feat: add banned words filter functionality

Add banned words configuration and filtering logic to block messages containing prohibited content. Includes:
- Config file support for banned_words list
- Engine methods to set and check banned words
- Case-insensitive matching during message processing
- Localization support for blocked message response
- Documentation updates in config example

generated by llmgit

Co-Authored-By: Claude <noreply@anthropic.com>

cmd/cc-connect/main.go

@@ -205,6 +205,11 @@ func main() {
 			return config.RemoveAlias(name)
 		})
 
+		// Wire banned words
+		if len(cfg.BannedWords) > 0 {
+			engine.SetBannedWords(cfg.BannedWords)
+		}
+
 		// Wire display truncation settings
 		{
 			dcfg := core.DisplayCfg{
@@ -569,6 +574,9 @@ func reloadConfig(configPath, projName string, engine *core.Engine) (*core.Confi
 		engine.AddAlias(a.Name, a.Command)
 	}
 
+	// Reload banned words
+	engine.SetBannedWords(cfg.BannedWords)
+
 	slog.Info("config reloaded", "project", projName)
 	return result, nil
 }

config.example.toml

@@ -132,6 +132,16 @@ level = "info" # debug, info, warn, error
 # directory (e.g. .claude/commands/*.md, .gemini/commands/*.md).
 # 此外，cc-connect 还会自动发现 Agent 的 commands 目录下的 .md 文件。
 
+# =============================================================================
+# Banned Words / 违禁词
+# =============================================================================
+#
+# Messages containing any of these words will be blocked and NOT forwarded to
+# the AI agent. Matching is case-insensitive.
+# 消息中包含以下任一违禁词时，将被拦截，不会转发给 AI Agent。匹配不区分大小写。
+
+# banned_words = ["违禁词1", "违禁词2", "secret_project"]
+
 # =============================================================================
 # Command Aliases / 命令别名
 # =============================================================================

config/config.go

@@ -16,15 +16,16 @@ var configMu sync.Mutex
 var ConfigPath string
 
 type Config struct {
-	DataDir  string          `toml:"data_dir"` // session store directory, default ~/.cc-connect
-	Projects []ProjectConfig `toml:"projects"`
-	Commands []CommandConfig  `toml:"commands"` // global custom slash commands
-	Aliases  []AliasConfig   `toml:"aliases"`   // global command aliases
-	Log      LogConfig       `toml:"log"`
-	Language string          `toml:"language"` // "en" or "zh", default is "en"
-	Speech   SpeechConfig    `toml:"speech"`
-	Display  DisplayConfig   `toml:"display"`
-	Quiet    *bool           `toml:"quiet,omitempty"` // global default for quiet mode; project-level overrides this
+	DataDir     string          `toml:"data_dir"` // session store directory, default ~/.cc-connect
+	Projects    []ProjectConfig `toml:"projects"`
+	Commands    []CommandConfig `toml:"commands"`     // global custom slash commands
+	Aliases     []AliasConfig   `toml:"aliases"`     // global command aliases
+	BannedWords []string        `toml:"banned_words"` // messages containing any of these words are blocked
+	Log         LogConfig       `toml:"log"`
+	Language    string          `toml:"language"` // "en" or "zh", default is "en"
+	Speech      SpeechConfig    `toml:"speech"`
+	Display     DisplayConfig   `toml:"display"`
+	Quiet       *bool           `toml:"quiet,omitempty"` // global default for quiet mode; project-level overrides this
 }
 
 // DisplayConfig controls how intermediate messages (thinking, tool output) are shown.

core/engine.go

@@ -139,6 +139,9 @@ type Engine struct {
 	aliasSaveAddFunc func(name, command string) error
 	aliasSaveDelFunc func(name string) error
 
+	bannedWords []string
+	bannedMu    sync.RWMutex
+
 	// Interactive agent session management
 	interactiveMu     sync.Mutex
 	interactiveStates map[string]*interactiveState // key = sessionKey
@@ -293,6 +296,17 @@ func (e *Engine) ClearAliases() {
 	e.aliases = make(map[string]string)
 }
 
+// SetBannedWords replaces the banned words list.
+func (e *Engine) SetBannedWords(words []string) {
+	e.bannedMu.Lock()
+	defer e.bannedMu.Unlock()
+	lower := make([]string, len(words))
+	for i, w := range words {
+		lower[i] = strings.ToLower(w)
+	}
+	e.bannedWords = lower
+}
+
 // RemoveCommand removes a custom command by name. Returns false if not found.
 func (e *Engine) RemoveCommand(name string) bool {
 	return e.commands.Remove(name)
@@ -402,6 +416,22 @@ func (e *Engine) Stop() error {
 	return nil
 }
 
+// matchBannedWord returns the first banned word found in content, or "".
+func (e *Engine) matchBannedWord(content string) string {
+	e.bannedMu.RLock()
+	defer e.bannedMu.RUnlock()
+	if len(e.bannedWords) == 0 {
+		return ""
+	}
+	lower := strings.ToLower(content)
+	for _, w := range e.bannedWords {
+		if strings.Contains(lower, w) {
+			return w
+		}
+	}
+	return ""
+}
+
 // resolveAlias checks if the content (or its first word) matches an alias and replaces it.
 func (e *Engine) resolveAlias(content string) string {
 	e.aliasMu.RLock()
@@ -443,6 +473,15 @@ func (e *Engine) handleMessage(p Platform, msg *Message) {
 	content = e.resolveAlias(content)
 	msg.Content = content
 
+	// Banned words check (skip for slash commands)
+	if !strings.HasPrefix(content, "/") {
+		if word := e.matchBannedWord(content); word != "" {
+			slog.Info("message blocked by banned word", "word", word, "user", msg.UserName)
+			e.reply(p, msg.ReplyCtx, e.i18n.T(MsgBannedWordBlocked))
+			return
+		}
+	}
+
 	if len(msg.Images) == 0 && strings.HasPrefix(content, "/") {
 		if e.handleCommand(p, msg, content) {
 			return

core/i18n.go

@@ -279,6 +279,8 @@ const (
 	MsgDeleteSuccess      MsgKey = "delete_success"
 	MsgDeleteActiveDenied MsgKey = "delete_active_denied"
 	MsgDeleteNotSupported MsgKey = "delete_not_supported"
+
+	MsgBannedWordBlocked MsgKey = "banned_word_blocked"
 )
 
 var messages = map[MsgKey]map[Language]string{
@@ -1520,6 +1522,13 @@ var messages = map[MsgKey]map[Language]string{
 		LangJapanese:           "❌ このエージェントはセッション削除をサポートしていません。",
 		LangSpanish:            "❌ Este agente no admite la eliminación de sesiones.",
 	},
+	MsgBannedWordBlocked: {
+		LangEnglish:            "⚠️ Your message was blocked because it contains a prohibited word.",
+		LangChinese:            "⚠️ 消息已被拦截，包含违禁词。",
+		LangTraditionalChinese: "⚠️ 訊息已被攔截，包含違禁詞。",
+		LangJapanese:           "⚠️ 禁止ワードが含まれているため、メッセージがブロックされました。",
+		LangSpanish:            "⚠️ Su mensaje fue bloqueado porque contiene una palabra prohibida.",
+	},
 }
 
 func (i *I18n) T(key MsgKey) string {