MCP-based Knowledge Graph Construction System

Instructions

Implementation Reference

• kg_server_enhanced.py:219-290 (handler)

  The 'build_knowledge_graph_tool' function implementation in kg_server_enhanced.py, which serves as the handler for the 'build_knowledge_graph' MCP tool. It extracts entities and triples from the input text and saves a visualization.

  async def build_knowledge_graph_tool(arguments: dict[str, Any]) -> list[TextContent]:
      """
      构建知识图谱（不进行质量评估、知识补全或其他内容增强）
      """
      try:
          text = arguments.get("text", "")
          output_file = arguments.get("output_file", "knowledge_graph.html")
  
          if not text.strip():
              return [TextContent(
                  type="text",
                  text=json.dumps({
                      "success": False,
                      "error": "输入文本不能为空"
                  }, ensure_ascii=False, indent=2)
              )]
  
          start_time = time.time()
  
          # 直接构建知识图谱
          kg_result = await kg_builder.build_graph(text, use_llm=True)
  
          # 检查是否成功提取到实体和三元组
          if not kg_result["entities"] and not kg_result["triples"]:
              return [TextContent(
                  type="text",
                  text=json.dumps({
                      "success": False,
                      "error": "无法从输入文本中提取到有效的实体或关系",
                      "suggestion": "请尝试输入包含明确实体和关系的文本"
                  }, ensure_ascii=False, indent=2)
              )]
  
          # 生成可视化
          visualization_file = kg_visualizer.save_simple_visualization(
              kg_result["triples"],
              kg_result["entities"],
              kg_result["relations"],
              output_file
          )
  
          abs_path = os.path.abspath(visualization_file)
          visualization_url = f"file:///{abs_path.replace(os.sep, '/')}"
          http_url = f"http://localhost:8000/{visualization_file}"
          server_info = f"可手动启动HTTP服务器访问：在项目目录运行 'python -m http.server 8000'，然后访问 {http_url}"
  
          processing_time = time.time() - start_time
  
          # 构建结果
          result = {
              "success": True,
              "input_text": text,
              "processing_time": round(processing_time, 3),
              "knowledge_graph": {
                  "entities_count": len(kg_result["entities"]),
                  "relations_count": len(kg_result["relations"]),
                  "triples_count": len(kg_result["triples"]),
                  "entities": kg_result["entities"],
                  "relations": kg_result["relations"]
              },
              "visualization": {
                  "file_path": visualization_file,
                  "file_url": visualization_url,
                  "http_url": http_url,
                  "server_info": server_info
              }
          }
  
          return [TextContent(
              type="text",
              text=json.dumps(result, ensure_ascii=False, indent=2)
          )]

• kg_server_enhanced.py:84-88 (registration)

  Registration logic for 'build_knowledge_graph' within the server's tool handler dispatch logic in kg_server_enhanced.py.

  tools = [
      Tool(
          name="build_knowledge_graph",
          description="构建知识图谱：直接从文本提取实体与关系并生成可视化（不进行内容增强）",
          inputSchema={