diff --git a/src/TransclusionIndex.ts b/src/TransclusionIndex.ts
new file mode 100644
index 0000000..8ca6952
--- /dev/null
+++ b/src/TransclusionIndex.ts
@@ -0,0 +1,133 @@
+import {Vault,TFile,TAbstractFile} from 'obsidian';
+
+class TransclusionItem {
+  public excalidrawFilePath: string;
+  public sourceFilePath: string;
+  public startIndex: number;
+  public length: number;
+
+  constructor(excalidrawFilePath: string, sourceFilePath: string, startIndex: number, length: number ) {
+    this.excalidrawFilePath = excalidrawFilePath;
+    this.sourceFilePath = sourceFilePath;
+    this.startIndex = startIndex;
+    this.length = length;
+  }
+}
+
+class TransclusionIndex {
+  private vault: Vault;
+  private transclusions: Map<string, TransclusionItem[]>;
+  private listeners: ((transclusions: TransclusionItem[]) => void)[];
+
+  constructor(vault: Vault, listener: (todos: TransclusionItem[]) => void) {
+    this.vault = vault;
+    this.transclusions = new Map<string, TransclusionItem[]>();
+    this.listeners = [listener];
+  }
+
+  async reloadIndex() {
+    await this.initialize();
+  }
+
+  async initialize(): Promise<void> {
+    // TODO: persist index & last sync timestamp; only parse files that changed since then.
+    const transclusionMap = new Map<string, TransclusionItem[]>();
+    let numberOfTransclusions = 0;
+
+    const markdownFiles = this.vault.getMarkdownFiles();
+    for (const file of markdownFiles) {     
+      const transclusions = await this.parseTransclusionsInFile(file);
+      numberOfTransclusions += transclusions.length;
+      if (transclusions.length > 0) {
+        transclusionMap.set(file.path, transclusions);
+      }
+    }
+
+    this.transclusions = transclusionMap;
+    this.registerEventHandlers();
+    this.invokeListeners();
+  }
+
+  updateTransclusion(transclusion: TransclusionItem, newFilePath: string): void {
+    const file = this.vault.getAbstractFileByPath(transclusion.sourceFilePath) as TFile;
+    const fileContents = this.vault.read(file);
+    fileContents.then((c: string) => {
+      const newContents = c.substring(0, transclusion.startIndex) + newFilePath + c.substring(transclusion.startIndex + transclusion.length);
+      this.vault.modify(file, newContents);
+    });
+  }
+
+  private indexAbstractFile(file: TAbstractFile) {
+    if (!(file instanceof TFile)) {
+      return;
+    }
+    this.indexFile(file as TFile);
+  }
+
+  private indexFile(file: TFile) {
+    this.parseTransclusionsInFile(file).then((transclusions) => {
+      this.transclusions.set(file.path, transclusions);
+      this.invokeListeners();
+    });
+  }
+
+  private clearIndex(path: string, silent = false) {
+    this.transclusions.delete(path);
+    if (!silent) {
+      this.invokeListeners();
+    }
+  }
+
+  private async parseTransclusionsInFile(file: TFile): Promise<TransclusionItem[]> {
+    const transclusionParser = new TransclusionParser();
+    const fileContents = await this.vault.cachedRead(file);
+    return transclusionParser.parseTransclusions(file.path, fileContents);
+  }
+
+  private registerEventHandlers() {
+    this.vault.on('create', (file: TAbstractFile) => {
+      this.indexAbstractFile(file);
+    });
+    this.vault.on('modify', (file: TAbstractFile) => {
+      this.indexAbstractFile(file);
+    });
+    this.vault.on('delete', (file: TAbstractFile) => {
+      this.clearIndex(file.path);
+    });
+    // We could simply change the references to the old path, but parsing again does the trick as well
+    this.vault.on('rename', (file: TAbstractFile, oldPath: string) => {
+      this.clearIndex(oldPath);
+      this.indexAbstractFile(file);
+    });
+  }
+
+  private invokeListeners() {
+    const transclusions = ([] as TransclusionItem[]).concat(...Array.from(this.transclusions.values()));
+    this.listeners.forEach((listener) => listener(transclusions));
+  }
+}
+
+export class TransclusionParser {
+  constructor() {    
+  }
+
+  async parseTransclusions(filePath: string, fileContents: string): Promise<TransclusionItem[]> {
+    const pattern =  new RegExp('('+String.fromCharCode(96,96,96)+'excalidraw\\s+.*\\[{2})([^|\\]]*).*\\]{2}[\\s]+'+String.fromCharCode(96,96,96),'gm');
+    return [...fileContents.matchAll(pattern)].map((transclusion) => this.parseTransclusion(filePath, transclusion));
+  }
+
+  private parseTransclusion(filePath: string, entry: RegExpMatchArray): TransclusionItem {
+    const offset = entry[1].length;
+    const excalidrawFilePath = entry[2];
+    if(!excalidrawFilePath && !excalidrawFilePath.endsWith('.excalidraw')) {
+      return null;
+    }
+
+    return new TransclusionItem(
+      excalidrawFilePath,
+      filePath,
+      (entry.index ?? 0) + offset,
+      excalidrawFilePath.length,
+    );
+  }
+}
diff --git a/tsconfig.json b/tsconfig.json
index 989cd31..24e04a9 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -13,7 +13,7 @@
       "dom",
       "es5",
       "scripthost",
-      "es2015",
+      "es2020",
       "DOM.Iterable"
     ],
     "jsx": "react",