diff --git a/src/common/aliases/byte_buffer.hpp b/src/common/types/app/byte_buffer.hpp
similarity index 99%
rename from src/common/aliases/byte_buffer.hpp
rename to src/common/types/app/byte_buffer.hpp
index 65dd7b5..b0a8c6e 100644
--- a/src/common/aliases/byte_buffer.hpp
+++ b/src/common/types/app/byte_buffer.hpp
@@ -1,4 +1,5 @@
 #pragma once
+
 #include <cstdint>
 #include <vector>
 
diff --git a/src/common/types/app/chunk_index.hpp b/src/common/types/app/chunk_index.hpp
new file mode 100644
index 0000000..dcfd354
--- /dev/null
+++ b/src/common/types/app/chunk_index.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <cstdint>
+
+// Sequential file chunk index
+using ChunkIndex = std::uint32_t;
diff --git a/src/common/types/app/file_size.hpp b/src/common/types/app/file_size.hpp
new file mode 100644
index 0000000..1e19d89
--- /dev/null
+++ b/src/common/types/app/file_size.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <cstdint>
+
+// File total size in bytes
+using FileSize = std::uint64_t;
diff --git a/src/common/types/app/frame_length.hpp b/src/common/types/app/frame_length.hpp
new file mode 100644
index 0000000..1c90c05
--- /dev/null
+++ b/src/common/types/app/frame_length.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <cstdint>
+
+// Wire length prefix type for a single framed message (big-endian on the wire)
+using FrameLength = std::uint32_t;
diff --git a/src/common/types/app/id.hpp b/src/common/types/app/id.hpp
new file mode 100644
index 0000000..d88ee31
--- /dev/null
+++ b/src/common/types/app/id.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <cstdint>
+
+// Client, group, or message ID
+using Id = std::uint64_t;
diff --git a/src/common/aliases/boost_asio.hpp b/src/common/types/deps/boost_asio.hpp
similarity index 85%
rename from src/common/aliases/boost_asio.hpp
rename to src/common/types/deps/boost_asio.hpp
index 5006780..0285759 100644
--- a/src/common/aliases/boost_asio.hpp
+++ b/src/common/types/deps/boost_asio.hpp
@@ -1,5 +1,6 @@
 #pragma once
+
 #include <boost/asio/io_context.hpp>
 
-// IO Contextct
+// IO Context
 using IoContext = boost::asio::io_context;
diff --git a/src/common/aliases/boost_asio_ip_tcp.hpp b/src/common/types/deps/boost_asio_ip_tcp.hpp
similarity index 99%
rename from src/common/aliases/boost_asio_ip_tcp.hpp
rename to src/common/types/deps/boost_asio_ip_tcp.hpp
index fb1a120..a87a56b 100644
--- a/src/common/aliases/boost_asio_ip_tcp.hpp
+++ b/src/common/types/deps/boost_asio_ip_tcp.hpp
@@ -1,4 +1,5 @@
 #pragma once
+
 #include <boost/asio/ip/tcp.hpp>
 
 // TCP
diff --git a/src/common/aliases/boost_asio_steady_timer.hpp b/src/common/types/deps/boost_asio_steady_timer.hpp
similarity index 99%
rename from src/common/aliases/boost_asio_steady_timer.hpp
rename to src/common/types/deps/boost_asio_steady_timer.hpp
index 5954219..7130b98 100644
--- a/src/common/aliases/boost_asio_steady_timer.hpp
+++ b/src/common/types/deps/boost_asio_steady_timer.hpp
@@ -1,4 +1,5 @@
 #pragma once
+
 #include <boost/asio/steady_timer.hpp>
 
 // Timers
diff --git a/src/common/aliases/boost_system_error_code.hpp b/src/common/types/deps/boost_system_error_code.hpp
similarity index 99%
rename from src/common/aliases/boost_system_error_code.hpp
rename to src/common/types/deps/boost_system_error_code.hpp
index fc9eef1..02a1b55 100644
--- a/src/common/aliases/boost_system_error_code.hpp
+++ b/src/common/types/deps/boost_system_error_code.hpp
@@ -1,4 +1,5 @@
 #pragma once
+
 #include <boost/system/error_code.hpp>
 
 // Error handling