diff --git a/package.json b/package.json
index d63d8904c5836..ffdefcd2871ec 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
     "name": "typescript",
     "author": "Microsoft Corp.",
     "homepage": "https://www.typescriptlang.org/",
-    "version": "4.1.3",
+    "version": "4.1.3-lsif.1",
     "license": "Apache-2.0",
     "description": "TypeScript is a language for application scale JavaScript development",
     "keywords": [
@@ -128,6 +128,5 @@
         "@microsoft/typescript-etw": false,
         "source-map-support": false,
         "inspector": false
-    },
-    "dependencies": {}
+    }
 }
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1ac7a4475fdc4..07c9583e45ecc 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -381,6 +381,9 @@ namespace ts {
         // extra cost of calling `getParseTreeNode` when calling these functions from inside the
         // checker.
         const checker: TypeChecker = {
+            setSymbolChainCache: (cache: SymbolChainCache | undefined): void => {
+                nodeBuilder.setSymbolChainCache(cache);
+            },
             getNodeCount: () => sum(host.getSourceFiles(), "nodeCount"),
             getIdentifierCount: () => sum(host.getSourceFiles(), "identifierCount"),
             getSymbolCount: () => sum(host.getSourceFiles(), "symbolCount") + symbolCount,
@@ -4323,7 +4326,9 @@ namespace ts {
         }
 
         function createNodeBuilder() {
+            let symbolChainCache: SymbolChainCache | undefined;
             return {
+                setSymbolChainCache: (cache: SymbolChainCache | undefined): void => { symbolChainCache = cache },
                 typeToTypeNode: (type: Type, enclosingDeclaration?: Node, flags?: NodeBuilderFlags, tracker?: SymbolTracker) =>
                     withContext(enclosingDeclaration, flags, tracker, context => typeToTypeNodeHelper(type, context)),
                 indexInfoToIndexSignatureDeclaration: (indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags, tracker?: SymbolTracker) =>
@@ -4341,7 +4346,7 @@ namespace ts {
                 typeParameterToDeclaration: (parameter: TypeParameter, enclosingDeclaration?: Node, flags?: NodeBuilderFlags, tracker?: SymbolTracker) =>
                     withContext(enclosingDeclaration, flags, tracker, context => typeParameterToDeclaration(parameter, context)),
                 symbolTableToDeclarationStatements: (symbolTable: SymbolTable, enclosingDeclaration?: Node, flags?: NodeBuilderFlags, tracker?: SymbolTracker, bundled?: boolean) =>
-                    withContext(enclosingDeclaration, flags, tracker, context => symbolTableToDeclarationStatements(symbolTable, context, bundled)),
+                    withContext(enclosingDeclaration, flags, tracker, context => symbolTableToDeclarationStatements(symbolTable, context, bundled))
             };
 
             function withContext<T>(enclosingDeclaration: Node | undefined, flags: NodeBuilderFlags | undefined, tracker: SymbolTracker | undefined, cb: (context: NodeBuilderContext) => T): T | undefined {
@@ -4361,6 +4366,7 @@ namespace ts {
                         isSourceOfProjectReferenceRedirect: fileName => host.isSourceOfProjectReferenceRedirect(fileName),
                         fileExists: fileName => host.fileExists(fileName),
                     } : undefined },
+                    cache: symbolChainCache,
                     encounteredError: false,
                     visitedTypes: undefined,
                     symbolDepth: undefined,
@@ -5333,6 +5339,30 @@ namespace ts {
 
                 /** @param endOfChain Set to false for recursive calls; non-recursive calls should always output something. */
                 function getSymbolChain(symbol: Symbol, meaning: SymbolFlags, endOfChain: boolean): Symbol[] | undefined {
+                    let key: SymbolChainCacheKey | undefined;
+                    let result: Symbol[] | undefined;
+                    if (context.cache) {
+                        key = {
+                            symbol,
+                            enclosingDeclaration: context.enclosingDeclaration,
+                            flags: context.flags,
+                            meaning: meaning,
+                            yieldModuleSymbol: yieldModuleSymbol,
+                            endOfChain: endOfChain
+                        }
+                        result = context.cache.lookup(key);
+                        if (result) {
+                            return result;
+                        }
+                    }
+                    result = doGetSymbolChain(symbol, meaning, endOfChain);
+                    if (result && key && context.cache) {
+                        context.cache.cache(key, result);
+                    }
+                    return result;
+                }
+
+                function doGetSymbolChain(symbol: Symbol, meaning: SymbolFlags, endOfChain: boolean): Symbol[] | undefined {
                     let accessibleSymbolChain = getAccessibleSymbolChain(symbol, context.enclosingDeclaration, meaning, !!(context.flags & NodeBuilderFlags.UseOnlyExternalAliasing));
                     let parentSpecifiers: (string | undefined)[];
                     if (!accessibleSymbolChain ||
@@ -7446,6 +7476,7 @@ namespace ts {
             enclosingDeclaration: Node | undefined;
             flags: NodeBuilderFlags;
             tracker: SymbolTracker;
+            cache: SymbolChainCache | undefined;
 
             // State
             encounteredError: boolean;
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 72fc2ab72aae7..f956d6c5d0692 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3919,7 +3919,22 @@ namespace ts {
         readonly redirectTargetsMap: RedirectTargetsMap;
     }
 
+    export interface SymbolChainCacheKey {
+        symbol: Symbol;
+        enclosingDeclaration?: Node;
+        flags: NodeBuilderFlags;
+        meaning: SymbolFlags;
+        yieldModuleSymbol?: boolean;
+        endOfChain: boolean;
+    }
+
+    export interface SymbolChainCache {
+        lookup(key: SymbolChainCacheKey): Symbol[] | undefined;
+        cache(key: SymbolChainCacheKey, value: Symbol[]): void;
+    }
+
     export interface TypeChecker {
+        setSymbolChainCache(cache: SymbolChainCache | undefined): void;
         getTypeOfSymbolAtLocation(symbol: Symbol, node: Node): Type;
         getDeclaredTypeOfSymbol(symbol: Symbol): Type;
         getPropertiesOfType(type: Type): Symbol[];
diff --git a/src/harness/client.ts b/src/harness/client.ts
index 230517b599db9..e357c041c2456 100644
--- a/src/harness/client.ts
+++ b/src/harness/client.ts
@@ -163,7 +163,11 @@ namespace ts.server {
             return { line, character: offset };
         }
 
-        getQuickInfoAtPosition(fileName: string, position: number): QuickInfo {
+        getQuickInfoAtPosition(fileName: string, position: number): QuickInfo;
+        getQuickInfoAtPosition(node: ts.Node, sourceFile?: ts.SourceFile): QuickInfo;
+        getQuickInfoAtPosition(arg0: string | ts.Node, arg1: number | ts.SourceFile | undefined): QuickInfo {
+            const fileName = typeof arg0 === "string" ? arg0 : arg1 !== undefined ? (arg1 as ts.SourceFile).fileName : arg0.getSourceFile().fileName;
+            const position = typeof arg0 === "string" ? arg1 as number : arg0.getStart(arg1 as ts.SourceFile);
             const args = this.createFileLocationRequestArgs(fileName, position);
 
             const request = this.processRequest<protocol.QuickInfoRequest>(CommandNames.Quickinfo, args);
@@ -574,7 +578,10 @@ namespace ts.server {
             }));
         }
 
-        getOutliningSpans(file: string): OutliningSpan[] {
+        getOutliningSpans(file: string): OutliningSpan[];
+        getOutliningSpans(sourceFile: ts.SourceFile): OutliningSpan[];
+        getOutliningSpans(arg0: string | ts.SourceFile): OutliningSpan[] {
+            const file = typeof arg0 === "string" ? arg0 : arg0.fileName;
             const request = this.processRequest<protocol.OutliningSpansRequest>(CommandNames.GetOutliningSpans, { file });
             const response = this.processResponse<protocol.OutliningSpansResponse>(request);
 
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index cc2f285fc5c8f..df1a215d64065 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -480,8 +480,10 @@ namespace Harness.LanguageService {
         getCompletionEntrySymbol(): ts.Symbol {
             throw new Error("getCompletionEntrySymbol not implemented across the shim layer.");
         }
-        getQuickInfoAtPosition(fileName: string, position: number): ts.QuickInfo {
-            return unwrapJSONCallResult(this.shim.getQuickInfoAtPosition(fileName, position));
+        getQuickInfoAtPosition(filename: string, position: number): ts.QuickInfo | undefined;
+        getQuickInfoAtPosition(node: ts.Node, sourceFile: ts.SourceFile | undefined): ts.QuickInfo | undefined;
+        getQuickInfoAtPosition(arg0: string | ts.Node, arg1: number | ts.SourceFile | undefined): ts.QuickInfo | undefined {
+            return unwrapJSONCallResult(this.shim.getQuickInfoAtPosition(arg0 as any, arg1 as any));
         }
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): ts.TextSpan {
             return unwrapJSONCallResult(this.shim.getNameOrDottedNameSpan(fileName, startPos, endPos));
@@ -534,8 +536,8 @@ namespace Harness.LanguageService {
         getNavigationTree(fileName: string): ts.NavigationTree {
             return unwrapJSONCallResult(this.shim.getNavigationTree(fileName));
         }
-        getOutliningSpans(fileName: string): ts.OutliningSpan[] {
-            return unwrapJSONCallResult(this.shim.getOutliningSpans(fileName));
+        getOutliningSpans(arg0: string | ts.SourceFile): ts.OutliningSpan[] {
+            return unwrapJSONCallResult(this.shim.getOutliningSpans(arg0 as any));
         }
         getTodoComments(fileName: string, descriptors: ts.TodoCommentDescriptor[]): ts.TodoComment[] {
             return unwrapJSONCallResult(this.shim.getTodoComments(fileName, JSON.stringify(descriptors)));
@@ -855,7 +857,6 @@ namespace Harness.LanguageService {
                             create(info: ts.server.PluginCreateInfo) {
                                 const proxy = makeDefaultProxy(info);
                                 const langSvc: any = info.languageService;
-                                // eslint-disable-next-line only-arrow-functions
                                 proxy.getQuickInfoAtPosition = function () {
                                     const parts = langSvc.getQuickInfoAtPosition.apply(langSvc, arguments);
                                     if (parts.displayParts.length > 0) {
diff --git a/src/services/services.ts b/src/services/services.ts
index 89292f09cf5b0..a2988cc08ae48 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -1567,11 +1567,15 @@ namespace ts {
             return Completions.getCompletionEntrySymbol(program, log, getValidSourceFile(fileName), position, { name, source }, host, preferences);
         }
 
-        function getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined {
-            synchronizeHostData();
+        function getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined;
+        function getQuickInfoAtPosition(node: ts.Node, sourceFile?: ts.SourceFile): QuickInfo | undefined;
+        function getQuickInfoAtPosition(arg0: string | ts.Node, arg1: number | ts.SourceFile | undefined): QuickInfo | undefined {
+             synchronizeHostData();
+
+            const sourceFile: ts.SourceFile = typeof arg0 === 'string' ? getValidSourceFile(arg0) : (arg1 !== undefined) ? arg1 as ts.SourceFile : arg0.getSourceFile();
+            const node: ts.Node = typeof arg0 === 'string' ? getTouchingPropertyName(sourceFile, arg1 as number) : arg0;
+            const position: number = typeof arg1 === 'number' ? arg1 : node.getStart(sourceFile, false);
 
-            const sourceFile = getValidSourceFile(fileName);
-            const node = getTouchingPropertyName(sourceFile, position);
             if (node === sourceFile) {
                 // Avoid giving quickInfo for the sourceFile as a whole.
                 return undefined;
@@ -1870,11 +1874,13 @@ namespace ts {
             return ts.getEncodedSyntacticClassifications(cancellationToken, syntaxTreeCache.getCurrentSourceFile(fileName), span);
         }
 
-        function getOutliningSpans(fileName: string): OutliningSpan[] {
-            // doesn't use compiler - no need to synchronize with host
-            const sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);
-            return OutliningElementsCollector.collectElements(sourceFile, cancellationToken);
-        }
+        function getOutliningSpans(fileName: string): OutliningSpan[];
+        function getOutliningSpans(sourceFile: ts.SourceFile): OutliningSpan[];
+        function getOutliningSpans(arg0: string | ts.SourceFile): OutliningSpan[] {
+             // doesn't use compiler - no need to synchronize with host
+            const sourceFile = typeof arg0 === 'string' ? syntaxTreeCache.getCurrentSourceFile(arg0) : arg0;
+             return OutliningElementsCollector.collectElements(sourceFile, cancellationToken);
+         }
 
         const braceMatching = new Map(getEntries({
             [SyntaxKind.OpenBraceToken]: SyntaxKind.CloseBraceToken,
diff --git a/src/services/shims.ts b/src/services/shims.ts
index 14f6a61e7478f..eef7207195df6 100644
--- a/src/services/shims.ts
+++ b/src/services/shims.ts
@@ -756,12 +756,16 @@ namespace ts {
          * Computes a string representation of the type at the requested position
          * in the active file.
          */
-        public getQuickInfoAtPosition(fileName: string, position: number): string {
-            return this.forwardJSONCall(
-                `getQuickInfoAtPosition('${fileName}', ${position})`,
-                () => this.languageService.getQuickInfoAtPosition(fileName, position)
-            );
-        }
+        public getQuickInfoAtPosition(fileName: string, position: number): string;
+        public getQuickInfoAtPosition(node: ts.Node, sourceFile: ts.SourceFile | undefined): string;
+        public getQuickInfoAtPosition(arg0: string | ts.Node, arg1: number | ts.SourceFile | undefined): string {
+            const fileName = typeof arg0 === "string" ? arg0 : arg1 !== undefined ? (arg1 as ts.SourceFile).fileName : arg0.getSourceFile().fileName;
+            const position = typeof arg0 === "string" ? arg1 as number : arg0.getStart(arg1 as ts.SourceFile);
+             return this.forwardJSONCall(
+                 `getQuickInfoAtPosition('${fileName}', ${position})`,
+                () => this.languageService.getQuickInfoAtPosition(arg0 as any, arg1 as any)
+             );
+         }
 
 
         /// NAMEORDOTTEDNAMESPAN
@@ -1017,12 +1021,15 @@ namespace ts {
             );
         }
 
-        public getOutliningSpans(fileName: string): string {
-            return this.forwardJSONCall(
-                `getOutliningSpans('${fileName}')`,
-                () => this.languageService.getOutliningSpans(fileName)
-            );
-        }
+        public getOutliningSpans(fileName: string): string;
+        public getOutliningSpans(sourceFile: ts.SourceFile): string;
+        public getOutliningSpans(arg0: string | ts.SourceFile): string {
+            let fileName = typeof arg0 === "string" ? arg0 : arg0.fileName;
+             return this.forwardJSONCall(
+                 `getOutliningSpans('${fileName}')`,
+                () => this.languageService.getOutliningSpans(arg0 as any)
+             );
+         }
 
         public getTodoComments(fileName: string, descriptors: string): string {
             return this.forwardJSONCall(
diff --git a/src/services/types.ts b/src/services/types.ts
index 7fb1166eb19c8..bb54e018eb8fc 100644
--- a/src/services/types.ts
+++ b/src/services/types.ts
@@ -446,6 +446,7 @@ namespace ts {
          * @param position A zero-based index of the character where you want the quick info
          */
         getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined;
+        getQuickInfoAtPosition(node: ts.Node, sourceFile?: ts.SourceFile): QuickInfo | undefined;
 
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): TextSpan | undefined;
 
@@ -479,6 +480,7 @@ namespace ts {
         provideCallHierarchyOutgoingCalls(fileName: string, position: number): CallHierarchyOutgoingCall[];
 
         getOutliningSpans(fileName: string): OutliningSpan[];
+        getOutliningSpans(sourceFile: ts.SourceFile): OutliningSpan[];
         getTodoComments(fileName: string, descriptors: TodoCommentDescriptor[]): TodoComment[];
         getBraceMatchingAtPosition(fileName: string, position: number): TextSpan[];
         getIndentationAtPosition(fileName: string, position: number, options: EditorOptions | EditorSettings): number;