diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -367,7 +367,7 @@
   auto End = positionToOffset(AST.Inputs.Contents, Sel.end);
   if (!End)
     return End.takeError();
-  return Tweak::Selection(AST.AST, *Begin, *End);
+  return Tweak::Selection(AST.Inputs.Index, AST.AST, *Begin, *End);
 }
 
 void ClangdServer::enumerateTweaks(PathRef File, Range Sel,
diff --git a/clang-tools-extra/clangd/refactor/Tweak.h b/clang-tools-extra/clangd/refactor/Tweak.h
--- a/clang-tools-extra/clangd/refactor/Tweak.h
+++ b/clang-tools-extra/clangd/refactor/Tweak.h
@@ -24,6 +24,7 @@
 #include "Protocol.h"
 #include "Selection.h"
 #include "SourceCode.h"
+#include "index/Index.h"
 #include "clang/Tooling/Core/Replacement.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringMap.h"
@@ -46,9 +47,12 @@
 public:
   /// Input to prepare and apply tweaks.
   struct Selection {
-    Selection(ParsedAST &AST, unsigned RangeBegin, unsigned RangeEnd);
+    Selection(const SymbolIndex *Index, ParsedAST &AST, unsigned RangeBegin,
+              unsigned RangeEnd);
     /// The text of the active document.
     llvm::StringRef Code;
+    /// The Index for handling codebase related queries.
+    const SymbolIndex *Index = nullptr;
     /// Parsed AST of the active file.
     ParsedAST *
     /// A location of the cursor in the editor.
diff --git a/clang-tools-extra/clangd/refactor/Tweak.cpp b/clang-tools-extra/clangd/refactor/Tweak.cpp
--- a/clang-tools-extra/clangd/refactor/Tweak.cpp
+++ b/clang-tools-extra/clangd/refactor/Tweak.cpp
@@ -9,6 +9,7 @@
 #include "Logger.h"
 #include "Path.h"
 #include "SourceCode.h"
+#include "index/Index.h"
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/STLExtras.h"
@@ -44,9 +45,10 @@
 }
 } // namespace
 
-Tweak::Selection::Selection(ParsedAST &AST, unsigned RangeBegin,
-                            unsigned RangeEnd)
-    : AST(AST), SelectionBegin(RangeBegin), SelectionEnd(RangeEnd),
+Tweak::Selection::Selection(const SymbolIndex *Index, ParsedAST &AST,
+                            unsigned RangeBegin, unsigned RangeEnd)
+    : Index(Index), AST(AST), SelectionBegin(RangeBegin),
+      SelectionEnd(RangeEnd),
       ASTSelection(AST.getASTContext(), AST.getTokens(), RangeBegin, RangeEnd) {
   auto &SM = AST.getSourceManager();
   Code = SM.getBufferData(SM.getMainFileID());
diff --git a/clang-tools-extra/clangd/unittests/TweakTesting.h b/clang-tools-extra/clangd/unittests/TweakTesting.h
--- a/clang-tools-extra/clangd/unittests/TweakTesting.h
+++ b/clang-tools-extra/clangd/unittests/TweakTesting.h
@@ -10,9 +10,11 @@
 #define LLVM_CLANG_TOOLS_EXTRA_UNITTESTS_CLANGD_TWEAKTESTING_H
 
 #include "TestTU.h"
+#include "index/Index.h"
 #include "llvm/ADT/StringMap.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <memory>
 #include <string>
 
 namespace clang {
@@ -66,6 +68,9 @@
   // Context in which snippets of code should be placed to run tweaks.
   CodeContext Context = File;
 
+  // Index to be passed into Tweak::Selection.
+  std::unique_ptr<const SymbolIndex> Index = nullptr;
+
   // Apply the current tweak to the range (or point) in MarkedCode.
   // MarkedCode will be wrapped according to the Context.
   //  - if the tweak produces edits, returns the edited code (without markings)
diff --git a/clang-tools-extra/clangd/unittests/TweakTesting.cpp b/clang-tools-extra/clangd/unittests/TweakTesting.cpp
--- a/clang-tools-extra/clangd/unittests/TweakTesting.cpp
+++ b/clang-tools-extra/clangd/unittests/TweakTesting.cpp
@@ -14,6 +14,7 @@
 #include "refactor/Tweak.h"
 #include "clang/Tooling/Core/Replacement.h"
 #include "llvm/Support/Error.h"
+#include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <string>
 
@@ -62,7 +63,7 @@
           cantFail(positionToOffset(A.code(), SelectionRng.end))};
 }
 
-MATCHER_P4(TweakIsAvailable, TweakID, Ctx, Header, ExtraFiles,
+MATCHER_P5(TweakIsAvailable, TweakID, Ctx, Header, ExtraFiles, Index,
            (TweakID + (negation ? " is unavailable" : " is available")).str()) {
   std::string WrappedCode = wrap(Ctx, arg);
   Annotations Input(WrappedCode);
@@ -72,7 +73,7 @@
   TU.Code = Input.code();
   TU.AdditionalFiles = std::move(ExtraFiles);
   ParsedAST AST = TU.build();
-  Tweak::Selection S(AST, Selection.first, Selection.second);
+  Tweak::Selection S(Index, AST, Selection.first, Selection.second);
   auto PrepareResult = prepareTweak(TweakID, S);
   if (PrepareResult)
     return true;
@@ -94,7 +95,7 @@
   TU.Code = Input.code();
   TU.ExtraArgs = ExtraArgs;
   ParsedAST AST = TU.build();
-  Tweak::Selection S(AST, Selection.first, Selection.second);
+  Tweak::Selection S(Index.get(), AST, Selection.first, Selection.second);
 
   auto T = prepareTweak(TweakID, S);
   if (!T) {
@@ -129,8 +130,8 @@
 }
 
 ::testing::Matcher<llvm::StringRef> TweakTest::isAvailable() const {
-  return TweakIsAvailable(llvm::StringRef(TweakID), Context, Header,
-                          ExtraFiles);
+  return TweakIsAvailable(llvm::StringRef(TweakID), Context, Header, ExtraFiles,
+                          Index.get());
 }
 
 std::vector<std::string> TweakTest::expandCases(llvm::StringRef MarkedCode) {