feat: Implement translation prompt history injection for Chat/Mic/Speaker

- Added a history management system in model.py to store and retrieve recent messages from Chat, Mic, and Speaker.
- Updated controller.py to automatically add messages to the translation history after processing.
- Enhanced translation clients (OpenAI, Gemini, Groq, etc.) to accept and utilize context history for improved translation quality.
- Introduced YAML configuration options for enabling history injection and customizing its behavior across different translation models.
- Ensured that only original messages are stored in history to optimize token usage during translation.

src-python/controller.py

@@ -292,6 +292,8 @@ class Controller:
                                 "data": None
                             },
                         )
+                    else:
+                        pass
                 except Exception as e:
                     # VRAM不足エラーの検出
                     is_vram_error, error_message = model.detectVRAMError(e)
@@ -412,6 +414,8 @@ class Controller:
                     translation_text = f" ({'/'.join(translation)})" if translation else ""
                     model.logger.info(f"[SENT] {message}{translation_text}")
 
+            model.addTranslationHistory("mic", message)
+
     def speakerMessage(self, result:dict) -> None:
         message = result["text"]
         language = result["language"]
@@ -452,6 +456,8 @@ class Controller:
                                 "data": None
                             },
                         )
+                    else:
+                        pass
                 except Exception as e:
                     # VRAM不足エラーの検出
                     is_vram_error, error_message = model.detectVRAMError(e)
@@ -594,6 +600,8 @@ class Controller:
                     translation_text = f" ({'/'.join(translation)})" if translation else ""
                     model.logger.info(f"[RECEIVED] {message}{translation_text}")
 
+            model.addTranslationHistory("speaker", message)
+
     def chatMessage(self, data) -> dict:
         id = data["id"]
         message = data["message"]
@@ -625,6 +633,8 @@ class Controller:
                                 "data": None
                             },
                         )
+                    else:
+                        pass
                 except Exception as e:
                     # VRAM不足エラーの検出
                     is_vram_error, error_message = model.detectVRAMError(e)
@@ -744,6 +754,8 @@ class Controller:
                 translation_text = f" ({'/'.join(translation)})" if translation else ""
                 model.logger.info(f"[CHAT] {message}{translation_text}")
 
+        model.addTranslationHistory("chat", message)
+
         return {
                 "status":200,
                 "result":{

src-python/docs/details/translation_prompt_history.md

@@ -0,0 +1,186 @@
+# 翻訳プロンプトへの履歴注入（Chat/Mic/Speaker）
+
+LLM は直前までの会話文脈を理解して翻訳品質を向上させられます。そのため、システムプロンプトに最近の履歴（Chat/Mic/Speaker）を内包する機能を追加しました。大量のログでトークン消費が増えないよう、YAML 設定で取り込み範囲と上限を管理できます。
+
+## アーキテクチャ
+
+### 履歴管理（Model）
+
+**`model.py`** でChat/Mic/Speakerのメッセージ履歴を一元管理：
+
+```python
+# 履歴バッファ（最大50件）
+self.translation_history: list[dict] = []
+self.translation_history_max_items = 50
+
+# 履歴追加（オリジナルメッセージのみ、翻訳結果は保存しない）
+model.addTranslationHistory("chat", "こんにちは")
+model.addTranslationHistory("mic", "今日はいい天気")  
+model.addTranslationHistory("speaker", "Hello!")
+
+# 履歴取得
+history = model.getTranslationHistory(max_items=10)
+
+# 履歴クリア
+model.clearTranslationHistory()
+```
+
+### 自動注入（Model → Translator → 各LLMクライアント）
+
+- **`model.getTranslate()`** で履歴を取得し、`translator.translate(..., context_history=history)` に渡す。
+- **`Translator.translate()`** 側でエンジンごとの分岐直前に `setContextHistory()` を呼び、履歴をプロンプト組み立てに反映する。
+
+```python
+# model.getTranslate()
+history = self.getTranslationHistory()
+translation = self.translator.translate(
+  translator_name=translator_name,
+  weight_type=config.CTRANSLATE2_WEIGHT_TYPE,
+  source_language=source_language,
+  target_language=target_language,
+  target_country=target_country,
+  message=message,
+  context_history=history,
+)
+
+# Translator.translate() の一例（OpenAI）
+case "OpenAI_API":
+  if self.openai_client is None:
+    result = False
+  else:
+    if context_history:
+      self.openai_client.setContextHistory(context_history)
+    result = self.openai_client.translate(message, input_lang=source_language, output_lang=target_language)
+```
+
+### メッセージ処理（Controller）
+
+**`controller.py`** で各メッセージ処理完了後に履歴へ追加（翻訳の成否に関係なく、オリジナル文だけ保存）：
+
+- **Chat**: `chatMessage()` の末尾で `model.addTranslationHistory("chat", ...)`
+- **Mic**: `micMessage()` の末尾で `model.addTranslationHistory("mic", ...)`
+- **Speaker**: `speakerMessage()` の末尾で `model.addTranslationHistory("speaker", ...)`
+
+## 設定ファイル（例: OpenAI）
+
+`src-python/models/translation/translation_settings/prompt/translation_openai.yml`
+
+```yaml
+system_prompt: |
+  You are a helpful translation assistant.
+  Supported languages:
+  {supported_languages}
+
+  Translate the user provided text from {input_lang} to {output_lang}.
+  Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true               # 履歴をプロンプトへ注入するか
+  sources: [chat, mic, speaker]   # 取り込み対象の履歴種別
+  max_messages: 10                # 注入する履歴件数の上限（新しい順）
+  max_chars: 4000                 # 履歴整形後の最大文字数（超過時は先頭を切り捨て）
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"
+```
+
+- `system_prompt`: 従来どおり、`{supported_languages}`/`{input_lang}`/`{output_lang}` が利用可能。
+- `history.use_history`: 履歴注入を有効化します。
+- `history.sources`: 取り込み対象ソース。`chat`/`mic`/`speaker` から選択。
+- `history.max_messages`: 新しい順に N 件を取り込みます。
+- `history.max_chars`: 整形後の履歴文字列の最大長。上限を超えた場合は先頭側を切り捨て（新しい文脈を優先）。
+- `history.header_template`: 履歴ヘッダの整形テンプレート。`{max_messages}`/`{history}` が利用可能。
+- `history.item_template`: 各履歴アイテムの整形テンプレート。`{timestamp}`（HH:MM形式）/`{source}`/`{text}` が利用可能。
+
+## 実装（OpenAI クライアント）
+
+`src-python/models/translation/translation_openai.py`
+
+- `OpenAIClient.setContextHistory(history_items: list[dict])` を追加。
+  - `history_items` は以下のキーを含む辞書の配列：
+    - `source`: `"chat" | "mic" | "speaker"`
+    - `text`:   文字列
+    - `timestamp`: ISO形式の日時文字列（HH:MM形式にフォーマットされてプロンプトに挿入）
+- `translate()` 呼び出し時、YAML の `history` 設定に基づき、指定履歴をシステムプロンプト末尾へ整形して注入します。
+- 文字数上限は簡易的に `max_chars` で制御（トークンカウントは行わず、過剰消費抑制用の安全策）。
+
+## 使い方
+
+### 基本的な流れ
+
+1. **メッセージ発生時に履歴追加**（controller.py で自動実行）
+```python
+# Chat送信時（オリジナルメッセージのみ保存）
+model.addTranslationHistory("chat", user_message)
+
+# Mic入力時（音声認識結果のみ保存）
+model.addTranslationHistory("mic", transcribed_text)
+
+# Speaker受信時（受信したオリジナルメッセージのみ保存）
+model.addTranslationHistory("speaker", received_text)
+```
+
+2. **翻訳時に自動注入**（model.py で自動実行）
+```python
+# getTranslate() 内で自動的に履歴が各LLMクライアントへ注入される
+translation = model.getTranslate(translator_name, ...)
+```
+
+3. **設定の調整**（YAML編集）
+```yaml
+history:
+  use_history: true          # 有効/無効
+  sources: [chat, mic]       # chatとmicのみ使う場合
+  max_messages: 5            # 最新5件のみ
+  max_chars: 2000            # 2000文字まで
+```
+
+### 手動で履歴を操作（必要な場合のみ）
+
+```python
+# 履歴をクリア
+model.clearTranslationHistory()
+
+# 履歴を取得
+recent_history = model.getTranslationHistory(max_items=10)
+
+# 手動で追加
+model.addTranslationHistory("chat", "カスタムメッセージ")
+```
+
+## 連携方法（開発者向け）
+
+既存のcontroller/model統合により、**自動で動作**します：
+
+1. ユーザーがChat入力 → `controller.chatMessage()` → メッセージ処理完了後に `model.addTranslationHistory()` 呼び出し（翻訳の成功/失敗に関係なく）
+2. マイク音声 → `controller.micMessage()` → メッセージ処理完了後に `model.addTranslationHistory()` 呼び出し（翻訳の成功/失敗に関係なく）
+3. スピーカー受信 → `controller.speakerMessage()` → メッセージ処理完了後に `model.addTranslationHistory()` 呼び出し（翻訳の成功/失敗に関係なく）
+4. 翻訳実行 → `model.getTranslate()` → LLMクライアントへ履歴を自動注入 → `client.translate()` で履歴付きプロンプト生成
+
+**重要**: 履歴にはオリジナルメッセージのみが保存されます。翻訳結果は履歴に含まれません。これによりトークン消費を抑え、文脈として必要な情報のみを提供します。
+
+**追加実装は不要です。** YAML設定を変更するだけで履歴注入の有効/無効や範囲を制御できます。
+
+## 連携方法
+
+## 対応状況
+
+✅ **全LLMクライアントに展開済み**
+
+以下のすべてのクライアントで履歴注入機能が利用可能です：
+- OpenAI (`translation_openai.py` / `translation_openai.yml`)
+- Gemini (`translation_gemini.py` / `translation_gemini.yml`)
+- Groq (`translation_groq.py` / `translation_groq.yml`)
+- OpenRouter (`translation_openrouter.py` / `translation_openrouter.yml`)
+- LMStudio (`translation_lmstudio.py` / `translation_lmstudio.yml`)
+- Ollama (`translation_ollama.py` / `translation_ollama.yml`)
+- Plamo (`translation_plamo.py` / `translation_plamo.yml`)
+
+各クライアントで同一の設定形式とAPIインターフェースを使用します：
+- `setContextHistory(history_items: list[dict])` メソッド
+- YAML の `history` セクション
+
+## 今後の拡張案
+
+- 実トークン見積りに基づく切り詰め（tiktoken 等）
+- 要約モデルを使った古い履歴の縮約

src-python/model.py

@@ -117,6 +117,8 @@ class Model:
         self.previous_receive_message = ""
         self.translator = Translator()
         self.keyword_processor = KeywordProcessor()
+        self.translation_history: list[dict] = []
+        self.translation_history_max_items = 20
         overlay_small_log_settings = copy.deepcopy(config.OVERLAY_SMALL_LOG_SETTINGS)
         overlay_large_log_settings = copy.deepcopy(config.OVERLAY_LARGE_LOG_SETTINGS)
         overlay_large_log_settings["ui_scaling"] = overlay_large_log_settings["ui_scaling"] * 0.25
@@ -378,16 +380,62 @@ class Model:
 
         return compatible_engines
 
+    def addTranslationHistory(self, source: str, text: str) -> None:
+        """Add a message to translation context history.
+        
+        Args:
+            source: "chat" | "mic" | "speaker"
+            text: message content
+        """
+        self.ensure_initialized()
+        if not text or not text.strip():
+            return
+        
+        history_item = {
+            "source": source,
+            "text": text.strip(),
+            "timestamp": datetime.now().isoformat(),
+        }
+        self.translation_history.append(history_item)
+        
+        # 最大件数を超えた場合は古いものを削除
+        if len(self.translation_history) > self.translation_history_max_items:
+            self.translation_history = self.translation_history[-self.translation_history_max_items:]
+    
+    def getTranslationHistory(self, max_items: int = None) -> list[dict]:
+        """Get recent translation context history.
+        
+        Args:
+            max_items: Maximum number of items to return (newest first)
+        
+        Returns:
+            List of history items
+        """
+        self.ensure_initialized()
+        if max_items is None or max_items <= 0:
+            return self.translation_history
+        return self.translation_history[-max_items:]
+    
+    def clearTranslationHistory(self) -> None:
+        """Clear all translation context history."""
+        self.ensure_initialized()
+        self.translation_history = []
+
     def getTranslate(self, translator_name, source_language, target_language, target_country, message):
         self.ensure_initialized()
         success_flag = False
+        
+        # Get context history for LLM-based translators
+        history = self.getTranslationHistory()
+        
         translation = self.translator.translate(
                         translator_name=translator_name,
                         weight_type=config.CTRANSLATE2_WEIGHT_TYPE,
                         source_language=source_language,
                         target_language=target_language,
                         target_country=target_country,
-                        message=message
+                        message=message,
+                        context_history=history
                 )
 
         # 翻訳失敗時のフェールセーフ処理

src-python/models/translation/translation_gemini.py

@@ -60,6 +60,16 @@ class GeminiClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_gemini.yml")
         self.supported_languages = list(translation_lang["Gemini_API"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.gemini_llm = None
 
@@ -91,6 +101,16 @@ class GeminiClient:
             api_key=self.api_key,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
@@ -98,6 +118,41 @@ class GeminiClient:
             output_lang=output_lang
         )
 
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text}

src-python/models/translation/translation_groq.py

@@ -76,6 +76,16 @@ class GroqClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_groq.yml")
         self.supported_languages = list(translation_lang["Groq_API"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.groq_llm = None
 
@@ -109,12 +119,58 @@ class GroqClient:
             streaming=False,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang,
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_lmstudio.py

@@ -53,6 +53,16 @@ class LMStudioClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_lmstudio.yml")
         self.supported_languages = list(translation_lang["LMStudio"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.openai_llm = None
 
@@ -86,12 +96,58 @@ class LMStudioClient:
             streaming=False,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang,
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_ollama.py

@@ -51,6 +51,16 @@ class OllamaClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_ollama.yml")
         self.supported_languages = list(translation_lang["Ollama"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.openai_llm = None
 
@@ -79,12 +89,58 @@ class OllamaClient:
             streaming=False,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang,
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_openai.py

@@ -72,6 +72,16 @@ class OpenAIClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_openai.yml")
         self.supported_languages = list(translation_lang["OpenAI_API"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.openai_llm = None
 
@@ -105,12 +115,62 @@ class OpenAIClient:
             streaming=False,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang,
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            # filter by source and take newest N
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            # format items
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            # truncate by char limit to mitigate token use
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            # assemble header and append to system prompt
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_openrouter.py

@@ -76,6 +76,16 @@ class OpenRouterClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_openrouter.yml")
         self.supported_languages = list(translation_lang["OpenRouter_API"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.openrouter_llm = None
 
@@ -109,12 +119,58 @@ class OpenRouterClient:
             streaming=False,
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang,
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_plamo.py

@@ -47,6 +47,16 @@ class PlamoClient:
         prompt_config = loadTranslatePromptConfig(root_path, "translation_plamo.yml")
         self.supported_languages = list(translation_lang["Plamo_API"]["source"].keys())
         self.prompt_template = prompt_config["system_prompt"]
+        # history config (optional)
+        self.history_cfg = prompt_config.get("history", {
+            "use_history": False,
+            "sources": [],
+            "max_messages": 0,
+            "max_chars": 0,
+            "header_template": "",
+            "item_template": "[{source}] {role}: {text}",
+        })
+        self._context_history: list[dict] = []
 
         self.plamo_llm = None
 
@@ -80,12 +90,58 @@ class PlamoClient:
             api_key=SecretStr(self.api_key),
         )
 
+    def setContextHistory(self, history_items: list[dict]) -> None:
+        """Set recent conversation history for prompt injection.
+
+        Each item should be a dict containing:
+        - source: "chat" | "mic" | "speaker"
+        - text: message string
+        - timestamp: ISO format datetime string
+        """
+        self._context_history = history_items or []
+
     def translate(self, text: str, input_lang: str, output_lang: str) -> str:
         system_prompt = self.prompt_template.format(
             supported_languages=self.supported_languages,
             input_lang=input_lang,
             output_lang=output_lang
         )
+
+        # Inject recent conversation history if enabled by YAML config
+        if self.history_cfg.get("use_history"):
+            allowed_sources = set(self.history_cfg.get("sources", []))
+            max_messages = int(self.history_cfg.get("max_messages", 0))
+            max_chars = int(self.history_cfg.get("max_chars", 0))
+            item_tmpl = self.history_cfg.get("item_template", "[{source}] {role}: {text}")
+            header_tmpl = self.history_cfg.get("header_template", "{history}")
+
+            filtered = [h for h in self._context_history if h.get("source") in allowed_sources]
+            recent = filtered[-max_messages:] if max_messages > 0 else filtered
+            formatted_items = []
+            for h in recent:
+                # Format timestamp as HH:MM to save tokens
+                timestamp_str = ''
+                if 'timestamp' in h:
+                    from datetime import datetime
+                    try:
+                        ts = datetime.fromisoformat(h['timestamp'])
+                        timestamp_str = ts.strftime('%H:%M')
+                    except:
+                        timestamp_str = ''
+                formatted_items.append(
+                    item_tmpl.format(
+                        timestamp=timestamp_str,
+                        source=h.get("source", ""),
+                        text=h.get("text", ""),
+                    )
+                )
+            history_blob = "\n".join(formatted_items).strip()
+            if max_chars and len(history_blob) > max_chars:
+                history_blob = history_blob[-max_chars:]
+            history_header = header_tmpl.format(max_messages=max_messages, history=history_blob)
+            if history_header:
+                system_prompt = f"{system_prompt}\n\n{history_header}"
+
         messages = [
             {"role": "system", "content": system_prompt},
             {"role": "user", "content": text},

src-python/models/translation/translation_settings/prompt/translation_gemini.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_groq.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_lmstudio.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_ollama.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_openai.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker] # 取り込み対象の履歴種別
+  max_messages: 5               # 注入する履歴件数の上限（新しい順）
+  max_chars: 4000               # 履歴整形後の最大文字数（超過時は先頭を切り捨て）
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_openrouter.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the user provided text from {input_lang} to {output_lang}.
   Return ONLY the translated text. Do not add quotes or extra commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_settings/prompt/translation_plamo.yml

@@ -5,3 +5,12 @@ system_prompt: |
 
   Translate the following text from {input_lang} to {output_lang}.
   output only the translated text without any additional commentary.
+history:
+  use_history: true
+  sources: [chat, mic, speaker]
+  max_messages: 5
+  max_chars: 4000
+  header_template: |
+    Conversation context (recent {max_messages} messages):
+    {history}
+  item_template: "[{timestamp}][{source}] {text}"

src-python/models/translation/translation_translator.py

@@ -425,9 +425,18 @@ class Translator:
                 target_language = translation_lang[translator_name]["target"][target_language]
         return source_language, target_language
 
-    def translate(self, translator_name: str, weight_type: str, source_language: str, target_language: str, target_country: str, message: str) -> Any:
+    def translate(self, translator_name: str, weight_type: str, source_language: str, target_language: str, target_country: str, message: str, context_history: Optional[list[dict]] = None) -> Any:
         """Translate `message` using the named translator backend.
 
+        Args:
+            translator_name: Name of the translator backend to use
+            weight_type: Model weight type for CTranslate2
+            source_language: Source language name
+            target_language: Target language name
+            target_country: Target country for locale-specific translations
+            message: Text to translate
+            context_history: Optional conversation context (Chat/Mic/Speaker messages)
+
         Returns translated string on success, or False on failure. When
         source_language == target_language the original message is returned.
         """
@@ -460,6 +469,8 @@ class Translator:
                     if self.plamo_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.plamo_client.setContextHistory(context_history)
                         result = self.plamo_client.translate(
                             message,
                             input_lang=source_language,
@@ -469,6 +480,8 @@ class Translator:
                     if self.gemini_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.gemini_client.setContextHistory(context_history)
                         result = self.gemini_client.translate(
                             message,
                             input_lang=source_language,
@@ -478,6 +491,8 @@ class Translator:
                     if self.openai_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.openai_client.setContextHistory(context_history)
                         result = self.openai_client.translate(
                             message,
                             input_lang=source_language,
@@ -487,6 +502,8 @@ class Translator:
                     if self.groq_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.groq_client.setContextHistory(context_history)
                         result = self.groq_client.translate(
                             message,
                             input_lang=source_language,
@@ -496,6 +513,8 @@ class Translator:
                     if self.openrouter_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.openrouter_client.setContextHistory(context_history)
                         result = self.openrouter_client.translate(
                             message,
                             input_lang=source_language,
@@ -505,6 +524,8 @@ class Translator:
                     if self.lmstudio_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.lmstudio_client.setContextHistory(context_history)
                         result = self.lmstudio_client.translate(
                             message,
                             input_lang=source_language,
@@ -514,6 +535,8 @@ class Translator:
                     if self.ollama_client is None:
                         result = False
                     else:
+                        if context_history:
+                            self.ollama_client.setContextHistory(context_history)
                         result = self.ollama_client.translate(
                             message,
                             input_lang=source_language,