawing;
+using System.Windows.Forms;
+using ETTerms.Ai;
+using ETTerms.Connections;
+using ETTerms.Infrastructure;
+
+namespace ETTerms.App;
+
+/// <summary>
+/// 內建 AI Assistant 分頁（Workspace 的一種 pane，可與 serial 並排）。自然語言驅動 serial + PDU。
+///
+/// 呈現走「乾淨對話逐字稿」風格（與 ETTerms 終端機/log 美學一致，非氣泡卡片）：
+/// 使用者訊息靠右 accent 色、AI 回覆靠左段落、工具活動灰字縮排、思考中收進 Send 按鈕不洗版。
+/// （真氣泡 + Markdown 的 WebView2 版列為 v0.7.0。）
+///
+/// Provider 未設定（Base URL 空）時停用並提示。⚠️ 端點 / 金鑰皆由使用者設定,程式不含任何預設私人端點。
+/// </summary>
+public sealed class AiChatView : UserControl
+{
+    private readonly RichTextBox _log;
+    private readonly TextBox _input;
+    private readonly Button _send;
+    private readonly Label _hint;
+    private readonly ComboBox _modelBox;
+    private bool _suppressModelEvent;
+
+    private AgentHost? _agent;
+    private OpenAiChatClient? _client;
+    private AiTools? _tools;
+    private CancellationTokenSource? _cts;
+
+    private const string SendText = "Send  ⏎";
+
+    public AiChatView()
+    {
+        Dock = DockStyle.Fill;
+        BackColor = Theme.WorkspaceBack;
+
+        _log = new RichTextBox
+        {
+            Dock = DockStyle.Fill, ReadOnly = true, BorderStyle = BorderStyle.None,
+            BackColor = Color.FromArgb(28, 28, 32), ForeColor = Theme.Text,
+            Font = new Font("Cascadia Mono", 10f), DetectUrls = false
+        };
+
+        // ── 底部控制列：輸入框(Fill) + 右下角欄(模型下拉在上、Send 在下) ──
+        var bottom = new Panel { Dock = DockStyle.Bottom, Height = 96, BackColor = Theme.RailBack, Padding = new Padding(10, 8, 10, 8) };
+
+        _input = new TextBox
+        {
+            Dock = DockStyle.Fill, Multiline = true, BackColor = Theme.TabBack, ForeColor = Theme.Text,
+            Font = Theme.UiFont, BorderStyle = BorderStyle.FixedSingle
+        };
+        _input.KeyDown += (_, e) =>
+        {
+            if (e.KeyCode == Keys.Enter && !e.Shift) { e.Handled = e.SuppressKeyPress = true; OnSend(); }
+        };
+
+        var rightCol = new Panel { Dock = DockStyle.Right, Width = 178, BackColor = Theme.RailBack, Padding = new Padding(8, 0, 0, 0) };
+
+        var modelWrap = new Panel { Dock = DockStyle.Top, Height = 24, BackColor = Theme.RailBack };
+        _modelBox = new ComboBox
+        {
+            Dock = DockStyle.Fill, DropDownStyle = ComboBoxStyle.DropDownList,
+            BackColor = Theme.TabBack, ForeColor = Theme.Text, FlatStyle = FlatStyle.Flat, Font = Theme.UiFont
+        };
+        _modelBox.SelectedIndexChanged += (_, _) =>
+        {
+            if (_suppressModelEvent || _client == null || _modelBox.SelectedItem is not string m) return;
+            _client.Model = m;
+            AppSettings.Instance.AiModel = m;   // 記住選擇,下次開 pane 用同一個
+            AppSettings.Instance.Save();
+            AppendDim($"— 模型切換為 {m} —");
+        };
+        var refreshBtn = new Button
+        {
+            Text = "↻", Dock = DockStyle.Right, Width = 24, FlatStyle = FlatStyle.Flat,
+            ForeColor = Theme.TextDim, BackColor = Theme.TabBack, Font = Theme.UiFont, Cursor = Cursors.Hand
+        };
+        refreshBtn.FlatAppearance.BorderColor = Theme.Border;
+        refreshBtn.Click += (_, _) => _ = LoadModelsAsync();
+        modelWrap.Controls.Add(_modelBox);   // Fill
+        modelWrap.Controls.Add(refreshBtn);  // Right
+
+        var gap = new Panel { Dock = DockStyle.Top, Height = 6, BackColor = Theme.RailBack };
+
+        _send = new Button
+        {
+            Text = SendText, Dock = DockStyle.Fill, FlatStyle = FlatStyle.Flat,
+            ForeColor = Theme.Text, BackColor = Theme.TabBack, Font = Theme.UiFont, Cursor = Cursors.Hand
+        };
+        _send.FlatAppearance.BorderColor = Theme.Accent;
+        _send.Click += (_, _) => OnSend();
+
+        rightCol.Controls.Add(_send);      // Fill 先加
+        rightCol.Controls.Add(gap);        // Top（Send 上方間距）
+        rightCol.Controls.Add(modelWrap);  // Top（最上：模型下拉）
+
+        bottom.Controls.Add(_input);       // Fill 先加
+        bottom.Controls.Add(rightCol);     // Right（右下角）
+
+        _hint = new Label
+        {
+            Dock = DockStyle.Top, Height = 40, BackColor = Color.FromArgb(60, 50, 30), ForeColor = Theme.Text,
+            Font = Theme.UiFont, TextAlign = ContentAlignment.MiddleCenter, Visible = false,
+            Text = "尚未設定 AI Provider — 到 Settings → AI Assistant 填入 Base URL 與 API Key。"
+        };
+
+        Controls.Add(_log);      // Fill
+        Controls.Add(_hint);     // Top
+        Controls.Add(bottom);    // Bottom
+
+        AppendSystem("ETTerms AI Assistant — 用自然語言操作 serial 與 PDU。");
+        AppendSystem("例：「列出目前的 serial session」、「接上 COM3，送 help 看回應」、「連上 PDU 192.168.1.50，把 outlet 3 重開」");
+    }
+
+    /// <summary>開分頁時呼叫,依最新設定重建 client。Base URL 空＝停用。</summary>
+    public void RefreshProvider()
+    {
+        var s = AppSettings.Instance;
+        bool configured = !string.IsNullOrWhiteSpace(s.AiBaseUrl);
+        _hint.Visible = !configured;
+        _input.Enabled = _send.Enabled = _modelBox.Enabled = configured;
+
+        _client?.Dispose(); _client = null;
+        _tools?.Dispose(); _tools = null;
+        _agent = null;
+
+        if (!configured) return;
+
+        var key = CredentialVault.Get("ETTerms/AiApiKey") ?? "";
+        _client = new OpenAiChatClient(s.AiBaseUrl, key, s.AiModel);
+        _tools = new AiTools { ConfirmAsync = ConfirmOnUiAsync };
+        _agent = new AgentHost(_client, _tools, s.AiSystemPrompt);
+        _agent.AssistantText += t => Ui(() => AppendAssistant(t));
+        _agent.ToolActivity += t => Ui(() => AppendTool(t));
+        // thinking 不印進對話流（改由 Send 按鈕顯示忙碌）,避免洗版。
+
+        _ = LoadModelsAsync();
+    }
+
+    /// <summary>拉端點可用模型填入下拉選單（GET /v1/models）；沒設過模型就自動選第一個。</summary>
+    private async Task LoadModelsAsync()
+    {
+        if (_client == null) return;
+        var current = _client.Model;
+        List<string> models;
+        try { models = await _client.ListModelsAsync(CancellationToken.None); }
+        catch { models = new(); }
+        if (!string.IsNullOrEmpty(current) && !models.Contains(current)) models.Insert(0, current);
+
+        Ui(() =>
+        {
+            _suppressModelEvent = true;
+            _modelBox.Items.Clear();
+            foreach (var m in models) _modelBox.Items.Add(m);
+
+            string pick = !string.IsNullOrEmpty(current) && models.Contains(current) ? current
+                        : models.Count > 0 ? models[0] : "";
+            if (pick.Length > 0)
+            {
+                _modelBox.SelectedItem = pick;
+                _client!.Model = pick;
+                if (AppSettings.Instance.AiModel != pick)
+                {
+                    AppSettings.Instance.AiModel = pick;
+                    AppSettings.Instance.Save();
+                }
+            }
+            else AppendError("端點未回報任何模型 — 確認 Base URL 是否為 OpenAI 相容 /v1 端點。");
+            _suppressModelEvent = false;
+        });
+    }
+
+    private Task<bool> ConfirmOnUiAsync(string message)
+    {
+        var tcs = new TaskCompletionSource<bool>();
+        Ui(() =>
+        {
+            var r = MessageBox.Show(this, message, "AI 動作確認",
+                MessageBoxButtons.YesNo, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2);
+            tcs.SetResult(r == DialogResult.Yes);
+        });
+        return tcs.Task;
+    }
+
+    private async void OnSend()
+    {
+        if (_agent == null) return;
+        var text = _input.Text.Trim();
+        if (text.Length == 0) return;
+        _input.Clear();
+        AppendUser(text);
+        SetBusy(true);
+        _cts = new CancellationTokenSource();
+        try { await _agent.SendAsync(text, _cts.Token); }
+        catch (OperationCanceledException) { AppendDim("（已取消）"); }
+        catch (Exception ex) { AppendError(ex.Message); }
+        finally { SetBusy(false); }
+    }
+
+    private void SetBusy(bool busy)
+    {
+        _send.Enabled = !busy;
+        _send.Text = busy ? "…" : SendText;
+    }
+
+    // ── 輸出（乾淨 transcript）──
+    /// <summary>使用者訊息：靠右 accent 色,無前綴。</summary>
+    private void AppendUser(string t)
+    {
+        _log.SelectionStart = _log.TextLength;
+        _log.SelectionAlignment = HorizontalAlignment.Right;
+        _log.SelectionColor = Theme.Accent;
+        _log.SelectionFont = new Font(_log.Font, FontStyle.Bold);
+        _log.AppendText(t + "\n");
+        _log.SelectionAlignment = HorizontalAlignment.Left;
+        _log.AppendText("\n");
+        _log.ScrollToCaret();
+    }
+
+    /// <summary>AI 回覆：靠左段落。</summary>
+    private void AppendAssistant(string t)
+    {
+        _log.SelectionStart = _log.TextLength;
+        _log.SelectionAlignment = HorizontalAlignment.Left;
+        _log.SelectionColor = Theme.Text;
+        _log.SelectionFont = _log.Font;
+        _log.AppendText(t + "\n\n");
+        _log.ScrollToCaret();
+    }
+
+    private void AppendTool(string t) => AppendLine("⚙ " + t, Color.FromArgb(150, 150, 158));
+    private void AppendSystem(string t) => AppendLine(t, Theme.TextDim);
+    private void AppendError(string t) => AppendLine("⚠ " + t, Color.FromArgb(235, 120, 120));
+    private void AppendDim(string t) => AppendLine(t, Theme.TextDim);
+
+    private void AppendLine(string t, Color color)
+    {
+        _log.SelectionStart = _log.TextLength;
+        _log.SelectionAlignment = HorizontalAlignment.Left;
+        _log.SelectionColor = color;
+        _log.SelectionFont = _log.Font;
+        _log.AppendText(t + "\n");
+        _log.ScrollToCaret();
+    }
+
+    private void Ui(Action a)
+    {
+        if (IsDisposed || !IsHandleCreated) return;
+        if (InvokeRequired) BeginInvoke(a); else a();
+    }
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+        {
+            _cts?.Cancel();
+            _client?.Dispose();
+            _tools?.Dispose();
+        }
+        base.Dispose(disposing);
+    }
+}
diff --git a/src/ETTerms/App/SettingsView.cs b/src/ETTerms/App/SettingsView.cs
index 5acb3d5..93fcd5c 100644
--- a/src/ETTerms/App/SettingsView.cs
+++ b/src/ETTerms/App/SettingsView.cs
@@ -1,10 +1,11 @@
 using System.Drawing;
 using System.Windows.Forms;
+using ETTerms.Connections;
 using ETTerms.Infrastructure;
 
 namespace ETTerms.App;
 
-/// <summary>Settings page with tabs: Terminal / AI MCP.</summary>
+/// <summary>Settings page with tabs: Terminal / Highlight / AI Assistant / AI MCP.</summary>
 public sealed class SettingsView : UserControl
 {
     public SettingsView()
@@ -53,6 +54,7 @@ public sealed class SettingsView : UserControl
         var termBtn = MakeTab("Terminal", BuildTerminalTab());
         tabBar.Controls.Add(termBtn);
         tabBar.Controls.Add(MakeTab("Highlight", BuildHighlightTab()));
+        tabBar.Controls.Add(MakeTab("AI Assistant", BuildAiAssistantTab()));
         tabBar.Controls.Add(MakeTab("AI MCP", BuildAiMcpTab()));
 
         Controls.Add(body);
@@ -290,6 +292,93 @@ public sealed class SettingsView : UserControl
         return page;
     }
 
+    // ═══ AI Assistant Tab（內建 agent 的 BYO endpoint 設定）═══
+    private Panel BuildAiAssistantTab()
+    {
+        var page = new Panel { BackColor = Theme.WorkspaceBack, Padding = new Padding(20) };
+        var s = AppSettings.Instance;
+
+        var flow = new FlowLayoutPanel
+        {
+            Dock = DockStyle.Fill, FlowDirection = FlowDirection.TopDown,
+            WrapContents = false, BackColor = Theme.WorkspaceBack, AutoScroll = true
+        };
+
+        flow.Controls.Add(new Label
+        {
+            Text = "Built-in AI Assistant", AutoSize = true,
+            ForeColor = Theme.Accent, Font = Theme.UiFontBold, Margin = new Padding(0, 0, 0, 4)
+        });
+        flow.Controls.Add(new Label
+        {
+            Text = "Bring your own OpenAI-compatible endpoint (Ollama / LiteLLM / a company gateway / OpenAI…).\n" +
+                   "Leave blank to keep the AI Assistant disabled. Pick the model from the dropdown inside the\n" +
+                   "AI Chat pane (it lists what your endpoint offers). The model must support function calling.\n" +
+                   "The API key is stored in Windows Credential Manager, never in settings.json or the app.",
+            AutoSize = false, Width = 620, Height = 68,
+            ForeColor = Theme.TextDim, Font = Theme.UiFont, Margin = new Padding(0, 0, 0, 10)
+        });
+
+        var baseUrl = new TextBox
+        {
+            Width = 380, BackColor = Theme.TabBack, ForeColor = Theme.Text, Font = Theme.UiFont,
+            BorderStyle = BorderStyle.FixedSingle, Text = s.AiBaseUrl,
+            PlaceholderText = "http://localhost:11434/v1"
+        };
+        var apiKey = new TextBox
+        {
+            Width = 380, BackColor = Theme.TabBack, ForeColor = Theme.Text, Font = Theme.UiFont,
+            BorderStyle = BorderStyle.FixedSingle, UseSystemPasswordChar = true,
+            Text = CredentialVault.Get("ETTerms/AiApiKey") ?? "",
+            PlaceholderText = "(stored in Credential Manager)"
+        };
+        var sysPrompt = new TextBox
+        {
+            Width = 560, Height = 70, Multiline = true, BackColor = Theme.TabBack, ForeColor = Theme.Text,
+            Font = Theme.UiFont, BorderStyle = BorderStyle.FixedSingle, Text = s.AiSystemPrompt,
+            PlaceholderText = "(optional) override the assistant persona / system prompt"
+        };
+
+        flow.Controls.Add(MakeRow("Base URL (with /v1)", baseUrl));
+        flow.Controls.Add(MakeRow("API Key", apiKey));
+        flow.Controls.Add(MakeSpacer(4));
+        flow.Controls.Add(new Label
+        {
+            Text = "System prompt (optional):", AutoSize = true,
+            ForeColor = Theme.Text, Font = Theme.UiFont, Margin = new Padding(0, 4, 0, 2)
+        });
+        flow.Controls.Add(sysPrompt);
+        flow.Controls.Add(MakeSpacer(6));
+
+        flow.Controls.Add(new Label
+        {
+            Text = "Tools the assistant can call: serial send/read (via the GUI's open Serial session, shown as [AI]),\n" +
+                   "and PDU control over SNMP. Turning an outlet off / power-cycling always asks you to confirm.",
+            AutoSize = false, Width = 620, Height = 36,
+            ForeColor = Theme.TextDim, Font = Theme.UiFont, Margin = new Padding(0, 0, 0, 8)
+        });
+
+        var save = MakeButton("Save", Theme.Accent);
+        save.Click += (_, _) =>
+        {
+            s.AiBaseUrl = baseUrl.Text.Trim();
+            s.AiSystemPrompt = sysPrompt.Text.Trim();
+            s.Save();
+            var key = apiKey.Text;
+            if (string.IsNullOrEmpty(key)) CredentialVault.Delete("ETTerms/AiApiKey");
+            else CredentialVault.Set("ETTerms/AiApiKey", key);
+            MessageBox.Show(this,
+                string.IsNullOrWhiteSpace(s.AiBaseUrl)
+                    ? "Saved. AI Assistant stays disabled until you set a Base URL."
+                    : "Saved. Open ✨ AI Chat in the workspace toolbar, then pick a model from the dropdown.",
+                "AI Assistant", MessageBoxButtons.OK, MessageBoxIcon.Information);
+        };
+        flow.Controls.Add(save);
+
+        page.Controls.Add(flow);
+        return page;
+    }
+
     // ═══ AI MCP Tab ═══
     private Panel BuildAiMcpTab()
     {
diff --git a/src/ETTerms/App/Workspace/WorkspaceView.cs b/src/ETTerms/App/Workspace/WorkspaceView.cs
index 1166503..21a4efa 100644
--- a/src/ETTerms/App/Workspace/WorkspaceView.cs
+++ b/src/ETTerms/App/Workspace/WorkspaceView.cs
@@ -17,7 +17,11 @@ public sealed class WorkspaceView : UserControl
     {
         public required string Title;
         public required bool IsSsh;
-        public required SessionPage Page;
+        public SessionPage? Page;      // 連線分頁（serial/ssh/shell）；AI 分頁時為 null
+        public AiChatView? Ai;         // AI 聊天分頁；連線分頁時為 null
+        public bool IsAi => Ai != null;
+        /// <summary>可塞進格子的內容控制項（SessionPage 或 AiChatView，二擇一）。</summary>
+        public Control Content => (Control?)Page ?? Ai!;
         public Rectangle TabBounds;
         public Rectangle CloseRect;
         public bool Alert;   // 背景分頁出現高亮關鍵字 → 標紅點，切到該分頁時清除
@@ -61,6 +65,17 @@ public sealed class WorkspaceView : UserControl
             Dock = DockStyle.Fill, BackColor = Theme.RailBack,
             Padding = new Padding(8, 6, 8, 6), WrapContents = false
         };
+        // ── ✨ New AI Chat（開一個 AI 分頁,可用 Layout 與 serial 並排）──
+        var aiBtn = MakeActionButton("✨ AI Chat", 92, 0, (_, _) => OpenAiPane());
+        aiBtn.ForeColor = Theme.Accent;
+        aiBtn.FlatAppearance.BorderColor = Theme.Accent;
+        _toolbar.Controls.Add(aiBtn);
+        _toolbar.Controls.Add(new Label
+        {
+            Text = "│", AutoSize = true, ForeColor = Theme.Border,
+            Font = Theme.UiFont, Margin = new Padding(4, 6, 4, 0)
+        });
+
         _toolbar.Controls.Add(new Label
         {
             Text = "Layout", AutoSize = true, ForeColor = Theme.TextDim,
@@ -126,6 +141,17 @@ public sealed class WorkspaceView : UserControl
         Relayout();
     }
 
+    /// <summary>開啟一個 AI Assistant 分頁（跟連線分頁一樣可用 Layout 並排,與 serial 同時使用）。</summary>
+    public void OpenAiPane()
+    {
+        var view = new AiChatView();
+        var s = new Session { Title = "AI Assistant", IsSsh = false, Ai = view };
+        _sessions.Add(s);
+        _active = s;
+        Relayout();
+        view.RefreshProvider();
+    }
+
     private void OnConnectFailed(Session s, string msg)
     {
         if (IsDisposed) return;
@@ -150,17 +176,18 @@ public sealed class WorkspaceView : UserControl
     private void CloseSession(Session s)
     {
         int idx = _sessions.IndexOf(s);
-        s.Page.Parent = null;
+        s.Content.Parent = null;
         _sessions.Remove(s);
-        s.Page.Dispose();
+        s.Content.Dispose();
         if (_active == s) _active = _sessions.Count > 0 ? _sessions[Math.Min(idx, _sessions.Count - 1)] : null;
         RefreshGroupLabels();
         Relayout();
     }
 
-    // ── Group 管理 ───────────────────────────────────────────
+    // ── Group 管理（AI 分頁無 Group）─────────────────────────
     private void SetSessionGroup(Session s, int group)
     {
+        if (s.Page == null) return;
         s.Page.Group = group;
         RefreshGroupLabels();
         Relayout();
@@ -171,17 +198,17 @@ public sealed class WorkspaceView : UserControl
         for (int g = 1; g <= 3; g++)
         {
             char letter = 'A';
-            foreach (var s in _sessions.Where(x => x.Page.Group == g))
-                s.Page.GroupLabel = $"Group{g}-{letter++}";
+            foreach (var s in _sessions.Where(x => x.Page != null && x.Page.Group == g))
+                s.Page!.GroupLabel = $"Group{g}-{letter++}";
         }
-        foreach (var s in _sessions.Where(x => x.Page.Group == 0))
-            s.Page.GroupLabel = "";
+        foreach (var s in _sessions.Where(x => x.Page != null && x.Page.Group == 0))
+            s.Page!.GroupLabel = "";
     }
 
     // ── 依目前 Layout 把分頁鋪進格子 ─────────────────────────
     private void Relayout()
     {
-        foreach (var s in _sessions) s.Page.Parent = null;     // 先卸下（保留存活）
+        foreach (var s in _sessions) s.Content.Parent = null;  // 先卸下（保留存活）
         _body.SuspendLayout();
         for (int i = _body.Controls.Count - 1; i >= 0; i--)
         {
@@ -229,14 +256,16 @@ public sealed class WorkspaceView : UserControl
     private Control MakeCell(Session s, bool withLabel)
     {
         var cell = new Panel { Dock = DockStyle.Fill, BackColor = Theme.WorkspaceBack, Margin = Padding.Empty, Padding = new Padding(1) };
-        s.Page.Dock = DockStyle.Fill;
-        s.Page.Visible = true;
-        cell.Controls.Add(s.Page);                              // Fill 先加
+        s.Content.Dock = DockStyle.Fill;
+        s.Content.Visible = true;
+        cell.Controls.Add(s.Content);                           // Fill 先加
         if (withLabel)
         {
-            string labelText = string.IsNullOrEmpty(s.Page.GroupLabel)
-                ? $"{(s.IsSsh ? "🖧" : "🔌")}  {s.Title}"
-                : $"{(s.IsSsh ? "🖧" : "🔌")}  {s.Title}  [{s.Page.GroupLabel}]";
+            string icon = s.IsAi ? "✨" : s.IsSsh ? "🖧" : "🔌";
+            string glabel = s.Page?.GroupLabel ?? "";
+            string labelText = string.IsNullOrEmpty(glabel)
+                ? $"{icon}  {s.Title}"
+                : $"{icon}  {s.Title}  [{glabel}]";
             var lbl = new Label
             {
                 Dock = DockStyle.Bottom, Height = 22,
@@ -253,8 +282,8 @@ public sealed class WorkspaceView : UserControl
 
     private void FocusActive()
     {
-        if (_active?.Page is { IsDisposed: false } p && p.IsHandleCreated)
-            p.Focus();
+        if (_active?.Content is { IsDisposed: false } c && c.IsHandleCreated)
+            c.Focus();
     }
 
     // ── 頂部 Tab 列 ──────────────────────────────────────────
@@ -276,7 +305,7 @@ public sealed class WorkspaceView : UserControl
         {
             foreach (var s in _sessions)
             {
-                if (s.TabBounds.Contains(e.Location)) { ShowGroupMenu(s, e.Location); return; }
+                if (s.TabBounds.Contains(e.Location)) { if (!s.IsAi) ShowGroupMenu(s, e.Location); return; }
             }
             return;
         }
@@ -303,7 +332,7 @@ public sealed class WorkspaceView : UserControl
         menu.Items.Add("Group 2", null, (_, _) => SetSessionGroup(s, 2));
         menu.Items.Add("Group 3", null, (_, _) => SetSessionGroup(s, 3));
         // Check current
-        int current = s.Page.Group;
+        int current = s.Page?.Group ?? 0;
         ((ToolStripMenuItem)menu.Items[current]).Checked = true;
         menu.Show(_tabStrip, pt);
     }
@@ -368,8 +397,10 @@ public sealed class WorkspaceView : UserControl
             if (drag)
                 using (var pen = new Pen(Theme.Accent, 1))
                     g.DrawRectangle(pen, new Rectangle(s.TabBounds.Left, s.TabBounds.Top, s.TabBounds.Width - 1, s.TabBounds.Height - 1));
-            // 警示中的背景分頁：型別圓點改紅色，切過去看時清除
-            using (var dot = new SolidBrush(s.Alert ? Color.FromArgb(235, 85, 85) : s.IsSsh ? Theme.SshColor : Theme.SerialColor))
+            // 警示中的背景分頁：型別圓點改紅色，切過去看時清除。AI 分頁用 accent 紫。
+            Color dotColor = s.Alert ? Color.FromArgb(235, 85, 85)
+                : s.IsAi ? Theme.Accent : s.IsSsh ? Theme.SshColor : Theme.SerialColor;
+            using (var dot = new SolidBrush(dotColor))
                 g.FillEllipse(dot, s.TabBounds.Left + 9, StripH / 2 - 4, 8, 8);
             var tr = new Rectangle(s.TabBounds.Left + 22, s.TabBounds.Top, s.TabBounds.Width - 22 - CloseSz - 10, StripH);
             TextRenderer.DrawText(g, s.Title, Theme.UiFont, tr, active ? Theme.Text : Theme.TextDim,
@@ -415,19 +446,20 @@ public sealed class WorkspaceView : UserControl
     // ── Log All（一次開/關所有分頁側錄） ──────────────────────
     private void OnToggleLogAll(object? sender, EventArgs e)
     {
-        if (_sessions.Count == 0)
+        var loggable = _sessions.Where(s => s.Page != null).Select(s => s.Page!).ToList();
+        if (loggable.Count == 0)
         {
             MessageBox.Show(this, "No open sessions to log.", "Log All", MessageBoxButtons.OK, MessageBoxIcon.Information);
             return;
         }
 
-        // 只要還有分頁沒在側錄 → 全部開始；否則全部停止。
-        bool startAll = _sessions.Any(s => !s.Page.IsLogging);
+        // 只要還有分頁沒在側錄 → 全部開始；否則全部停止。（AI 分頁無側錄）
+        bool startAll = loggable.Any(p => !p.IsLogging);
         if (startAll)
         {
             int failed = 0;
-            foreach (var s in _sessions)
-                if (!s.Page.StartLog()) failed++;
+            foreach (var p in loggable)
+                if (!p.StartLog()) failed++;
             SetLogAllActive(true);
             if (failed > 0)
                 MessageBox.Show(this, $"{failed} session(s) failed to start logging. See app log for details.",
@@ -435,7 +467,7 @@ public sealed class WorkspaceView : UserControl
         }
         else
         {
-            foreach (var s in _sessions) s.Page.StopLog();
+            foreach (var p in loggable) p.StopLog();
             SetLogAllActive(false);
         }
     }
@@ -451,8 +483,8 @@ public sealed class WorkspaceView : UserControl
     private async void OnRunAllSerial(object? sender, EventArgs e)
     {
         var serials = _sessions
-            .Where(s => !s.IsSsh && s.Page.IsSerial && !s.Page.IsScriptRunning)
-            .Select(s => s.Page)
+            .Where(s => s.Page != null && !s.IsSsh && s.Page.IsSerial && !s.Page.IsScriptRunning)
+            .Select(s => s.Page!)
             .ToList();
 
         if (serials.Count == 0)
@@ -472,8 +504,8 @@ public sealed class WorkspaceView : UserControl
     private async void OnRunGroup(int group)
     {
         var members = _sessions
-            .Where(s => s.Page.Group == group && !s.Page.IsScriptRunning)
-            .Select(s => s.Page)
+            .Where(s => s.Page != null && s.Page.Group == group && !s.Page.IsScriptRunning)
+            .Select(s => s.Page!)
             .ToList();
 
         if (members.Count == 0)
@@ -491,7 +523,7 @@ public sealed class WorkspaceView : UserControl
     protected override void Dispose(bool disposing)
     {
         if (disposing)
-            foreach (var s in _sessions) { try { s.Page.Dispose(); } catch { } }
+            foreach (var s in _sessions) { try { s.Content.Dispose(); } catch { } }
         base.Dispose(disposing);
     }
 
diff --git a/src/ETTerms/ETTerms.csproj b/src/ETTerms/ETTerms.csproj
index 5a37617..240a5c1 100644
--- a/src/ETTerms/ETTerms.csproj
+++ b/src/ETTerms/ETTerms.csproj
@@ -10,7 +10,7 @@
     <AssemblyName>ETTerms</AssemblyName>
 
     <!-- 版本資訊 -->
-    <Version>0.5.0</Version>
+    <Version>0.6.0</Version>
     <Product>ETTerms</Product>
     <Company>ETTerms Project</Company>
 
diff --git a/src/ETTerms/Infrastructure/AppSettings.cs b/src/ETTerms/Infrastructure/AppSettings.cs
index fb9dd46..d469c9d 100644
--- a/src/ETTerms/Infrastructure/AppSettings.cs
+++ b/src/ETTerms/Infrastructure/AppSettings.cs
@@ -30,6 +30,16 @@ public sealed class AppSettings
     public string ShellType { get; set; } = "PowerShell";       // PowerShell, Bash, Cmd
     public string ShellStartupDir { get; set; } = "";
 
+    // ── AI Assistant（BYO endpoint）──
+    // ⚠️ 預設全空白＝內建 AI 停用。任何私人端點 / 金鑰不得寫死於此或程式碼——
+    // 使用者自己在 Settings → AI Assistant 填。API key 存 Credential Manager（ETTerms/AiApiKey），不在此檔。
+    /// <summary>OpenAI 相容端點,含 /v1（例：http://localhost:11434/v1）。空＝AI 停用。</summary>
+    public string AiBaseUrl { get; set; } = "";
+    /// <summary>模型名（需支援 function calling）。</summary>
+    public string AiModel { get; set; } = "";
+    /// <summary>系統提示詞（人設）；空則用內建預設。</summary>
+    public string AiSystemPrompt { get; set; } = "";
+
     // ── Keyword highlight（終端機關鍵字標色 + 分頁警示；Settings → Highlight 分頁設定）──
     public bool KeywordHighlightEnabled { get; set; } = true;
     public List<KeywordRule> KeywordRules { get; set; } = new();