diff --git a/.gitignore b/.gitignore
index e24ec1b8..d241a82b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,7 +6,12 @@ __pycache__/
 .mypy_cache/
 dist/
 build/
+**/tl/__init__.py
 **/tl/layer.py
 **/tl/abcs/
 **/tl/functions/
 **/tl/types/
+**/mtproto/layer.py
+**/mtproto/abcs/
+**/mtproto/functions/
+**/mtproto/types/
diff --git a/DEVELOPING.md b/DEVELOPING.md
new file mode 100644
index 00000000..342e776d
--- /dev/null
+++ b/DEVELOPING.md
@@ -0,0 +1,5 @@
+```sh
+pip install -e generator/
+python -m telethon_generator.codegen api.tl telethon/src/_impl/tl
+python -m telethon_generator.codegen mtproto.tl telethon/src/_impl/tl/mtproto
+```
diff --git a/client/LICENSE b/client/LICENSE
new file mode 100644
index 00000000..ce874a09
--- /dev/null
+++ b/client/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2016-Present LonamiWebs
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/client/README.md b/client/README.md
new file mode 100644
index 00000000..5047ec13
--- /dev/null
+++ b/client/README.md
@@ -0,0 +1,3 @@
+# Telethon
+
+Full-featured Telegram client library.
diff --git a/client/pyproject.toml b/client/pyproject.toml
new file mode 100644
index 00000000..3052714c
--- /dev/null
+++ b/client/pyproject.toml
@@ -0,0 +1,41 @@
+
+[project]
+name = "Telethon"
+description = "Full-featured Telegram client library"
+authors = [
+  { name="Lonami", email="totufals@hotmail.com" },
+]
+readme = "README.md"
+license = {file = "LICENSE"}
+requires-python = ">=3.8"
+keywords = ["telegram", "chat", "messaging", "mtproto", "telethon"]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python :: 3",
+    "Topic :: Communications :: Chat",
+    "Typing :: Typed",
+]
+dependencies = [
+  "pyaes~=1.6",
+  "rsa~=4.9",
+]
+dynamic = ["version"]
+
+[project.optional-dependencies]
+cryptg = ["cryptg~=0.4"]
+
+[project.urls]
+"Homepage" = "https://telethon.dev/"
+"Source" = "https://telethon.dev/code/"
+"Documentation" = "https://telethon.dev/docs/"
+"Bug Tracker" = "https://telethon.dev/issues/"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.dynamic]
+version = {attr = "telethon.__version__"}
diff --git a/client/src/telethon/__init__.py b/client/src/telethon/__init__.py
new file mode 100644
index 00000000..58f3ace6
--- /dev/null
+++ b/client/src/telethon/__init__.py
@@ -0,0 +1 @@
+from .version import __version__
diff --git a/client/src/telethon/_impl/tl/__init__.py b/client/src/telethon/_impl/tl/__init__.py
new file mode 100644
index 00000000..ce48616f
--- /dev/null
+++ b/client/src/telethon/_impl/tl/__init__.py
@@ -0,0 +1,4 @@
+from . import abcs, core, functions, mtproto, types
+from .layer import LAYER, TYPE_MAPPING
+
+__all__ = ["abcs", "core", "functions", "mtproto", "types", "LAYER", "TYPE_MAPPING"]
diff --git a/client/src/telethon/_impl/tl/core/__init__.py b/client/src/telethon/_impl/tl/core/__init__.py
new file mode 100644
index 00000000..eb86687f
--- /dev/null
+++ b/client/src/telethon/_impl/tl/core/__init__.py
@@ -0,0 +1,5 @@
+from .reader import Reader
+from .request import Request
+from .serializable import Serializable, serialize_bytes_to
+
+__all__ = ["Reader", "Request", "Serializable", "serialize_bytes_to"]
diff --git a/client/src/telethon/_impl/tl/core/reader.py b/client/src/telethon/_impl/tl/core/reader.py
new file mode 100644
index 00000000..cd608a36
--- /dev/null
+++ b/client/src/telethon/_impl/tl/core/reader.py
@@ -0,0 +1,64 @@
+import struct
+from typing import TYPE_CHECKING, Any, Type, TypeVar
+
+if TYPE_CHECKING:
+    from .serializable import Serializable
+
+
+T = TypeVar("T", bound="Serializable")
+
+
+class Reader:
+    __slots__ = ("_buffer", "_pos", "_view")
+
+    def __init__(self, buffer: bytes) -> None:
+        self._buffer = buffer
+        self._pos = 0
+        self._view = memoryview(self._buffer)
+
+    def read(self, n: int) -> bytes:
+        self._pos += n
+        return self._view[self._pos - n : n]
+
+    def read_fmt(self, fmt: str, size: int) -> tuple[Any, ...]:
+        assert struct.calcsize(fmt) == size
+        self._pos += size
+        return struct.unpack(fmt, self._view[self._pos - size : self._pos])
+
+    def read_bytes(self) -> bytes:
+        if self._buffer[self._pos] == 254:
+            self._pos += 4
+            (length,) = struct.unpack(
+                "<i", self._buffer[self._pos - 3 : self._pos] + b"\0"
+            )
+            padding = length % 4
+        else:
+            length = self._buffer[self._pos]
+            padding = (length + 1) % 4
+            self._pos += 1
+
+        self._pos += length
+        data = self._view[self._pos - length : self._pos]
+        if padding > 0:
+            self._pos += 4 - padding
+
+        return data
+
+    @staticmethod
+    def _get_ty(_: int) -> Type["Serializable"]:
+        # Implementation replaced during import to prevent cycles,
+        # without the performance hit of having the import inside.
+        raise NotImplementedError
+
+    def read_serializable(self, cls: Type[T]) -> T:
+        # Calls to this method likely need to ignore "type-abstract".
+        # See https://github.com/python/mypy/issues/4717.
+        # Unfortunately `typing.cast` would add a tiny amount of runtime overhead
+        # which cannot be removed with optimization enabled.
+        self._pos += 4
+        cid = struct.unpack("<I", self._view[self._pos - 4 : self._pos])[0]
+        ty = self._get_ty(cid)
+        if ty is None:
+            raise ValueError(f"No type found for constructor ID: {cid:x}")
+        assert issubclass(ty, cls)
+        return ty._read_from(self)
diff --git a/client/src/telethon/_impl/tl/core/request.py b/client/src/telethon/_impl/tl/core/request.py
new file mode 100644
index 00000000..ef07c4c7
--- /dev/null
+++ b/client/src/telethon/_impl/tl/core/request.py
@@ -0,0 +1,20 @@
+import struct
+
+
+class Request:
+    __slots__ = "_body"
+
+    def __init__(self, body: bytes):
+        self._body = body
+
+    @property
+    def constructor_id(self) -> int:
+        try:
+            cid = struct.unpack("<i", self._body[:4])[0]
+            assert isinstance(cid, int)
+            return cid
+        except struct.error:
+            return 0
+
+    def debug_name(self) -> str:
+        return f"request#{self.constructor_id:x}"
diff --git a/client/src/telethon/_impl/tl/core/serializable.py b/client/src/telethon/_impl/tl/core/serializable.py
new file mode 100644
index 00000000..e5072559
--- /dev/null
+++ b/client/src/telethon/_impl/tl/core/serializable.py
@@ -0,0 +1,52 @@
+import abc
+import struct
+from typing import Self, Tuple
+
+from .reader import Reader
+
+
+class Serializable(abc.ABC):
+    __slots__: Tuple[str, ...] = ()
+
+    @classmethod
+    @abc.abstractmethod
+    def constructor_id(cls) -> int:
+        pass
+
+    @classmethod
+    def _read_from(cls, reader: Reader) -> Self:
+        return reader.read_serializable(cls)
+
+    def _write_boxed_to(self, buffer: bytearray) -> None:
+        buffer += struct.pack("<I", self.constructor_id())
+        self._write_to(buffer)
+
+    @abc.abstractmethod
+    def _write_to(self, buffer: bytearray) -> None:
+        pass
+
+    @classmethod
+    def from_bytes(cls, blob: bytes) -> Self:
+        return Reader(blob).read_serializable(cls)
+
+    def __bytes__(self) -> bytes:
+        buffer = bytearray()
+        self._write_boxed_to(buffer)
+        return bytes(buffer)
+
+    def __repr__(self) -> str:
+        attrs = ", ".join(repr(getattr(self, attr)) for attr in self.__slots__)
+        return f"{self.__class__.__name__}({attrs})"
+
+
+def serialize_bytes_to(buffer: bytearray, data: bytes) -> None:
+    length = len(data)
+    if length < 0xFE:
+        buffer += struct.pack("<B", length)
+        length += 1
+    else:
+        buffer += b"\xfe"
+        buffer += struct.pack("<i", length)[:-1]
+
+    buffer += data
+    buffer += bytes((4 - (length % 4)) % 4)
diff --git a/client/src/telethon/_impl/tl/mtproto/core.py b/client/src/telethon/_impl/tl/mtproto/core.py
new file mode 100644
index 00000000..4fcabbf3
--- /dev/null
+++ b/client/src/telethon/_impl/tl/mtproto/core.py
@@ -0,0 +1 @@
+from ..core import *
diff --git a/client/src/telethon/version.py b/client/src/telethon/version.py
new file mode 100644
index 00000000..53368364
--- /dev/null
+++ b/client/src/telethon/version.py
@@ -0,0 +1,2 @@
+# https://peps.python.org/pep-0440/
+__version__ = "2.0.0a0"
diff --git a/client/tests/reader_test.py b/client/tests/reader_test.py
new file mode 100644
index 00000000..52636f81
--- /dev/null
+++ b/client/tests/reader_test.py
@@ -0,0 +1,26 @@
+from pytest import mark
+from telethon._impl.tl.core import Reader
+
+
+@mark.parametrize(
+    ("string", "prefix", "suffix"),
+    [
+        ("", b"\00", b"\00\x00\x00"),
+        ("Hi", b"\02", b"\00"),
+        ("Hi!", b"\03", b""),
+        ("Hello", b"\05", b"\00\x00"),
+        ("Hello, world!", b"\x0d", b"\00\x00"),
+        (
+            "This is a very long string, and it has to be longer than 253 \
+characters, which are quite a few but we can make it! Although, \
+it is quite challenging. The quick brown fox jumps over the lazy \
+fox. There is still some more text we need to type. Oh, this \
+sentence made it past!",
+            b"\xfe\x11\x01\x00",
+            b"\x00\x00\x00",
+        ),
+    ],
+)
+def test_string(string: str, prefix: bytes, suffix: bytes) -> None:
+    data = prefix + string.encode("ascii") + suffix
+    assert str(Reader(data).read_bytes(), "ascii") == string
diff --git a/client/tests/serializable_test.py b/client/tests/serializable_test.py
new file mode 100644
index 00000000..f402186e
--- /dev/null
+++ b/client/tests/serializable_test.py
@@ -0,0 +1,28 @@
+from pytest import mark
+from telethon._impl.tl.core import serialize_bytes_to
+
+
+@mark.parametrize(
+    ("string", "prefix", "suffix"),
+    [
+        ("", b"\00", b"\00\x00\x00"),
+        ("Hi", b"\02", b"\00"),
+        ("Hi!", b"\03", b""),
+        ("Hello", b"\05", b"\00\x00"),
+        ("Hello, world!", b"\x0d", b"\00\x00"),
+        (
+            "This is a very long string, and it has to be longer than 253 \
+characters, which are quite a few but we can make it! Although, \
+it is quite challenging. The quick brown fox jumps over the lazy \
+fox. There is still some more text we need to type. Oh, this \
+sentence made it past!",
+            b"\xfe\x11\x01\x00",
+            b"\x00\x00\x00",
+        ),
+    ],
+)
+def test_string(string: str, prefix: bytes, suffix: bytes) -> None:
+    expected = prefix + string.encode("ascii") + suffix
+    buffer = bytearray()
+    serialize_bytes_to(buffer, string.encode("ascii"))
+    assert bytes(buffer) == expected
diff --git a/generator/src/telethon_generator/_impl/codegen/generator.py b/generator/src/telethon_generator/_impl/codegen/generator.py
index a5019c49..15617d73 100644
--- a/generator/src/telethon_generator/_impl/codegen/generator.py
+++ b/generator/src/telethon_generator/_impl/codegen/generator.py
@@ -14,17 +14,23 @@ from .serde.deserialization import generate_read
 from .serde.serialization import generate_function, generate_write
 
 
-def generate_init(writer: SourceWriter, namespaces: Set[str]) -> None:
-    sorted_ns = list(namespaces)
-    sorted_ns.sort()
+def generate_init(
+    writer: SourceWriter, namespaces: Set[str], classes: Set[str]
+) -> None:
+    sorted_cls = list(sorted(classes))
+    sorted_ns = list(sorted(namespaces))
+
+    if sorted_cls:
+        sorted_import = ", ".join(sorted_cls)
+        writer.write(f"from ._nons import {sorted_import}")
 
     if sorted_ns:
         sorted_import = ", ".join(sorted_ns)
-        writer.write(f"from ._nons import *")
         writer.write(f"from . import {sorted_import}")
 
-    sorted_all = ", ".join(f"{ns!r}" for ns in sorted_ns)
-    writer.write(f"__all__ = [{sorted_all}]")
+    if sorted_cls or sorted_ns:
+        sorted_all = ", ".join(f"{ns!r}" for ns in sorted_cls + sorted_ns)
+        writer.write(f"__all__ = [{sorted_all}]")
 
 
 def generate(fs: FakeFs, tl: ParsedTl) -> None:
@@ -39,7 +45,10 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
     type_namespaces = set()
     function_namespaces = set()
 
-    generated_type_names = []
+    abc_class_names = set()
+    type_class_names = set()
+    function_def_names = set()
+    generated_type_names = set()
 
     for typedef in tl.typedefs:
         if typedef.ty.full_name not in generated_types:
@@ -49,11 +58,12 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
                 abc_namespaces.add(typedef.ty.namespace[0])
                 abc_path = (Path("abcs") / typedef.ty.namespace[0]).with_suffix(".py")
             else:
+                abc_class_names.add(to_class_name(typedef.ty.name))
                 abc_path = Path("abcs/_nons.py")
 
             if abc_path not in fs:
                 fs.write(abc_path, "from abc import ABCMeta\n")
-                fs.write(abc_path, "from ..core.serializable import Serializable\n")
+                fs.write(abc_path, "from ..core import Serializable\n")
 
             fs.write(
                 abc_path,
@@ -72,6 +82,7 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
             type_namespaces.add(typedef.namespace[0])
             type_path = (Path("types") / typedef.namespace[0]).with_suffix(".py")
         else:
+            type_class_names.add(to_class_name(typedef.name))
             type_path = Path("types/_nons.py")
 
         writer = fs.open(type_path)
@@ -80,11 +91,10 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
             writer.write(f"import struct")
             writer.write(f"from typing import List, Optional, Self")
             writer.write(f"from .. import abcs")
-            writer.write(f"from ..core.reader import Reader")
-            writer.write(f"from ..core.serializable import serialize_bytes_to")
+            writer.write(f"from ..core import Reader, serialize_bytes_to")
 
         ns = f"{typedef.namespace[0]}." if typedef.namespace else ""
-        generated_type_names.append(f"{ns}{to_class_name(typedef.name)}")
+        generated_type_names.add(f"{ns}{to_class_name(typedef.name)}")
 
         # class Type(BaseType)
         writer.write(
@@ -138,6 +148,7 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
                 ".py"
             )
         else:
+            function_def_names.add(to_method_name(functiondef.name))
             function_path = Path("functions/_nons.py")
 
         writer = fs.open(function_path)
@@ -146,8 +157,7 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
             writer.write(f"import struct")
             writer.write(f"from typing import List, Optional, Self")
             writer.write(f"from .. import abcs")
-            writer.write(f"from ..core.request import Request")
-            writer.write(f"from ..core.serializable import serialize_bytes_to")
+            writer.write(f"from ..core import Request, serialize_bytes_to")
 
         #   def name(params, ...)
         params = ", ".join(f"{p.name}: {param_type_fmt(p.ty)}" for p in required_params)
@@ -156,11 +166,12 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
         generate_function(writer, functiondef)
         writer.dedent(2)
 
-    generate_init(fs.open(Path("abcs/__init__.py")), abc_namespaces)
-    generate_init(fs.open(Path("types/__init__.py")), type_namespaces)
-    generate_init(fs.open(Path("functions/__init__.py")), function_namespaces)
+    generate_init(fs.open(Path("abcs/__init__.py")), abc_namespaces, abc_class_names)
+    generate_init(fs.open(Path("types/__init__.py")), type_namespaces, type_class_names)
+    generate_init(
+        fs.open(Path("functions/__init__.py")), function_namespaces, function_def_names
+    )
 
-    generated_type_names.sort()
     writer = fs.open(Path("layer.py"))
     writer.write(f"from . import types")
     writer.write(f"from .core import Serializable, Reader")
@@ -169,7 +180,7 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
     writer.write(
         "TYPE_MAPPING = {t.constructor_id(): t for t in cast(Tuple[Type[Serializable]], ("
     )
-    for name in generated_type_names:
+    for name in sorted(generated_type_names):
         writer.write(f"  types.{name},")
     writer.write("))}")
     writer.write(
diff --git a/generator/src/telethon_generator/_impl/codegen/serde/serialization.py b/generator/src/telethon_generator/_impl/codegen/serde/serialization.py
index bb283c8a..984fdd5c 100644
--- a/generator/src/telethon_generator/_impl/codegen/serde/serialization.py
+++ b/generator/src/telethon_generator/_impl/codegen/serde/serialization.py
@@ -1,3 +1,4 @@
+import struct
 from itertools import groupby
 from typing import Iterator
 
@@ -127,7 +128,8 @@ def generate_write(writer: SourceWriter, defn: Definition) -> None:
 
 def generate_function(writer: SourceWriter, defn: Definition) -> None:
     tmp_names = gen_tmp_names()
-    writer.write("_buffer = bytearray()")
+    serialized_cid = struct.pack("<I", defn.id)
+    writer.write(f"_buffer = bytearray({serialized_cid!r})")
     for trivial, iter in groupby(
         defn.params,
         key=lambda p: is_trivial(p.ty),
diff --git a/generator/src/telethon_generator/version.py b/generator/src/telethon_generator/version.py
index 3dc1f76b..50340b7c 100644
--- a/generator/src/telethon_generator/version.py
+++ b/generator/src/telethon_generator/version.py
@@ -1 +1,2 @@
+# https://peps.python.org/pep-0440/
 __version__ = "0.1.0"