diff --git a/include/Protocol/Lifecycle/Initialize.h b/include/Protocol/Lifecycle/Initialize.h
index 041eec2c..3a1d81a7 100644
--- a/include/Protocol/Lifecycle/Initialize.h
+++ b/include/Protocol/Lifecycle/Initialize.h
@@ -2,8 +2,15 @@
 
 namespace clice::protocol {
 
+enum class TextDocumentSyncKind {
+    None = 0,
+    Full = 1,
+    Incremental = 2,
+};
+
 struct ServerCapabilities {
     std::string_view positionEncoding = "utf-16";
+    TextDocumentSyncKind textDocumentSync = TextDocumentSyncKind::Full;
     SemanticTokensOptions semanticTokensProvider;
 };
 
diff --git a/include/Server/Command.h b/include/Server/Command.h
index 47e7288d..0d9d9028 100644
--- a/include/Server/Command.h
+++ b/include/Server/Command.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <clang/Tooling/CompilationDatabase.h>
 
 namespace clice {
@@ -13,10 +15,4 @@ private:
     std::unique_ptr<clang::tooling::CompilationDatabase> CDB;
 };
 
-namespace global {
-
-extern CompilationDatabase CDB;
-
-};
-
 }  // namespace clice
diff --git a/include/Server/Option.h b/include/Server/Option.h
index fcc2f0f4..b18c3c59 100644
--- a/include/Server/Option.h
+++ b/include/Server/Option.h
@@ -11,8 +11,4 @@ struct Option {
     void parse(int argc, const char** argv);
 };
 
-namespace global {
-extern struct Option option;
-};
-
 }  // namespace clice
diff --git a/include/Server/Scheduler .h b/include/Server/Scheduler .h
new file mode 100644
index 00000000..eb33f2c6
--- /dev/null
+++ b/include/Server/Scheduler .h	
@@ -0,0 +1,26 @@
+#include <llvm/ADT/StringMap.h>
+#include <Support/JSON.h>
+#include <AST/Preamble.h>
+#include <AST/ParsedAST.h>
+
+namespace clice {
+
+/// responsible for file management and scheduling tasks.
+class Scheduler {
+private:
+    struct TU {
+        using message = llvm::unique_function<json::Object()>;
+        std::string content;
+        std::deque<message> messages;
+        std::unique_ptr<ParsedAST> ast;
+        std::unique_ptr<Preamble> preamble;
+    };
+
+public:
+    void update(std::string_view path, std::string_view content);
+
+private:
+    llvm::StringMap<TU> files;
+};
+
+}  // namespace clice
diff --git a/include/Server/Server.h b/include/Server/Server.h
index 58197faa..8be75c66 100644
--- a/include/Server/Server.h
+++ b/include/Server/Server.h
@@ -1,5 +1,9 @@
 #pragma once
 
+#include <Server/Option.h>
+#include <Server/Command.h>
+#include <Server/Scheduler .h>
+
 namespace clice {
 
 class Server {
@@ -7,6 +11,11 @@ public:
     int run(int argc, const char** argv);
 
     void handleMessage(std::string_view message);
+
+private:
+    Option option;
+    Scheduler scheduler;
+    CompilationDatabase CDB;
 };
 
 namespace global {
diff --git a/include/Support/FileSystem.h b/include/Support/FileSystem.h
index 2bd55824..9dd17dbc 100644
--- a/include/Support/FileSystem.h
+++ b/include/Support/FileSystem.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <llvm/Support/FileSystem.h>
 
 namespace clice {
diff --git a/include/Support/JSON.h b/include/Support/JSON.h
index 2ab59ad5..836cb9f0 100644
--- a/include/Support/JSON.h
+++ b/include/Support/JSON.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <llvm/Support/JSON.h>
 #include <Support/Reflection.h>
 #include <array>
@@ -28,6 +30,8 @@ Object serialize(const T& object) {
             result.try_emplace(name, std::move(array));
         } else if constexpr(std::is_constructible_v<json::Value, Value&>) {
             result.try_emplace(name, value);
+        } else if constexpr(std::is_enum_v<Value>) {
+            result.try_emplace(name, static_cast<std::underlying_type_t<Value>>(value));
         } else {
             result.try_emplace(name, serialize(value));
         }
diff --git a/src/Server/Command.cpp b/src/Server/Command.cpp
index 0ff0da5a..b336bc91 100644
--- a/src/Server/Command.cpp
+++ b/src/Server/Command.cpp
@@ -25,8 +25,4 @@ void CompilationDatabase::load(clang::StringRef path) {
     }
 }
 
-namespace global {
-CompilationDatabase CDB;
-}
-
 }  // namespace clice