diff --git a/nac-ai-inference/src/engine/ragEngine.ts b/nac-ai-inference/src/engine/ragEngine.ts
new file mode 100644
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+++ b/nac-ai-inference/src/engine/ragEngine.ts
@@ -0,0 +1,228 @@
+/**
+ * NAC RAG检索引擎
+ * 
+ * 从MongoDB知识库（compliance_rules + nac_tech_docs）检索相关内容
+ * 支持关键词匹配、辖区过滤、资产类型过滤
+ */
+
+import { Db } from "mongodb";
+
+export interface RAGDocument {
+  _id?: unknown;
+  ruleId?: string;
+  ruleName?: string;
+  ruleNameI18n?: Record<string, string>;
+  jurisdiction?: string;
+  category?: string;
+  assetClass?: string;
+  description?: string;
+  descriptionI18n?: Record<string, string>;
+  content?: string;
+  tags?: string[];
+  relevance?: number;
+  score?: number;
+  source?: "compliance_rules" | "nac_tech_docs";
+}
+
+export interface RAGContext {
+  documents: RAGDocument[];
+  totalFound: number;
+  queryKeywords: string[];
+  jurisdiction?: string;
+  assetClass?: string;
+}
+
+// ─── 关键词提取 ───────────────────────────────────────────────────
+
+const STOP_WORDS = new Set([
+  "的", "了", "是", "在", "我", "有", "和", "就", "不", "人", "都", "一",
+  "上", "也", "很", "到", "说", "要", "去", "你", "会", "着", "没有", "看",
+  "自己", "这", "那", "什么", "如何", "怎么", "请问", "帮我", "告诉", "介绍",
+  "关于", "对于", "针对", "需要", "可以", "应该", "必须", "规定", "要求",
+  "the", "a", "an", "is", "are", "was", "were", "be", "been",
+  "have", "has", "had", "do", "does", "did", "will", "would", "could",
+  "what", "how", "when", "where", "why", "which", "who",
+]);
+
+const JURISDICTION_MAP: Record<string, string> = {
+  "香港": "HK", "港": "HK", "HK": "HK",
+  "新加坡": "SG", "狮城": "SG", "SG": "SG",
+  "迪拜": "AE", "阿联酋": "AE", "AE": "AE",
+  "中国": "CN", "大陆": "CN", "CN": "CN",
+  "美国": "US", "US": "US",
+  "欧盟": "EU", "EU": "EU",
+  "日本": "JP", "JP": "JP",
+  "澳大利亚": "AU", "AU": "AU",
+};
+
+const ASSET_CLASS_MAP: Record<string, string> = {
+  "房地产": "RealEstate", "不动产": "RealEstate", "房产": "RealEstate",
+  "证券": "FinancialSecurities", "股票": "FinancialSecurities", "债券": "FinancialSecurities",
+  "大宗商品": "Commodities", "黄金": "Commodities", "原油": "Commodities",
+  "数字资产": "DigitalAssets", "代币": "DigitalAssets", "NFT": "DigitalAssets",
+  "碳排放": "EnvironmentalRights", "碳信用": "EnvironmentalRights",
+  "知识产权": "IntellectualProperty", "专利": "IntellectualProperty",
+  "基础设施": "Infrastructure",
+  "应收账款": "Receivables",
+};
+
+function extractKeywords(query: string): { keywords: string[]; jurisdiction?: string; assetClass?: string } {
+  const q = String(query ?? "");
+  let jurisdiction: string | undefined;
+  let assetClass: string | undefined;
+
+  for (const [term, code] of Object.entries(JURISDICTION_MAP)) {
+    if (q.includes(term)) { jurisdiction = code; break; }
+  }
+  for (const [term, cls] of Object.entries(ASSET_CLASS_MAP)) {
+    if (q.toLowerCase().includes(term.toLowerCase())) { assetClass = cls; break; }
+  }
+
+  const chineseTerms = q.match(/[\u4e00-\u9fa5]{2,8}/g) || [];
+  const englishTerms = q.match(/[a-zA-Z]{3,}/g) || [];
+  const keywords = Array.from(new Set([...chineseTerms, ...englishTerms]))
+    .filter(t => !STOP_WORDS.has(t.toLowerCase()))
+    .slice(0, 8);
+
+  return { keywords, jurisdiction, assetClass };
+}
+
+// ─── 主检索函数 ───────────────────────────────────────────────────
+
+export async function retrieveRelevantDocs(
+  db: Db,
+  query: string,
+  options: {
+    maxResults?: number;
+    language?: string;
+    jurisdiction?: string;
+    assetClass?: string;
+    includeCompliance?: boolean;
+    includeTechDocs?: boolean;
+  } = {}
+): Promise<RAGContext> {
+  const {
+    maxResults = 8,
+    language = "zh",
+    includeCompliance = true,
+    includeTechDocs = true,
+  } = options;
+
+  const { keywords, jurisdiction, assetClass } = extractKeywords(query);
+  const effectiveJurisdiction = options.jurisdiction ?? jurisdiction;
+  const effectiveAssetClass = options.assetClass ?? assetClass;
+
+  const results: RAGDocument[] = [];
+
+  // ── 检索 compliance_rules ──────────────────────────────────────
+  if (includeCompliance) {
+    try {
+      const filter: Record<string, unknown> = {};
+      if (effectiveJurisdiction) filter.jurisdiction = effectiveJurisdiction;
+      if (effectiveAssetClass) filter.assetClass = effectiveAssetClass;
+
+      // 尝试全文搜索
+      let complianceDocs: RAGDocument[] = [];
+      if (keywords.length > 0) {
+        try {
+          complianceDocs = await db.collection("compliance_rules")
+            .find({ ...filter, $text: { $search: keywords.join(" ") } })
+            .project({ score: { $meta: "textScore" } })
+            .sort({ score: { $meta: "textScore" } })
+            .limit(Math.ceil(maxResults * 0.6))
+            .toArray() as RAGDocument[];
+        } catch {
+          // 全文索引不可用时，退回正则匹配
+          const regexPattern = keywords.slice(0, 3).join("|");
+          const regex = new RegExp(regexPattern, "i");
+          complianceDocs = await db.collection("compliance_rules")
+            .find({
+              ...filter,
+              $or: [
+                { ruleName: regex },
+                { description: regex },
+                { content: regex },
+                { tags: { $in: keywords } },
+              ],
+            })
+            .limit(Math.ceil(maxResults * 0.6))
+            .toArray() as RAGDocument[];
+        }
+      } else {
+        complianceDocs = await db.collection("compliance_rules")
+          .find(filter)
+          .sort({ relevance: -1 })
+          .limit(Math.ceil(maxResults * 0.6))
+          .toArray() as RAGDocument[];
+      }
+
+      complianceDocs.forEach(doc => {
+        results.push({ ...doc, source: "compliance_rules" });
+      });
+    } catch (err) {
+      console.warn("[ragEngine] compliance_rules检索失败:", err);
+    }
+  }
+  // ── 检索 nac_tech_docs ─────────────────────────────────────────────
+  if (includeTechDocs) {
+    try {
+      // 扩展的技术关键词过滤器：覆盖所有NAC原生技术概念
+      const techKeywords = keywords.filter(k =>
+        /charter|nvm|cbpp|csnp|cnnl|gnacs|acc|xtzh|xic|nrpc|rwa|token|合约|虚拟机|共识|协议|治理|宪法|收据|估值|地址|主权|辖区|合规|身份|kyc|aml|erc|solidity|evm|pos|pow|比特币|以太坊|稳定币|代币|资产|上链|流程|注册|浏览器|量子|跨链|互操作|联盟链|公有链|私有链|第四种|私法监管|流体区块|七层|sdr|黄金|香港|新加坡|迪拜|sfc|mas|vara|adgm|difc|acc20|cee|did|nac公链|宪政|神经网络|编程语言|开发者|生态|对比|区别|不同|比较|什么是|如何工作|原理|架构|技术栈/i.test(k)
+      );
+      // 扩展的触发条件：更广泛地触发知识库检索
+      const shouldSearchTechDocs = techKeywords.length > 0 ||
+        keywords.some(k => /技术|开发|编程|合约|虚拟机|治理|合规|身份|估值|资产|上链|区别|对比|比较|什么|如何|怎么|为什么|原理|架构|生态|公链|区块链/i.test(k)) ||
+        query.length > 10; // 任何较长的查询都尝试检索知识库
+
+      if (shouldSearchTechDocs) {
+        // 使用所有关键词构建更全面的正则表达式
+        const searchTerms = techKeywords.length > 0 ? techKeywords : keywords;
+        const regexPattern = searchTerms.slice(0, 5).join("|");
+        const regex = new RegExp(regexPattern, "i");
+        const techDocs = await db.collection("nac_tech_docs")
+          .find({
+            $or: [
+              { title: regex },
+              { content: regex },
+              { tags: { $in: keywords } },
+              { category: { $in: ["overview", "comparison", "governance", "consensus", "economics", "compliance", "identity", "development", "network", "asset_standard", "process", "valuation", "tools"] } },
+            ],
+          })
+          .limit(Math.ceil(maxResults * 0.6))
+          .toArray() as RAGDocument[];
+
+        techDocs.forEach(doc => {
+          results.push({ ...doc, source: "nac_tech_docs" });
+        });
+      }
+    } catch (err) {
+      console.warn("[ragEngine] nac_tech_docs检索失败:", err);
+    }
+  }
+
+  return {
+    documents: results.slice(0, maxResults),
+    totalFound: results.length,
+    queryKeywords: keywords,
+    jurisdiction: effectiveJurisdiction,
+    assetClass: effectiveAssetClass,
+  };
+}
+
+// ─── 构建RAG上下文字符串 ──────────────────────────────────────────
+
+export function buildContextString(ragCtx: RAGContext, language: string = "zh"): string {
+  if (ragCtx.documents.length === 0) return "";
+
+  const lines: string[] = ["=== 相关知识库内容 ==="];
+  ragCtx.documents.slice(0, 6).forEach((doc, i) => {
+    const name = doc.ruleNameI18n?.[language] ?? doc.ruleName ?? (doc as any).title ?? "未命名";
+    const desc = doc.descriptionI18n?.[language] ?? doc.description ?? doc.content ?? "";
+    lines.push(`\n[${i + 1}] ${name}`);
+    if (doc.jurisdiction) lines.push(`辖区: ${doc.jurisdiction}`);
+    if (doc.category) lines.push(`类别: ${doc.category}`);
+    lines.push(desc.slice(0, 400));
+  });
+  return lines.join("\n");
+}