diff --git a/src/bytecode/bytearray.cc b/src/bytecode/bytearray.cc
index 9968642..e8fbbd9 100644
--- a/src/bytecode/bytearray.cc
+++ b/src/bytecode/bytearray.cc
@@ -24,6 +24,14 @@ void ByteArray::add_int(uint32_t addr, int32_t value)
     add_byte(addr, zz & 0x7F);
 }
 
+void ByteArray::add_uint32(uint32_t addr, uint32_t value)
+{
+    add_byte(addr, (uint8_t)(value));
+    add_byte(addr+1, (uint8_t)(value >> 8));
+    add_byte(addr+2, (uint8_t)(value >> 16));
+    add_byte(addr+3, (uint8_t)(value >> 24));
+}
+
 void ByteArray::add_float(uint32_t addr, float value)
 {
     uint32_t bits;
@@ -46,6 +54,14 @@ uint8_t ByteArray::get_byte(uint32_t addr) const
     return data_.at(addr);
 }
 
+uint32_t ByteArray::get_uint32(uint32_t addr) const
+{
+    return (uint32_t) get_byte(addr)
+            | (uint32_t) get_byte(addr+1) << 8
+            | (uint32_t) get_byte(addr+2) << 16
+            | (uint32_t) get_byte(addr+3) << 24;
+}
+
 std::pair<int32_t, size_t> ByteArray::get_int(uint32_t addr) const
 {
     uint32_t zz = 0;
diff --git a/src/bytecode/bytearray.hh b/src/bytecode/bytearray.hh
index 4b25e2f..c189ba6 100644
--- a/src/bytecode/bytearray.hh
+++ b/src/bytecode/bytearray.hh
@@ -10,17 +10,23 @@ namespace tyche {
 
 class ByteArray {
 public:
+    ByteArray() = default;
+    explicit ByteArray(std::vector<uint8_t> data) : data_(std::move(data)) {}
+
     void add_byte(uint32_t addr, uint8_t byte);
+    void add_uint32(uint32_t addr, uint32_t value);
     void add_int(uint32_t addr, int32_t value);
     void add_float(uint32_t addr, float value);
     void add_string(uint32_t addr, std::string const& str);
 
     void append_byte(uint32_t addr, uint8_t byte) { add_byte(data_.size(), byte); }
+    void append_uint32(uint32_t addr, uint32_t value) { add_uint32(data_.size(), value); }
     void append_int(uint32_t addr, int32_t value) { add_int(data_.size(), value); }
     void append_float(uint32_t addr, float value) { add_float(data_.size(), value); }
     void append_string(uint32_t addr, std::string const& str) { add_string(data_.size(), str); }
 
     [[nodiscard]] uint8_t                        get_byte(uint32_t addr) const;
+    [[nodiscard]] uint32_t                       get_uint32(uint32_t addr) const;
     [[nodiscard]] std::pair<int32_t, size_t>     get_int(uint32_t addr) const;
     [[nodiscard]] std::pair<float, size_t>       get_float(uint32_t addr) const;
     [[nodiscard]] std::pair<std::string, size_t> get_string(uint32_t addr) const;
diff --git a/src/bytecode/bytecode.cc b/src/bytecode/bytecode.cc
index d9171fc..5069221 100644
--- a/src/bytecode/bytecode.cc
+++ b/src/bytecode/bytecode.cc
@@ -2,5 +2,67 @@
 
 namespace tyche {
 
+Bytecode::Bytecode(BytecodePrototype const& bp)
+{
+    // header
+    byte_array_.add_uint32(0, MAGIC);
+    byte_array_.add_byte(4, VERSION);
+
+    // constants
+    std::vector<uint32_t> constant_indexes;
+    std::vector<uint8_t> constant_array;
+    for (auto const& constant: bp.constants) {
+
+    }
+
+    // constants table
+
+    // function table
+}
+
+uint32_t Bytecode::n_constants() const
+{
+    return 0;
+}
+
+uint32_t Bytecode::n_functions() const
+{
+    return 0;
+}
+
+int32_t Bytecode::get_constant_int(uint32_t addr) const
+{
+    return 0;
+}
+
+float Bytecode::get_constant_float(uint32_t addr) const
+{
+    return 0;
+}
+
+std::string Bytecode::get_constant_string(uint32_t addr) const
+{
+    return std::string();
+}
+
+Bytecode::FunctionDef Bytecode::get_function_def(uint32_t function_id) const
+{
+    return Bytecode::FunctionDef();
+}
+
+uint8_t Bytecode::get_code_byte(uint32_t function_id, uint32_t idx) const
+{
+    return 0;
+}
+
+int32_t Bytecode::get_code_int(uint32_t function_id, uint32_t idx) const
+{
+    return 0;
+}
+
+float Bytecode::get_code_float(uint32_t function_id, uint32_t idx) const
+{
+    return 0;
+}
 
 }
\ No newline at end of file
diff --git a/src/bytecode/bytecode.hh b/src/bytecode/bytecode.hh
index 4b2e69a..2095bba 100644
--- a/src/bytecode/bytecode.hh
+++ b/src/bytecode/bytecode.hh
@@ -8,8 +8,8 @@ namespace tyche {
 
 class Bytecode {
 public:
-    Bytecode(std::vector<uint8_t> data);
-    Bytecode(BytecodePrototype const& bp);
+    explicit Bytecode(std::vector<uint8_t> data) : byte_array_(std::move(data)) {}
+    explicit Bytecode(BytecodePrototype const& bp);
 
     [[nodiscard]] uint32_t n_constants() const;
     [[nodiscard]] uint32_t n_functions() const;
@@ -29,6 +29,8 @@ public:
 
 private:
     ByteArray byte_array_;
+    static constexpr uint8_t VERSION = 1;
+    static constexpr uint32_t MAGIC = 0x74b3c138;
 };
 
 }