from __future__ import annotations from collections.abc import Callable from pathlib import PurePosixPath from typing import Annotated, Any, NotRequired from deepagents.middleware.skills import SKILLS_SYSTEM_PROMPT from langchain.agents import AgentState from langchain.agents.middleware import AgentMiddleware, ModelRequest, ModelResponse from langchain.tools.tool_node import ToolCallRequest from langchain_core.messages import SystemMessage, ToolMessage from langgraph.types import Command from src.agents.common import load_chat_model from src.agents.common.tools import get_buildin_tools, get_kb_based_tools from src.services.mcp_service import get_enabled_mcp_tools from src.services.skill_service import get_dependency_bundle_for_activated_skills, get_skill_prompt_metadata_by_slugs from src.utils.datetime_utils import shanghai_now from src.utils.logging_config import logger def _activated_skills_reducer(left: list[str] | None, right: list[str] | None) -> list[str]: merged: list[str] = [] seen: set[str] = set() for group in (left or [], right or []): for value in group: if not isinstance(value, str): continue slug = value.strip() if not slug or slug in seen: continue seen.add(slug) merged.append(slug) return merged class RuntimeConfigState(AgentState): activated_skills: NotRequired[Annotated[list[str], _activated_skills_reducer]] class RuntimeConfigMiddleware(AgentMiddleware): """运行时配置中间件 - 应用模型/工具/知识库/MCP/提示词配置 注意：所有可能用到的知识库工具必须在初始化时预加载并注册到 self.tools 运行时根据配置从 self.tools 中筛选工具，不能动态添加新工具 支持自定义上下文字段名称，以便在不同场景（如主智能体/子智能体）使用不同的配置字段 """ state_schema = RuntimeConfigState def __init__( self, *, extra_tools: list[Any] | None = None, model_context_name: str = "model", system_prompt_context_name: str = "system_prompt", tools_context_name: str = "tools", knowledges_context_name: str = "knowledges", mcps_context_name: str = "mcps", skills_context_name: str = "skills", enable_model_override: bool = True, enable_system_prompt_override: bool = True, enable_tools_override: bool = True, enable_skills_prompt_override: bool = True, skills_sources_for_prompt: list[str] | None = None, ): """初始化中间件 Args: extra_tools: 额外工具列表（从 create_agent 的 tools 参数传入） model_context_name: 上下文中的模型字段名称（默认 "model"） system_prompt_context_name: 上下文中的系统提示词字段名称（默认 "system_prompt"） tools_context_name: 上下文中的工具列表字段名称（默认 "tools"） knowledges_context_name: 上下文中的知识库列表字段名称（默认 "knowledges"） mcps_context_name: 上下文中的 MCP 服务器列表字段名称（默认 "mcps"） skills_context_name: 上下文中的 skills 列表字段名称（默认 "skills"） enable_model_override: 是否允许覆盖模型配置（默认 True） enable_system_prompt_override: 是否允许覆盖系统提示词（默认 True） enable_tools_override: 是否允许覆盖工具列表（默认 True） enable_skills_prompt_override: 是否启用 skills 提示段注入（默认 True） skills_sources_for_prompt: skills 来源路径（用于提示词展示，默认 ["/skills/"]） """ super().__init__() # 存储自定义字段名称 self.model_context_name = model_context_name self.system_prompt_context_name = system_prompt_context_name self.tools_context_name = tools_context_name self.knowledges_context_name = knowledges_context_name self.mcps_context_name = mcps_context_name self.skills_context_name = skills_context_name # 存储覆盖配置 self.enable_model_override = enable_model_override self.enable_system_prompt_override = enable_system_prompt_override self.enable_tools_override = enable_tools_override self.enable_skills_prompt_override = enable_skills_prompt_override self.skills_sources_for_prompt = skills_sources_for_prompt or ["/skills/"] self.tools: list[Any] = [] # 预加载工具列表（仅当启用工具覆盖时） if self.enable_tools_override: self.kb_tools = get_kb_based_tools() self.buildin_tools = get_buildin_tools() self.tools = self.kb_tools + self.buildin_tools + (extra_tools or []) elif extra_tools: logger.warning( "RuntimeConfigMiddleware: extra_tools 参数已提供，但 enable_tools_override=False，" "将忽略 extra_tools 并不会应用任何工具覆盖。" ) logger.debug( f"Initialized RuntimeConfigMiddleware with custom field names: model={model_context_name}, " f"system_prompt={system_prompt_context_name}, tools={tools_context_name}, " f"knowledges={knowledges_context_name}, mcps={mcps_context_name}, " f"skills={skills_context_name}" ) async def awrap_model_call( self, request: ModelRequest, handler: Callable[[ModelRequest], ModelResponse] ) -> ModelResponse: runtime_context = request.runtime.context overrides: dict[str, Any] = {} # 1. 模型覆盖（可选） if self.enable_model_override: model = load_chat_model(getattr(runtime_context, self.model_context_name, None)) overrides["model"] = model # 2. 工具覆盖（可选） if self.enable_tools_override: activated_skills = request.state.get("activated_skills", []) if request.state else [] if not isinstance(activated_skills, list): activated_skills = [] deps_bundle = get_dependency_bundle_for_activated_skills(activated_skills) enabled_tools = await self.get_tools_from_context( runtime_context, extra_tool_names=deps_bundle["tools"], extra_mcps=deps_bundle["mcps"], ) existing_tools = list(request.tools or []) enabled_tool_names = {t.name for t in enabled_tools} managed_tool_names = {t.name for t in self.tools} merged_tools = [] for t_bind in existing_tools: # (1) 已启用的工具保留 # (2) 非本中间件管理的工具保留 if t_bind.name in enabled_tool_names or t_bind.name not in managed_tool_names: merged_tools.append(t_bind) overrides["tools"] = merged_tools logger.debug(f"RuntimeConfigMiddleware selected tools: {[t.name for t in merged_tools]}") # 3. 系统提示词覆盖（可选） if self.enable_system_prompt_override: cur_datetime = f"当前时间：{shanghai_now().strftime('%Y-%m-%d %H:%M:%S')} UTC" system_prompt = getattr(runtime_context, self.system_prompt_context_name, "") or "" merged_system_prompt = f"{cur_datetime}\n\n{system_prompt}" configured_skills = getattr(runtime_context, self.skills_context_name, None) or [] if self.enable_skills_prompt_override and configured_skills: if self._supports_skill_prompt(request): skills_meta = get_skill_prompt_metadata_by_slugs(configured_skills) skills_section = self._build_skills_section(skills_meta) merged_system_prompt = f"{merged_system_prompt}\n\n{skills_section}" else: logger.warning( "RuntimeConfigMiddleware: skills configured but read_file unavailable, skip skills prompt" ) content_blocks = list(request.system_message.content_blocks) if request.system_message else [] new_content = content_blocks + [{"type": "text", "text": merged_system_prompt}] new_system_message = SystemMessage(content=new_content) overrides["system_message"] = new_system_message if overrides: request = request.override(**overrides) return await handler(request) async def get_tools_from_context( self, context, *, extra_tool_names: list[str] | None = None, extra_mcps: list[str] | None = None, ) -> list: """从上下文配置中获取工具列表""" selected_tools = [] selected_tool_names: set[str] = set() # 1. 基础工具 (从 context.tools 中筛选) tools = getattr(context, self.tools_context_name, None) or [] all_tool_names = [] for tool_name in tools: if isinstance(tool_name, str): all_tool_names.append(tool_name) for tool_name in extra_tool_names or []: if isinstance(tool_name, str): all_tool_names.append(tool_name) tools_map = {t.name: t for t in self.tools} for tool_name in all_tool_names: if tool_name in selected_tool_names: continue if tool_name in tools_map: selected_tools.append(tools_map[tool_name]) selected_tool_names.add(tool_name) continue logger.warning(f"RuntimeConfigMiddleware: tool dependency not found, skip: {tool_name}") # 2. 知识库工具 knowledges = getattr(context, self.knowledges_context_name, None) if knowledges: kb_tools = get_kb_based_tools(db_names=knowledges) selected_tools.extend(kb_tools) # 3. MCP 工具（使用统一入口，自动过滤 disabled_tools） mcps = getattr(context, self.mcps_context_name, None) or [] all_mcp_names: list[str] = [] for server_name in mcps: if isinstance(server_name, str): all_mcp_names.append(server_name) for server_name in extra_mcps or []: if isinstance(server_name, str): all_mcp_names.append(server_name) selected_mcp_servers: set[str] = set() for server_name in all_mcp_names: if server_name in selected_mcp_servers: continue selected_mcp_servers.add(server_name) try: mcp_tools = await get_enabled_mcp_tools(server_name) if not mcp_tools: logger.warning(f"RuntimeConfigMiddleware: mcp dependency unavailable, skip: {server_name}") selected_tools.extend(mcp_tools) except Exception as e: logger.warning(f"RuntimeConfigMiddleware: failed to load mcp dependency '{server_name}': {e}") return selected_tools async def awrap_tool_call( self, request: ToolCallRequest, handler: Callable[[ToolCallRequest], Any], ): result = await handler(request) if request.tool_call.get("name") != "read_file": return result args = request.tool_call.get("args") or {} file_path = args.get("file_path") if isinstance(args, dict) else None slug = self._extract_skill_slug_from_skill_md_path(file_path) if not slug: return result logger.debug(f"RuntimeConfigMiddleware: activated skill by read_file: {slug}") return self._merge_activated_skill_update(result, slug) def wrap_tool_call( self, request: ToolCallRequest, handler: Callable[[ToolCallRequest], Any], ): result = handler(request) if request.tool_call.get("name") != "read_file": return result args = request.tool_call.get("args") or {} file_path = args.get("file_path") if isinstance(args, dict) else None slug = self._extract_skill_slug_from_skill_md_path(file_path) if not slug: return result logger.debug(f"RuntimeConfigMiddleware: activated skill by read_file: {slug}") return self._merge_activated_skill_update(result, slug) def _extract_skill_slug_from_skill_md_path(self, file_path: Any) -> str | None: if not isinstance(file_path, str): return None raw = file_path.strip() if not raw: return None pure = PurePosixPath(raw if raw.startswith("/") else f"/{raw}") parts = [p for p in pure.parts if p not in ("/", "")] if len(parts) != 3: return None if parts[0] != "skills" or parts[2] != "SKILL.md": return None return parts[1] def _merge_activated_skill_update(self, result: Any, slug: str): if isinstance(result, Command): update = dict(result.update or {}) current = update.get("activated_skills") or [] update["activated_skills"] = _activated_skills_reducer(current, [slug]) return Command(graph=result.graph, update=update, resume=result.resume, goto=result.goto) if isinstance(result, ToolMessage): return Command(update={"messages": [result], "activated_skills": [slug]}) return result def _supports_skill_prompt(self, request: ModelRequest) -> bool: """仅当请求工具中包含 read_file 时，才注入 skills 指引。""" for tool in request.tools or []: if getattr(tool, "name", None) == "read_file": return True return False def _format_skills_locations(self, sources: list[str]) -> str: locations = [] for i, source_path in enumerate(sources): name = PurePosixPath(source_path.rstrip("/")).name.capitalize() suffix = " (higher priority)" if i == len(sources) - 1 else "" locations.append(f"**{name} Skills**: `{source_path}`{suffix}") return "\n".join(locations) def _format_skills_list(self, skills_meta: list[dict[str, str]]) -> str: if not skills_meta: return f"(No skills available yet. You can create skills in {' or '.join(self.skills_sources_for_prompt)})" lines = [] for skill in skills_meta: lines.append(f"- **{skill['name']}**: {skill['description']}") lines.append(f" -> Read `{skill['path']}` for full instructions") return "\n".join(lines) def _build_skills_section(self, skills_meta: list[dict[str, str]]) -> str: skills_locations = self._format_skills_locations(self.skills_sources_for_prompt) skills_list = self._format_skills_list(skills_meta) return SKILLS_SYSTEM_PROMPT.format( skills_locations=skills_locations, skills_list=skills_list, )