Merge remote-tracking branch 'upstream/main' into feat/websocket-chat-channel

2026-02-24 22:21:03 +08:00 · 2026-02-24 22:21:03 +08:00 · bdd0009d77
commit bdd0009d77
parent e7c3e6e4ba 100356e8ec
50 changed files with 1207 additions and 449 deletions
--- a/.golangci.yaml
+++ b/.golangci.yaml
@ -66,7 +66,6 @@ linters:
    - testifylint
    - thelper
    - unparam
-    - unused
    - usestdlibvars
    - usetesting
    - wastedassign
@ -152,6 +151,9 @@ linters:
          - gocognit
          - gocyclo
        path: _test\.go$
+      - linters:
+          - nolintlint
+        path: 'pkg/tools/(i2c\.go|spi\.go)$'

 issues:
  max-issues-per-linter: 0
--- a/2
+++ b/2
@ -1,7 +1,7 @@
 # ============================================================
 # Stage 1: Build the picoclaw binary
 # ============================================================
-FROM golang:1.26.0-alpine AS builder
+FROM golang:1.25-alpine AS builder

 RUN apk add --no-cache git make

--- a/15
+++ b/15
@ -14,7 +14,7 @@ GO_VERSION=$(shell $(GO) version | awk '{print $$3}')
 LDFLAGS=-ldflags "-X main.version=$(VERSION) -X main.gitCommit=$(GIT_COMMIT) -X main.buildTime=$(BUILD_TIME) -X main.goVersion=$(GO_VERSION) -s -w"

 # Go variables
-GO?=go
+GO?=CGO_ENABLED=0 go
 GOFLAGS?=-v -tags stdjson

 # Golangci-lint
@ -24,6 +24,7 @@ GOLANGCI_LINT?=golangci-lint
 INSTALL_PREFIX?=$(HOME)/.local
 INSTALL_BIN_DIR=$(INSTALL_PREFIX)/bin
 INSTALL_MAN_DIR=$(INSTALL_PREFIX)/share/man/man1
+INSTALL_TMP_SUFFIX=.new

 # Workspace and Skills
 PICOCLAW_HOME?=$(HOME)/.picoclaw
@ -105,8 +106,10 @@ build-riscv64: generate
 install: build
 	@echo "Installing $(BINARY_NAME)..."
 	@mkdir -p $(INSTALL_BIN_DIR)
-	@cp $(BUILD_DIR)/$(BINARY_NAME) $(INSTALL_BIN_DIR)/$(BINARY_NAME)
-	@chmod +x $(INSTALL_BIN_DIR)/$(BINARY_NAME)
+	# Copy binary with temporary suffix to ensure atomic update
+	@cp $(BUILD_DIR)/$(BINARY_NAME) $(INSTALL_BIN_DIR)/$(BINARY_NAME)$(INSTALL_TMP_SUFFIX)
+	@chmod +x $(INSTALL_BIN_DIR)/$(BINARY_NAME)$(INSTALL_TMP_SUFFIX)
+	@mv -f $(INSTALL_BIN_DIR)/$(BINARY_NAME)$(INSTALL_TMP_SUFFIX) $(INSTALL_BIN_DIR)/$(BINARY_NAME)
 	@echo "Installed binary to $(INSTALL_BIN_DIR)/$(BINARY_NAME)"
 	@echo "Installation complete!"

@ -147,6 +150,10 @@ fmt:
 lint:
 	@$(GOLANGCI_LINT) run

+## fix: Fix linting issues
+fix:
+	@$(GOLANGCI_LINT) run --fix
+
 ## deps: Download dependencies
 deps:
 	@$(GO) mod download
@ -172,7 +179,7 @@ help:
 	@echo "  make [target]"
 	@echo ""
 	@echo "Targets:"
-	@grep -E '^## ' $(MAKEFILE_LIST) | sed 's/## /  /'
+	@grep -E '^## ' $(MAKEFILE_LIST) | sort | awk -F': ' '{printf "  %-16s %s\n", substr($$1, 4), $$2}'
 	@echo ""
 	@echo "Examples:"
 	@echo "  make build              # Build for current platform"
--- a/README.fr.md
+++ b/README.fr.md
@ -171,6 +171,10 @@ vim config/config.json      # Configurez DISCORD_BOT_TOKEN, clés API, etc.
 # 3. Compiler & Démarrer
 docker compose --profile gateway up -d

+> [!TIP]
+> **Utilisateurs Docker** : Par défaut, le Gateway écoute sur `127.0.0.1`, ce qui n'est pas accessible depuis l'hôte. Si vous avez besoin d'accéder aux endpoints de santé ou d'exposer des ports, définissez `PICOCLAW_GATEWAY_HOST=0.0.0.0` dans votre environnement ou mettez à jour `config.json`.
+
+
 # 4. Voir les logs
 docker compose logs -f picoclaw-gateway

@ -222,7 +226,7 @@ picoclaw onboard
  ],
  "agents": {
    "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
    }
  },
  "channels": {
--- a/README.ja.md
+++ b/README.ja.md
@ -133,6 +133,10 @@ vim config/config.json      # DISCORD_BOT_TOKEN, プロバイダーの API キ
 # 3. ビルドと起動
 docker compose --profile gateway up -d

+> [!TIP]
+> **Docker ユーザー**: デフォルトでは、Gateway は `127.0.0.1` でリッスンしており、ホストからアクセスできません。ヘルスチェックエンドポイントにアクセスしたり、ポートを公開したりする必要がある場合は、環境変数で `PICOCLAW_GATEWAY_HOST=0.0.0.0` を設定するか、`config.json` を更新してください。
+
+
 # 4. ログ確認
 docker compose logs -f picoclaw-gateway

@ -184,7 +188,7 @@ picoclaw onboard
  ],
  "agents": {
    "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
    }
  },
  "channels": {
--- a/README.md
+++ b/README.md
@ -12,6 +12,9 @@
    <br>
    <a href="https://picoclaw.io"><img src="https://img.shields.io/badge/Website-picoclaw.io-blue?style=flat&logo=google-chrome&logoColor=white" alt="Website"></a>
    <a href="https://x.com/SipeedIO"><img src="https://img.shields.io/badge/X_(Twitter)-SipeedIO-black?style=flat&logo=x&logoColor=white" alt="Twitter"></a>
+    <br>
+    <a href="./assets/wechat.png"><img src="https://img.shields.io/badge/WeChat-Group-41d56b?style=flat&logo=wechat&logoColor=white"></a>
+    <a href="https://discord.gg/V4sAZ9XWpN"><img src="https://img.shields.io/badge/Discord-Community-4c60eb?style=flat&logo=discord&logoColor=white" alt="Discord"></a>
  </p>

 [中文](README.zh.md) | [日本語](README.ja.md) | [Português](README.pt-br.md) | [Tiếng Việt](README.vi.md) | [Français](README.fr.md) | **English**
@ -171,6 +174,10 @@ vim config/config.json      # Set DISCORD_BOT_TOKEN, API keys, etc.
 # 3. Build & Start
 docker compose --profile gateway up -d

+> [!TIP]
+> **Docker Users**: By default, the Gateway listens on `127.0.0.1` which is not accessible from the host. If you need to access the health endpoints or expose ports, set `PICOCLAW_GATEWAY_HOST=0.0.0.0` in your environment or update `config.json`.
+
+
 # 4. Check logs
 docker compose logs -f picoclaw-gateway

@ -215,7 +222,7 @@ picoclaw onboard
  "agents": {
    "defaults": {
      "workspace": "~/.picoclaw/workspace",
-      "model": "gpt4",
+      "model_name": "gpt4",
      "max_tokens": 8192,
      "temperature": 0.7,
      "max_tool_iterations": 20
--- a/README.pt-br.md
+++ b/README.pt-br.md
@ -172,6 +172,10 @@ vim config/config.json      # Configure DISCORD_BOT_TOKEN, API keys, etc.
 # 3. Build & Iniciar
 docker compose --profile gateway up -d

+> [!TIP]
+> **Usuários Docker**: Por padrão, o Gateway ouve em `127.0.0.1`, o que não é acessível a partir do host. Se você precisar acessar os endpoints de integridade ou expor portas, defina `PICOCLAW_GATEWAY_HOST=0.0.0.0` em seu ambiente ou atualize o `config.json`.
+
+
 # 4. Ver logs
 docker compose logs -f picoclaw-gateway

@ -223,7 +227,7 @@ picoclaw onboard
  ],
  "agents": {
    "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
    }
  },
  "tools": {
--- a/README.vi.md
+++ b/README.vi.md
@ -152,6 +152,10 @@ vim config/config.json      # Thiết lập DISCORD_BOT_TOKEN, API keys, v.v.
 # 3. Build & Khởi động
 docker compose --profile gateway up -d

+> [!TIP]
+> **Người dùng Docker**: Theo mặc định, Gateway lắng nghe trên `127.0.0.1`, không thể truy cập từ máy chủ. Nếu bạn cần truy cập các endpoint kiểm tra sức khỏe hoặc mở cổng, hãy đặt `PICOCLAW_GATEWAY_HOST=0.0.0.0` trong môi trường của bạn hoặc cập nhật `config.json`.
+
+
 # 4. Xem logs
 docker compose logs -f picoclaw-gateway

@ -203,7 +207,7 @@ picoclaw onboard
  ],
  "agents": {
    "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
    }
  },
  "channels": {
--- a/README.zh.md
+++ b/README.zh.md
@ -173,6 +173,9 @@ vim config/config.json      # 设置 DISCORD_BOT_TOKEN, API keys 等
 # 3. 构建并启动
 docker compose --profile gateway up -d

+> [!TIP]
+**Docker 用户**: 默认情况下, Gateway监听 `127.0.0.1`，这使得这个端口未暴露到容器外。如果你需要通过端口映射访问健康检查接口, 请在环境变量中设置 `PICOCLAW_GATEWAY_HOST=0.0.0.0` 或修改 `config.json`。
+
 # 4. 查看日志
 docker compose logs -f picoclaw-gateway

@ -221,7 +224,7 @@ picoclaw onboard
  "agents": {
    "defaults": {
      "workspace": "~/.picoclaw/workspace",
-      "model": "gpt4",
+      "model_name": "gpt4",
      "max_tokens": 8192,
      "temperature": 0.7,
      "max_tool_iterations": 20
--- a/assets/wechat.png
+++ b/assets/wechat.png
--- a/cmd/picoclaw/cmd_agent.go
+++ b/cmd/picoclaw/cmd_agent.go
@ -56,7 +56,7 @@ func agentCmd() {
 	}

 	if modelOverride != "" {
-		cfg.Agents.Defaults.Model = modelOverride
+		cfg.Agents.Defaults.ModelName = modelOverride
 	}

 	provider, modelID, err := providers.CreateProvider(cfg)
@ -66,7 +66,7 @@ func agentCmd() {
 	}
 	// Use the resolved model ID from provider creation
 	if modelID != "" {
-		cfg.Agents.Defaults.Model = modelID
+		cfg.Agents.Defaults.ModelName = modelID
 	}

 	msgBus := bus.NewMessageBus()
--- a/cmd/picoclaw/cmd_auth.go
+++ b/cmd/picoclaw/cmd_auth.go
@ -144,7 +144,7 @@ func authLoginOpenAI(useDeviceCode bool) {
 		}

 		// Update default model to use OpenAI
-		appCfg.Agents.Defaults.Model = "gpt-5.2"
+		appCfg.Agents.Defaults.ModelName = "gpt-5.2"

 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@ -218,7 +218,7 @@ func authLoginGoogleAntigravity() {
 		}

 		// Update default model
-		appCfg.Agents.Defaults.Model = "gemini-flash"
+		appCfg.Agents.Defaults.ModelName = "gemini-flash"

 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@ -292,7 +292,7 @@ func authLoginPasteToken(provider string) {
 				})
 			}
 			// Update default model
-			appCfg.Agents.Defaults.Model = "claude-sonnet-4.6"
+			appCfg.Agents.Defaults.ModelName = "claude-sonnet-4.6"
 		case "openai":
 			appCfg.Providers.OpenAI.AuthMethod = "token"
 			// Update ModelList
@ -312,7 +312,7 @@ func authLoginPasteToken(provider string) {
 				})
 			}
 			// Update default model
-			appCfg.Agents.Defaults.Model = "gpt-5.2"
+			appCfg.Agents.Defaults.ModelName = "gpt-5.2"
 		}
 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@ -320,7 +320,7 @@ func authLoginPasteToken(provider string) {
 	}

 	fmt.Printf("Token saved for %s!\n", provider)
-	fmt.Printf("Default model set to: %s\n", appCfg.Agents.Defaults.Model)
+	fmt.Printf("Default model set to: %s\n", appCfg.Agents.Defaults.GetModelName())
 }

 func authLogoutCmd() {
--- a/cmd/picoclaw/cmd_gateway.go
+++ b/cmd/picoclaw/cmd_gateway.go
@ -52,7 +52,7 @@ func gatewayCmd() {
 	}
 	// Use the resolved model ID from provider creation
 	if modelID != "" {
-		cfg.Agents.Defaults.Model = modelID
+		cfg.Agents.Defaults.ModelName = modelID
 	}

 	msgBus := bus.NewMessageBus()
--- a/cmd/picoclaw/cmd_status.go
+++ b/cmd/picoclaw/cmd_status.go
@ -41,7 +41,7 @@ func statusCmd() {
 	}

 	if _, err := os.Stat(configPath); err == nil {
-		fmt.Printf("Model: %s\n", cfg.Agents.Defaults.Model)
+		fmt.Printf("Model: %s\n", cfg.Agents.Defaults.GetModelName())

 		hasOpenRouter := cfg.Providers.OpenRouter.APIKey != ""
 		hasAnthropic := cfg.Providers.Anthropic.APIKey != ""
--- a/cmd/picoclaw/main.go
+++ b/cmd/picoclaw/main.go
@ -131,7 +131,7 @@ func main() {

 		workspace := cfg.WorkspacePath()
 		installer := skills.NewSkillInstaller(workspace)
-		// 获取全局配置目录和内置 skills 目录
+		// get global config directory and builtin skills directory
 		globalDir := filepath.Dir(getConfigPath())
 		globalSkillsDir := filepath.Join(globalDir, "skills")
 		builtinSkillsDir := filepath.Join(globalDir, "picoclaw", "skills")
--- a/config/config.example.json
+++ b/config/config.example.json
@ -3,7 +3,7 @@
    "defaults": {
      "workspace": "~/.picoclaw/workspace",
      "restrict_to_workspace": true,
-      "model": "gpt4",
+      "model_name": "gpt4",
      "max_tokens": 8192,
      "temperature": 0.7,
      "max_tool_iterations": 20
@ -203,6 +203,10 @@
    "volcengine": {
      "api_key": "",
      "api_base": ""
+    },
+    "mistral": {
+      "api_key": "",
+      "api_base": "https://api.mistral.ai/v1"
    }
  },
  "tools": {
@ -250,7 +254,7 @@
    "monitor_usb": true
  },
  "gateway": {
-    "host": "0.0.0.0",
+    "host": "127.0.0.1",
    "port": 18790
  }
 }
--- a/pkg/agent/context.go
+++ b/pkg/agent/context.go
@ -288,25 +288,6 @@ func (cb *ContextBuilder) AddAssistantMessage(
 	return messages
 }

-func (cb *ContextBuilder) loadSkills() string {
-	allSkills := cb.skillsLoader.ListSkills()
-	if len(allSkills) == 0 {
-		return ""
-	}
-
-	var skillNames []string
-	for _, s := range allSkills {
-		skillNames = append(skillNames, s.Name)
-	}
-
-	content := cb.skillsLoader.LoadSkillsForContext(skillNames)
-	if content == "" {
-		return ""
-	}
-
-	return "# Skill Definitions\n\n" + content
-}
-
 // GetSkillsInfo returns information about loaded skills.
 func (cb *ContextBuilder) GetSkillsInfo() map[string]any {
 	allSkills := cb.skillsLoader.ListSkills()
--- a/pkg/agent/instance.go
+++ b/pkg/agent/instance.go
@ -133,7 +133,7 @@ func resolveAgentModel(agentCfg *config.AgentConfig, defaults *config.AgentDefau
 	if agentCfg != nil && agentCfg.Model != nil && strings.TrimSpace(agentCfg.Model.Primary) != "" {
 		return strings.TrimSpace(agentCfg.Model.Primary)
 	}
-	return defaults.Model
+	return defaults.GetModelName()
 }

 // resolveAgentFallbacks resolves the fallback models for an agent.
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@ -626,8 +626,9 @@ func (al *AgentLoop) runLLMIteration(

 		// Build assistant message with tool calls
 		assistantMsg := providers.Message{
-			Role:    "assistant",
-			Content: response.Content,
+			Role:             "assistant",
+			Content:          response.Content,
+			ReasoningContent: response.ReasoningContent,
 		}
 		for _, tc := range normalizedToolCalls {
 			argumentsJSON, _ := json.Marshal(tc.Arguments)
--- a/pkg/channels/qq.go
+++ b/pkg/channels/qq.go
@ -47,31 +47,31 @@ func (c *QQChannel) Start(ctx context.Context) error {

 	logger.InfoC("qq", "Starting QQ bot (WebSocket mode)")

-	// 创建 token source
+	// create token source
 	credentials := &token.QQBotCredentials{
 		AppID:     c.config.AppID,
 		AppSecret: c.config.AppSecret,
 	}
 	c.tokenSource = token.NewQQBotTokenSource(credentials)

-	// 创建子 context
+	// create child context
 	c.ctx, c.cancel = context.WithCancel(ctx)

-	// 启动自动刷新 token 协程
+	// start auto-refresh token goroutine
 	if err := token.StartRefreshAccessToken(c.ctx, c.tokenSource); err != nil {
 		return fmt.Errorf("failed to start token refresh: %w", err)
 	}

-	// 初始化 OpenAPI 客户端
+	// initialize OpenAPI client
 	c.api = botgo.NewOpenAPI(c.config.AppID, c.tokenSource).WithTimeout(5 * time.Second)

-	// 注册事件处理器
+	// register event handlers
 	intent := event.RegisterHandlers(
 		c.handleC2CMessage(),
 		c.handleGroupATMessage(),
 	)

-	// 获取 WebSocket 接入点
+	// get WebSocket endpoint
 	wsInfo, err := c.api.WS(c.ctx, nil, "")
 	if err != nil {
 		return fmt.Errorf("failed to get websocket info: %w", err)
@ -81,10 +81,10 @@ func (c *QQChannel) Start(ctx context.Context) error {
 		"shards": wsInfo.Shards,
 	})

-	// 创建并保存 sessionManager
+	// create and save sessionManager
 	c.sessionManager = botgo.NewSessionManager()

-	// 在 goroutine 中启动 WebSocket 连接，避免阻塞
+	// start WebSocket connection in goroutine to avoid blocking
 	go func() {
 		if err := c.sessionManager.Start(wsInfo, c.tokenSource, &intent); err != nil {
 			logger.ErrorCF("qq", "WebSocket session error", map[string]any{
@ -116,12 +116,12 @@ func (c *QQChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
 		return fmt.Errorf("QQ bot not running")
 	}

-	// 构造消息
+	// construct message
 	msgToCreate := &dto.MessageToCreate{
 		Content: msg.Content,
 	}

-	// C2C 消息发送
+	// send C2C message
 	_, err := c.api.PostC2CMessage(ctx, msg.ChatID, msgToCreate)
 	if err != nil {
 		logger.ErrorCF("qq", "Failed to send C2C message", map[string]any{
@ -133,15 +133,15 @@ func (c *QQChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
 	return nil
 }

-// handleC2CMessage 处理 QQ 私聊消息
+// handleC2CMessage handles QQ private messages
 func (c *QQChannel) handleC2CMessage() event.C2CMessageEventHandler {
 	return func(event *dto.WSPayload, data *dto.WSC2CMessageData) error {
-		// 去重检查
+		// deduplication check
 		if c.isDuplicate(data.ID) {
 			return nil
 		}

-		// 提取用户信息
+		// extract user info
 		var senderID string
 		if data.Author != nil && data.Author.ID != "" {
 			senderID = data.Author.ID
@ -150,7 +150,7 @@ func (c *QQChannel) handleC2CMessage() event.C2CMessageEventHandler {
 			return nil
 		}

-		// 提取消息内容
+		// extract message content
 		content := data.Content
 		if content == "" {
 			logger.DebugC("qq", "Received empty message, ignoring")
@ -162,7 +162,7 @@ func (c *QQChannel) handleC2CMessage() event.C2CMessageEventHandler {
 			"length": len(content),
 		})

-		// 转发到消息总线
+		// forward to message bus
 		metadata := map[string]string{
 			"message_id": data.ID,
 			"peer_kind":  "direct",
@ -175,15 +175,15 @@ func (c *QQChannel) handleC2CMessage() event.C2CMessageEventHandler {
 	}
 }

-// handleGroupATMessage 处理群@消息
+// handleGroupATMessage handles group @messages
 func (c *QQChannel) handleGroupATMessage() event.GroupATMessageEventHandler {
 	return func(event *dto.WSPayload, data *dto.WSGroupATMessageData) error {
-		// 去重检查
+		// deduplication check
 		if c.isDuplicate(data.ID) {
 			return nil
 		}

-		// 提取用户信息
+		// extract user info
 		var senderID string
 		if data.Author != nil && data.Author.ID != "" {
 			senderID = data.Author.ID
@ -192,7 +192,7 @@ func (c *QQChannel) handleGroupATMessage() event.GroupATMessageEventHandler {
 			return nil
 		}

-		// 提取消息内容（去掉 @ 机器人部分）
+		// extract message content (remove @bot part)
 		content := data.Content
 		if content == "" {
 			logger.DebugC("qq", "Received empty group message, ignoring")
@ -205,7 +205,7 @@ func (c *QQChannel) handleGroupATMessage() event.GroupATMessageEventHandler {
 			"length": len(content),
 		})

-		// 转发到消息总线（使用 GroupID 作为 ChatID）
+		// forward to message bus (use GroupID as ChatID)
 		metadata := map[string]string{
 			"message_id": data.ID,
 			"group_id":   data.GroupID,
@ -219,7 +219,7 @@ func (c *QQChannel) handleGroupATMessage() event.GroupATMessageEventHandler {
 	}
 }

-// isDuplicate 检查消息是否重复
+// isDuplicate checks if message is duplicate
 func (c *QQChannel) isDuplicate(messageID string) bool {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@ -230,9 +230,9 @@ func (c *QQChannel) isDuplicate(messageID string) bool {

 	c.processedIDs[messageID] = true

-	// 简单清理：限制 map 大小
+	// simple cleanup: limit map size
 	if len(c.processedIDs) > 10000 {
-		// 清空一半
+		// clear half
 		count := 0
 		for id := range c.processedIDs {
 			if count >= 5000 {
--- a/pkg/channels/slack.go
+++ b/pkg/channels/slack.go
@ -200,7 +200,7 @@ func (c *SlackChannel) handleMessageEvent(ev *slackevents.MessageEvent) {
 		return
 	}

-	// 检查白名单，避免为被拒绝的用户下载附件
+	// check allowlist to avoid downloading attachments for rejected users
 	if !c.IsAllowed(ev.User) {
 		logger.DebugCF("slack", "Message rejected by allowlist", map[string]any{
 			"user_id": ev.User,
@ -232,9 +232,9 @@ func (c *SlackChannel) handleMessageEvent(ev *slackevents.MessageEvent) {
 	content = c.stripBotMention(content)

 	var mediaPaths []string
-	localFiles := []string{} // 跟踪需要清理的本地文件
+	localFiles := []string{} // track local files that need cleanup

-	// 确保临时文件在函数返回时被清理
+	// ensure temp files are cleaned up when function returns
 	defer func() {
 		for _, file := range localFiles {
 			if err := os.Remove(file); err != nil {
--- a/pkg/channels/telegram.go
+++ b/pkg/channels/telegram.go
@ -208,7 +208,7 @@ func (c *TelegramChannel) handleMessage(ctx context.Context, message *telego.Mes
 		senderID = fmt.Sprintf("%d|%s", user.ID, user.Username)
 	}

-	// 检查白名单，避免为被拒绝的用户下载附件
+	// check allowlist to avoid downloading attachments for rejected users
 	if !c.IsAllowed(senderID) {
 		logger.DebugCF("telegram", "Message rejected by allowlist", map[string]any{
 			"user_id": senderID,
@ -221,9 +221,9 @@ func (c *TelegramChannel) handleMessage(ctx context.Context, message *telego.Mes

 	content := ""
 	mediaPaths := []string{}
-	localFiles := []string{} // 跟踪需要清理的本地文件
+	localFiles := []string{} // track local files that need cleanup

-	// 确保临时文件在函数返回时被清理
+	// ensure temp files are cleaned up when function returns
 	defer func() {
 		for _, file := range localFiles {
 			if err := os.Remove(file); err != nil {
--- a/pkg/channels/telegram_commands.go
+++ b/pkg/channels/telegram_commands.go
@ -81,7 +81,7 @@ func (c *cmd) Show(ctx context.Context, message telego.Message) error {
 	switch args {
 	case "model":
 		response = fmt.Sprintf("Current Model: %s (Provider: %s)",
-			c.config.Agents.Defaults.Model,
+			c.config.Agents.Defaults.GetModelName(),
 			c.config.Agents.Defaults.Provider)
 	case "channel":
 		response = "Current Channel: telegram"
@ -120,7 +120,7 @@ func (c *cmd) List(ctx context.Context, message telego.Message) error {
 			provider = "configured default"
 		}
 		response = fmt.Sprintf("Configured Model: %s\nProvider: %s\n\nTo change models, update config.yaml",
-			c.config.Agents.Defaults.Model, provider)
+			c.config.Agents.Defaults.GetModelName(), provider)

 	case "channels":
 		var enabled []string
--- a/pkg/channels/wecom_app.go
+++ b/pkg/channels/wecom_app.go
@ -571,61 +571,6 @@ func (c *WeComAppChannel) sendTextMessage(ctx context.Context, accessToken, user
 	return nil
 }

-// sendMarkdownMessage sends a markdown message to a user
-func (c *WeComAppChannel) sendMarkdownMessage(ctx context.Context, accessToken, userID, content string) error {
-	apiURL := fmt.Sprintf("%s/cgi-bin/message/send?access_token=%s", wecomAPIBase, accessToken)
-
-	msg := WeComMarkdownMessage{
-		ToUser:  userID,
-		MsgType: "markdown",
-		AgentID: c.config.AgentID,
-	}
-	msg.Markdown.Content = content
-
-	jsonData, err := json.Marshal(msg)
-	if err != nil {
-		return fmt.Errorf("failed to marshal message: %w", err)
-	}
-
-	// Use configurable timeout (default 5 seconds)
-	timeout := c.config.ReplyTimeout
-	if timeout <= 0 {
-		timeout = 5
-	}
-
-	reqCtx, cancel := context.WithTimeout(ctx, time.Duration(timeout)*time.Second)
-	defer cancel()
-
-	req, err := http.NewRequestWithContext(reqCtx, http.MethodPost, apiURL, bytes.NewBuffer(jsonData))
-	if err != nil {
-		return fmt.Errorf("failed to create request: %w", err)
-	}
-	req.Header.Set("Content-Type", "application/json")
-
-	client := &http.Client{Timeout: time.Duration(timeout) * time.Second}
-	resp, err := client.Do(req)
-	if err != nil {
-		return fmt.Errorf("failed to send message: %w", err)
-	}
-	defer resp.Body.Close()
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return fmt.Errorf("failed to read response: %w", err)
-	}
-
-	var sendResp WeComSendMessageResponse
-	if err := json.Unmarshal(body, &sendResp); err != nil {
-		return fmt.Errorf("failed to parse response: %w", err)
-	}
-
-	if sendResp.ErrCode != 0 {
-		return fmt.Errorf("API error: %s (code: %d)", sendResp.ErrMsg, sendResp.ErrCode)
-	}
-
-	return nil
-}
-
 // handleHealth handles health check requests
 func (c *WeComAppChannel) handleHealth(w http.ResponseWriter, r *http.Request) {
 	status := map[string]any{
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@ -170,7 +170,8 @@ type AgentDefaults struct {
 	Workspace           string   `json:"workspace"                       env:"PICOCLAW_AGENTS_DEFAULTS_WORKSPACE"`
 	RestrictToWorkspace bool     `json:"restrict_to_workspace"           env:"PICOCLAW_AGENTS_DEFAULTS_RESTRICT_TO_WORKSPACE"`
 	Provider            string   `json:"provider"                        env:"PICOCLAW_AGENTS_DEFAULTS_PROVIDER"`
-	Model               string   `json:"model"                           env:"PICOCLAW_AGENTS_DEFAULTS_MODEL"`
+	ModelName           string   `json:"model_name,omitempty"            env:"PICOCLAW_AGENTS_DEFAULTS_MODEL_NAME"`
+	Model               string   `json:"model,omitempty"                 env:"PICOCLAW_AGENTS_DEFAULTS_MODEL"` // Deprecated: use model_name instead
 	ModelFallbacks      []string `json:"model_fallbacks,omitempty"`
 	ImageModel          string   `json:"image_model,omitempty"           env:"PICOCLAW_AGENTS_DEFAULTS_IMAGE_MODEL"`
 	ImageModelFallbacks []string `json:"image_model_fallbacks,omitempty"`
@ -179,6 +180,15 @@ type AgentDefaults struct {
 	MaxToolIterations   int      `json:"max_tool_iterations"             env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOOL_ITERATIONS"`
 }

+// GetModelName returns the effective model name for the agent defaults.
+// It prefers the new "model_name" field but falls back to "model" for backward compatibility.
+func (d *AgentDefaults) GetModelName() string {
+	if d.ModelName != "" {
+		return d.ModelName
+	}
+	return d.Model
+}
+
 type ChannelsConfig struct {
 	WhatsApp  WhatsAppConfig  `json:"whatsapp"`
 	Telegram  TelegramConfig  `json:"telegram"`
@ -333,6 +343,7 @@ type ProvidersConfig struct {
 	GitHubCopilot ProviderConfig       `json:"github_copilot"`
 	Antigravity   ProviderConfig       `json:"antigravity"`
 	Qwen          ProviderConfig       `json:"qwen"`
+	Mistral       ProviderConfig       `json:"mistral"`
 }

 // IsEmpty checks if all provider configs are empty (no API keys or API bases set)
@ -354,7 +365,8 @@ func (p ProvidersConfig) IsEmpty() bool {
 		p.VolcEngine.APIKey == "" && p.VolcEngine.APIBase == "" &&
 		p.GitHubCopilot.APIKey == "" && p.GitHubCopilot.APIBase == "" &&
 		p.Antigravity.APIKey == "" && p.Antigravity.APIBase == "" &&
-		p.Qwen.APIKey == "" && p.Qwen.APIBase == ""
+		p.Qwen.APIKey == "" && p.Qwen.APIBase == "" &&
+		p.Mistral.APIKey == "" && p.Mistral.APIBase == ""
 }

 // MarshalJSON implements custom JSON marshaling for ProvidersConfig
@ -506,6 +518,20 @@ func LoadConfig(path string) (*Config, error) {
 		return nil, err
 	}

+	// Pre-scan the JSON to check how many model_list entries the user provided.
+	// Go's JSON decoder reuses existing slice backing-array elements rather than
+	// zero-initializing them, so fields absent from the user's JSON (e.g. api_base)
+	// would silently inherit values from the DefaultConfig template at the same
+	// index position. We only reset cfg.ModelList when the user actually provides
+	// entries; when count is 0 we keep DefaultConfig's built-in list as fallback.
+	var tmp Config
+	if err := json.Unmarshal(data, &tmp); err != nil {
+		return nil, err
+	}
+	if len(tmp.ModelList) > 0 {
+		cfg.ModelList = nil
+	}
+
 	if err := json.Unmarshal(data, cfg); err != nil {
 		return nil, err
 	}
@ -653,7 +679,8 @@ func (c *Config) HasProvidersConfig() bool {
 		v.VolcEngine.APIKey != "" || v.VolcEngine.APIBase != "" ||
 		v.GitHubCopilot.APIKey != "" || v.GitHubCopilot.APIBase != "" ||
 		v.Antigravity.APIKey != "" || v.Antigravity.APIBase != "" ||
-		v.Qwen.APIKey != "" || v.Qwen.APIBase != ""
+		v.Qwen.APIKey != "" || v.Qwen.APIBase != "" ||
+		v.Mistral.APIKey != "" || v.Mistral.APIBase != ""
 }

 // ValidateModelList validates all ModelConfig entries in the model_list.
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@ -246,7 +246,7 @@ func TestDefaultConfig_Temperature(t *testing.T) {
 func TestDefaultConfig_Gateway(t *testing.T) {
 	cfg := DefaultConfig()

-	if cfg.Gateway.Host != "0.0.0.0" {
+	if cfg.Gateway.Host != "127.0.0.1" {
 		t.Error("Gateway host should have default value")
 	}
 	if cfg.Gateway.Port == 0 {
@ -343,7 +343,7 @@ func TestConfig_Complete(t *testing.T) {
 	if cfg.Agents.Defaults.MaxToolIterations == 0 {
 		t.Error("MaxToolIterations should not be zero")
 	}
-	if cfg.Gateway.Host != "0.0.0.0" {
+	if cfg.Gateway.Host != "127.0.0.1" {
 		t.Error("Gateway host should have default value")
 	}
 	if cfg.Gateway.Port == 0 {
--- a/pkg/config/defaults.go
+++ b/pkg/config/defaults.go
@ -262,6 +262,14 @@ func DefaultConfig() *Config {
 				APIKey:    "ollama",
 			},

+			// Mistral AI - https://console.mistral.ai/api-keys
+			{
+				ModelName: "mistral-small",
+				Model:     "mistral/mistral-small-latest",
+				APIBase:   "https://api.mistral.ai/v1",
+				APIKey:    "",
+			},
+
 			// VLLM (local) - http://localhost:8000
 			{
 				ModelName: "local-model",
@ -271,7 +279,7 @@ func DefaultConfig() *Config {
 			},
 		},
 		Gateway: GatewayConfig{
-			Host: "0.0.0.0",
+			Host: "127.0.0.1",
 			Port: 18790,
 		},
 		Tools: ToolsConfig{
--- a/pkg/config/migration.go
+++ b/pkg/config/migration.go
@ -41,7 +41,7 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {

 	// Get user's configured provider and model
 	userProvider := strings.ToLower(cfg.Agents.Defaults.Provider)
-	userModel := cfg.Agents.Defaults.Model
+	userModel := cfg.Agents.Defaults.GetModelName()

 	p := cfg.Providers

@ -324,6 +324,22 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {
 				}, true
 			},
 		},
+		{
+			providerNames: []string{"mistral"},
+			protocol:      "mistral",
+			buildConfig: func(p ProvidersConfig) (ModelConfig, bool) {
+				if p.Mistral.APIKey == "" && p.Mistral.APIBase == "" {
+					return ModelConfig{}, false
+				}
+				return ModelConfig{
+					ModelName: "mistral",
+					Model:     "mistral/mistral-small-latest",
+					APIKey:    p.Mistral.APIKey,
+					APIBase:   p.Mistral.APIBase,
+					Proxy:     p.Mistral.Proxy,
+				}, true
+			},
+		},
 	}

 	// Process each provider migration
--- a/pkg/config/migration_test.go
+++ b/pkg/config/migration_test.go
@ -131,14 +131,15 @@ func TestConvertProvidersToModelList_AllProviders(t *testing.T) {
 			GitHubCopilot: ProviderConfig{ConnectMode: "grpc"},
 			Antigravity:   ProviderConfig{AuthMethod: "oauth"},
 			Qwen:          ProviderConfig{APIKey: "key17"},
+			Mistral:       ProviderConfig{APIKey: "key18"},
 		},
 	}

 	result := ConvertProvidersToModelList(cfg)

-	// All 17 providers should be converted
-	if len(result) != 17 {
-		t.Errorf("len(result) = %d, want 17", len(result))
+	// All 18 providers should be converted
+	if len(result) != 18 {
+		t.Errorf("len(result) = %d, want 18", len(result))
 	}
 }

--- a/pkg/config/model_config_test.go
+++ b/pkg/config/model_config_test.go
@ -6,6 +6,7 @@
 package config

 import (
+	"encoding/json"
 	"strings"
 	"sync"
 	"testing"
@ -114,6 +115,137 @@ func TestGetModelConfig_Concurrent(t *testing.T) {
 	}
 }

+func TestAgentDefaults_GetModelName_BackwardCompat(t *testing.T) {
+	tests := []struct {
+		name     string
+		defaults AgentDefaults
+		wantName string
+	}{
+		{
+			name:     "new model_name field only",
+			defaults: AgentDefaults{ModelName: "new-model"},
+			wantName: "new-model",
+		},
+		{
+			name:     "old model field only",
+			defaults: AgentDefaults{Model: "legacy-model"},
+			wantName: "legacy-model",
+		},
+		{
+			name:     "both fields - model_name takes precedence",
+			defaults: AgentDefaults{ModelName: "new-model", Model: "old-model"},
+			wantName: "new-model",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.defaults.GetModelName(); got != tt.wantName {
+				t.Errorf("GetModelName() = %q, want %q", got, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestAgentDefaults_JSON_BackwardCompat(t *testing.T) {
+	tests := []struct {
+		name     string
+		json     string
+		wantName string
+	}{
+		{
+			name:     "new model_name field",
+			json:     `{"model_name": "gpt4"}`,
+			wantName: "gpt4",
+		},
+		{
+			name:     "old model field",
+			json:     `{"model": "gpt4"}`,
+			wantName: "gpt4",
+		},
+		{
+			name:     "both fields - model_name wins",
+			json:     `{"model_name": "new", "model": "old"}`,
+			wantName: "new",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var defaults AgentDefaults
+			if err := json.Unmarshal([]byte(tt.json), &defaults); err != nil {
+				t.Fatalf("Unmarshal error: %v", err)
+			}
+			if got := defaults.GetModelName(); got != tt.wantName {
+				t.Errorf("GetModelName() = %q, want %q", got, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestFullConfig_JSON_BackwardCompat(t *testing.T) {
+	// Test complete config with both old and new formats
+	oldFormat := `{
+		"agents": {
+			"defaults": {
+				"workspace": "~/.picoclaw/workspace",
+				"model": "gpt4",
+				"max_tokens": 4096
+			}
+		},
+		"model_list": [
+			{
+				"model_name": "gpt4",
+				"model": "openai/gpt-4o",
+				"api_key": "test-key"
+			}
+		]
+	}`
+
+	newFormat := `{
+		"agents": {
+			"defaults": {
+				"workspace": "~/.picoclaw/workspace",
+				"model_name": "gpt4",
+				"max_tokens": 4096
+			}
+		},
+		"model_list": [
+			{
+				"model_name": "gpt4",
+				"model": "openai/gpt-4o",
+				"api_key": "test-key"
+			}
+		]
+	}`
+
+	for name, jsonStr := range map[string]string{
+		"old format (model)":      oldFormat,
+		"new format (model_name)": newFormat,
+	} {
+		t.Run(name, func(t *testing.T) {
+			cfg := &Config{}
+			if err := json.Unmarshal([]byte(jsonStr), cfg); err != nil {
+				t.Fatalf("Unmarshal error: %v", err)
+			}
+
+			// Check that GetModelName returns correct value
+			if got := cfg.Agents.Defaults.GetModelName(); got != "gpt4" {
+				t.Errorf("GetModelName() = %q, want %q", got, "gpt4")
+			}
+
+			// Check that GetModelConfig works
+			modelCfg, err := cfg.GetModelConfig("gpt4")
+			if err != nil {
+				t.Fatalf("GetModelConfig error: %v", err)
+			}
+			if modelCfg.Model != "openai/gpt-4o" {
+				t.Errorf("Model = %q, want %q", modelCfg.Model, "openai/gpt-4o")
+			}
+		})
+	}
+}
+
 func TestModelConfig_Validate(t *testing.T) {
 	tests := []struct {
 		name    string
--- a/pkg/devices/sources/usb_linux.go
+++ b/pkg/devices/sources/usb_linux.go
@ -35,9 +35,8 @@ var usbClassToCapability = map[string]string{
 }

 type USBMonitor struct {
-	cmd    *exec.Cmd
-	cancel context.CancelFunc
-	mu     sync.Mutex
+	cmd *exec.Cmd
+	mu  sync.Mutex
 }

 func NewUSBMonitor() *USBMonitor {
--- a/pkg/logger/logger.go
+++ b/pkg/logger/logger.go
@ -119,13 +119,15 @@ func logMessage(level LogLevel, component string, message string, fields map[str
 	if logger.file != nil {
 		jsonData, err := json.Marshal(entry)
 		if err == nil {
-			logger.file.WriteString(string(jsonData) + "\n")
+			logger.file.Write(append(jsonData, '\n'))
 		}
 	}

 	var fieldStr string
 	if len(fields) > 0 {
 		fieldStr = " " + formatFields(fields)
+	} else {
+		fieldStr = ""
 	}

 	logLine := fmt.Sprintf("[%s] [%s]%s %s%s",
--- a/pkg/migrate/config.go
+++ b/pkg/migrate/config.go
@ -22,6 +22,7 @@ var supportedProviders = map[string]bool{
 	"qwen":           true,
 	"deepseek":       true,
 	"github_copilot": true,
+	"mistral":        true,
 }

 var supportedChannels = map[string]bool{
@ -72,7 +73,10 @@ func ConvertConfig(data map[string]any) (*config.Config, []string, error) {

 	if agents, ok := getMap(data, "agents"); ok {
 		if defaults, ok := getMap(agents, "defaults"); ok {
-			if v, ok := getString(defaults, "model"); ok {
+			// Prefer model_name, fallback to model for backward compatibility
+			if v, ok := getString(defaults, "model_name"); ok {
+				cfg.Agents.Defaults.ModelName = v
+			} else if v, ok := getString(defaults, "model"); ok {
 				cfg.Agents.Defaults.Model = v
 			}
 			if v, ok := getFloat(defaults, "max_tokens"); ok {
--- a/pkg/providers/antigravity_provider.go
+++ b/pkg/providers/antigravity_provider.go
@ -404,64 +404,6 @@ type antigravityJSONResponse struct {
 	} `json:"usageMetadata"`
 }

-func (p *AntigravityProvider) parseJSONResponse(body []byte) (*LLMResponse, error) {
-	var resp antigravityJSONResponse
-	if err := json.Unmarshal(body, &resp); err != nil {
-		return nil, fmt.Errorf("parsing antigravity response: %w", err)
-	}
-
-	if len(resp.Candidates) == 0 {
-		return nil, fmt.Errorf("antigravity: no candidates in response")
-	}
-
-	candidate := resp.Candidates[0]
-	var contentParts []string
-	var toolCalls []ToolCall
-
-	for _, part := range candidate.Content.Parts {
-		if part.Text != "" {
-			contentParts = append(contentParts, part.Text)
-		}
-		if part.FunctionCall != nil {
-			argumentsJSON, _ := json.Marshal(part.FunctionCall.Args)
-			toolCalls = append(toolCalls, ToolCall{
-				ID:        fmt.Sprintf("call_%s_%d", part.FunctionCall.Name, time.Now().UnixNano()),
-				Name:      part.FunctionCall.Name,
-				Arguments: part.FunctionCall.Args,
-				Function: &FunctionCall{
-					Name:             part.FunctionCall.Name,
-					Arguments:        string(argumentsJSON),
-					ThoughtSignature: extractPartThoughtSignature(part.ThoughtSignature, part.ThoughtSignatureSnake),
-				},
-			})
-		}
-	}
-
-	finishReason := "stop"
-	if len(toolCalls) > 0 {
-		finishReason = "tool_calls"
-	}
-	if candidate.FinishReason == "MAX_TOKENS" {
-		finishReason = "length"
-	}
-
-	var usage *UsageInfo
-	if resp.UsageMetadata.TotalTokenCount > 0 {
-		usage = &UsageInfo{
-			PromptTokens:     resp.UsageMetadata.PromptTokenCount,
-			CompletionTokens: resp.UsageMetadata.CandidatesTokenCount,
-			TotalTokens:      resp.UsageMetadata.TotalTokenCount,
-		}
-	}
-
-	return &LLMResponse{
-		Content:      strings.Join(contentParts, ""),
-		ToolCalls:    toolCalls,
-		FinishReason: finishReason,
-		Usage:        usage,
-	}, nil
-}
-
 func (p *AntigravityProvider) parseSSEResponse(body string) (*LLMResponse, error) {
 	var contentParts []string
 	var toolCalls []ToolCall
--- a/pkg/providers/factory.go
+++ b/pkg/providers/factory.go
@ -36,7 +36,7 @@ type providerSelection struct {
 }

 func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
-	model := cfg.Agents.Defaults.Model
+	model := cfg.Agents.Defaults.GetModelName()
 	providerName := strings.ToLower(cfg.Agents.Defaults.Provider)
 	lowerModel := strings.ToLower(model)

@ -172,6 +172,15 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 					sel.model = "deepseek-chat"
 				}
 			}
+		case "mistral":
+			if cfg.Providers.Mistral.APIKey != "" {
+				sel.apiKey = cfg.Providers.Mistral.APIKey
+				sel.apiBase = cfg.Providers.Mistral.APIBase
+				sel.proxy = cfg.Providers.Mistral.Proxy
+				if sel.apiBase == "" {
+					sel.apiBase = "https://api.mistral.ai/v1"
+				}
+			}
 		case "github_copilot", "copilot":
 			sel.providerType = providerTypeGitHubCopilot
 			if cfg.Providers.GitHubCopilot.APIBase != "" {
@ -275,6 +284,13 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 			if sel.apiBase == "" {
 				sel.apiBase = "http://localhost:11434/v1"
 			}
+		case (strings.Contains(lowerModel, "mistral") || strings.HasPrefix(model, "mistral/")) && cfg.Providers.Mistral.APIKey != "":
+			sel.apiKey = cfg.Providers.Mistral.APIKey
+			sel.apiBase = cfg.Providers.Mistral.APIBase
+			sel.proxy = cfg.Providers.Mistral.Proxy
+			if sel.apiBase == "" {
+				sel.apiBase = "https://api.mistral.ai/v1"
+			}
 		case cfg.Providers.VLLM.APIBase != "":
 			sel.apiKey = cfg.Providers.VLLM.APIKey
 			sel.apiBase = cfg.Providers.VLLM.APIBase
--- a/pkg/providers/factory_provider.go
+++ b/pkg/providers/factory_provider.go
@ -88,7 +88,7 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err

 	case "openrouter", "groq", "zhipu", "gemini", "nvidia",
 		"ollama", "moonshot", "shengsuanyun", "deepseek", "cerebras",
-		"volcengine", "vllm", "qwen":
+		"volcengine", "vllm", "qwen", "mistral":
 		// All other OpenAI-compatible HTTP providers
 		if cfg.APIKey == "" && cfg.APIBase == "" {
 			return nil, "", fmt.Errorf("api_key or api_base is required for HTTP-based protocol %q", protocol)
@ -186,6 +186,8 @@ func getDefaultAPIBase(protocol string) string {
 		return "https://dashscope.aliyuncs.com/compatible-mode/v1"
 	case "vllm":
 		return "http://localhost:8000/v1"
+	case "mistral":
+		return "https://api.mistral.ai/v1"
 	default:
 		return ""
 	}
--- a/pkg/providers/fallback_test.go
+++ b/pkg/providers/fallback_test.go
@ -17,12 +17,6 @@ func successRun(content string) func(ctx context.Context, provider, model string
 	}
 }

-func failRun(err error) func(ctx context.Context, provider, model string) (*LLMResponse, error) {
-	return func(ctx context.Context, provider, model string) (*LLMResponse, error) {
-		return nil, err
-	}
-}
-
 func TestFallback_SingleCandidate_Success(t *testing.T) {
 	ct := NewCooldownTracker()
 	fc := NewFallbackChain(ct)
--- a/pkg/providers/legacy_provider.go
+++ b/pkg/providers/legacy_provider.go
@ -16,7 +16,7 @@ import (
 // The old providers config is automatically converted to model_list during config loading.
 // Returns the provider, the model ID to use, and any error.
 func CreateProvider(cfg *config.Config) (LLMProvider, string, error) {
-	model := cfg.Agents.Defaults.Model
+	model := cfg.Agents.Defaults.GetModelName()

 	// Ensure model_list is populated (should be done by LoadConfig, but handle edge cases)
 	if len(cfg.ModelList) == 0 && cfg.HasProvidersConfig() {
--- a/pkg/providers/openai_compat/provider.go
+++ b/pkg/providers/openai_compat/provider.go
@ -148,8 +148,9 @@ func parseResponse(body []byte) (*LLMResponse, error) {
 	var apiResponse struct {
 		Choices []struct {
 			Message struct {
-				Content   string `json:"content"`
-				ToolCalls []struct {
+				Content          string `json:"content"`
+				ReasoningContent string `json:"reasoning_content"`
+				ToolCalls        []struct {
 					ID       string `json:"id"`
 					Type     string `json:"type"`
 					Function *struct {
@ -221,10 +222,11 @@ func parseResponse(body []byte) (*LLMResponse, error) {
 	}

 	return &LLMResponse{
-		Content:      choice.Message.Content,
-		ToolCalls:    toolCalls,
-		FinishReason: choice.FinishReason,
-		Usage:        apiResponse.Usage,
+		Content:          choice.Message.Content,
+		ReasoningContent: choice.Message.ReasoningContent,
+		ToolCalls:        toolCalls,
+		FinishReason:     choice.FinishReason,
+		Usage:            apiResponse.Usage,
 	}, nil
 }

@ -240,7 +242,7 @@ func normalizeModel(model, apiBase string) string {

 	prefix := strings.ToLower(model[:idx])
 	switch prefix {
-	case "moonshot", "nvidia", "groq", "ollama", "deepseek", "google", "openrouter", "zhipu":
+	case "moonshot", "nvidia", "groq", "ollama", "deepseek", "google", "openrouter", "zhipu", "mistral":
 		return model[idx+1:]
 	default:
 		return model
--- a/pkg/providers/openai_compat/provider_test.go
+++ b/pkg/providers/openai_compat/provider_test.go
@ -101,6 +101,50 @@ func TestProviderChat_ParsesToolCalls(t *testing.T) {
 	}
 }

+func TestProviderChat_ParsesReasoningContent(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{
+					"message": map[string]any{
+						"content":           "The answer is 2",
+						"reasoning_content": "Let me think step by step... 1+1=2",
+						"tool_calls": []map[string]any{
+							{
+								"id":   "call_1",
+								"type": "function",
+								"function": map[string]any{
+									"name":      "calculator",
+									"arguments": "{\"expr\":\"1+1\"}",
+								},
+							},
+						},
+					},
+					"finish_reason": "tool_calls",
+				},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	p := NewProvider("key", server.URL, "")
+	out, err := p.Chat(t.Context(), []Message{{Role: "user", Content: "1+1=?"}}, nil, "kimi-k2.5", nil)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+	if out.ReasoningContent != "Let me think step by step... 1+1=2" {
+		t.Fatalf("ReasoningContent = %q, want %q", out.ReasoningContent, "Let me think step by step... 1+1=2")
+	}
+	if out.Content != "The answer is 2" {
+		t.Fatalf("Content = %q, want %q", out.Content, "The answer is 2")
+	}
+	if len(out.ToolCalls) != 1 {
+		t.Fatalf("len(ToolCalls) = %d, want 1", len(out.ToolCalls))
+	}
+}
+
 func TestProviderChat_HTTPError(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "bad request", http.StatusBadRequest)
--- a/pkg/providers/protocoltypes/types.go
+++ b/pkg/providers/protocoltypes/types.go
@ -4,8 +4,8 @@ type ToolCall struct {
 	ID               string         `json:"id"`
 	Type             string         `json:"type,omitempty"`
 	Function         *FunctionCall  `json:"function,omitempty"`
-	Name             string         `json:"name,omitempty"`
-	Arguments        map[string]any `json:"arguments,omitempty"`
+	Name             string         `json:"-"`
+	Arguments        map[string]any `json:"-"`
 	ThoughtSignature string         `json:"-"` // Internal use only
 	ExtraContent     *ExtraContent  `json:"extra_content,omitempty"`
 }
@ -25,10 +25,11 @@ type FunctionCall struct {
 }

 type LLMResponse struct {
-	Content      string     `json:"content"`
-	ToolCalls    []ToolCall `json:"tool_calls,omitempty"`
-	FinishReason string     `json:"finish_reason"`
-	Usage        *UsageInfo `json:"usage,omitempty"`
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"`
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	FinishReason     string     `json:"finish_reason"`
+	Usage            *UsageInfo `json:"usage,omitempty"`
 }

 type UsageInfo struct {
@ -38,10 +39,11 @@ type UsageInfo struct {
 }

 type Message struct {
-	Role       string     `json:"role"`
-	Content    string     `json:"content"`
-	ToolCalls  []ToolCall `json:"tool_calls,omitempty"`
-	ToolCallID string     `json:"tool_call_id,omitempty"`
+	Role             string     `json:"role"`
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"`
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	ToolCallID       string     `json:"tool_call_id,omitempty"`
 }

 type ToolDefinition struct {
--- a/pkg/skills/loader.go
+++ b/pkg/skills/loader.go
@ -55,9 +55,9 @@ func (info SkillInfo) validate() error {

 type SkillsLoader struct {
 	workspace       string
-	workspaceSkills string // workspace skills (项目级别)
-	globalSkills    string // 全局 skills (~/.picoclaw/skills)
-	builtinSkills   string // 内置 skills
+	workspaceSkills string // workspace skills (project-level)
+	globalSkills    string // global skills (~/.picoclaw/skills)
+	builtinSkills   string // builtin skills
 }

 func NewSkillsLoader(workspace string, globalSkills string, builtinSkills string) *SkillsLoader {
@ -71,118 +71,56 @@ func NewSkillsLoader(workspace string, globalSkills string, builtinSkills string

 func (sl *SkillsLoader) ListSkills() []SkillInfo {
 	skills := make([]SkillInfo, 0)
+	seen := make(map[string]bool)

-	if sl.workspaceSkills != "" {
-		if dirs, err := os.ReadDir(sl.workspaceSkills); err == nil {
-			for _, dir := range dirs {
-				if dir.IsDir() {
-					skillFile := filepath.Join(sl.workspaceSkills, dir.Name(), "SKILL.md")
-					if _, err := os.Stat(skillFile); err == nil {
-						info := SkillInfo{
-							Name:   dir.Name(),
-							Path:   skillFile,
-							Source: "workspace",
-						}
-						metadata := sl.getSkillMetadata(skillFile)
-						if metadata != nil {
-							info.Description = metadata.Description
-							info.Name = metadata.Name
-						}
-						if err := info.validate(); err != nil {
-							slog.Warn("invalid skill from workspace", "name", info.Name, "error", err)
-							continue
-						}
-						skills = append(skills, info)
-					}
-				}
+	addSkills := func(dir, source string) {
+		if dir == "" {
+			return
+		}
+		dirs, err := os.ReadDir(dir)
+		if err != nil {
+			return
+		}
+		for _, d := range dirs {
+			if !d.IsDir() {
+				continue
 			}
+			skillFile := filepath.Join(dir, d.Name(), "SKILL.md")
+			if _, err := os.Stat(skillFile); err != nil {
+				continue
+			}
+			info := SkillInfo{
+				Name:   d.Name(),
+				Path:   skillFile,
+				Source: source,
+			}
+			metadata := sl.getSkillMetadata(skillFile)
+			if metadata != nil {
+				info.Description = metadata.Description
+				info.Name = metadata.Name
+			}
+			if err := info.validate(); err != nil {
+				slog.Warn("invalid skill from "+source, "name", info.Name, "error", err)
+				continue
+			}
+			if seen[info.Name] {
+				continue
+			}
+			seen[info.Name] = true
+			skills = append(skills, info)
 		}
 	}

-	// 全局 skills (~/.picoclaw/skills) - 被 workspace skills 覆盖
-	if sl.globalSkills != "" {
-		if dirs, err := os.ReadDir(sl.globalSkills); err == nil {
-			for _, dir := range dirs {
-				if dir.IsDir() {
-					skillFile := filepath.Join(sl.globalSkills, dir.Name(), "SKILL.md")
-					if _, err := os.Stat(skillFile); err == nil {
-						// 检查是否已被 workspace skills 覆盖
-						exists := false
-						for _, s := range skills {
-							if s.Name == dir.Name() && s.Source == "workspace" {
-								exists = true
-								break
-							}
-						}
-						if exists {
-							continue
-						}
-
-						info := SkillInfo{
-							Name:   dir.Name(),
-							Path:   skillFile,
-							Source: "global",
-						}
-						metadata := sl.getSkillMetadata(skillFile)
-						if metadata != nil {
-							info.Description = metadata.Description
-							info.Name = metadata.Name
-						}
-						if err := info.validate(); err != nil {
-							slog.Warn("invalid skill from global", "name", info.Name, "error", err)
-							continue
-						}
-						skills = append(skills, info)
-					}
-				}
-			}
-		}
-	}
-
-	if sl.builtinSkills != "" {
-		if dirs, err := os.ReadDir(sl.builtinSkills); err == nil {
-			for _, dir := range dirs {
-				if dir.IsDir() {
-					skillFile := filepath.Join(sl.builtinSkills, dir.Name(), "SKILL.md")
-					if _, err := os.Stat(skillFile); err == nil {
-						// 检查是否已被 workspace 或 global skills 覆盖
-						exists := false
-						for _, s := range skills {
-							if s.Name == dir.Name() && (s.Source == "workspace" || s.Source == "global") {
-								exists = true
-								break
-							}
-						}
-						if exists {
-							continue
-						}
-
-						info := SkillInfo{
-							Name:   dir.Name(),
-							Path:   skillFile,
-							Source: "builtin",
-						}
-						metadata := sl.getSkillMetadata(skillFile)
-						if metadata != nil {
-							info.Description = metadata.Description
-							info.Name = metadata.Name
-						}
-						if err := info.validate(); err != nil {
-							slog.Warn("invalid skill from builtin", "name", info.Name, "error", err)
-							continue
-						}
-						skills = append(skills, info)
-					}
-				}
-			}
-		}
-	}
+	// Priority: workspace > global > builtin
+	addSkills(sl.workspaceSkills, "workspace")
+	addSkills(sl.globalSkills, "global")
+	addSkills(sl.builtinSkills, "builtin")

 	return skills
 }

 func (sl *SkillsLoader) LoadSkill(name string) (string, bool) {
-	// 1. 优先从 workspace skills 加载（项目级别）
+	// 1. load from workspace skills first (project-level)
 	if sl.workspaceSkills != "" {
 		skillFile := filepath.Join(sl.workspaceSkills, name, "SKILL.md")
 		if content, err := os.ReadFile(skillFile); err == nil {
@ -190,7 +128,7 @@ func (sl *SkillsLoader) LoadSkill(name string) (string, bool) {
 		}
 	}

-	// 2. 其次从全局 skills 加载 (~/.picoclaw/skills)
+	// 2. then load from global skills (~/.picoclaw/skills)
 	if sl.globalSkills != "" {
 		skillFile := filepath.Join(sl.globalSkills, name, "SKILL.md")
 		if content, err := os.ReadFile(skillFile); err == nil {
@ -198,7 +136,7 @@ func (sl *SkillsLoader) LoadSkill(name string) (string, bool) {
 		}
 	}

-	// 3. 最后从内置 skills 加载
+	// 3. finally load from builtin skills
 	if sl.builtinSkills != "" {
 		skillFile := filepath.Join(sl.builtinSkills, name, "SKILL.md")
 		if content, err := os.ReadFile(skillFile); err == nil {
--- a/pkg/skills/loader_test.go
+++ b/pkg/skills/loader_test.go
@ -1,9 +1,12 @@
 package skills

 import (
+	"os"
+	"path/filepath"
 	"testing"

 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )

 func TestSkillsInfoValidate(t *testing.T) {
@ -135,6 +138,134 @@ func TestExtractFrontmatter(t *testing.T) {
 	}
 }

+// createSkillDir creates a skill directory with a SKILL.md file containing the given frontmatter.
+func createSkillDir(t *testing.T, base, dirName, name, description string) {
+	t.Helper()
+	dir := filepath.Join(base, dirName)
+	require.NoError(t, os.MkdirAll(dir, 0o755))
+	content := "---\nname: " + name + "\ndescription: " + description + "\n---\n\n# " + name
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "SKILL.md"), []byte(content), 0o644))
+}
+
+func TestListSkillsWorkspaceOverridesGlobal(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+
+	createSkillDir(t, filepath.Join(ws, "skills"), "my-skill", "my-skill", "workspace version")
+	createSkillDir(t, global, "my-skill", "my-skill", "global version")
+
+	sl := NewSkillsLoader(ws, global, "")
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 1)
+	assert.Equal(t, "workspace", skills[0].Source)
+	assert.Equal(t, "workspace version", skills[0].Description)
+}
+
+func TestListSkillsGlobalOverridesBuiltin(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+	builtin := filepath.Join(tmp, "builtin")
+
+	createSkillDir(t, global, "my-skill", "my-skill", "global version")
+	createSkillDir(t, builtin, "my-skill", "my-skill", "builtin version")
+
+	sl := NewSkillsLoader(ws, global, builtin)
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 1)
+	assert.Equal(t, "global", skills[0].Source)
+	assert.Equal(t, "global version", skills[0].Description)
+}
+
+func TestListSkillsMetadataNameDedup(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+
+	// Different directory names but same metadata name
+	createSkillDir(t, filepath.Join(ws, "skills"), "dir-a", "shared-name", "workspace version")
+	createSkillDir(t, global, "dir-b", "shared-name", "global version")
+
+	sl := NewSkillsLoader(ws, global, "")
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 1)
+	assert.Equal(t, "shared-name", skills[0].Name)
+	assert.Equal(t, "workspace", skills[0].Source)
+}
+
+func TestListSkillsMultipleDistinctSkills(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+	builtin := filepath.Join(tmp, "builtin")
+
+	createSkillDir(t, filepath.Join(ws, "skills"), "skill-a", "skill-a", "desc a")
+	createSkillDir(t, global, "skill-b", "skill-b", "desc b")
+	createSkillDir(t, builtin, "skill-c", "skill-c", "desc c")
+
+	sl := NewSkillsLoader(ws, global, builtin)
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 3)
+	names := map[string]string{}
+	for _, s := range skills {
+		names[s.Name] = s.Source
+	}
+	assert.Equal(t, "workspace", names["skill-a"])
+	assert.Equal(t, "global", names["skill-b"])
+	assert.Equal(t, "builtin", names["skill-c"])
+}
+
+func TestListSkillsInvalidSkillSkipped(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+
+	// Invalid name (underscore)
+	createSkillDir(t, filepath.Join(ws, "skills"), "bad_skill", "bad_skill", "desc")
+	// Valid skill
+	createSkillDir(t, global, "good-skill", "good-skill", "desc")
+
+	sl := NewSkillsLoader(ws, global, "")
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 1)
+	assert.Equal(t, "good-skill", skills[0].Name)
+}
+
+func TestListSkillsEmptyAndNonexistentDirs(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	emptyDir := filepath.Join(tmp, "empty")
+	require.NoError(t, os.MkdirAll(emptyDir, 0o755))
+
+	sl := NewSkillsLoader(ws, emptyDir, filepath.Join(tmp, "nonexistent"))
+	skills := sl.ListSkills()
+
+	assert.Empty(t, skills)
+}
+
+func TestListSkillsDirWithoutSkillMD(t *testing.T) {
+	tmp := t.TempDir()
+	ws := filepath.Join(tmp, "workspace")
+	global := filepath.Join(tmp, "global")
+
+	// Directory exists but has no SKILL.md
+	require.NoError(t, os.MkdirAll(filepath.Join(global, "no-skillmd"), 0o755))
+	// Valid skill alongside
+	createSkillDir(t, global, "real-skill", "real-skill", "desc")
+
+	sl := NewSkillsLoader(ws, global, "")
+	skills := sl.ListSkills()
+
+	assert.Len(t, skills, 1)
+	assert.Equal(t, "real-skill", skills[0].Name)
+}
+
 func TestStripFrontmatter(t *testing.T) {
 	sl := &SkillsLoader{}

--- a/pkg/tools/edit.go
+++ b/pkg/tools/edit.go
@ -2,24 +2,27 @@ package tools

 import (
 	"context"
+	"errors"
 	"fmt"
-	"os"
+	"io/fs"
 	"strings"
 )

 // EditFileTool edits a file by replacing old_text with new_text.
 // The old_text must exist exactly in the file.
 type EditFileTool struct {
-	allowedDir string
-	restrict   bool
+	fs fileSystem
 }

 // NewEditFileTool creates a new EditFileTool with optional directory restriction.
-func NewEditFileTool(allowedDir string, restrict bool) *EditFileTool {
-	return &EditFileTool{
-		allowedDir: allowedDir,
-		restrict:   restrict,
+func NewEditFileTool(workspace string, restrict bool) *EditFileTool {
+	var fs fileSystem
+	if restrict {
+		fs = &sandboxFs{workspace: workspace}
+	} else {
+		fs = &hostFs{}
 	}
+	return &EditFileTool{fs: fs}
 }

 func (t *EditFileTool) Name() string {
@ -67,49 +70,24 @@ func (t *EditFileTool) Execute(ctx context.Context, args map[string]any) *ToolRe
 		return ErrorResult("new_text is required")
 	}

-	resolvedPath, err := validatePath(path, t.allowedDir, t.restrict)
-	if err != nil {
+	if err := editFile(t.fs, path, oldText, newText); err != nil {
 		return ErrorResult(err.Error())
 	}
-
-	if _, err = os.Stat(resolvedPath); os.IsNotExist(err) {
-		return ErrorResult(fmt.Sprintf("file not found: %s", path))
-	}
-
-	content, err := os.ReadFile(resolvedPath)
-	if err != nil {
-		return ErrorResult(fmt.Sprintf("failed to read file: %v", err))
-	}
-
-	contentStr := string(content)
-
-	if !strings.Contains(contentStr, oldText) {
-		return ErrorResult("old_text not found in file. Make sure it matches exactly")
-	}
-
-	count := strings.Count(contentStr, oldText)
-	if count > 1 {
-		return ErrorResult(
-			fmt.Sprintf("old_text appears %d times. Please provide more context to make it unique", count),
-		)
-	}
-
-	newContent := strings.Replace(contentStr, oldText, newText, 1)
-
-	if err := os.WriteFile(resolvedPath, []byte(newContent), 0o644); err != nil {
-		return ErrorResult(fmt.Sprintf("failed to write file: %v", err))
-	}
-
 	return SilentResult(fmt.Sprintf("File edited: %s", path))
 }

 type AppendFileTool struct {
-	workspace string
-	restrict  bool
+	fs fileSystem
 }

 func NewAppendFileTool(workspace string, restrict bool) *AppendFileTool {
-	return &AppendFileTool{workspace: workspace, restrict: restrict}
+	var fs fileSystem
+	if restrict {
+		fs = &sandboxFs{workspace: workspace}
+	} else {
+		fs = &hostFs{}
+	}
+	return &AppendFileTool{fs: fs}
 }

 func (t *AppendFileTool) Name() string {
@ -148,20 +126,52 @@ func (t *AppendFileTool) Execute(ctx context.Context, args map[string]any) *Tool
 		return ErrorResult("content is required")
 	}

-	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
-	if err != nil {
+	if err := appendFile(t.fs, path, content); err != nil {
 		return ErrorResult(err.Error())
 	}
-
-	f, err := os.OpenFile(resolvedPath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
-	if err != nil {
-		return ErrorResult(fmt.Sprintf("failed to open file: %v", err))
-	}
-	defer f.Close()
-
-	if _, err := f.WriteString(content); err != nil {
-		return ErrorResult(fmt.Sprintf("failed to append to file: %v", err))
-	}
-
 	return SilentResult(fmt.Sprintf("Appended to %s", path))
 }
+
+// editFile reads the file via sysFs, performs the replacement, and writes back.
+// It uses a fileSystem interface, allowing the same logic for both restricted and unrestricted modes.
+func editFile(sysFs fileSystem, path, oldText, newText string) error {
+	content, err := sysFs.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	newContent, err := replaceEditContent(content, oldText, newText)
+	if err != nil {
+		return err
+	}
+
+	return sysFs.WriteFile(path, newContent)
+}
+
+// appendFile reads the existing content (if any) via sysFs, appends new content, and writes back.
+func appendFile(sysFs fileSystem, path, appendContent string) error {
+	content, err := sysFs.ReadFile(path)
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return err
+	}
+
+	newContent := append(content, []byte(appendContent)...)
+	return sysFs.WriteFile(path, newContent)
+}
+
+// replaceEditContent handles the core logic of finding and replacing a single occurrence of oldText.
+func replaceEditContent(content []byte, oldText, newText string) ([]byte, error) {
+	contentStr := string(content)
+
+	if !strings.Contains(contentStr, oldText) {
+		return nil, fmt.Errorf("old_text not found in file. Make sure it matches exactly")
+	}
+
+	count := strings.Count(contentStr, oldText)
+	if count > 1 {
+		return nil, fmt.Errorf("old_text appears %d times. Please provide more context to make it unique", count)
+	}
+
+	newContent := strings.Replace(contentStr, oldText, newText, 1)
+	return []byte(newContent), nil
+}
--- a/pkg/tools/edit_test.go
+++ b/pkg/tools/edit_test.go
@ -6,6 +6,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )

 // TestEditTool_EditFile_Success verifies successful file editing
@ -151,14 +153,18 @@ func TestEditTool_EditFile_OutsideAllowedDir(t *testing.T) {
 	result := tool.Execute(ctx, args)

 	// Should return error result
-	if !result.IsError {
-		t.Errorf("Expected error when path is outside allowed directory")
-	}
+	assert.True(t, result.IsError, "Expected error when path is outside allowed directory")

 	// Should mention outside allowed directory
-	if !strings.Contains(result.ForLLM, "outside") && !strings.Contains(result.ForUser, "outside") {
-		t.Errorf("Expected 'outside allowed' message, got ForLLM: %s", result.ForLLM)
-	}
+	// Note: ErrorResult only sets ForLLM by default, so ForUser might be empty.
+	// We check ForLLM as it's the primary error channel.
+	assert.True(
+		t,
+		strings.Contains(result.ForLLM, "outside") || strings.Contains(result.ForLLM, "access denied") ||
+			strings.Contains(result.ForLLM, "escapes"),
+		"Expected 'outside allowed' or 'access denied' message, got ForLLM: %s",
+		result.ForLLM,
+	)
 }

 // TestEditTool_EditFile_MissingPath verifies error handling for missing path
@ -287,3 +293,145 @@ func TestEditTool_AppendFile_MissingContent(t *testing.T) {
 		t.Errorf("Expected error when content is missing")
 	}
 }
+
+// TestReplaceEditContent verifies the helper function replaceEditContent
+func TestReplaceEditContent(t *testing.T) {
+	tests := []struct {
+		name        string
+		content     []byte
+		oldText     string
+		newText     string
+		expected    []byte
+		expectError bool
+	}{
+		{
+			name:        "successful replacement",
+			content:     []byte("hello world"),
+			oldText:     "world",
+			newText:     "universe",
+			expected:    []byte("hello universe"),
+			expectError: false,
+		},
+		{
+			name:        "old text not found",
+			content:     []byte("hello world"),
+			oldText:     "golang",
+			newText:     "rust",
+			expected:    nil,
+			expectError: true,
+		},
+		{
+			name:        "multiple matches found",
+			content:     []byte("test text test"),
+			oldText:     "test",
+			newText:     "done",
+			expected:    nil,
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := replaceEditContent(tt.content, tt.oldText, tt.newText)
+			if tt.expectError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, result)
+			}
+		})
+	}
+}
+
+// TestAppendFileTool_AppendToNonExistent_Restricted verifies that AppendFileTool in restricted mode
+// can append to a file that does not yet exist — it should silently create the file.
+// This exercises the errors.Is(err, fs.ErrNotExist) path in appendFileWithRW + rootRW.
+func TestAppendFileTool_AppendToNonExistent_Restricted(t *testing.T) {
+	workspace := t.TempDir()
+	tool := NewAppendFileTool(workspace, true)
+	ctx := context.Background()
+
+	args := map[string]any{
+		"path":    "brand_new_file.txt",
+		"content": "first content",
+	}
+
+	result := tool.Execute(ctx, args)
+	assert.False(
+		t,
+		result.IsError,
+		"Expected success when appending to non-existent file in restricted mode, got: %s",
+		result.ForLLM,
+	)
+
+	// Verify the file was created with correct content
+	data, err := os.ReadFile(filepath.Join(workspace, "brand_new_file.txt"))
+	assert.NoError(t, err)
+	assert.Equal(t, "first content", string(data))
+}
+
+// TestAppendFileTool_Restricted_Success verifies that AppendFileTool in restricted mode
+// correctly appends to an existing file within the sandbox.
+func TestAppendFileTool_Restricted_Success(t *testing.T) {
+	workspace := t.TempDir()
+	testFile := "existing.txt"
+	err := os.WriteFile(filepath.Join(workspace, testFile), []byte("initial"), 0o644)
+	assert.NoError(t, err)
+
+	tool := NewAppendFileTool(workspace, true)
+	ctx := context.Background()
+	args := map[string]any{
+		"path":    testFile,
+		"content": " appended",
+	}
+
+	result := tool.Execute(ctx, args)
+	assert.False(t, result.IsError, "Expected success, got: %s", result.ForLLM)
+	assert.True(t, result.Silent)
+
+	data, err := os.ReadFile(filepath.Join(workspace, testFile))
+	assert.NoError(t, err)
+	assert.Equal(t, "initial appended", string(data))
+}
+
+// TestEditFileTool_Restricted_InPlaceEdit verifies that EditFileTool in restricted mode
+// correctly edits a file using the single-open editFileInRoot path.
+func TestEditFileTool_Restricted_InPlaceEdit(t *testing.T) {
+	workspace := t.TempDir()
+	testFile := "edit_target.txt"
+	err := os.WriteFile(filepath.Join(workspace, testFile), []byte("Hello World"), 0o644)
+	assert.NoError(t, err)
+
+	tool := NewEditFileTool(workspace, true)
+	ctx := context.Background()
+	args := map[string]any{
+		"path":     testFile,
+		"old_text": "World",
+		"new_text": "Go",
+	}
+
+	result := tool.Execute(ctx, args)
+	assert.False(t, result.IsError, "Expected success, got: %s", result.ForLLM)
+	assert.True(t, result.Silent)
+
+	data, err := os.ReadFile(filepath.Join(workspace, testFile))
+	assert.NoError(t, err)
+	assert.Equal(t, "Hello Go", string(data))
+}
+
+// TestEditFileTool_Restricted_FileNotFound verifies that editFileInRoot returns a proper
+// error message when the target file does not exist.
+func TestEditFileTool_Restricted_FileNotFound(t *testing.T) {
+	workspace := t.TempDir()
+	tool := NewEditFileTool(workspace, true)
+	ctx := context.Background()
+	args := map[string]any{
+		"path":     "no_such_file.txt",
+		"old_text": "old",
+		"new_text": "new",
+	}
+
+	result := tool.Execute(ctx, args)
+	assert.True(t, result.IsError)
+	assert.Contains(t, result.ForLLM, "not found")
+}
--- a/pkg/tools/filesystem.go
+++ b/pkg/tools/filesystem.go
@ -3,15 +3,17 @@ package tools
 import (
 	"context"
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 )

 // validatePath ensures the given path is within the workspace if restrict is true.
 func validatePath(path, workspace string, restrict bool) (string, error) {
 	if workspace == "" {
-		return path, nil
+		return path, fmt.Errorf("workspace is not defined")
 	}

 	absWorkspace, err := filepath.Abs(workspace)
@ -76,16 +78,21 @@ func resolveExistingAncestor(path string) (string, error) {

 func isWithinWorkspace(candidate, workspace string) bool {
 	rel, err := filepath.Rel(filepath.Clean(workspace), filepath.Clean(candidate))
-	return err == nil && rel != ".." && !strings.HasPrefix(rel, ".."+string(os.PathSeparator))
+	return err == nil && filepath.IsLocal(rel)
 }

 type ReadFileTool struct {
-	workspace string
-	restrict  bool
+	fs fileSystem
 }

 func NewReadFileTool(workspace string, restrict bool) *ReadFileTool {
-	return &ReadFileTool{workspace: workspace, restrict: restrict}
+	var fs fileSystem
+	if restrict {
+		fs = &sandboxFs{workspace: workspace}
+	} else {
+		fs = &hostFs{}
+	}
+	return &ReadFileTool{fs: fs}
 }

 func (t *ReadFileTool) Name() string {
@ -115,26 +122,25 @@ func (t *ReadFileTool) Execute(ctx context.Context, args map[string]any) *ToolRe
 		return ErrorResult("path is required")
 	}

-	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
+	content, err := t.fs.ReadFile(path)
 	if err != nil {
 		return ErrorResult(err.Error())
 	}
-
-	content, err := os.ReadFile(resolvedPath)
-	if err != nil {
-		return ErrorResult(fmt.Sprintf("failed to read file: %v", err))
-	}
-
 	return NewToolResult(string(content))
 }

 type WriteFileTool struct {
-	workspace string
-	restrict  bool
+	fs fileSystem
 }

 func NewWriteFileTool(workspace string, restrict bool) *WriteFileTool {
-	return &WriteFileTool{workspace: workspace, restrict: restrict}
+	var fs fileSystem
+	if restrict {
+		fs = &sandboxFs{workspace: workspace}
+	} else {
+		fs = &hostFs{}
+	}
+	return &WriteFileTool{fs: fs}
 }

 func (t *WriteFileTool) Name() string {
@ -173,30 +179,25 @@ func (t *WriteFileTool) Execute(ctx context.Context, args map[string]any) *ToolR
 		return ErrorResult("content is required")
 	}

-	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
-	if err != nil {
+	if err := t.fs.WriteFile(path, []byte(content)); err != nil {
 		return ErrorResult(err.Error())
 	}

-	dir := filepath.Dir(resolvedPath)
-	if err := os.MkdirAll(dir, 0o755); err != nil {
-		return ErrorResult(fmt.Sprintf("failed to create directory: %v", err))
-	}
-
-	if err := os.WriteFile(resolvedPath, []byte(content), 0o644); err != nil {
-		return ErrorResult(fmt.Sprintf("failed to write file: %v", err))
-	}
-
 	return SilentResult(fmt.Sprintf("File written: %s", path))
 }

 type ListDirTool struct {
-	workspace string
-	restrict  bool
+	fs fileSystem
 }

 func NewListDirTool(workspace string, restrict bool) *ListDirTool {
-	return &ListDirTool{workspace: workspace, restrict: restrict}
+	var fs fileSystem
+	if restrict {
+		fs = &sandboxFs{workspace: workspace}
+	} else {
+		fs = &hostFs{}
+	}
+	return &ListDirTool{fs: fs}
 }

 func (t *ListDirTool) Name() string {
@ -226,24 +227,179 @@ func (t *ListDirTool) Execute(ctx context.Context, args map[string]any) *ToolRes
 		path = "."
 	}

-	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
-	if err != nil {
-		return ErrorResult(err.Error())
-	}
-
-	entries, err := os.ReadDir(resolvedPath)
+	entries, err := t.fs.ReadDir(path)
 	if err != nil {
 		return ErrorResult(fmt.Sprintf("failed to read directory: %v", err))
 	}
+	return formatDirEntries(entries)
+}

-	result := ""
+func formatDirEntries(entries []os.DirEntry) *ToolResult {
+	var result strings.Builder
 	for _, entry := range entries {
 		if entry.IsDir() {
-			result += "DIR:  " + entry.Name() + "\n"
+			result.WriteString("DIR:  " + entry.Name() + "\n")
 		} else {
-			result += "FILE: " + entry.Name() + "\n"
+			result.WriteString("FILE: " + entry.Name() + "\n")
+		}
+	}
+	return NewToolResult(result.String())
+}
+
+// fileSystem abstracts reading, writing, and listing files, allowing both
+// unrestricted (host filesystem) and sandbox (os.Root) implementations to share the same polymorphic interface.
+type fileSystem interface {
+	ReadFile(path string) ([]byte, error)
+	WriteFile(path string, data []byte) error
+	ReadDir(path string) ([]os.DirEntry, error)
+}
+
+// hostFs is an unrestricted fileReadWriter that operates directly on the host filesystem.
+type hostFs struct{}
+
+func (h *hostFs) ReadFile(path string) ([]byte, error) {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, fmt.Errorf("failed to read file: file not found: %w", err)
+		}
+		if os.IsPermission(err) {
+			return nil, fmt.Errorf("failed to read file: access denied: %w", err)
+		}
+		return nil, fmt.Errorf("failed to read file: %w", err)
+	}
+	return content, nil
+}
+
+func (h *hostFs) ReadDir(path string) ([]os.DirEntry, error) {
+	return os.ReadDir(path)
+}
+
+func (h *hostFs) WriteFile(path string, data []byte) error {
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return fmt.Errorf("failed to create parent directories: %w", err)
+	}
+
+	// We use a "write-then-rename" pattern here to ensure an atomic write.
+	// This prevents the target file from being left in a truncated or partial state
+	// if the operation is interrupted, as the rename operation is atomic on Linux.
+	tmpPath := fmt.Sprintf("%s.%d.tmp", path, time.Now().UnixNano())
+	if err := os.WriteFile(tmpPath, data, 0o644); err != nil {
+		os.Remove(tmpPath) // Ensure cleanup of partial/empty temp file
+		return fmt.Errorf("failed to write temp file: %w", err)
+	}
+
+	if err := os.Rename(tmpPath, path); err != nil {
+		os.Remove(tmpPath)
+		return fmt.Errorf("failed to replace original file: %w", err)
+	}
+	return nil
+}
+
+// sandboxFs is a sandboxed fileSystem that operates within a strictly defined workspace using os.Root.
+type sandboxFs struct {
+	workspace string
+}
+
+func (r *sandboxFs) execute(path string, fn func(root *os.Root, relPath string) error) error {
+	if r.workspace == "" {
+		return fmt.Errorf("workspace is not defined")
+	}
+
+	root, err := os.OpenRoot(r.workspace)
+	if err != nil {
+		return fmt.Errorf("failed to open workspace: %w", err)
+	}
+	defer root.Close()
+
+	relPath, err := getSafeRelPath(r.workspace, path)
+	if err != nil {
+		return err
+	}
+
+	return fn(root, relPath)
+}
+
+func (r *sandboxFs) ReadFile(path string) ([]byte, error) {
+	var content []byte
+	err := r.execute(path, func(root *os.Root, relPath string) error {
+		fileContent, err := root.ReadFile(relPath)
+		if err != nil {
+			if os.IsNotExist(err) {
+				return fmt.Errorf("failed to read file: file not found: %w", err)
+			}
+			// os.Root returns "escapes from parent" for paths outside the root
+			if os.IsPermission(err) || strings.Contains(err.Error(), "escapes from parent") ||
+				strings.Contains(err.Error(), "permission denied") {
+				return fmt.Errorf("failed to read file: access denied: %w", err)
+			}
+			return fmt.Errorf("failed to read file: %w", err)
+		}
+		content = fileContent
+		return nil
+	})
+	return content, err
+}
+
+func (r *sandboxFs) WriteFile(path string, data []byte) error {
+	return r.execute(path, func(root *os.Root, relPath string) error {
+		dir := filepath.Dir(relPath)
+		if dir != "." && dir != "/" {
+			if err := root.MkdirAll(dir, 0o755); err != nil {
+				return fmt.Errorf("failed to create parent directories: %w", err)
+			}
+		}
+
+		// We use a "write-then-rename" pattern here to ensure an atomic write.
+		// This prevents the target file from being left in a truncated or partial state
+		// if the operation is interrupted, as the rename operation is atomic on Linux.
+		tmpRelPath := fmt.Sprintf("%s.%d.tmp", relPath, time.Now().UnixNano())
+
+		if err := root.WriteFile(tmpRelPath, data, 0o644); err != nil {
+			root.Remove(tmpRelPath) // Ensure cleanup of partial/empty temp file
+			return fmt.Errorf("failed to write to temp file: %w", err)
+		}
+
+		if err := root.Rename(tmpRelPath, relPath); err != nil {
+			root.Remove(tmpRelPath)
+			return fmt.Errorf("failed to rename temp file over target: %w", err)
+		}
+		return nil
+	})
+}
+
+func (r *sandboxFs) ReadDir(path string) ([]os.DirEntry, error) {
+	var entries []os.DirEntry
+	err := r.execute(path, func(root *os.Root, relPath string) error {
+		dirEntries, err := fs.ReadDir(root.FS(), relPath)
+		if err != nil {
+			return err
+		}
+		entries = dirEntries
+		return nil
+	})
+	return entries, err
+}
+
+// Helper to get a safe relative path for os.Root usage
+func getSafeRelPath(workspace, path string) (string, error) {
+	if workspace == "" {
+		return "", fmt.Errorf("workspace is not defined")
+	}
+
+	rel := filepath.Clean(path)
+	if filepath.IsAbs(rel) {
+		var err error
+		rel, err = filepath.Rel(workspace, rel)
+		if err != nil {
+			return "", fmt.Errorf("failed to calculate relative path: %w", err)
 		}
 	}

-	return NewToolResult(result)
+	if !filepath.IsLocal(rel) {
+		return "", fmt.Errorf("path escapes workspace: %s", path)
+	}
+
+	return rel, nil
 }
--- a/pkg/tools/filesystem_test.go
+++ b/pkg/tools/filesystem_test.go
@ -2,10 +2,13 @@ package tools

 import (
 	"context"
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )

 // TestFilesystemTool_ReadFile_Success verifies successful file reading
@ -14,7 +17,7 @@ func TestFilesystemTool_ReadFile_Success(t *testing.T) {
 	testFile := filepath.Join(tmpDir, "test.txt")
 	os.WriteFile(testFile, []byte("test content"), 0o644)

-	tool := &ReadFileTool{}
+	tool := NewReadFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path": testFile,
@ -41,7 +44,7 @@ func TestFilesystemTool_ReadFile_Success(t *testing.T) {

 // TestFilesystemTool_ReadFile_NotFound verifies error handling for missing file
 func TestFilesystemTool_ReadFile_NotFound(t *testing.T) {
-	tool := &ReadFileTool{}
+	tool := NewReadFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path": "/nonexistent_file_12345.txt",
@ -84,7 +87,7 @@ func TestFilesystemTool_WriteFile_Success(t *testing.T) {
 	tmpDir := t.TempDir()
 	testFile := filepath.Join(tmpDir, "newfile.txt")

-	tool := &WriteFileTool{}
+	tool := NewWriteFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path":    testFile,
@ -123,7 +126,7 @@ func TestFilesystemTool_WriteFile_CreateDir(t *testing.T) {
 	tmpDir := t.TempDir()
 	testFile := filepath.Join(tmpDir, "subdir", "newfile.txt")

-	tool := &WriteFileTool{}
+	tool := NewWriteFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path":    testFile,
@ -149,7 +152,7 @@ func TestFilesystemTool_WriteFile_CreateDir(t *testing.T) {

 // TestFilesystemTool_WriteFile_MissingPath verifies error handling for missing path
 func TestFilesystemTool_WriteFile_MissingPath(t *testing.T) {
-	tool := &WriteFileTool{}
+	tool := NewWriteFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"content": "test",
@ -165,7 +168,7 @@ func TestFilesystemTool_WriteFile_MissingPath(t *testing.T) {

 // TestFilesystemTool_WriteFile_MissingContent verifies error handling for missing content
 func TestFilesystemTool_WriteFile_MissingContent(t *testing.T) {
-	tool := &WriteFileTool{}
+	tool := NewWriteFileTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path": "/tmp/test.txt",
@ -192,7 +195,7 @@ func TestFilesystemTool_ListDir_Success(t *testing.T) {
 	os.WriteFile(filepath.Join(tmpDir, "file2.txt"), []byte("content"), 0o644)
 	os.Mkdir(filepath.Join(tmpDir, "subdir"), 0o755)

-	tool := &ListDirTool{}
+	tool := NewListDirTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path": tmpDir,
@ -216,7 +219,7 @@ func TestFilesystemTool_ListDir_Success(t *testing.T) {

 // TestFilesystemTool_ListDir_NotFound verifies error handling for non-existent directory
 func TestFilesystemTool_ListDir_NotFound(t *testing.T) {
-	tool := &ListDirTool{}
+	tool := NewListDirTool("", false)
 	ctx := context.Background()
 	args := map[string]any{
 		"path": "/nonexistent_directory_12345",
@ -237,7 +240,7 @@ func TestFilesystemTool_ListDir_NotFound(t *testing.T) {

 // TestFilesystemTool_ListDir_DefaultPath verifies default to current directory
 func TestFilesystemTool_ListDir_DefaultPath(t *testing.T) {
-	tool := &ListDirTool{}
+	tool := NewListDirTool("", false)
 	ctx := context.Background()
 	args := map[string]any{}

@ -275,7 +278,211 @@ func TestFilesystemTool_ReadFile_RejectsSymlinkEscape(t *testing.T) {
 	if !result.IsError {
 		t.Fatalf("expected symlink escape to be blocked")
 	}
-	if !strings.Contains(result.ForLLM, "symlink resolves outside workspace") {
+	// os.Root might return different errors depending on platform/implementation
+	// but it definitely should error.
+	// Our wrapper returns "access denied or file not found"
+	if !strings.Contains(result.ForLLM, "access denied") && !strings.Contains(result.ForLLM, "file not found") &&
+		!strings.Contains(result.ForLLM, "no such file") {
 		t.Fatalf("expected symlink escape error, got: %s", result.ForLLM)
 	}
 }
+
+func TestFilesystemTool_EmptyWorkspace_AccessDenied(t *testing.T) {
+	tool := NewReadFileTool("", true) // restrict=true but workspace=""
+
+	// Try to read a sensitive file (simulated by a temp file outside workspace)
+	tmpDir := t.TempDir()
+	secretFile := filepath.Join(tmpDir, "shadow")
+	os.WriteFile(secretFile, []byte("secret data"), 0o600)
+
+	result := tool.Execute(context.Background(), map[string]any{
+		"path": secretFile,
+	})
+
+	// We EXPECT IsError=true (access blocked due to empty workspace)
+	assert.True(t, result.IsError, "Security Regression: Empty workspace allowed access! content: %s", result.ForLLM)
+
+	// Verify it failed for the right reason
+	assert.Contains(t, result.ForLLM, "workspace is not defined", "Expected 'workspace is not defined' error")
+}
+
+// TestRootMkdirAll verifies that root.MkdirAll (used by atomicWriteFileInRoot) handles all cases:
+// single dir, deeply nested dirs, already-existing dirs, and a file blocking a directory path.
+func TestRootMkdirAll(t *testing.T) {
+	workspace := t.TempDir()
+	root, err := os.OpenRoot(workspace)
+	if err != nil {
+		t.Fatalf("failed to open root: %v", err)
+	}
+	defer root.Close()
+
+	// Case 1: Single directory
+	err = root.MkdirAll("dir1", 0o755)
+	assert.NoError(t, err)
+	_, err = os.Stat(filepath.Join(workspace, "dir1"))
+	assert.NoError(t, err)
+
+	// Case 2: Deeply nested directory
+	err = root.MkdirAll("a/b/c/d", 0o755)
+	assert.NoError(t, err)
+	_, err = os.Stat(filepath.Join(workspace, "a/b/c/d"))
+	assert.NoError(t, err)
+
+	// Case 3: Already exists — must be idempotent
+	err = root.MkdirAll("a/b/c/d", 0o755)
+	assert.NoError(t, err)
+
+	// Case 4: A regular file blocks directory creation — must error
+	err = os.WriteFile(filepath.Join(workspace, "file_exists"), []byte("data"), 0o644)
+	assert.NoError(t, err)
+	err = root.MkdirAll("file_exists", 0o755)
+	assert.Error(t, err, "expected error when a file exists at the directory path")
+}
+
+func TestFilesystemTool_WriteFile_Restricted_CreateDir(t *testing.T) {
+	workspace := t.TempDir()
+	tool := NewWriteFileTool(workspace, true)
+	ctx := context.Background()
+
+	testFile := "deep/nested/path/to/file.txt"
+	content := "deep content"
+	args := map[string]any{
+		"path":    testFile,
+		"content": content,
+	}
+
+	result := tool.Execute(ctx, args)
+	assert.False(t, result.IsError, "Expected success, got: %s", result.ForLLM)
+
+	// Verify file content
+	actualPath := filepath.Join(workspace, testFile)
+	data, err := os.ReadFile(actualPath)
+	assert.NoError(t, err)
+	assert.Equal(t, content, string(data))
+}
+
+// TestHostRW_Read_PermissionDenied verifies that hostRW.Read surfaces access denied errors.
+func TestHostRW_Read_PermissionDenied(t *testing.T) {
+	if os.Getuid() == 0 {
+		t.Skip("skipping permission test: running as root")
+	}
+	tmpDir := t.TempDir()
+	protected := filepath.Join(tmpDir, "protected.txt")
+	err := os.WriteFile(protected, []byte("secret"), 0o000)
+	assert.NoError(t, err)
+	defer os.Chmod(protected, 0o644) // ensure cleanup
+
+	_, err = (&hostFs{}).ReadFile(protected)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "access denied")
+}
+
+// TestHostRW_Read_Directory verifies that hostRW.Read returns an error when given a directory path.
+func TestHostRW_Read_Directory(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	_, err := (&hostFs{}).ReadFile(tmpDir)
+	assert.Error(t, err, "expected error when reading a directory as a file")
+}
+
+// TestRootRW_Read_Directory verifies that rootRW.Read returns an error when given a directory.
+func TestRootRW_Read_Directory(t *testing.T) {
+	workspace := t.TempDir()
+	root, err := os.OpenRoot(workspace)
+	assert.NoError(t, err)
+	defer root.Close()
+
+	// Create a subdirectory
+	err = root.Mkdir("subdir", 0o755)
+	assert.NoError(t, err)
+
+	_, err = (&sandboxFs{workspace: workspace}).ReadFile("subdir")
+	assert.Error(t, err, "expected error when reading a directory as a file")
+}
+
+// TestHostRW_Write_ParentDirMissing verifies that hostRW.Write creates parent dirs automatically.
+func TestHostRW_Write_ParentDirMissing(t *testing.T) {
+	tmpDir := t.TempDir()
+	target := filepath.Join(tmpDir, "a", "b", "c", "file.txt")
+
+	err := (&hostFs{}).WriteFile(target, []byte("hello"))
+	assert.NoError(t, err)
+
+	data, err := os.ReadFile(target)
+	assert.NoError(t, err)
+	assert.Equal(t, "hello", string(data))
+}
+
+// TestRootRW_Write_ParentDirMissing verifies that rootRW.Write creates
+// nested parent directories automatically within the sandbox.
+func TestRootRW_Write_ParentDirMissing(t *testing.T) {
+	workspace := t.TempDir()
+
+	relPath := "x/y/z/file.txt"
+	err := (&sandboxFs{workspace: workspace}).WriteFile(relPath, []byte("nested"))
+	assert.NoError(t, err)
+
+	data, err := os.ReadFile(filepath.Join(workspace, relPath))
+	assert.NoError(t, err)
+	assert.Equal(t, "nested", string(data))
+}
+
+// TestHostRW_Write verifies the hostRW.Write helper function
+func TestHostRW_Write(t *testing.T) {
+	tmpDir := t.TempDir()
+	testFile := filepath.Join(tmpDir, "atomic_test.txt")
+	testData := []byte("atomic test content")
+
+	err := (&hostFs{}).WriteFile(testFile, testData)
+	assert.NoError(t, err)
+
+	content, err := os.ReadFile(testFile)
+	assert.NoError(t, err)
+	assert.Equal(t, testData, content)
+
+	// Verify it overwrites correctly
+	newData := []byte("new atomic content")
+	err = (&hostFs{}).WriteFile(testFile, newData)
+	assert.NoError(t, err)
+
+	content, err = os.ReadFile(testFile)
+	assert.NoError(t, err)
+	assert.Equal(t, newData, content)
+}
+
+// TestRootRW_Write verifies the rootRW.Write helper function
+func TestRootRW_Write(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	relPath := "atomic_root_test.txt"
+	testData := []byte("atomic root test content")
+
+	erw := &sandboxFs{workspace: tmpDir}
+	err := erw.WriteFile(relPath, testData)
+	assert.NoError(t, err)
+
+	root, err := os.OpenRoot(tmpDir)
+	assert.NoError(t, err)
+	defer root.Close()
+
+	f, err := root.Open(relPath)
+	assert.NoError(t, err)
+	defer f.Close()
+
+	content, err := io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.Equal(t, testData, content)
+
+	// Verify it overwrites correctly
+	newData := []byte("new root atomic content")
+	err = erw.WriteFile(relPath, newData)
+	assert.NoError(t, err)
+
+	f2, err := root.Open(relPath)
+	assert.NoError(t, err)
+	defer f2.Close()
+
+	content, err = io.ReadAll(f2)
+	assert.NoError(t, err)
+	assert.Equal(t, newData, content)
+}
--- a/pkg/tools/i2c.go
+++ b/pkg/tools/i2c.go
@ -117,13 +117,19 @@ func (t *I2CTool) detect() *ToolResult {
 	return SilentResult(fmt.Sprintf("Found %d I2C bus(es):\n%s", len(buses), string(result)))
 }

+// Helper functions for I2C operations (used by platform-specific implementations)
+
 // isValidBusID checks that a bus identifier is a simple number (prevents path injection)
+//
+//nolint:unused // Used by i2c_linux.go
 func isValidBusID(id string) bool {
 	matched, _ := regexp.MatchString(`^\d+$`, id)
 	return matched
 }

 // parseI2CAddress extracts and validates an I2C address from args
+//
+//nolint:unused // Used by i2c_linux.go
 func parseI2CAddress(args map[string]any) (int, *ToolResult) {
 	addrFloat, ok := args["address"].(float64)
 	if !ok {
@ -137,6 +143,8 @@ func parseI2CAddress(args map[string]any) (int, *ToolResult) {
 }

 // parseI2CBus extracts and validates an I2C bus from args
+//
+//nolint:unused // Used by i2c_linux.go
 func parseI2CBus(args map[string]any) (string, *ToolResult) {
 	bus, ok := args["bus"].(string)
 	if !ok || bus == "" {
--- a/pkg/tools/shell.go
+++ b/pkg/tools/shell.go
@ -81,6 +81,7 @@ func NewExecToolWithConfig(workingDir string, restrict bool, config *config.Conf
 		execConfig := config.Tools.Exec
 		enableDenyPatterns = execConfig.EnableDenyPatterns
 		if enableDenyPatterns {
+			denyPatterns = append(denyPatterns, defaultDenyPatterns...)
 			if len(execConfig.CustomDenyPatterns) > 0 {
 				fmt.Printf("Using custom deny patterns: %v\n", execConfig.CustomDenyPatterns)
 				for _, pattern := range execConfig.CustomDenyPatterns {
@ -91,8 +92,6 @@ func NewExecToolWithConfig(workingDir string, restrict bool, config *config.Conf
 					}
 					denyPatterns = append(denyPatterns, re)
 				}
-			} else {
-				denyPatterns = append(denyPatterns, defaultDenyPatterns...)
 			}
 		} else {
 			// If deny patterns are disabled, we won't add any patterns, allowing all commands.
--- a/pkg/tools/spi.go
+++ b/pkg/tools/spi.go
@ -119,7 +119,11 @@ func (t *SPITool) list() *ToolResult {
 	return SilentResult(fmt.Sprintf("Found %d SPI device(s):\n%s", len(devices), string(result)))
 }

+// Helper function for SPI operations (used by platform-specific implementations)
+
 // parseSPIArgs extracts and validates common SPI parameters
+//
+//nolint:unused // Used by spi_linux.go
 func parseSPIArgs(args map[string]any) (device string, speed uint32, mode uint8, bits uint8, errMsg string) {
 	dev, ok := args["device"].(string)
 	if !ok || dev == "" {