diff --git a/extensions/html-language-features/server/src/htmlServer.ts b/extensions/html-language-features/server/src/htmlServer.ts
index 29aa041746c..22ab2e18076 100644
--- a/extensions/html-language-features/server/src/htmlServer.ts
+++ b/extensions/html-language-features/server/src/htmlServer.ts
@@ -7,11 +7,12 @@ import {
 	Connection, TextDocuments, InitializeParams, InitializeResult, RequestType,
 	DocumentRangeFormattingRequest, Disposable, ServerCapabilities,
 	ConfigurationRequest, ConfigurationParams, DidChangeWorkspaceFoldersNotification,
-	DocumentColorRequest, ColorPresentationRequest, TextDocumentSyncKind, NotificationType, RequestType0, DocumentFormattingRequest, FormattingOptions, TextEdit
+	DocumentColorRequest, ColorPresentationRequest, TextDocumentSyncKind, NotificationType, RequestType0, DocumentFormattingRequest, FormattingOptions, TextEdit,
+	TextDocumentContentRequest
 } from 'vscode-languageserver';
 import {
 	getLanguageModes, LanguageModes, Settings, TextDocument, Position, Diagnostic, WorkspaceFolder, ColorInformation,
-	Range, DocumentLink, SymbolInformation, TextDocumentIdentifier, isCompletionItemData
+	Range, DocumentLink, SymbolInformation, TextDocumentIdentifier, isCompletionItemData, FILE_PROTOCOL
 } from './modes/languageModes';
 
 import { format } from './modes/formatting';
@@ -213,6 +214,9 @@ export function startServer(connection: Connection, runtime: RuntimeEnvironment)
 				documentSelector: null,
 				interFileDependencies: false,
 				workspaceDiagnostics: false
+			},
+			workspace: {
+				textDocumentContent: { schemes: [FILE_PROTOCOL] }
 			}
 		};
 		return { capabilities };
@@ -584,6 +588,18 @@ export function startServer(connection: Connection, runtime: RuntimeEnvironment)
 		});
 	});
 
+	connection.onRequest(TextDocumentContentRequest.type, (params, token) => {
+		return runSafe(runtime, async () => {
+			for (const languageMode of languageModes.getAllModes()) {
+				const content = await languageMode.getTextDocumentContent?.(params.uri);
+				if (content) {
+					return { text: content };
+				}
+			}
+			return null;
+		}, null, `Error while computing text document content for ${params.uri}`, token);
+	});
+
 	// Listen on the connection
 	connection.listen();
 }
diff --git a/extensions/html-language-features/server/src/modes/javascriptMode.ts b/extensions/html-language-features/server/src/modes/javascriptMode.ts
index d820810c920..aafb54a64b5 100644
--- a/extensions/html-language-features/server/src/modes/javascriptMode.ts
+++ b/extensions/html-language-features/server/src/modes/javascriptMode.ts
@@ -8,7 +8,7 @@ import {
 	SymbolInformation, SymbolKind, CompletionItem, Location, SignatureHelp, SignatureInformation, ParameterInformation,
 	Definition, TextEdit, TextDocument, Diagnostic, DiagnosticSeverity, Range, CompletionItemKind, Hover,
 	DocumentHighlight, DocumentHighlightKind, CompletionList, Position, FormattingOptions, FoldingRange, FoldingRangeKind, SelectionRange,
-	LanguageMode, Settings, SemanticTokenData, Workspace, DocumentContext, CompletionItemData, isCompletionItemData
+	LanguageMode, Settings, SemanticTokenData, Workspace, DocumentContext, CompletionItemData, isCompletionItemData, FILE_PROTOCOL, DocumentUri
 } from './languageModes';
 import { getWordAtText, isWhitespaceOnly, repeat } from '../utils/strings';
 import { HTMLDocumentRegions } from './embeddedSupport';
@@ -77,18 +77,24 @@ function getLanguageServiceHost(scriptKind: ts.ScriptKind) {
 
 			}
 		};
-		return ts.createLanguageService(host);
+		return {
+			service: ts.createLanguageService(host),
+			loadLibrary: libs.loadLibrary,
+		};
 	});
 	return {
 		async getLanguageService(jsDocument: TextDocument): Promise<ts.LanguageService> {
 			currentTextDocument = jsDocument;
-			return jsLanguageService;
+			return (await jsLanguageService).service;
 		},
 		getCompilationSettings() {
 			return compilerOptions;
 		},
+		async loadLibrary(fileName: string) {
+			return (await jsLanguageService).loadLibrary(fileName);
+		},
 		dispose() {
-			jsLanguageService.then(s => s.dispose());
+			jsLanguageService.then(s => s.service.dispose());
 		}
 	};
 }
@@ -104,6 +110,8 @@ export function getJavaScriptMode(documentRegions: LanguageModelCache<HTMLDocume
 	const host = getLanguageServiceHost(languageId === 'javascript' ? ts.ScriptKind.JS : ts.ScriptKind.TS);
 	const globalSettings: Settings = {};
 
+	const libParentUri = `${FILE_PROTOCOL}://${languageId}/libs/`;
+
 	function updateHostSettings(settings: Settings) {
 		const hostSettings = host.getCompilationSettings();
 		hostSettings.experimentalDecorators = settings?.['js/ts']?.implicitProjectConfig?.experimentalDecorators;
@@ -302,12 +310,25 @@ export function getJavaScriptMode(documentRegions: LanguageModelCache<HTMLDocume
 			const jsLanguageService = await host.getLanguageService(jsDocument);
 			const definition = jsLanguageService.getDefinitionAtPosition(jsDocument.uri, jsDocument.offsetAt(position));
 			if (definition) {
-				return definition.filter(d => d.fileName === jsDocument.uri).map(d => {
-					return {
-						uri: document.uri,
-						range: convertRange(jsDocument, d.textSpan)
-					};
-				});
+				return (await Promise.all(definition.map(async d => {
+					if (d.fileName === jsDocument.uri) {
+						return {
+							uri: document.uri,
+							range: convertRange(jsDocument, d.textSpan)
+						};
+					} else {
+						const libUri = libParentUri + d.fileName;
+						const content = await host.loadLibrary(d.fileName);
+						if (!content) {
+							return undefined;
+						}
+						const libDocument = TextDocument.create(libUri, languageId, 1, content);
+						return {
+							uri: libUri,
+							range: convertRange(libDocument, d.textSpan)
+						};
+					}
+				}))).filter(d => !!d);
 			}
 			return null;
 		},
@@ -402,6 +423,12 @@ export function getJavaScriptMode(documentRegions: LanguageModelCache<HTMLDocume
 		getSemanticTokenLegend(): { types: string[]; modifiers: string[] } {
 			return getSemanticTokenLegend();
 		},
+		async getTextDocumentContent(documentUri: DocumentUri): Promise<string | undefined> {
+			if (documentUri.startsWith(libParentUri)) {
+				return host.loadLibrary(documentUri.substring(libParentUri.length));
+			}
+			return undefined;
+		},
 		dispose() {
 			host.dispose();
 			jsDocuments.dispose();
diff --git a/extensions/html-language-features/server/src/modes/languageModes.ts b/extensions/html-language-features/server/src/modes/languageModes.ts
index 803fa6c1c87..45d0b8fabe7 100644
--- a/extensions/html-language-features/server/src/modes/languageModes.ts
+++ b/extensions/html-language-features/server/src/modes/languageModes.ts
@@ -14,7 +14,7 @@ import {
 	Color, ColorInformation, ColorPresentation, WorkspaceEdit,
 	WorkspaceFolder
 } from 'vscode-languageserver';
-import { TextDocument } from 'vscode-languageserver-textdocument';
+import { DocumentUri, TextDocument } from 'vscode-languageserver-textdocument';
 
 import { getLanguageModelCache, LanguageModelCache } from '../languageModelCache';
 import { getCSSMode } from './cssMode';
@@ -34,7 +34,7 @@ export {
 
 export { ClientCapabilities, DocumentContext, LanguageService, HTMLDocument, HTMLFormatConfiguration, TokenType } from 'vscode-html-languageservice';
 
-export { TextDocument } from 'vscode-languageserver-textdocument';
+export { TextDocument, DocumentUri } from 'vscode-languageserver-textdocument';
 
 export interface Settings {
 	readonly css?: any;
@@ -89,6 +89,7 @@ export interface LanguageMode {
 	onDocumentRemoved(document: TextDocument): void;
 	getSemanticTokens?(document: TextDocument): Promise<SemanticTokenData[]>;
 	getSemanticTokenLegend?(): { types: string[]; modifiers: string[] };
+	getTextDocumentContent?(uri: DocumentUri): Promise<string | undefined>;
 	dispose(): void;
 }
 
@@ -108,6 +109,8 @@ export interface LanguageModeRange extends Range {
 	attributeValue?: boolean;
 }
 
+export const FILE_PROTOCOL = 'html-server';
+
 export function getLanguageModes(supportedLanguages: { [languageId: string]: boolean }, workspace: Workspace, clientCapabilities: ClientCapabilities, requestService: FileSystemProvider): LanguageModes {
 	const htmlLanguageService = getHTMLLanguageService({ clientCapabilities, fileSystemProvider: requestService });
 	const cssLanguageService = getCSSLanguageService({ clientCapabilities, fileSystemProvider: requestService });