feat: message truncation

src/askui/chat/api/assistants/service.py

@@ -50,7 +50,11 @@ def retrieve(
     ) -> Assistant:
         try:
             assistant_path = self._get_assistant_path(assistant_id)
-            assistant = Assistant.model_validate_json(assistant_path.read_text())
+            content = assistant_path.read_text()
+            if not content.strip():
+                error_msg = f"Assistant {assistant_id} not found"
+                raise NotFoundError(error_msg)
+            assistant = Assistant.model_validate_json(content)
             if not (
                 assistant.workspace_id is None or assistant.workspace_id == workspace_id
             ):
@@ -59,6 +63,10 @@ def retrieve(
         except FileNotFoundError as e:
             error_msg = f"Assistant {assistant_id} not found"
             raise NotFoundError(error_msg) from e
+        except (ValueError, TypeError) as e:
+            # Handle JSON parsing errors
+            error_msg = f"Assistant {assistant_id} not found"
+            raise NotFoundError(error_msg) from e
         else:
             return assistant
 
@@ -76,6 +84,9 @@ def modify(
         params: AssistantModifyParams,
     ) -> Assistant:
         assistant = self.retrieve(workspace_id, assistant_id)
+        if assistant.workspace_id is None:
+            error_msg = f"Default assistant {assistant_id} cannot be modified"
+            raise ForbiddenError(error_msg)
         modified = assistant.modify(params)
         self._save(modified)
         return modified
@@ -91,10 +102,19 @@ def delete(
             if assistant.workspace_id is None and not force:
                 error_msg = f"Default assistant {assistant_id} cannot be deleted"
                 raise ForbiddenError(error_msg)
-            self._get_assistant_path(assistant_id).unlink()
+            try:
+                self._get_assistant_path(assistant_id).unlink()
+            except FileNotFoundError:
+                # File already deleted, that's fine
+                pass
         except FileNotFoundError as e:
             error_msg = f"Assistant {assistant_id} not found"
             raise NotFoundError(error_msg) from e
+        except NotFoundError:
+            # If force=True and assistant doesn't exist, just ignore
+            if not force:
+                raise
+            # For force=True, we can ignore the NotFoundError
 
     def _save(self, assistant: Assistant, new: bool = False) -> None:
         self._assistants_dir.mkdir(parents=True, exist_ok=True)

src/askui/chat/api/mcp_configs/service.py

@@ -109,6 +109,9 @@ def modify(
         params: McpConfigModifyParams,
     ) -> McpConfig:
         mcp_config = self.retrieve(workspace_id, mcp_config_id)
+        if mcp_config.workspace_id is None:
+            error_msg = f"Default MCP configuration {mcp_config_id} cannot be modified"
+            raise ForbiddenError(error_msg)
         modified = mcp_config.modify(params)
         self._save(modified)
         return modified
@@ -129,7 +132,11 @@ def delete(
             self._get_mcp_config_path(mcp_config_id).unlink()
         except FileNotFoundError as e:
             error_msg = f"MCP configuration {mcp_config_id} not found"
-            raise NotFoundError(error_msg) from e
+            if not force:
+                raise NotFoundError(error_msg) from e
+        except NotFoundError:
+            if not force:
+                raise
 
     def _save(self, mcp_config: McpConfig, new: bool = False) -> None:
         self._mcp_configs_dir.mkdir(parents=True, exist_ok=True)

src/askui/chat/api/messages/chat_history_manager.py

@@ -0,0 +1,91 @@
+from anthropic.types.beta import BetaTextBlockParam, BetaToolUnionParam
+
+from askui.chat.api.messages.models import Message, MessageCreateParams
+from askui.chat.api.messages.service import MessageService
+from askui.chat.api.messages.translator import MessageTranslator
+from askui.chat.api.models import ThreadId
+from askui.models.shared.agent_message_param import MessageParam
+from askui.models.shared.truncation_strategies import TruncationStrategyFactory
+
+
+class ChatHistoryManager:
+    """
+    Manages chat history by providing methods to retrieve and add messages.
+
+    This service encapsulates the interaction between MessageService and MessageTranslator
+    to provide a clean interface for managing chat history in the context of AI agents.
+    """
+
+    def __init__(
+        self,
+        message_service: MessageService,
+        message_translator: MessageTranslator,
+        truncation_strategy_factory: TruncationStrategyFactory,
+    ) -> None:
+        """
+        Initialize the chat history manager.
+
+        Args:
+            message_service (MessageService): Service for managing message persistence.
+            message_translator (MessageTranslator): Translator for converting between
+                message formats.
+            truncation_strategy_factory (TruncationStrategyFactory): Factory for creating truncation strategies.
+        """
+        self._message_service = message_service
+        self._message_translator = message_translator
+        self._message_content_translator = message_translator.content_translator
+        self._truncation_strategy_factory = truncation_strategy_factory
+
+    async def retrieve_message_params(
+        self,
+        thread_id: ThreadId,
+        model: str,
+        system: str | list[BetaTextBlockParam] | None,
+        tools: list[BetaToolUnionParam],
+    ) -> list[MessageParam]:
+        truncation_strategy = (
+            self._truncation_strategy_factory.create_truncation_strategy(
+                system=system,
+                tools=tools,
+                messages=[],
+                model=model,
+            )
+        )
+        for msg in self._message_service.iter(thread_id=thread_id):
+            anthropic_message = await self._message_translator.to_anthropic(msg)
+            truncation_strategy.append_message(anthropic_message)
+        return truncation_strategy.messages
+
+    async def append_message(
+        self,
+        thread_id: ThreadId,
+        assistant_id: str | None,
+        run_id: str,
+        message: MessageParam,
+    ) -> Message:
+        """
+        Add a message to the chat history and return both the created message and original message param.
+
+        This method creates a message in the database and returns both the created
+        message object and the original message parameter for further processing.
+
+        Args:
+            thread_id (ThreadId): The thread ID to add the message to.
+            assistant_id (str | None): The assistant ID if the message is from an assistant.
+            run_id (str): The run ID associated with this message.
+            message (MessageParam): The message to add.
+
+        Returns:
+            Message: The created message object
+        """
+        return self._message_service.create(
+            thread_id=thread_id,
+            params=MessageCreateParams(
+                assistant_id=assistant_id if message.role == "assistant" else None,
+                role=message.role,
+                content=await self._message_content_translator.from_anthropic(
+                    message.content
+                ),
+                run_id=run_id,
+            ),
+        )

src/askui/chat/api/messages/dependencies.py

@@ -5,8 +5,13 @@
 from askui.chat.api.dependencies import WorkspaceDirDep
 from askui.chat.api.files.dependencies import FileServiceDep
 from askui.chat.api.files.service import FileService
+from askui.chat.api.messages.chat_history_manager import ChatHistoryManager
 from askui.chat.api.messages.service import MessageService
 from askui.chat.api.messages.translator import MessageTranslator
+from askui.models.shared.truncation_strategies import (
+    SimpleTruncationStrategyFactory,
+    TruncationStrategyFactory,
+)
 
 
 def get_message_service(
@@ -26,3 +31,25 @@ def get_message_translator(
 
 
 MessageTranslatorDep = Depends(get_message_translator)
+
+
+def get_truncation_strategy_factory() -> TruncationStrategyFactory:
+    return SimpleTruncationStrategyFactory()
+
+
+TruncationStrategyFactoryDep = Depends(get_truncation_strategy_factory)
+
+
+def get_chat_history_manager(
+    message_service: MessageService = MessageServiceDep,
+    message_translator: MessageTranslator = MessageTranslatorDep,
+    truncation_strategy_factory: TruncationStrategyFactory = TruncationStrategyFactoryDep,
+) -> ChatHistoryManager:
+    return ChatHistoryManager(
+        message_service=message_service,
+        message_translator=message_translator,
+        truncation_strategy_factory=truncation_strategy_factory,
+    )
+
+
+ChatHistoryManagerDep = Depends(get_chat_history_manager)

src/askui/chat/api/messages/service.py

@@ -1,9 +1,12 @@
 from pathlib import Path
+from typing import Iterator
 
 from askui.chat.api.messages.models import Message, MessageCreateParams
 from askui.chat.api.models import MessageId, ThreadId
 from askui.utils.api_utils import (
+    LIST_LIMIT_DEFAULT,
     ConflictError,
+    ListOrder,
     ListQuery,
     ListResponse,
     NotFoundError,
@@ -40,6 +43,24 @@ def list_(self, thread_id: ThreadId, query: ListQuery) -> ListResponse[Message]:
         messages_dir = self.get_messages_dir(thread_id)
         return list_resources(messages_dir, query, Message)
 
+    def iter(
+        self,
+        thread_id: ThreadId,
+        order: ListOrder = "asc",
+        batch_size: int = LIST_LIMIT_DEFAULT,
+    ) -> Iterator[Message]:
+        has_more = True
+        last_id: str | None = None
+        while has_more:
+            list_messages_response = self.list_(
+                thread_id=thread_id,
+                query=ListQuery(limit=batch_size, order=order, after=last_id),
+            )
+            has_more = list_messages_response.has_more
+            last_id = list_messages_response.last_id
+            for msg in list_messages_response.data:
+                yield msg
+
     def retrieve(self, thread_id: ThreadId, message_id: MessageId) -> Message:
         try:
             message_file = self._get_message_path(thread_id, message_id)

src/askui/chat/api/runs/dependencies.py

@@ -7,27 +7,23 @@
 from askui.chat.api.dependencies import WorkspaceDirDep
 from askui.chat.api.mcp_clients.dependencies import McpClientManagerManagerDep
 from askui.chat.api.mcp_clients.manager import McpClientManagerManager
-from askui.chat.api.messages.dependencies import MessageServiceDep, MessageTranslatorDep
-from askui.chat.api.messages.service import MessageService
-from askui.chat.api.messages.translator import MessageTranslator
+from askui.chat.api.messages.chat_history_manager import ChatHistoryManager
+from askui.chat.api.messages.dependencies import ChatHistoryManagerDep
 
 from .service import RunService
 
 
 def get_runs_service(
     workspace_dir: Path = WorkspaceDirDep,
     assistant_service: AssistantService = AssistantServiceDep,
+    chat_history_manager: ChatHistoryManager = ChatHistoryManagerDep,
     mcp_client_manager_manager: McpClientManagerManager = McpClientManagerManagerDep,
-    message_service: MessageService = MessageServiceDep,
-    message_translator: MessageTranslator = MessageTranslatorDep,
 ) -> RunService:
-    """Get RunService instance."""
     return RunService(
         base_dir=workspace_dir,
         assistant_service=assistant_service,
         mcp_client_manager_manager=mcp_client_manager_manager,
-        message_service=message_service,
-        message_translator=message_translator,
+        chat_history_manager=chat_history_manager,
     )