diff --git a/src/diagnostic/diagnostic.hpp b/src/diagnostic/diagnostic.hpp
index 43e296b..c9e3e9a 100644
--- a/src/diagnostic/diagnostic.hpp
+++ b/src/diagnostic/diagnostic.hpp
@@ -37,6 +37,7 @@
 #include <string>
 #include <vector>
 #include "core/location.hpp"
+#include "tools.hpp"   // jsonEscape — TEK tanım (tools.hpp); çakışmayı önler
 
 // ============================================================================
 // DiagLevel — Tanı seviyesi
@@ -65,22 +66,7 @@ inline const char* diagLevelNameTr(DiagLevel l) {
     return "?";
 }
 
-// JSON string kaçışı (mesaj/ipucu tırnak veya satır sonu içerebilir)
-inline std::string jsonEscape(const std::string& s) {
-    std::string out;
-    out.reserve(s.size() + 8);
-    for (char c : s) {
-        switch (c) {
-            case '"':  out += "\\\""; break;
-            case '\\': out += "\\\\"; break;
-            case '\n': out += "\\n";  break;
-            case '\r': out += "\\r";  break;
-            case '\t': out += "\\t";  break;
-            default:   out += c;       break;
-        }
-    }
-    return out;
-}
+// NOT: jsonEscape() tools.hpp'de tanımlıdır (tek tanım — ODR çakışması olmaz).
 
 // ============================================================================
 // Diagnostic — Tek bir tanı (hata/uyarı/not/ipucu)
diff --git a/src/parser/ast_node.hpp b/src/parser/ast_node.hpp
index 3739c70..d41053a 100644
--- a/src/parser/ast_node.hpp
+++ b/src/parser/ast_node.hpp
@@ -31,6 +31,7 @@
 #include <string>
 #include <vector>
 #include "core/location.hpp"
+#include "core/type.hpp"
 #include "parser/token.hpp"
 #include "tools.hpp"
 
@@ -247,6 +248,47 @@ protected:
     std::vector<ASTNode*> children;
 };
 
+// ============================================================================
+// ExpressionNode — Değer Üreten Düğümlerin Tabanı (Faz 1, ADR-012)
+// ============================================================================
+//
+// Bir DEĞER üreten her düğüm (Literal, Identifier, BinaryExpression, Call,
+// Postfix, MemberAccess, IndexExpression) buradan türer. Bir ifadenin bir
+// TİPİ vardır; analiz/optimizasyon alanları burada toplanır.
+//
+class ExpressionNode : public ASTNode {
+public:
+    // TODO(faz-3): tip denetleyici doldurur. Şimdilik Error = "henüz çözülmedi".
+    Type resolvedType;
+
+    // TODO(faz-4): sabit katlama (constant folding) bayrağı.
+    bool isConstant = false;
+    // TODO(faz-4): foldedValue — katlanmış sabit değer (temsil Faz 4'te netleşir).
+
+    // resolvedType'ın JSON karşılığı (henüz çözülmemişse null gösterilir).
+    std::string resolvedTypeJson() const {
+        return resolvedType.isError() ? std::string("null") : resolvedType.toJson();
+    }
+};
+
+// ============================================================================
+// StatementNode — Eylem/Kontrol Akışı Yürüten Düğümlerin Tabanı (Faz 1)
+// ============================================================================
+//
+// Değer üretmeyen, bir iş/kontrol akışı yürüten her düğüm (Block, If, For,
+// While, DoWhile, Return, Break, Continue, ExpressionStatement ve şimdilik
+// VariableDecl) buradan türer. Tipi yoktur; akış-analizi alanları taşır.
+//
+// TODO(faz-1 gözden geçirme): VariableDecl/FunctionDecl/StructDecl'in tam
+// sınıflandırması provizyonel — VariableDecl burada (blok içinde erişilebilirliğe
+// tabi), Function/StructDecl doğrudan ASTNode altında kaldı.
+//
+class StatementNode : public ASTNode {
+public:
+    // TODO(faz-3/4): erişilebilirlik (dead-code) analizi günceller.
+    bool isReachable = true;
+};
+
 // ============================================================================
 // childrenToJson — Düğümün çocuklarını JSON array olarak yaz
 // ============================================================================
diff --git a/src/parser/nodes/binary_expr.cpp b/src/parser/nodes/binary_expr.cpp
index d15731b..fc3daa9 100644
--- a/src/parser/nodes/binary_expr.cpp
+++ b/src/parser/nodes/binary_expr.cpp
@@ -18,6 +18,7 @@ std::string BinaryExpressionNode::toJson(int depth) {
     obj.add("operator", std::string(OPERATOR_MAP_REV.count(Operator) ? OPERATOR_MAP_REV.at(Operator) : "?"));
     if (Left)  obj.addRaw("left", Left->toJson(depth + 1));
     if (Right) obj.addRaw("right", Right->toJson(depth + 1));
+    obj.addRaw("resolvedType", resolvedTypeJson());
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
diff --git a/src/parser/nodes/binary_expr.hpp b/src/parser/nodes/binary_expr.hpp
index c760937..b67ee35 100644
--- a/src/parser/nodes/binary_expr.hpp
+++ b/src/parser/nodes/binary_expr.hpp
@@ -3,7 +3,7 @@
 
 #include "parser/ast_node.hpp"
 
-class BinaryExpressionNode : public ASTNode {
+class BinaryExpressionNode : public ExpressionNode {
 public:
     TokenType Operator;
     ASTNode*  Left  = nullptr;
diff --git a/src/parser/nodes/declarations.cpp b/src/parser/nodes/declarations.cpp
index 4edc7d2..e4357fb 100644
--- a/src/parser/nodes/declarations.cpp
+++ b/src/parser/nodes/declarations.cpp
@@ -30,6 +30,7 @@ std::string VariableDeclNode::toJson(int depth) {
     obj.add("kind", "VariableDecl");
     obj.add("name", name);
     obj.add("varType", varType);
+    obj.add("isReachable", isReachable);
     if (initExpr) obj.addRaw("init", initExpr->toJson(depth + 1));
     obj.addRaw("location", loc.toJson());
     return obj.str();
diff --git a/src/parser/nodes/declarations.hpp b/src/parser/nodes/declarations.hpp
index 2638eda..20bf751 100644
--- a/src/parser/nodes/declarations.hpp
+++ b/src/parser/nodes/declarations.hpp
@@ -12,7 +12,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class VariableDeclNode : public ASTNode {
+class VariableDeclNode : public StatementNode {
 public:
     std::string varType;
     std::string name;
diff --git a/src/parser/nodes/expressions.cpp b/src/parser/nodes/expressions.cpp
index 5cab82a..9c68517 100644
--- a/src/parser/nodes/expressions.cpp
+++ b/src/parser/nodes/expressions.cpp
@@ -12,6 +12,7 @@ std::string PostfixNode::toJson(int depth) {
     obj.add("kind", "Postfix");
     obj.add("operator", std::string(OPERATOR_MAP_REV.count(Operator) ? OPERATOR_MAP_REV.at(Operator) : "?"));
     if (operand) obj.addRaw("operand", operand->toJson(depth + 1));
+    obj.addRaw("resolvedType", resolvedTypeJson());
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -30,6 +31,7 @@ std::string CallExpressionNode::toJson(int depth) {
     obj.addArray("arguments", [&]() {
         for (auto* arg : arguments) obj.addItem(arg->toJson(depth + 2));
     });
+    obj.addRaw("resolvedType", resolvedTypeJson());
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -46,6 +48,7 @@ std::string MemberAccessNode::toJson(int depth) {
     obj.add("member", member);
     obj.add("arrow", arrow);
     if (object) obj.addRaw("object", object->toJson(depth + 1));
+    obj.addRaw("resolvedType", resolvedTypeJson());
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -62,6 +65,7 @@ std::string IndexExpressionNode::toJson(int depth) {
     obj.add("kind", "IndexExpression");
     if (object) obj.addRaw("object", object->toJson(depth + 1));
     if (index) obj.addRaw("index", index->toJson(depth + 1));
+    obj.addRaw("resolvedType", resolvedTypeJson());
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
diff --git a/src/parser/nodes/expressions.hpp b/src/parser/nodes/expressions.hpp
index 0efae4f..731a6a3 100644
--- a/src/parser/nodes/expressions.hpp
+++ b/src/parser/nodes/expressions.hpp
@@ -3,7 +3,7 @@
 
 #include "parser/ast_node.hpp"
 
-class PostfixNode : public ASTNode {
+class PostfixNode : public ExpressionNode {
 public:
     ASTNode*  operand  = nullptr;
     TokenType Operator;
@@ -12,7 +12,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class CallExpressionNode : public ASTNode {
+class CallExpressionNode : public ExpressionNode {
 public:
     ASTNode* callee = nullptr;
     std::vector<ASTNode*> arguments;
@@ -21,7 +21,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class MemberAccessNode : public ASTNode {
+class MemberAccessNode : public ExpressionNode {
 public:
     ASTNode*   object = nullptr;
     std::string member;
@@ -31,7 +31,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class IndexExpressionNode : public ASTNode {
+class IndexExpressionNode : public ExpressionNode {
 public:
     ASTNode* object = nullptr;
     ASTNode* index  = nullptr;
diff --git a/src/parser/nodes/identifier.cpp b/src/parser/nodes/identifier.cpp
index 55e3df4..f2286de 100644
--- a/src/parser/nodes/identifier.cpp
+++ b/src/parser/nodes/identifier.cpp
@@ -17,6 +17,7 @@ std::string IdentifierNode::toJson(int depth) {
     ss << "{\n"
        << in << "  \"kind\": \"Identifier\",\n"
        << in << "  \"name\": \"" << jsonEscape(name) << "\",\n"
+       << in << "  \"resolvedType\": " << resolvedTypeJson() << ",\n"
        << in << "  \"location\": " << loc.toJson() << "\n"
        << in << "}";
     return ss.str();
diff --git a/src/parser/nodes/identifier.hpp b/src/parser/nodes/identifier.hpp
index f993096..4d4b80d 100644
--- a/src/parser/nodes/identifier.hpp
+++ b/src/parser/nodes/identifier.hpp
@@ -3,11 +3,16 @@
 
 #include "parser/ast_node.hpp"
 
-class IdentifierNode : public ASTNode {
+struct Symbol; // TODO(faz-2): sembol tablosu (Symbol) tanımlandığında bağlanacak
+
+class IdentifierNode : public ExpressionNode {
 public:
     Token*       lexerToken  = nullptr;
     ParserToken  parserToken;
 
+    // TODO(faz-2): isim çözümlemede sembol tablosundaki tanıma bağlanır.
+    Symbol* resolvedSymbol = nullptr;
+
     IdentifierNode();
     void log(int indent = 0) override;
     std::string toJson(int depth = 0) override;
diff --git a/src/parser/nodes/literal.cpp b/src/parser/nodes/literal.cpp
index 94e32b8..1cd578f 100644
--- a/src/parser/nodes/literal.cpp
+++ b/src/parser/nodes/literal.cpp
@@ -28,6 +28,7 @@ std::string LiteralNode::toJson(int depth) {
     if (literalType == LiteralType::FLOAT) {
         ss << ",\n" << in << "  \"isFloat\": true";
     }
+    ss << ",\n" << in << "  \"resolvedType\": " << resolvedTypeJson();
     ss << ",\n" << in << "  \"location\": " << loc.toJson() << "\n"
        << in << "}";
     return ss.str();
diff --git a/src/parser/nodes/literal.hpp b/src/parser/nodes/literal.hpp
index 850dc5a..dee1207 100644
--- a/src/parser/nodes/literal.hpp
+++ b/src/parser/nodes/literal.hpp
@@ -3,7 +3,7 @@
 
 #include "parser/ast_node.hpp"
 
-class LiteralNode : public ASTNode {
+class LiteralNode : public ExpressionNode {
 public:
     Token*       lexerToken  = nullptr;
     ParserToken  parserToken;
diff --git a/src/parser/nodes/statements.cpp b/src/parser/nodes/statements.cpp
index 99e2038..a395bbe 100644
--- a/src/parser/nodes/statements.cpp
+++ b/src/parser/nodes/statements.cpp
@@ -13,6 +13,7 @@ std::string BlockNode::toJson(int depth) {
     obj.addArray("children", [&]() {
         for (auto* child : children) obj.addItem(child->toJson(depth + 2));
     });
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -31,6 +32,7 @@ std::string IfStatementNode::toJson(int depth) {
     if (condition) obj.addRaw("condition", condition->toJson(depth + 1));
     if (thenBranch) obj.addRaw("then", thenBranch->toJson(depth + 1));
     if (elseBranch) obj.addRaw("else", elseBranch->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -47,6 +49,7 @@ std::string WhileStatementNode::toJson(int depth) {
     obj.add("kind", "WhileStatement");
     if (condition) obj.addRaw("condition", condition->toJson(depth + 1));
     if (body) obj.addRaw("body", body->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -67,6 +70,7 @@ std::string ForStatementNode::toJson(int depth) {
     if (condition) obj.addRaw("condition", condition->toJson(depth + 1));
     if (update) obj.addRaw("update", update->toJson(depth + 1));
     if (body) obj.addRaw("body", body->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -83,6 +87,7 @@ std::string DoWhileStatementNode::toJson(int depth) {
     obj.add("kind", "DoWhileStatement");
     if (condition) obj.addRaw("condition", condition->toJson(depth + 1));
     if (body) obj.addRaw("body", body->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -97,6 +102,7 @@ std::string ReturnStatementNode::toJson(int depth) {
     JsonObject obj(depth);
     obj.add("kind", "ReturnStatement");
     if (value) obj.addRaw("value", value->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -109,6 +115,7 @@ void BreakStatementNode::log(int indent) {
 std::string BreakStatementNode::toJson(int depth) {
     JsonObject obj(depth);
     obj.add("kind", "BreakStatement");
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -121,6 +128,7 @@ void ContinueStatementNode::log(int indent) {
 std::string ContinueStatementNode::toJson(int depth) {
     JsonObject obj(depth);
     obj.add("kind", "ContinueStatement");
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
@@ -135,6 +143,7 @@ std::string ExpressionStatementNode::toJson(int depth) {
     JsonObject obj(depth);
     obj.add("kind", "ExpressionStatement");
     if (expression) obj.addRaw("expression", expression->toJson(depth + 1));
+    obj.add("isReachable", isReachable);
     obj.addRaw("location", loc.toJson());
     return obj.str();
 }
diff --git a/src/parser/nodes/statements.hpp b/src/parser/nodes/statements.hpp
index 9ec9662..5b68b49 100644
--- a/src/parser/nodes/statements.hpp
+++ b/src/parser/nodes/statements.hpp
@@ -3,14 +3,14 @@
 
 #include "parser/ast_node.hpp"
 
-class BlockNode : public ASTNode {
+class BlockNode : public StatementNode {
 public:
     BlockNode();
     void log(int indent = 0) override;
     std::string toJson(int depth = 0) override;
 };
 
-class IfStatementNode : public ASTNode {
+class IfStatementNode : public StatementNode {
 public:
     ASTNode* condition  = nullptr;
     ASTNode* thenBranch = nullptr;
@@ -20,7 +20,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class WhileStatementNode : public ASTNode {
+class WhileStatementNode : public StatementNode {
 public:
     ASTNode* condition = nullptr;
     ASTNode* body      = nullptr;
@@ -29,7 +29,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class ForStatementNode : public ASTNode {
+class ForStatementNode : public StatementNode {
 public:
     ASTNode* init      = nullptr;
     ASTNode* condition = nullptr;
@@ -40,7 +40,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class DoWhileStatementNode : public ASTNode {
+class DoWhileStatementNode : public StatementNode {
 public:
     ASTNode* condition = nullptr;
     ASTNode* body      = nullptr;
@@ -49,7 +49,7 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class ReturnStatementNode : public ASTNode {
+class ReturnStatementNode : public StatementNode {
 public:
     ASTNode* value = nullptr;
     ReturnStatementNode();
@@ -57,21 +57,21 @@ public:
     std::string toJson(int depth = 0) override;
 };
 
-class BreakStatementNode : public ASTNode {
+class BreakStatementNode : public StatementNode {
 public:
     BreakStatementNode();
     void log(int indent = 0) override;
     std::string toJson(int depth = 0) override;
 };
 
-class ContinueStatementNode : public ASTNode {
+class ContinueStatementNode : public StatementNode {
 public:
     ContinueStatementNode();
     void log(int indent = 0) override;
     std::string toJson(int depth = 0) override;
 };
 
-class ExpressionStatementNode : public ASTNode {
+class ExpressionStatementNode : public StatementNode {
 public:
     ASTNode* expression = nullptr;
     ExpressionStatementNode();