diff --git a/README.md b/README.md
index 2d9204e..1ad3b07 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,9 @@
   `Model@Name`、`Hierarchy`、`Mesh` 等引用可以解析、悬停与跳转。超大模型
   （几十 MB 的顶点/三角形数据）采用浅扫描——只提取顶层资产记录、不建 DOM 树，
   结果在 workspace 级缓存并跨重建复用，保存文件触发的重建不会重读未变化的模型文件。
+- **大项目性能**：索引记录（资产 / Define / Include / 行号）与 include 解析结果
+  跨重建缓存，保存触发的重建零 stat、零重读（Corona 实测约 2 秒）；DOM 树只按需
+  保留并设元素预算，避免内存膨胀。
 
 ## 使用
 
@@ -78,8 +81,10 @@ src/
     fileScanner.ts        目录扫描与 Include source 候选
     refs.ts               引用目标解析（按引用类型过滤）
     shallowScan.ts        .w3x 等大体积美术资产顶层浅扫描（纯 TS，不建 DOM）
-    caches.ts             跨重建持久缓存（DocumentCache / ShallowScanCache）
-    indexer.ts            工作区索引器（后台、缓存、增量重建）
+    records.ts            每文件紧凑索引记录（资产/Define/Include/xi + 行号）
+    caches.ts             跨重建持久缓存（DocumentCache / IndexRecordsCache /
+                          IncludeResolveCache）
+    indexer.ts            工作区索引器（后台、缓存、记录驱动重建）
   features/               completion / hover / navigation / diagnostics / semanticTokens
 syntaxes/                 TextMate 注入语法
 tools/                    XSD → 模型、AssetType 枚举提取
diff --git a/docs/analysis-issues.md b/docs/analysis-issues.md
index 2666076..cce1246 100644
--- a/docs/analysis-issues.md
+++ b/docs/analysis-issues.md
@@ -685,3 +685,80 @@ AttachTest `Harbinger Gunship\GameObject.xml` 中 `<Model Name="AUGunship_SKN"/>
   关联为 xml，完整解析仍会发生在打开的文档上（VS Code 自身行为）。
 - UTF-16 XML 的 w3x 会被嗅探判定为二进制（文件头含 NUL）；实测生态中不存在，
   如遇可再扩展解码。
+
+---
+
+## 十四、问题分析（第九轮，2026-08-02）：Corona 重建性能与内存
+
+### 目标与基线
+
+第八轮后 Corona 的实测基线：
+
+| 场景 | 耗时 |
+|---|---|
+| 首次全量建索引 | ~180-290s（机械盘波动） |
+| 信任二次构建（保存触发） | 8-21s |
+| 强制 reindex | 26-38s |
+| 首建后保留堆 | ~2.5GB（原因不明） |
+
+### 调查 1：二次构建为何仍有 8-21s
+
+插桩 `fs.statSync` 后发现：**每次构建（含信任重建）都会执行约 11 万次同步 statSync**，
+全部来自 `resolveSource` 的 include 目标存在性检查（BAB 搜索路径逐 base `statSync`）。
+机械盘上这就是 10-20s 的来源——即使文件内容全部命中缓存，include 解析仍在逐路径 stat。
+
+修复：新增 `IncludeResolveCache`（workspace 级、跨重建复用）：
+- 键 = 当前文件目录 + source 字符串；命中直接返回，不 stat；
+- 内容编辑不影响"文件是否存在"，因此保存触发的重建**不清除**解析缓存；
+- 文件创建/删除（watcher `onDidCreate` / `onDidDelete`）与 `ra3modxml.reindex`
+  （强制校验）清除缓存；
+- `reference` 的 manifest 查找（`builtmods/*.manifest` 存在性）同样缓存；
+- 配置变更（搜索路径 / builtmods 目录）时清除。
+
+### 调查 2：首建后保留堆 2.5GB 是什么
+
+逐级清空测量（构建 → 清 DOM 缓存 → 清 records → 清 walker → 清索引 Map）：
+
+- `DocumentCache`（元素预算 1M、64 条）：实际只保留 64 条 / 1788 个元素 ≈ 1MB；
+- `IndexRecordsCache`（8976 个文件的紧凑记录）：约 11MB；
+- 目录 walker：约 4MB；
+- 全部索引 Map（manifests + assets + assetsById + defines + files + streams +
+  candidates + diagnostics）：约 75MB；
+- 全部清空并强制 GC 后，堆回到基线（0MB 保留）。
+
+结论：2.5GB 是**构建期可回收垃圾**（60MB XML 的 DOM 瞬态 + 2.6GB w3x 扫描文本/行映射
+的分配压力），不是常驻泄漏；VSCode 正常 GC 压力下会回收。扩展常驻内存约为
+基线 + ~100MB。顺带修复了一个潜在常驻风险：w3x 的 `LineMap`（Corona 全量约 700MB）
+不再随 `ShallowScanCache` 保留，浅扫描结果以"带行号的紧凑记录"形式缓存。
+
+### 其他改动
+
+1. **`IndexRecordsCache` 取代 DOM 依赖的重建**：新增 `src/indexer/records.ts`，
+   每个文件解析时提取紧凑索引记录（顶层资产 / Define / Include / xi:include +
+   1-based 行号），跨重建缓存；信任重建完全不接触 DOM。
+2. **`DocumentCache` 双重淘汰**：条数（LRU）+ 元素预算（超预算先淘汰最大树），
+   把 DOM 常驻内存封顶；DOM 只服务于按需特性（跳转精确范围等）。
+3. **候选目录扫描并行化**（`collectSourceCandidates` 各目录 `Promise.all`）。
+4. **阶段计时**：`stats.candidatesMs` / `stats.walkMs` / `stats.resolveCalls` /
+   `stats.resolveCacheHits` 进入索引报告，便于后续定位耗时。
+5. 版本 0.1.0 → **0.1.1**。
+
+### 实测（Corona，D: 机械盘）
+
+| 场景 | 优化前 | 优化后 |
+|---|---|---|
+| 首次全量建索引 | ~180-290s | ~250s（含 2.6GB w3x 读取+浅扫描、~7.6 万次冷 statSync） |
+| 信任二次构建 | 8-21s | **2.0s**（statSync 0 次，resolveHits 15,333） |
+| 强制 reindex | 26-38s | ~5s（保留解析缓存时）；显式命令会清解析缓存，约 15-25s |
+| 首建后保留堆 | ~2.5GB（疑为泄漏） | 确认是可回收垃圾；常驻 ~100MB |
+
+单元测试 **63 → 73 全绿**：新增 `records.test.mjs`（DOM→记录提取、浅扫描→记录）、
+`caches.test.mjs`（元素预算淘汰、LRU、records/resolve 缓存），indexer 测试补充
+resolve 缓存命中与"信任重建 0 次重解析"断言。
+
+### 遗留
+
+- 首次全量建索引仍受限于机械盘读 2.6GB + 冷 statSync（~4 分钟）；后续可考虑
+  并行浅扫描（worker）或把 w3x 顶层记录持久化到磁盘缓存。
+- `ra3modxml.reindex` 出于正确性会清空解析缓存（可能 ~15-25s）；如接受 watcher
+  可靠性可改为保留。
diff --git a/docs/plan.md b/docs/plan.md
index 52485e2..adb8c58 100644
--- a/docs/plan.md
+++ b/docs/plan.md
@@ -86,7 +86,9 @@ src/
     fileScanner.ts     目录遍历缓存 + Include source 候选收集
     refs.ts            引用目标解析（按 refType / isRef / inheritFrom 过滤，纯 TS）
     shallowScan.ts     大体积美术资产（.w3x 等）顶层浅扫描（纯 TS，不建 DOM）
-    caches.ts          跨重建持久缓存（DocumentCache / ShallowScanCache）
+    records.ts         每文件紧凑索引记录（资产/Define/Include/xi + 行号）
+    caches.ts          跨重建持久缓存（DocumentCache / IndexRecordsCache /
+                       IncludeResolveCache）
     indexer.ts         工作区索引器（资产/Define/流/manifest/w3x 合并）
     types.ts           共享类型
   features/
@@ -149,6 +151,19 @@ test/
       w3x 重扫数为 0（4,829 次缓存命中）。
     - 读取整个文件不可避免（顶层边界需要全量扫描），但建 DOM 不是；优化的是
       "不分配子节点对象"与"跨重建不重读"，两者叠加后方案可行。
+15. **重建零 stat + 记录驱动索引**（第九轮，2026-08-02，v0.1.1）：
+    - 插桩发现每次重建（含信任重建）都有约 11 万次同步 `statSync`
+      （`resolveSource` 的 include 存在性检查），机械盘上占 10-20s；
+      `IncludeResolveCache` 按（目录 + source）缓存解析结果，内容编辑不清、
+      创建/删除文件与强制 reindex 才清。信任重建 statSync 降到 0。
+    - `IndexRecordsCache` 缓存每文件紧凑索引记录（顶层资产 / Define / Include /
+      xi:include + 1-based 行号），信任重建完全不接触 DOM；`DocumentCache`
+      双重淘汰（条数 LRU + 元素预算，超预算先淘汰最大树）把 DOM 常驻内存封顶。
+    - w3x 缓存不再保留 LineMap（Corona 全量约 700MB），浅扫描直接产出带行号的记录。
+    - 实测：Corona 信任二次构建 21s → **2.0s**（statSync 0）；首建后 2.5GB
+      堆保留确认为构建期可回收垃圾，常驻 ~100MB；强制 reindex ~5-25s。
+    - 候选目录扫描并行化；`stats` 新增 `candidatesMs` / `walkMs` / `resolveCalls` /
+      `resolveCacheHits` 供索引报告定位耗时。
 
 ## 三、实施步骤
 
@@ -157,13 +172,16 @@ test/
 3. [x] 生成模型：`schema-model.json`（XSD，295 顶层元素 / 1851 类型）与 `asset-types.json`（79 个 AssetType 哈希）。
 4. [x] 纯 TS 核心：include 解析、manifest 解析、XML 解析封装、索引器、引用解析。
 5. [x] 功能层：补全、hover、导航、诊断、大纲、高亮 grammar。
-6. [x] 单测（fixture Mod，63 个用例全绿：含 xs:list 枚举、未闭合引号恢复、list 多值
+6. [x] 单测（fixture Mod，73 个用例全绿：含 xs:list 枚举、未闭合引号恢复、list 多值
    分段、带 vscode stub 的补全集成、语义 token 兜底）+ 编译 + `vsce package` 打包
-   （ra3-mod-xml-0.1.0.vsix，约 495KB）。
+   （ra3-mod-xml-0.1.1.vsix，约 499KB）。
 7. [x] 在 AttachTest / GenEvoTest / Corona 上做冒烟验证，并按真实项目反馈修复问题（详见 `docs/analysis-issues.md` 八轮分析）。
 8. [x] w3x 美术资产索引（第八轮）：新增 `shallowScan.ts` / `caches.ts`，w3x 与内容嗅探
    XML 走浅扫描，Include source 补全候选加入 w3x，BOM 剥离，缓存跨重建持久化；
    AttachTest 报错场景（`AUGunship_SKN`）修复，Corona 首次/二次构建实测验证。
+9. [x] Corona 性能与内存优化（第九轮，v0.1.1）：`records.ts` 记录驱动索引、
+   `IncludeResolveCache` 零 stat 重建、DOM 元素预算淘汰、w3x LineMap 移除、
+   候选并行扫描、阶段计时；Corona 信任重建 2.0s；确认首建 2.5GB 为可回收垃圾。
 
 ## 四、验证结果（实测）
 
@@ -171,11 +189,11 @@ test/
 |---|---|---|---|---|
 | AttachTest | 88 文件 | ~1.2s | 35,607（manifest 35,322，w3x 浅扫 62） | 2 个流（static + mapmetadata）；二次构建 354ms / 62 缓存命中 |
 | GenEvoTest | 66 文件 | 首次 ~2.6s / 二次 ~0.4s | 35,502（manifest 35,322，w3x 浅扫 38） | 2 个流、73 个 Define；二次构建 0 重扫 / 38 缓存命中 |
-| Corona | 8,976 文件 | 首次 ~241s / 二次 ~38s | 64,868（manifest 35,322，w3x 浅扫 4,829） | 3 个流、183 个 Define、0 诊断；二次构建 0 重扫 / 4,829 缓存命中 |
+| Corona | 8,976 文件 | 首次 ~250s / 信任二次 ~2s / 强制 ~5-25s | 64,868（manifest 35,322，w3x 浅扫 4,829） | 3 个流、183 个 Define、0 诊断；二次构建 statSync 0、resolveHits 15,333 |
 
 单元测试覆盖：XML 解析（自闭合/容错/偏移/未闭合引号行尾恢复）、补全上下文（未闭合引号仍为 attribute-value、list 多值分段）、补全集成（vscode stub 下 `LocomotorTemplate@Surfaces` 未闭合引号枚举补全、空格后第二段过滤与替换范围）、语义 token（标签/属性/值范围、合法文档返回空、malformed 返回兜底 token）、include 解析（BAB 顺序、SDK 根优先于 SageXml）、manifest 二进制解析（合成 v5 样本、类型/ID 推导）、索引器（资产/Define/流/缺失 include/嵌套 xi:include）、XSD 模型（上下文类型、`childTypeOf`、大小写规范化、属性级 refType、外来命名空间判定、`xs:list` 枚举继承与 `isList` 标记）、引用过滤（`Weapon="X"` 只跳 `WeaponTemplate`、模块 `id` 定义点、Poid 局部引用、`xi:include` 不校验、`Side="Allies"` 命中 manifest 的 `PlayerTemplate`）。
 
-> 注：D: 盘移动硬盘已恢复连接；Corona 已按上述新数据回归（第八轮）。
+> 注：D: 盘移动硬盘已恢复连接；Corona 已在第八 / 九轮按上述新数据回归。
 
 ## 五、假设与开放问题
 
diff --git a/docs/requirements.md b/docs/requirements.md
index ca62a5a..cc5ca5b 100644
--- a/docs/requirements.md
+++ b/docs/requirements.md
@@ -76,7 +76,8 @@ XML 之间的组织靠 `<Include>` 标签，共有三种语义：
   补全、悬停、导航与诊断——`Model@Name`、`Hierarchy`、`Mesh` 等引用依赖这些定义；
 - 大模型文件（实测 Corona 最大 22.8 MB，顶点/三角形数据占大头）采用**顶层浅扫描**
   （不建 DOM 树），结果在 workspace 级缓存并跨重建复用，避免每次保存都重读整个
-  美术资产目录（Corona 约 2.6 GB）。
+  美术资产目录（Corona 约 2.6 GB）；索引记录与 include 解析结果同样跨重建缓存，
+  保存触发的重建零 stat、零重读（Corona 实测约 2 秒）。
 
 ### P1：非近期目标（本期不做，但预留扩展点）
 
diff --git a/package-lock.json b/package-lock.json
index 9a4c71f..4ef5a32 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "ra3-mod-xml",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "ra3-mod-xml",
-      "version": "0.1.0",
+      "version": "0.1.1",
       "license": "MIT",
       "dependencies": {
         "fast-xml-parser": "^4.5.0"
diff --git a/package.json b/package.json
index b2bccc2..7e8d3d8 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "ra3-mod-xml",
   "displayName": "RA3 Mod XML",
   "description": "Red Alert 3 Mod XML tooling: syntax highlighting, completions, reference navigation and diagnostics for SAGE/BinaryAssetBuilder XML.",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "publisher": "ra3-mod-xml",
   "license": "MIT",
   "engines": {
diff --git a/src/extension.ts b/src/extension.ts
index 07e5618..b73c088 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -109,18 +109,24 @@ export function activate(context: vscode.ExtensionContext): void {
   context.subscriptions.push(
     vscode.workspace.onDidSaveTextDocument((doc) => {
       if (doc.languageId !== "xml") return;
+      ws.invalidate(doc.uri.fsPath);
       ws.scheduleRebuild();
       void diagnostics.update(doc);
     }),
   );
   context.subscriptions.push(
     vscode.workspace.onDidChangeConfiguration((e) => {
-      if (e.affectsConfiguration("ra3modxml")) ws.scheduleRebuild();
+      if (e.affectsConfiguration("ra3modxml")) {
+        // Search paths / builtmods locations may have changed: cached include
+        // resolutions and manifest lookups are no longer valid.
+        ws.invalidateExistence();
+        ws.scheduleRebuild();
+      }
     }),
   );
 
   context.subscriptions.push(
-    vscode.commands.registerCommand("ra3modxml.reindex", () => ws.rebuild()),
+    vscode.commands.registerCommand("ra3modxml.reindex", () => ws.rebuild(true)),
   );
   context.subscriptions.push(
     vscode.commands.registerCommand("ra3modxml.openIndexReport", () => {
@@ -135,7 +141,7 @@ export function activate(context: vscode.ExtensionContext): void {
       void vscode.window.showInformationMessage(
         `RA3 Mod XML index\n` +
           `Project: ${s.projectDir}\n` +
-          `Files: ${s.indexedFiles} (${s.parsedFiles} parsed, ${s.shallowScannedFiles} shallow-scanned, ${s.shallowCacheHits} cached)\n` +
+          `Files: ${s.indexedFiles} (${s.parsedFiles} parsed, ${s.shallowScannedFiles} shallow-scanned, ${s.shallowCacheHits + s.recordsCacheHits} cache hits)\n` +
           `Assets: ${s.assetCount} (${s.manifestAssetCount} from ${s.manifestFiles} manifests)\n` +
           `Defines: ${s.defineCount} · Streams: ${s.streams} · Candidates: ${s.sourceCandidates}\n` +
           `Indexed in ${(s.elapsedMs / 1000).toFixed(1)}s`,
diff --git a/src/indexer/caches.ts b/src/indexer/caches.ts
index 010e92f..d798fc7 100644
--- a/src/indexer/caches.ts
+++ b/src/indexer/caches.ts
@@ -10,7 +10,9 @@
  */
 
 import { resolve } from "node:path";
-import type { ParsedFile } from "./types";
+import type { IndexedFile, ParsedFile } from "./types";
+import type { IndexRecords } from "./records";
+import type { ResolveResult } from "./includeResolver";
 
 /** Case-insensitive absolute path key. */
 export function normKey(path: string): string {
@@ -18,14 +20,21 @@ export function normKey(path: string): string {
 }
 
 /**
- * LRU cache for fully parsed XML documents. Parse trees of huge mods can be
- * memory-heavy, so only a bounded number of recent documents is retained;
- * evicted entries are re-read from disk on demand.
+ * LRU cache for fully parsed XML documents.
+ *
+ * Parse trees of huge mods can be memory-heavy (~17x the source text), so
+ * retention is bounded twice: by entry count (least-recently-used eviction)
+ * and by a total element budget (largest trees are evicted first). Evicted
+ * entries are re-read from disk on demand.
  */
 export class DocumentCache {
   private map = new Map<string, ParsedFile>();
+  private totalElements = 0;
 
-  constructor(private capacity = 64) {}
+  constructor(
+    private capacity = 64,
+    private elementBudget = 2_000_000,
+  ) {}
 
   get(path: string): ParsedFile | undefined {
     const key = normKey(path);
@@ -36,10 +45,111 @@ export class DocumentCache {
     return hit;
   }
 
+  /** Number of cached documents (for diagnostics). */
+  get size(): number {
+    return this.map.size;
+  }
+
+  /** Total elements held by cached parse trees (for diagnostics). */
+  get elements(): number {
+    return this.totalElements;
+  }
+
   set(parsed: ParsedFile): void {
     const key = normKey(parsed.file.path);
+    const prev = this.map.get(key);
+    if (prev) this.totalElements -= elementCount(prev);
     this.map.delete(key);
     this.map.set(key, parsed);
+    this.totalElements += elementCount(parsed);
+    this.evict();
+  }
+
+  invalidate(path: string): void {
+    const key = normKey(path);
+    const prev = this.map.get(key);
+    if (prev) this.totalElements -= elementCount(prev);
+    this.map.delete(key);
+  }
+
+  clear(): void {
+    this.map.clear();
+    this.totalElements = 0;
+  }
+
+  private evict(): void {
+    while (this.map.size > this.capacity || this.totalElements > this.elementBudget) {
+      if (this.map.size === 0) break;
+      if (this.map.size > this.capacity) {
+        // Over capacity: drop the least recently used entry.
+        const oldest = this.map.keys().next().value;
+        if (oldest === undefined) break;
+        this.remove(oldest);
+      } else {
+        // Over the element budget: drop the largest tree, which frees the
+        // most memory per eviction.
+        let largestKey: string | undefined;
+        let largest = -1;
+        for (const [key, value] of this.map) {
+          const n = elementCount(value);
+          if (n > largest) {
+            largest = n;
+            largestKey = key;
+          }
+        }
+        if (largestKey === undefined || largest <= 0) break;
+        this.remove(largestKey);
+      }
+    }
+  }
+
+  private remove(key: string): void {
+    const prev = this.map.get(key);
+    if (prev) this.totalElements -= elementCount(prev);
+    this.map.delete(key);
+  }
+}
+
+function elementCount(parsed: ParsedFile): number {
+  return parsed.parse?.elements.length ?? 0;
+}
+
+export interface IndexRecordsCacheEntry {
+  stat: IndexedFile["stat"];
+  records: IndexRecords;
+  /** "shallow" for art-asset scans (.w3x), "full" for parsed XML. */
+  kind: "shallow" | "full";
+}
+
+/**
+ * Cache for per-file index records (top-level assets, defines, includes,
+ * xi:include targets). Records are tiny compared to DOM trees or line maps of
+ * multi-megabyte model files, so the capacity comfortably covers a whole mod
+ * (Corona: ~9k files) and rebuilds never re-read unchanged files.
+ */
+export class IndexRecordsCache {
+  private map = new Map<string, IndexRecordsCacheEntry>();
+
+  constructor(private capacity = 16384) {}
+
+  get(path: string): IndexRecordsCacheEntry | undefined {
+    const key = normKey(path);
+    const hit = this.map.get(key);
+    if (!hit) return undefined;
+    this.map.delete(key);
+    this.map.set(key, hit);
+    return hit;
+  }
+
+  /** Number of cached record sets (for diagnostics). */
+  get size(): number {
+    return this.map.size;
+  }
+
+  set(path: string, entry: IndexRecordsCacheEntry): void {
+    const key = normKey(path);
+    this.map.delete(key);
+    this.map.set(key, entry);
     if (this.map.size > this.capacity) {
       const oldest = this.map.keys().next().value;
       if (oldest !== undefined) this.map.delete(oldest);
@@ -56,17 +166,21 @@ export class DocumentCache {
 }
 
 /**
- * Cache for shallow-scanned art-asset documents (.w3x and content-sniffed
- * XML files). The retained records are tiny (top-level assets, includes,
- * defines) compared to a full DOM, so the capacity can be much larger.
+ * Cache for Include/@source (and xi:include/@href) resolution results.
+ *
+ * Resolving a source performs synchronous statSync existence checks against
+ * every search base; a Corona build issues ~110k of them (tens of seconds on
+ * a mechanical drive). Content edits never change *existence*, so this cache
+ * survives content rebuilds and is only cleared when files are created or
+ * deleted (or on a forced reindex).
  */
-export class ShallowScanCache {
-  private map = new Map<string, ParsedFile>();
+export class IncludeResolveCache {
+  private map = new Map<string, ResolveResult>();
+  private manifestMap = new Map<string, string | null>();
 
-  constructor(private capacity = 8192) {}
+  constructor(private capacity = 262144) {}
 
-  get(path: string): ParsedFile | undefined {
-    const key = normKey(path);
+  get(key: string): ResolveResult | undefined {
     const hit = this.map.get(key);
     if (!hit) return undefined;
     this.map.delete(key);
@@ -74,21 +188,39 @@ export class ShallowScanCache {
     return hit;
   }
 
-  set(parsed: ParsedFile): void {
-    const key = normKey(parsed.file.path);
+  set(key: string, result: ResolveResult): void {
     this.map.delete(key);
-    this.map.set(key, parsed);
+    this.map.set(key, result);
     if (this.map.size > this.capacity) {
       const oldest = this.map.keys().next().value;
       if (oldest !== undefined) this.map.delete(oldest);
     }
   }
 
-  invalidate(path: string): void {
-    this.map.delete(normKey(path));
+  getManifest(key: string): string | null | undefined {
+    const hit = this.manifestMap.get(key);
+    if (hit === undefined) return undefined;
+    this.manifestMap.delete(key);
+    this.manifestMap.set(key, hit);
+    return hit;
+  }
+
+  setManifest(key: string, path: string | null): void {
+    this.manifestMap.delete(key);
+    this.manifestMap.set(key, path);
+    if (this.manifestMap.size > this.capacity) {
+      const oldest = this.manifestMap.keys().next().value;
+      if (oldest !== undefined) this.manifestMap.delete(oldest);
+    }
   }
 
   clear(): void {
     this.map.clear();
+    this.manifestMap.clear();
+  }
+
+  /** Number of cached resolutions (for diagnostics). */
+  get size(): number {
+    return this.map.size;
   }
 }
diff --git a/src/indexer/fileScanner.ts b/src/indexer/fileScanner.ts
index 7fc430d..e74a3c2 100644
--- a/src/indexer/fileScanner.ts
+++ b/src/indexer/fileScanner.ts
@@ -87,8 +87,15 @@ export async function collectSourceCandidates(
     out.push({ source, path: resolve(path), prefix, baseDir: resolve(baseDir) });
   };
 
-  for (const dir of dataDirs) {
-    const files = await walker.listFiles(dir);
+  // List directories in parallel; the walker caches each directory by its
+  // mtime, so rebuilds after the first are still cheap.
+  const [dataLists, artLists, audioLists] = await Promise.all([
+    Promise.all(dataDirs.map(async (dir) => ({ dir, files: await walker.listFiles(dir) }))),
+    Promise.all(artDirs.map(async (dir) => ({ dir, files: await walker.listFiles(dir) }))),
+    Promise.all(audioDirs.map(async (dir) => ({ dir, files: await walker.listFiles(dir) }))),
+  ]);
+
+  for (const { dir, files } of dataLists) {
     for (const f of files) {
       if (!isDataCandidate(f)) continue;
       add(f, dir, "DATA");
@@ -101,15 +108,11 @@ export async function collectSourceCandidates(
     }
   }
 
-  for (const dir of artDirs) {
-    for (const f of await walker.listFiles(dir)) {
-      add(f, dir, "ART");
-    }
+  for (const { dir, files } of artLists) {
+    for (const f of files) add(f, dir, "ART");
   }
-  for (const dir of audioDirs) {
-    for (const f of await walker.listFiles(dir)) {
-      add(f, dir, "AUDIO");
-    }
+  for (const { dir, files } of audioLists) {
+    for (const f of files) add(f, dir, "AUDIO");
   }
 
   return out;
diff --git a/src/indexer/indexer.ts b/src/indexer/indexer.ts
index 81b3012..c6d681f 100644
--- a/src/indexer/indexer.ts
+++ b/src/indexer/indexer.ts
@@ -12,6 +12,7 @@
  */
 
 import { open, readFile, readdir, stat } from "node:fs/promises";
+import type { Stats } from "node:fs";
 import { basename, dirname, extname, join, resolve } from "node:path";
 import {
   LineMap,
@@ -24,6 +25,7 @@ import {
   buildSearchPaths,
   manifestPathForReference,
   resolveSource,
+  type ResolveResult,
   type SearchPaths,
 } from "./includeResolver";
 import {
@@ -34,8 +36,14 @@ import {
 } from "./manifestParser";
 import { canonicalTypeName } from "../model/schemaModel";
 import { collectSourceCandidates } from "./fileScanner";
-import { DocumentCache, ShallowScanCache, normKey } from "./caches";
+import { DocumentCache, IncludeResolveCache, IndexRecordsCache, normKey } from "./caches";
+import type { IndexRecordsCacheEntry } from "./caches";
 import { scanXmlShallow } from "./shallowScan";
+import {
+  extractIndexRecords,
+  recordsFromShallow,
+  type IndexRecordXi,
+} from "./records";
 import type {
   AssetDef,
   DefineDef,
@@ -69,8 +77,16 @@ type XmlMode = "full" | "shallow" | "binary";
 export class ModIndexer {
   private searchPaths: SearchPaths;
   private docs: DocumentCache;
-  private shallowDocs: ShallowScanCache;
-  private scanCounters = { shallowScannedFiles: 0, shallowCacheHits: 0 };
+  private recordsCache: IndexRecordsCache;
+  private resolveCache: IncludeResolveCache;
+  private scanCounters = {
+    shallowScannedFiles: 0,
+    shallowCacheHits: 0,
+    recordsCacheHits: 0,
+    resolveCacheHits: 0,
+    resolveCalls: 0,
+  };
+  private phase = { candidatesMs: 0, walkMs: 0 };
   private assets = new Map<string, Map<string, AssetDef[]>>();
   private assetsById = new Map<string, AssetDef[]>();
   private defines = new Map<string, DefineDef[]>();
@@ -89,7 +105,8 @@ export class ModIndexer {
     });
     // Caches may be owned by the workspace so they survive rebuilds.
     this.docs = opts.documentCache ?? new DocumentCache();
-    this.shallowDocs = opts.shallowCache ?? new ShallowScanCache();
+    this.recordsCache = opts.recordsCache ?? new IndexRecordsCache();
+    this.resolveCache = opts.resolveCache ?? new IncludeResolveCache();
   }
 
   /**
@@ -105,22 +122,30 @@ export class ModIndexer {
    */
   async readDocument(path: string): Promise<ParsedFile | null> {
     const key = normKey(path);
-    const mode = await this.detectXmlMode(path);
-    if (mode === "shallow") return this.scanShallow(path);
-    if (mode === "binary") {
-      try {
-        const st = await stat(path);
-        const file: IndexedFile = { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } };
-        this.files.set(key, file);
-        return { file, parse: null, shallow: null, lineMap: null };
-      } catch {
-        const file: IndexedFile = { path: resolve(path), stat: null };
-        this.files.set(key, file);
-        return { file, parse: null, shallow: null, lineMap: null };
+    const trust =
+      this.opts.trustUnchanged === true && !this.opts.changedFiles?.has(key);
+
+    // Trusted fast path: a file that the watcher has not reported as changed
+    // is reused without any stat / content sniff / read at all. This is what
+    // makes save-triggered rebuilds cheap on huge corpora (Corona: ~9k files,
+    // ~2.6 GB of art assets on a mechanical drive).
+    if (trust) {
+      const rec = this.recordsCache.get(key);
+      if (rec) return this.recordsParsed(path, rec);
+      const cached = this.docs.get(key);
+      if (cached) {
+        this.files.set(key, cached.file);
+        return cached;
       }
     }
+
+    // Untrusted / cache miss: verify the stat against caches, then read.
     try {
       const st = await stat(path);
+      const rec = this.recordsCache.get(key);
+      if (rec?.stat && rec.stat.mtimeMs === st.mtimeMs && rec.stat.size === st.size) {
+        return this.recordsParsed(path, rec);
+      }
       const hit = this.docs.get(key);
       if (
         hit?.file.stat &&
@@ -130,29 +155,41 @@ export class ModIndexer {
         this.files.set(key, hit.file);
         return hit;
       }
+      const mode = await this.detectXmlMode(path);
+      if (mode === "shallow") return this.scanShallow(path, st);
+      if (mode === "binary") {
+        const file: IndexedFile = { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } };
+        const parsed: ParsedFile = { file, parse: null, records: null, lineMap: null };
+        this.docs.set(parsed);
+        this.files.set(key, file);
+        return parsed;
+      }
       if (st.size > MAX_PARSE_BYTES) {
         const file: IndexedFile = { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } };
-        const parsed: ParsedFile = { file, parse: null, shallow: null, lineMap: null };
+        const parsed: ParsedFile = { file, parse: null, records: null, lineMap: null };
         this.docs.set(parsed);
         this.files.set(key, file);
         return parsed;
       }
       const text = stripBom(await readFile(path, "utf8"));
+      const lineMap = new LineMap(text);
       const parse = parseXml(text);
+      const records = extractIndexRecords(parse, lineMap);
       const parsed: ParsedFile = {
         file: { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } },
         parse,
-        shallow: null,
-        lineMap: new LineMap(text),
+        records,
+        lineMap,
       };
       this.docs.set(parsed);
+      this.recordsCache.set(key, { stat: parsed.file.stat, records, kind: "full" });
       this.files.set(key, parsed.file);
       return parsed;
     } catch {
       const parsed: ParsedFile = {
         file: { path: resolve(path), stat: null },
         parse: null,
-        shallow: null,
+        records: null,
         lineMap: null,
       };
       this.docs.set(parsed);
@@ -163,32 +200,23 @@ export class ModIndexer {
 
   /**
    * Shallow-scans a large art-asset XML document (no DOM built) and caches
-   * the top-level records. Cache hits are counted separately so tests and
-   * the index report can verify that rebuilds skip unchanged files.
+   * its compact index records. The transient LineMap used to compute record
+   * lines is discarded, so the cache never retains megabytes of line offsets
+   * for model files (Corona w3x alone would otherwise keep ~700 MB).
    */
-  private async scanShallow(path: string): Promise<ParsedFile | null> {
+  private async scanShallow(path: string, st: Stats): Promise<ParsedFile | null> {
     const key = normKey(path);
     try {
-      const st = await stat(path);
-      const hit = this.shallowDocs.get(key);
-      if (
-        hit?.file.stat &&
-        hit.file.stat.mtimeMs === st.mtimeMs &&
-        hit.file.stat.size === st.size
-      ) {
-        this.scanCounters.shallowCacheHits++;
-        this.files.set(key, hit.file);
-        return hit;
-      }
       const text = stripBom(await readFile(path, "utf8"));
-      const shallow = scanXmlShallow(text);
+      const lineMap = new LineMap(text);
+      const records = recordsFromShallow(scanXmlShallow(text), lineMap);
       const parsed: ParsedFile = {
         file: { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } },
         parse: null,
-        shallow,
-        lineMap: new LineMap(text),
+        records,
+        lineMap: null,
       };
-      this.shallowDocs.set(parsed);
+      this.recordsCache.set(key, { stat: parsed.file.stat, records, kind: "shallow" });
       this.files.set(key, parsed.file);
       this.scanCounters.shallowScannedFiles++;
       return parsed;
@@ -197,6 +225,59 @@ export class ModIndexer {
     }
   }
 
+  /** Builds a lean ParsedFile from cached index records (no DOM / line map). */
+  private recordsParsed(path: string, entry: IndexRecordsCacheEntry): ParsedFile {
+    if (entry.kind === "shallow") this.scanCounters.shallowCacheHits++;
+    else this.scanCounters.recordsCacheHits++;
+    const file: IndexedFile = { path: resolve(path), stat: entry.stat };
+    this.files.set(normKey(path), file);
+    return { file, parse: null, records: entry.records, lineMap: null };
+  }
+
+  /**
+   * Reads a document and guarantees a DOM parse tree. Used only for
+   * root-level <xi:include> xpointer selection (rare), where the target's
+   * container children are needed.
+   */
+  private async readDom(path: string): Promise<ParsedFile | null> {
+    const key = normKey(path);
+    const cached = this.docs.get(key);
+    if (cached?.parse?.root) {
+      this.files.set(key, cached.file);
+      return cached;
+    }
+    try {
+      const st = await stat(path);
+      const hit = this.docs.get(key);
+      if (
+        hit?.parse?.root &&
+        hit.file.stat &&
+        hit.file.stat.mtimeMs === st.mtimeMs &&
+        hit.file.stat.size === st.size
+      ) {
+        this.files.set(key, hit.file);
+        return hit;
+      }
+      if (st.size > MAX_PARSE_BYTES) return null;
+      const text = stripBom(await readFile(path, "utf8"));
+      const lineMap = new LineMap(text);
+      const parse = parseXml(text);
+      const records = extractIndexRecords(parse, lineMap);
+      const parsed: ParsedFile = {
+        file: { path: resolve(path), stat: { mtimeMs: st.mtimeMs, size: st.size } },
+        parse,
+        records,
+        lineMap,
+      };
+      this.docs.set(parsed);
+      this.recordsCache.set(key, { stat: parsed.file.stat, records, kind: "full" });
+      this.files.set(key, parsed.file);
+      return parsed;
+    } catch {
+      return null;
+    }
+  }
+
   /** Decides how a resolved include target should be consumed. */
   private async detectXmlMode(path: string): Promise<XmlMode> {
     const ext = extname(path).toLowerCase();
@@ -205,6 +286,38 @@ export class ModIndexer {
     return (await looksLikeXml(path)) ? "shallow" : "binary";
   }
 
+  /**
+   * Resolves an include source through the cross-rebuild cache. Existence
+   * does not change on content edits, so trusted rebuilds pay zero statSync
+   * for include resolution (Corona does ~110k checks per build otherwise).
+   */
+  private resolveCached(source: string, currentDir: string | null): ResolveResult {
+    const key = `${normKey(currentDir ?? "")}\u0000${source}`;
+    const hit = this.resolveCache.get(key);
+    if (hit) {
+      this.scanCounters.resolveCacheHits++;
+      return hit;
+    }
+    this.scanCounters.resolveCalls++;
+    const result = resolveSource(source, currentDir, this.searchPaths);
+    this.resolveCache.set(key, result);
+    return result;
+  }
+
+  /** Cached manifest lookup for `reference` includes. */
+  private manifestPathCached(source: string): string | null {
+    const key = source.toLowerCase();
+    const hit = this.resolveCache.getManifest(key);
+    if (hit !== undefined) {
+      this.scanCounters.resolveCacheHits++;
+      return hit;
+    }
+    this.scanCounters.resolveCalls++;
+    const path = manifestPathForReference(source, this.opts.builtmodsDirs);
+    this.resolveCache.setManifest(key, path);
+    return path;
+  }
+
   /** Returns the cached parse if present (does not read from disk). */
   cachedDocument(path: string): ParsedFile | undefined {
     return this.docs.get(path);
@@ -218,6 +331,7 @@ export class ModIndexer {
       : null;
 
     // ── Streams ──
+    const walkStart = Date.now();
     const staticEntry = projectData ? join(projectData, "Mod.xml") : null;
     if (staticEntry) {
       const stream: StreamInfo = { name: "static", entry: staticEntry, files: new Set() };
@@ -246,8 +360,10 @@ export class ModIndexer {
         await this.walk(entry, "all", stream, 0);
       }
     }
+    this.phase.walkMs = Date.now() - walkStart;
 
     // ── Source completion candidates ──
+    const candidatesStart = Date.now();
     const dataDirs = [
       projectData ?? join(this.opts.projectDir, "Data"),
       join(this.opts.sdkDir, "SageXml"),
@@ -292,6 +408,7 @@ export class ModIndexer {
       ...sdkRootCandidates,
       ...this.sourceCandidates,
     ]);
+    this.phase.candidatesMs = Date.now() - candidatesStart;
 
     const manifestAssetCount = [...this.manifests.values()].reduce(
       (sum, m) => sum + m.assets.length,
@@ -318,6 +435,11 @@ export class ModIndexer {
         ).length,
         shallowScannedFiles: this.scanCounters.shallowScannedFiles,
         shallowCacheHits: this.scanCounters.shallowCacheHits,
+        recordsCacheHits: this.scanCounters.recordsCacheHits,
+        resolveCacheHits: this.scanCounters.resolveCacheHits,
+        resolveCalls: this.scanCounters.resolveCalls,
+        candidatesMs: this.phase.candidatesMs,
+        walkMs: this.phase.walkMs,
         assetCount: [...this.assets.values()].reduce((sum, byId) => sum + byId.size, 0),
         defineCount: this.defines.size,
         manifestFiles: this.manifests.size,
@@ -359,167 +481,64 @@ export class ModIndexer {
 
     stream.files.add(key);
 
-    // readDocument handles every mode: full XML parse, shallow scan for
-    // art-asset XML (.w3x / content-sniffed), or binary registration only.
+    // readDocument returns compact index records for every indexable XML
+    // document (full parse or shallow scan), or a bare file registration
+    // for binary / unparseable targets.
     const parsed = await this.readDocument(path);
     if (!parsed) return;
-    if (parsed.shallow) {
-      await this.walkShallow(parsed, stream, depth, mode === "instance");
+    if (parsed.records) {
+      await this.applyRecords(parsed, stream, depth, mode === "instance");
       return;
     }
-    if (!parsed.parse?.root) return;
-    const root = parsed.parse.root;
-
-    for (const child of root.children) {
-      const local = localName(child.name);
-      if (local === "Tags" || local === "Includes" || local === "Defines") continue;
-      if (local === "include") {
-        await this.handleXiInclude(child, parsed, stream, depth);
-        continue;
-      }
-      const idAttr = child.attrs.find((a) => a.name === "id");
-      if (idAttr) {
-        this.addAsset({
-          type: local,
-          id: idAttr.value,
-          file: parsed.file.path,
-          line: lineOf(parsed, idAttr.valueStart),
-          origin: this.originOf(parsed.file.path),
-          stream: stream.name,
-          viaInstance: mode === "instance",
-        });
-      }
-    }
-
-    for (const child of root.children) {
-      if (localName(child.name) !== "Defines") continue;
-      for (const define of child.children) {
-        if (localName(define.name) !== "Define") continue;
-        const name = define.attrs.find((a) => a.name === "name")?.value;
-        const value = define.attrs.find((a) => a.name === "value")?.value;
-        if (!name) continue;
-        const entry: DefineDef = {
-          name,
-          value: value ?? "",
-          file: parsed.file.path,
-          line: lineOf(parsed, define.start),
-          origin: this.originOf(parsed.file.path),
-        };
-        const arr = this.defines.get(name.toLowerCase());
-        if (arr) arr.push(entry);
-        else this.defines.set(name.toLowerCase(), [entry]);
-      }
-    }
-
-    const includesElem = root.children.find((c) => localName(c.name) === "Includes");
-    if (includesElem) {
-      for (const inc of includesElem.children) {
-        if (localName(inc.name) !== "Include") continue;
-        const type = inc.attrs.find((a) => a.name === "type")?.value;
-        const source = inc.attrs.find((a) => a.name === "source")?.value;
-        if (!source) continue;
-        const resolved = resolveSource(source, dirname(parsed.file.path), this.searchPaths);
-        if (!resolved.path) {
-          this.diagnostics.push({
-            file: parsed.file.path,
-            line: lineOf(parsed, inc.start),
-            message: `Include target not found: ${source}`,
-            severity: "warning",
-            code: "include-not-found",
-          });
-          continue;
-        }
-        if (type === "all" || type === "instance") {
-          await this.walk(resolved.path, type === "all" ? "all" : "instance", stream, depth + 1);
-        } else if (type === "reference") {
-          const manifestPath = manifestPathForReference(source, this.opts.builtmodsDirs);
-          if (manifestPath) {
-            const loaded = await this.loadManifest(manifestPath, stream.name);
-            if (!loaded) {
-              // The manifest could not be parsed (missing/invalid): fall back
-              // to the placeholder target so its content is still available.
-              await this.walk(resolved.path, "instance", stream, depth + 1);
-            }
-          } else {
-            // reference to a real XML file: treat its assets as available
-            await this.walk(resolved.path, "instance", stream, depth + 1);
-          }
-        }
-      }
-    }
-
-    // Nested <xi:include> anywhere in the tree (not just under the root):
-    // the target content is inlined into the parent element. We make the
-    // target file available and surface missing targets instead of ignoring
-    // them silently.
-    for (const el of parsed.parse.elements) {
-      if (localName(el.name) !== "include") continue;
-      if (el.parent === root) continue; // already handled in the loop above
-      const href = el.attrs.find((a) => a.name === "href")?.value;
-      if (!href) continue;
-      const resolved = resolveSource(href, dirname(parsed.file.path), this.searchPaths);
-      if (!resolved.path) {
-        this.diagnostics.push({
-          file: parsed.file.path,
-          line: lineOf(parsed, el.start),
-          message: `xi:include target not found: ${href}`,
-          severity: "warning",
-          code: "include-not-found",
-        });
-        continue;
-      }
-      stream.files.add(normKey(resolved.path));
-      if ((await this.detectXmlMode(resolved.path)) !== "binary") {
-        await this.walk(resolved.path, "all", stream, depth + 1);
-      }
-    }
   }
 
   /**
-   * Consumes a shallow-scanned art-asset document: top-level assets,
-   * top-level <Includes>, <Defines> and nested <xi:include> targets.
+   * Applies a document's compact index records: top-level assets, defines,
+   * <Includes>, nested <xi:include> and root-level <xi:include> targets.
+   * Works identically for fully parsed XML and shallow-scanned art assets.
    */
-  private async walkShallow(
+  private async applyRecords(
     parsed: ParsedFile,
     stream: StreamInfo,
     depth: number,
     viaInstance: boolean,
   ): Promise<void> {
-    const scan = parsed.shallow;
-    if (!scan) return;
+    const records = parsed.records;
+    if (!records) return;
     const file = parsed.file.path;
+    const origin = this.originOf(file);
 
-    for (const asset of scan.assets) {
+    for (const asset of records.assets) {
       this.addAsset({
-        type: asset.name,
+        type: asset.type,
         id: asset.id,
         file,
-        line: lineOf(parsed, asset.idValueStart),
-        origin: this.originOf(file),
+        line: asset.line,
+        origin,
         stream: stream.name,
         viaInstance,
       });
     }
 
-    for (const define of scan.defines) {
+    for (const define of records.defines) {
       const entry: DefineDef = {
         name: define.name,
         value: define.value,
         file,
-        line: lineOf(parsed, define.start),
-        origin: this.originOf(file),
+        line: define.line,
+        origin,
       };
       const arr = this.defines.get(define.name.toLowerCase());
       if (arr) arr.push(entry);
       else this.defines.set(define.name.toLowerCase(), [entry]);
     }
 
-    for (const inc of scan.includes) {
-      const resolved = resolveSource(inc.source, dirname(file), this.searchPaths);
+    for (const inc of records.includes) {
+      const resolved = this.resolveCached(inc.source, dirname(file));
       if (!resolved.path) {
         this.diagnostics.push({
           file,
-          line: lineOf(parsed, inc.start),
+          line: inc.line,
           message: `Include target not found: ${inc.source}`,
           severity: "warning",
           code: "include-not-found",
@@ -534,7 +553,7 @@ export class ModIndexer {
           depth + 1,
         );
       } else if (inc.type === "reference") {
-        const manifestPath = manifestPathForReference(inc.source, this.opts.builtmodsDirs);
+        const manifestPath = this.manifestPathCached(inc.source);
         if (manifestPath) {
           const loaded = await this.loadManifest(manifestPath, stream.name);
           if (!loaded) await this.walk(resolved.path, "instance", stream, depth + 1);
@@ -544,12 +563,12 @@ export class ModIndexer {
       }
     }
 
-    for (const xi of scan.xiIncludes) {
-      const resolved = resolveSource(xi.href, dirname(file), this.searchPaths);
+    for (const xi of records.nestedXiIncludes) {
+      const resolved = this.resolveCached(xi.href, dirname(file));
       if (!resolved.path) {
         this.diagnostics.push({
           file,
-          line: lineOf(parsed, xi.start),
+          line: xi.line,
           message: `xi:include target not found: ${xi.href}`,
           severity: "warning",
           code: "include-not-found",
@@ -557,68 +576,65 @@ export class ModIndexer {
         continue;
       }
       stream.files.add(normKey(resolved.path));
-      if ((await this.detectXmlMode(resolved.path)) !== "binary") {
-        await this.walk(resolved.path, "all", stream, depth + 1);
-      }
+      await this.walk(resolved.path, "all", stream, depth + 1);
+    }
+
+    for (const xi of records.rootXiIncludes) {
+      await this.handleRootXiInclude(xi, file, stream, depth);
     }
   }
 
-  private async handleXiInclude(
-    xi: XmlElement,
-    parent: ParsedFile,
+  /**
+   * Root-level <xi:include> with an xpointer selects a named container's
+   * children in the target document, so the target's DOM is needed. These
+   * targets are rare, so they are parsed on demand (the tree is also cached).
+   */
+  private async handleRootXiInclude(
+    xi: IndexRecordXi,
+    parentFile: string,
     stream: StreamInfo,
     depth: number,
   ): Promise<void> {
-    const href = xi.attrs.find((a) => a.name === "href")?.value;
-    if (!href) return;
-    const resolved = resolveSource(href, dirname(parent.file.path), this.searchPaths);
+    const resolved = this.resolveCached(xi.href, dirname(parentFile));
     if (!resolved.path) {
       this.diagnostics.push({
-        file: parent.file.path,
-        line: lineOf(parent, xi.start),
-        message: `xi:include target not found: ${href}`,
+        file: parentFile,
+        line: xi.line,
+        message: `xi:include target not found: ${xi.href}`,
         severity: "warning",
         code: "include-not-found",
       });
       return;
     }
-    if ((await this.detectXmlMode(resolved.path)) === "binary") return;
-    const target = await this.readDocument(resolved.path);
-    if (!target) return;
-    if (target.shallow) {
-      // Shallow-scanned targets have no tree to select xpointer children
-      // from; index their top-level content as a whole.
-      stream.files.add(normKey(target.file.path));
-      await this.walk(target.file.path, "all", stream, depth + 1);
-      return;
-    }
-    if (!target.parse?.root) return;
 
-    const xpointer = xi.attrs.find((a) => a.name === "xpointer")?.value ?? "";
-    let candidates: XmlElement[];
-    if (xpointer) {
-      const container = findXPointerContainer(target.parse, xpointer);
-      candidates = container ? container.children : [];
-    } else {
-      candidates = target.parse.root.children;
-    }
-    for (const el of candidates) {
-      const local = localName(el.name);
-      if (local === "Tags" || local === "Includes" || local === "Defines") continue;
-      const idAttr = el.attrs.find((a) => a.name === "id");
-      if (idAttr) {
-        this.addAsset({
-          type: local,
-          id: idAttr.value,
-          file: target.file.path,
-          line: lineOf(target, idAttr.valueStart),
-          origin: this.originOf(target.file.path),
-          stream: stream.name,
-        });
+    const target = await this.readDom(resolved.path);
+    if (target?.parse?.root) {
+      const xpointer = xi.xpointer ?? "";
+      let candidates: XmlElement[];
+      if (xpointer) {
+        const container = findXPointerContainer(target.parse, xpointer);
+        candidates = container ? container.children : [];
+      } else {
+        candidates = target.parse.root.children;
+      }
+      for (const el of candidates) {
+        const local = localName(el.name);
+        if (local === "Tags" || local === "Includes" || local === "Defines") continue;
+        const idAttr = el.attrs.find((a) => a.name === "id");
+        if (idAttr) {
+          this.addAsset({
+            type: local,
+            id: idAttr.value,
+            file: target.file.path,
+            line: lineOf(target, idAttr.valueStart),
+            origin: this.originOf(target.file.path),
+            stream: stream.name,
+          });
+        }
       }
     }
-    stream.files.add(normKey(target.file.path));
-    await this.walk(target.file.path, "all", stream, depth + 1);
+    stream.files.add(normKey(resolved.path));
+    await this.walk(resolved.path, "all", stream, depth + 1);
   }
 
   // ── Manifest loading ──────────────────────────────────────────────
diff --git a/src/indexer/records.ts b/src/indexer/records.ts
new file mode 100644
index 0000000..822565d
--- /dev/null
+++ b/src/indexer/records.ts
@@ -0,0 +1,177 @@
+/**
+ * Compact per-file index records.
+ *
+ * A rebuild only needs each file's top-level assets, defines, includes and
+ * xi:include targets — not the DOM. Extracting these records at parse time
+ * and caching them across rebuilds lets Corona-scale rebuilds skip both the
+ * DOM and the file I/O for unchanged files, while keeping the DOM cache small
+ * for on-demand features (hover / navigation / outline).
+ *
+ * Pure TypeScript: no vscode dependency.
+ */
+
+import type { LineMap, XmlDocument } from "../language/xmlParser";
+import type { ShallowDocument } from "./shallowScan";
+
+export interface IndexRecordAsset {
+  /** Top-level element name, e.g. "W3DContainer". */
+  type: string;
+  id: string;
+  /** 1-based line of the id attribute value. */
+  line: number;
+}
+
+export interface IndexRecordDefine {
+  name: string;
+  value: string;
+  /** 1-based line of the <Define> element. */
+  line: number;
+}
+
+export interface IndexRecordInclude {
+  type: "all" | "instance" | "reference" | null;
+  source: string;
+  /** 1-based line of the <Include> element. */
+  line: number;
+}
+
+export interface IndexRecordXi {
+  href: string;
+  xpointer: string | null;
+  /** 1-based line of the <xi:include> element. */
+  line: number;
+}
+
+export interface IndexRecords {
+  assets: IndexRecordAsset[];
+  defines: IndexRecordDefine[];
+  includes: IndexRecordInclude[];
+  /** <xi:include> elements that are direct children of the root. */
+  rootXiIncludes: IndexRecordXi[];
+  /** <xi:include> elements nested anywhere else in the document. */
+  nestedXiIncludes: IndexRecordXi[];
+}
+
+const INCLUDE_TYPES = new Set(["all", "instance", "reference"]);
+
+function lineOf(lineMap: LineMap, offset: number): number {
+  return lineMap.positionAt(offset).line + 1;
+}
+
+function localName(tag: string): string {
+  const idx = tag.lastIndexOf(":");
+  return idx >= 0 ? tag.slice(idx + 1) : tag;
+}
+
+/**
+ * Extracts the index records of a fully parsed document. Mirrors the walk
+ * semantics of the indexer exactly: top-level assets (excluding
+ * Tags/Includes/Defines), $DEFINE constants, the top-level <Includes> block
+ * and root/nested <xi:include> elements.
+ */
+export function extractIndexRecords(parse: XmlDocument, lineMap: LineMap): IndexRecords {
+  const assets: IndexRecordAsset[] = [];
+  const defines: IndexRecordDefine[] = [];
+  const includes: IndexRecordInclude[] = [];
+  const rootXiIncludes: IndexRecordXi[] = [];
+  const nestedXiIncludes: IndexRecordXi[] = [];
+  const root = parse.root;
+  if (!root) return { assets, defines, includes, rootXiIncludes, nestedXiIncludes };
+
+  for (const child of root.children) {
+    const local = localName(child.name);
+    if (local === "Tags" || local === "Includes" || local === "Defines") continue;
+    if (local === "include") {
+      const href = child.attrs.find((a) => a.name === "href")?.value;
+      if (href) {
+        rootXiIncludes.push({
+          href,
+          xpointer: child.attrs.find((a) => a.name === "xpointer")?.value ?? null,
+          line: lineOf(lineMap, child.start),
+        });
+      }
+      continue;
+    }
+    const idAttr = child.attrs.find((a) => a.name === "id");
+    if (idAttr) {
+      assets.push({ type: local, id: idAttr.value, line: lineOf(lineMap, idAttr.valueStart) });
+    }
+  }
+
+  for (const child of root.children) {
+    if (localName(child.name) !== "Defines") continue;
+    for (const define of child.children) {
+      if (localName(define.name) !== "Define") continue;
+      const name = define.attrs.find((a) => a.name === "name")?.value;
+      if (!name) continue;
+      defines.push({
+        name,
+        value: define.attrs.find((a) => a.name === "value")?.value ?? "",
+        line: lineOf(lineMap, define.start),
+      });
+    }
+  }
+
+  const includesElem = root.children.find((c) => localName(c.name) === "Includes");
+  if (includesElem) {
+    for (const inc of includesElem.children) {
+      if (localName(inc.name) !== "Include") continue;
+      const source = inc.attrs.find((a) => a.name === "source")?.value;
+      if (!source) continue;
+      const type = inc.attrs.find((a) => a.name === "type")?.value;
+      includes.push({
+        type:
+          type && INCLUDE_TYPES.has(type)
+            ? (type as "all" | "instance" | "reference")
+            : null,
+        source,
+        line: lineOf(lineMap, inc.start),
+      });
+    }
+  }
+
+  for (const el of parse.elements) {
+    if (localName(el.name) !== "include") continue;
+    if (el.parent === root) continue; // already handled above
+    const href = el.attrs.find((a) => a.name === "href")?.value;
+    if (!href) continue;
+    nestedXiIncludes.push({
+      href,
+      xpointer: el.attrs.find((a) => a.name === "xpointer")?.value ?? null,
+      line: lineOf(lineMap, el.start),
+    });
+  }
+
+  return { assets, defines, includes, rootXiIncludes, nestedXiIncludes };
+}
+
+/** Converts a shallow scan (offsets) into index records (1-based lines). */
+export function recordsFromShallow(scan: ShallowDocument, lineMap: LineMap): IndexRecords {
+  return {
+    assets: scan.assets.map((a) => ({
+      type: a.name,
+      id: a.id,
+      line: lineOf(lineMap, a.idValueStart),
+    })),
+    defines: scan.defines.map((d) => ({
+      name: d.name,
+      value: d.value,
+      line: lineOf(lineMap, d.start),
+    })),
+    includes: scan.includes.map((i) => ({
+      type: i.type,
+      source: i.source,
+      line: lineOf(lineMap, i.start),
+    })),
+    rootXiIncludes: scan.rootXiIncludes.map((x) => ({
+      href: x.href,
+      xpointer: x.xpointer,
+      line: lineOf(lineMap, x.start),
+    })),
+    nestedXiIncludes: scan.nestedXiIncludes.map((x) => ({
+      href: x.href,
+      xpointer: x.xpointer,
+      line: lineOf(lineMap, x.start),
+    })),
+  };
+}
diff --git a/src/indexer/shallowScan.ts b/src/indexer/shallowScan.ts
index d3d7845..9930d54 100644
--- a/src/indexer/shallowScan.ts
+++ b/src/indexer/shallowScan.ts
@@ -60,7 +60,10 @@ export interface ShallowScanError {
 export interface ShallowDocument {
   assets: ShallowAssetRecord[];
   includes: ShallowIncludeRecord[];
-  xiIncludes: ShallowXiIncludeRecord[];
+  /** <xi:include> elements that are direct children of the root. */
+  rootXiIncludes: ShallowXiIncludeRecord[];
+  /** <xi:include> elements nested anywhere else in the document. */
+  nestedXiIncludes: ShallowXiIncludeRecord[];
   defines: ShallowDefineRecord[];
   errors: ShallowScanError[];
 }
@@ -81,7 +84,8 @@ export function scanXmlShallow(text: string): ShallowDocument {
   const errors: ShallowScanError[] = [];
   const assets: ShallowAssetRecord[] = [];
   const includes: ShallowIncludeRecord[] = [];
-  const xiIncludes: ShallowXiIncludeRecord[] = [];
+  const rootXiIncludes: ShallowXiIncludeRecord[] = [];
+  const nestedXiIncludes: ShallowXiIncludeRecord[] = [];
   const defines: ShallowDefineRecord[] = [];
 
   // Depth of the currently open element stack. The document root opens at
@@ -196,11 +200,13 @@ export function scanXmlShallow(text: string): ShallowDocument {
         const href = findAttr(inner, base, "href");
         const xpointer = findAttr(inner, base, "xpointer");
         if (href?.value) {
-          xiIncludes.push({
+          const rec: ShallowXiIncludeRecord = {
             href: href.value,
             xpointer: xpointer?.value ?? null,
             start: lt,
-          });
+          };
+          if (depth === 1) rootXiIncludes.push(rec);
+          else nestedXiIncludes.push(rec);
         }
       }
       if (!selfClosing) depth++;
@@ -210,7 +216,7 @@ export function scanXmlShallow(text: string): ShallowDocument {
     i = gt + 1;
   }
 
-  return { assets, includes, xiIncludes, defines, errors };
+  return { assets, includes, rootXiIncludes, nestedXiIncludes, defines, errors };
 }
 
 /**
diff --git a/src/indexer/types.ts b/src/indexer/types.ts
index 626e393..cdd4fa2 100644
--- a/src/indexer/types.ts
+++ b/src/indexer/types.ts
@@ -1,8 +1,8 @@
 import type { XmlDocument } from "../language/xmlParser";
 import type { ManifestInfo } from "./manifestParser";
 import type { LineMap } from "../language/xmlParser";
-import type { ShallowDocument } from "./shallowScan";
-import type { DocumentCache, ShallowScanCache } from "./caches";
+import type { IndexRecords } from "./records";
+import type { DocumentCache, IncludeResolveCache, IndexRecordsCache } from "./caches";
 
 export type AssetOrigin = "project" | "sdk" | "manifest";
 
@@ -71,6 +71,16 @@ export interface IndexStats {
   shallowScannedFiles: number;
   /** Shallow scans served from the persistent cache (unchanged files). */
   shallowCacheHits: number;
+  /** Parsed XML files served from the persistent records cache. */
+  recordsCacheHits: number;
+  /** Include/xi:include resolutions served from the resolve cache. */
+  resolveCacheHits: number;
+  /** Include/xi:include resolutions performed during this build. */
+  resolveCalls: number;
+  /** Time spent enumerating Include source candidates (ms). */
+  candidatesMs: number;
+  /** Time spent walking the include graph (ms). */
+  walkMs: number;
   assetCount: number;
   defineCount: number;
   manifestFiles: number;
@@ -110,8 +120,21 @@ export interface IndexOptions {
   walker: FileWalker;
   /** Optional parse-tree cache shared across rebuilds (owned by the workspace). */
   documentCache?: DocumentCache;
-  /** Optional shallow-scan cache shared across rebuilds (owned by the workspace). */
-  shallowCache?: ShallowScanCache;
+  /** Optional index-records cache shared across rebuilds (owned by the workspace). */
+  recordsCache?: IndexRecordsCache;
+  /** Optional include-resolution cache shared across rebuilds (owned by the workspace). */
+  resolveCache?: IncludeResolveCache;
+  /**
+   * When true, cached documents whose path is not in `changedFiles` are used
+   * without a per-file stat. The workspace enables this while a file watcher
+   * invalidates caches for changed paths; a forced reindex passes false.
+   */
+  trustUnchanged?: boolean;
+  /**
+   * Normalized paths (see `normKey`) known to have changed since the caches
+   * were populated. Only consulted when `trustUnchanged` is true.
+   */
+  changedFiles?: ReadonlySet<string>;
 }
 
 export interface FileWalker {
@@ -132,9 +155,9 @@ export interface ParsedFile {
   file: IndexedFile;
   parse: XmlDocument | null;
   /**
-   * Shallow records for large art-asset XML documents (.w3x etc.); null for
-   * fully parsed XML and for binary files.
+   * Compact index records (assets/defines/includes/xi:include with lines).
+   * Present for every indexable XML document; null for binary files.
    */
-  shallow: ShallowDocument | null;
+  records: IndexRecords | null;
   lineMap: LineMap | null;
 }
diff --git a/src/workspace.ts b/src/workspace.ts
index 997e862..7930791 100644
--- a/src/workspace.ts
+++ b/src/workspace.ts
@@ -3,7 +3,7 @@ import { existsSync } from "node:fs";
 import { join, dirname } from "node:path";
 import { CachedDirectoryWalker } from "./indexer/fileScanner";
 import { ModIndexer } from "./indexer/indexer";
-import { DocumentCache, ShallowScanCache } from "./indexer/caches";
+import { DocumentCache, IncludeResolveCache, IndexRecordsCache } from "./indexer/caches";
 import type { ModIndex } from "./indexer/types";
 import { readSettings, type ExtensionSettings } from "./settings";
 
@@ -20,13 +20,17 @@ export class ModWorkspace {
   // only re-reads files whose stat changed (crucial for the ~2.6 GB of .w3x
   // art assets in a project like Corona).
   private documentCache = new DocumentCache();
-  private shallowCache = new ShallowScanCache();
+  private recordsCache = new IndexRecordsCache();
+  private resolveCache = new IncludeResolveCache();
+  private context: vscode.ExtensionContext;
+  private watchers: vscode.FileSystemWatcher[] = [];
   private statusBar: vscode.StatusBarItem;
   private rebuildTimer: ReturnType<typeof setTimeout> | null = null;
   private building = false;
   private dirty = false;
 
   constructor(context: vscode.ExtensionContext) {
+    this.context = context;
     this.settings = readSettings();
     this.statusBar = vscode.window.createStatusBarItem(
       vscode.StatusBarAlignment.Left,
@@ -57,11 +61,69 @@ export class ModWorkspace {
       this.statusBar.hide();
       return;
     }
+    this.startWatching();
     this.statusBar.text = "$(sync~spin) RA3 XML: indexing…";
     this.statusBar.show();
     await this.rebuild();
   }
 
+  /**
+   * Invalidates cached documents for a path (called by the file watcher and
+   * on document save), so the next rebuild re-reads it instead of trusting
+   * the cached copy.
+   */
+  invalidate(path: string): void {
+    if (!path) return;
+    this.documentCache.invalidate(path);
+    this.recordsCache.invalidate(path);
+  }
+
+  /**
+   * Called when files are created or deleted: include-resolution results
+   * (which encode file existence) are no longer trustworthy.
+   */
+  invalidateExistence(): void {
+    this.resolveCache.clear();
+  }
+
+  /**
+   * Watches the project, SDK and extra DATA roots for file changes and
+   * invalidates the corresponding cache entries. With caches invalidated
+   * precisely, rebuilds can trust every other cached file and skip per-file
+   * stats (huge win on mechanical drives; Corona rebuild dropped from ~38s
+   * to a few seconds).
+   */
+  private startWatching(): void {
+    if (!this.projectRoot) return;
+    const roots = new Set([
+      this.projectRoot,
+      this.settings.sdkPath,
+      ...this.settings.additionalDataSearchPaths,
+    ]);
+    for (const root of roots) {
+      if (!existsSync(root)) continue;
+      try {
+        const watcher = vscode.workspace.createFileSystemWatcher(
+          new vscode.RelativePattern(root, "**/*"),
+        );
+        watcher.onDidCreate((uri) => {
+          this.invalidate(uri.fsPath);
+          this.invalidateExistence();
+        });
+        watcher.onDidChange((uri) => this.invalidate(uri.fsPath));
+        watcher.onDidDelete((uri) => {
+          this.invalidate(uri.fsPath);
+          this.invalidateExistence();
+        });
+        this.watchers.push(watcher);
+        this.context.subscriptions.push(watcher);
+      } catch {
+        // The root may be temporarily unavailable (e.g. removable drive);
+        // indexing still works, just without watcher-based invalidation.
+      }
+    }
+  }
+
   scheduleRebuild(): void {
     if (!this.projectRoot) return;
     if (this.rebuildTimer) clearTimeout(this.rebuildTimer);
@@ -70,12 +132,13 @@ export class ModWorkspace {
     }, REBUILD_DEBOUNCE_MS);
   }
 
-  async rebuild(): Promise<void> {
+  async rebuild(force = false): Promise<void> {
     if (!this.projectRoot) return;
     if (this.building) {
       this.dirty = true;
       return;
     }
+    if (force) this.resolveCache.clear();
     this.building = true;
     this.settings = readSettings();
     try {
@@ -88,7 +151,11 @@ export class ModWorkspace {
         additionalDataSearchPaths: this.settings.additionalDataSearchPaths,
         walker: this.walker,
         documentCache: this.documentCache,
-        shallowCache: this.shallowCache,
+        recordsCache: this.recordsCache,
+        resolveCache: this.resolveCache,
+        // Trust cache entries unless the user explicitly asked for a full
+        // verification (ra3modxml.reindex).
+        trustUnchanged: !force,
       });
       const started = Date.now();
       this.index = await indexer.build();
@@ -121,7 +188,7 @@ export class ModWorkspace {
     return {
       file: { path, stat: null },
       parse,
-      shallow: null,
+      records: null,
       lineMap: new LineMap(text),
     };
   }
diff --git a/test/caches.test.mjs b/test/caches.test.mjs
new file mode 100644
index 0000000..9f7b85a
--- /dev/null
+++ b/test/caches.test.mjs
@@ -0,0 +1,73 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import {
+  DocumentCache,
+  IncludeResolveCache,
+  IndexRecordsCache,
+} from "../out/indexer/caches.js";
+
+function parsed(path, elements) {
+  return {
+    file: { path, stat: { mtimeMs: 1, size: 1 } },
+    parse: { root: { name: "r" }, elements: new Array(elements), errors: [] },
+    records: null,
+    lineMap: null,
+  };
+}
+
+test("DocumentCache evicts the largest tree when over the element budget", () => {
+  const cache = new DocumentCache(64, 100);
+  cache.set(parsed("a.xml", 60));
+  cache.set(parsed("b.xml", 60));
+  assert.equal(cache.get("a.xml"), undefined, "largest tree evicted first");
+  assert.ok(cache.get("b.xml"));
+});
+
+test("DocumentCache evicts least recently used when over capacity", () => {
+  const cache = new DocumentCache(2, 1_000_000);
+  cache.set(parsed("a.xml", 10));
+  cache.set(parsed("b.xml", 10));
+  cache.set(parsed("c.xml", 10));
+  assert.equal(cache.get("a.xml"), undefined);
+  assert.ok(cache.get("b.xml"));
+  assert.ok(cache.get("c.xml"));
+});
+
+test("DocumentCache invalidate frees budget", () => {
+  const cache = new DocumentCache(64, 100);
+  cache.set(parsed("a.xml", 60));
+  cache.invalidate("a.xml");
+  cache.set(parsed("b.xml", 60));
+  assert.ok(cache.get("b.xml"), "invalidating a freed its budget share");
+  cache.set(parsed("c.xml", 60));
+  assert.equal(cache.get("a.xml"), undefined);
+  assert.ok(cache.get("c.xml"));
+});
+
+test("IndexRecordsCache stores and invalidates entries", () => {
+  const cache = new IndexRecordsCache();
+  const entry = {
+    stat: { mtimeMs: 1, size: 1 },
+    records: { assets: [], defines: [], includes: [], rootXiIncludes: [], nestedXiIncludes: [] },
+    kind: "full",
+  };
+  cache.set("a.xml", entry);
+  assert.equal(cache.get("a.xml"), entry);
+  cache.invalidate("a.xml");
+  assert.equal(cache.get("a.xml"), undefined);
+});
+
+test("IncludeResolveCache stores sources and manifest lookups", () => {
+  const cache = new IncludeResolveCache();
+  const key = "dir|DATA:static.xml";
+  const result = { path: "C:/sdk/static.xml", prefix: "DATA", raw: "DATA:static.xml" };
+  assert.equal(cache.get(key), undefined);
+  cache.set(key, result);
+  assert.equal(cache.get(key), result);
+  assert.equal(cache.getManifest("static.xml"), undefined);
+  cache.setManifest("static.xml", "C:/sdk/builtmods/static.manifest");
+  assert.equal(cache.getManifest("static.xml"), "C:/sdk/builtmods/static.manifest");
+  cache.clear();
+  assert.equal(cache.get(key), undefined);
+  assert.equal(cache.getManifest("static.xml"), undefined);
+});
diff --git a/test/indexer.test.mjs b/test/indexer.test.mjs
index 4b784f1..9cd0933 100644
--- a/test/indexer.test.mjs
+++ b/test/indexer.test.mjs
@@ -6,7 +6,11 @@ import fs from "node:fs";
 import os from "node:os";
 import { ModIndexer } from "../out/indexer/indexer.js";
 import { CachedDirectoryWalker } from "../out/indexer/fileScanner.js";
-import { DocumentCache, ShallowScanCache } from "../out/indexer/caches.js";
+import {
+  DocumentCache,
+  IncludeResolveCache,
+  IndexRecordsCache,
+} from "../out/indexer/caches.js";
 import { resolveReferenceTargetsForType } from "../out/indexer/refs.js";
 
 const root = dirname(dirname(fileURLToPath(import.meta.url)));
@@ -131,7 +135,8 @@ test("w3x files appear in Include source completion candidates", async () => {
 
 test("shallow scans and full parses are cached across rebuilds", async () => {
   const documentCache = new DocumentCache();
-  const shallowCache = new ShallowScanCache();
+  const recordsCache = new IndexRecordsCache();
+  const resolveCache = new IncludeResolveCache();
   const makeIndexer = () =>
     new ModIndexer({
       projectDir: project,
@@ -141,7 +146,8 @@ test("shallow scans and full parses are cached across rebuilds", async () => {
       additionalDataSearchPaths: [],
       walker: new CachedDirectoryWalker(),
       documentCache,
-      shallowCache,
+      recordsCache,
+      resolveCache,
     });
 
   const first = await makeIndexer().build();
@@ -150,10 +156,70 @@ test("shallow scans and full parses are cached across rebuilds", async () => {
   assert.equal(first.stats.shallowScannedFiles, 2, "w3x + sniffed w3d scanned on first build");
   assert.equal(second.stats.shallowScannedFiles, 0, "unchanged art assets are not re-scanned");
   assert.equal(second.stats.shallowCacheHits, 2);
+  assert.ok(second.stats.recordsCacheHits > 0, "XML records served from cache");
+  assert.ok(second.stats.resolveCacheHits > 0, "include resolutions served from cache");
+  assert.equal(second.stats.resolveCalls, 0, "no include re-resolved on a trusted rebuild");
   assert.equal(second.stats.assetCount, first.stats.assetCount);
   assert.equal(second.stats.indexedFiles, first.stats.indexedFiles);
 });
 
+test("trusted rebuilds skip unchanged files; invalidation forces re-reads", async () => {
+  const documentCache = new DocumentCache();
+  const recordsCache = new IndexRecordsCache();
+  const resolveCache = new IncludeResolveCache();
+  const opts = () => ({
+    projectDir: project,
+    sdkDir: sdk,
+    builtmodsDirs: [join(sdk, "builtmods")],
+    indexSageXml: true,
+    additionalDataSearchPaths: [],
+    walker: new CachedDirectoryWalker(),
+    documentCache,
+    recordsCache,
+    resolveCache,
+  });
+
+  // Trusted rebuild: cached files are reused without any per-file stat/read.
+  const first = await new ModIndexer({ ...opts(), trustUnchanged: true }).build();
+  assert.equal(first.stats.shallowScannedFiles, 2);
+  const second = await new ModIndexer({ ...opts(), trustUnchanged: true }).build();
+  assert.equal(second.stats.shallowScannedFiles, 0);
+  assert.equal(second.stats.shallowCacheHits, 2);
+  assert.ok(second.stats.recordsCacheHits > 0);
+
+  // Simulate the file watcher / save handler: invalidate one art asset.
+  // The next trusted rebuild must re-scan exactly that file.
+  recordsCache.invalidate(join(project, "Data", "Includes", "Models", "Tank_SKN.w3x"));
+  const third = await new ModIndexer({ ...opts(), trustUnchanged: true }).build();
+  assert.equal(third.stats.shallowScannedFiles, 1);
+  assert.equal(third.stats.shallowCacheHits, 1);
+  assert.ok(
+    third.assetsById.get("tank_skn")?.some((d) => d.type === "W3DContainer"),
+    "re-scanned w3x asset present",
+  );
+
+  // Invalidate one XML file: exactly its records are re-extracted.
+  recordsCache.invalidate(join(project, "Data", "Includes", "Units.xml"));
+  const fourth = await new ModIndexer({ ...opts(), trustUnchanged: true }).build();
+  assert.equal(fourth.stats.recordsCacheHits, third.stats.recordsCacheHits - 1);
+  assert.ok(
+    fourth.assetsById.get("testtank")?.some((d) => d.type === "GameObject"),
+    "re-parsed XML asset present",
+  );
+
+  // A forced rebuild (ra3modxml.reindex) verifies stats but still reuses
+  // content caches for unchanged files.
+  const forced = await new ModIndexer({ ...opts(), trustUnchanged: false }).build();
+  assert.equal(forced.stats.shallowScannedFiles, 0);
+  assert.equal(forced.stats.shallowCacheHits, 2);
+});
+
+test("index stats include candidate/walk phase timings", async () => {
+  const idx = await buildIndex();
+  assert.equal(typeof idx.stats.candidatesMs, "number");
+  assert.equal(typeof idx.stats.walkMs, "number");
+});
+
 test("w3x with a UTF-8 BOM is indexed with correct offsets", async (t) => {
   const tmp = fs.mkdtempSync(join(os.tmpdir(), "ra3modxml-bom-"));
   t.after(() => fs.rmSync(tmp, { recursive: true, force: true }));
diff --git a/test/records.test.mjs b/test/records.test.mjs
new file mode 100644
index 0000000..3ece3d5
--- /dev/null
+++ b/test/records.test.mjs
@@ -0,0 +1,65 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { parseXml, LineMap } from "../out/language/xmlParser.js";
+import { extractIndexRecords, recordsFromShallow } from "../out/indexer/records.js";
+import { scanXmlShallow } from "../out/indexer/shallowScan.js";
+
+test("extractIndexRecords mirrors the walk semantics", () => {
+  const text = `<?xml version="1.0"?>
+<AssetDeclaration>
+  <Defines>
+    <Define name="HP" value="100"/>
+  </Defines>
+  <Includes>
+    <Include type="all" source="Units.xml"/>
+    <Include type="instance" source="Base.xml"/>
+  </Includes>
+  <GameObject id="Tank" CommandSet="TankCommandSet"/>
+  <WeaponTemplate id="TankGun"/>
+  <xi:include href="DATA:Extra.xml" xpointer="xmlns(n=uri:ea.com:eala:asset) xpointer(/n:Extra/child::*)"/>
+  <GameObject id="Tank2">
+    <Draws>
+      <xi:include href="DATA:Nested.xml"/>
+    </Draws>
+  </GameObject>
+</AssetDeclaration>`;
+  const lineMap = new LineMap(text);
+  const records = extractIndexRecords(parseXml(text), lineMap);
+  assert.deepEqual(
+    records.assets.map((a) => [a.type, a.id, a.line]),
+    [
+      ["GameObject", "Tank", 10],
+      ["WeaponTemplate", "TankGun", 11],
+      ["GameObject", "Tank2", 13],
+    ],
+  );
+  assert.deepEqual(
+    records.defines.map((d) => [d.name, d.value]),
+    [["HP", "100"]],
+  );
+  assert.deepEqual(
+    records.includes.map((i) => [i.type, i.source]),
+    [
+      ["all", "Units.xml"],
+      ["instance", "Base.xml"],
+    ],
+  );
+  assert.deepEqual(
+    records.rootXiIncludes.map((x) => [x.href, x.line]),
+    [["DATA:Extra.xml", 12]],
+  );
+  assert.deepEqual(
+    records.nestedXiIncludes.map((x) => [x.href, x.line]),
+    [["DATA:Nested.xml", 15]],
+  );
+});
+
+test("recordsFromShallow converts offsets to 1-based lines", () => {
+  const text = `<AssetDeclaration>\n  <W3DContainer id="A"/>\n</AssetDeclaration>`;
+  const lineMap = new LineMap(text);
+  const records = recordsFromShallow(scanXmlShallow(text), lineMap);
+  assert.equal(records.assets.length, 1);
+  assert.equal(records.assets[0].type, "W3DContainer");
+  assert.equal(records.assets[0].id, "A");
+  assert.equal(records.assets[0].line, 2);
+});
diff --git a/test/shallowScan.test.mjs b/test/shallowScan.test.mjs
index 499793e..a461953 100644
--- a/test/shallowScan.test.mjs
+++ b/test/shallowScan.test.mjs
@@ -33,9 +33,10 @@ test("extracts top-level assets, includes, defines and xi:include", () => {
   assert.equal(doc.defines.length, 1);
   assert.equal(doc.defines[0].name, "MODEL_SCALE");
   assert.equal(doc.defines[0].value, "1.0");
-  assert.equal(doc.xiIncludes.length, 1);
-  assert.equal(doc.xiIncludes[0].href, "DATA:Includes/Extra.xml");
-  assert.match(doc.xiIncludes[0].xpointer, /xpointer\(/);
+  assert.equal(doc.rootXiIncludes.length, 1);
+  assert.equal(doc.rootXiIncludes[0].href, "DATA:Includes/Extra.xml");
+  assert.match(doc.rootXiIncludes[0].xpointer, /xpointer\(/);
+  assert.equal(doc.nestedXiIncludes.length, 0);
 
   // Recorded offsets must slice the original text back out.
   const container = doc.assets[0];
@@ -98,3 +99,24 @@ test("nested module payload does not create asset records", () => {
     ["MESH"],
   );
 });
+
+test("distinguishes root-level and nested xi:include", () => {
+  const doc = scanXmlShallow(`<AssetDeclaration>
+  <xi:include href="DATA:Top.xml"/>
+  <W3DMesh id="MESH">
+    <SubObject>
+      <RenderObject>
+        <xi:include href="DATA:Nested.xml" xpointer="xmlns(n=uri:ea.com:eala:asset) xpointer(/n:X/child::*)"/>
+      </RenderObject>
+    </SubObject>
+  </W3DMesh>
+</AssetDeclaration>`);
+  assert.deepEqual(
+    doc.rootXiIncludes.map((x) => x.href),
+    ["DATA:Top.xml"],
+  );
+  assert.deepEqual(
+    doc.nestedXiIncludes.map((x) => x.href),
+    ["DATA:Nested.xml"],
+  );
+});