diff --git a/setup.py b/setup.py
index 7c27011b..4414fa4c 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,323 @@
+from __future__ import annotations
 from setuptools import setup
 
+import os
+import shlex
+import sys
+import typing
+import subprocess
+from contextlib import contextmanager
+from ctypes.util import find_library
+from functools import wraps
+from pathlib import Path
+
+import distutils
+import setuptools
+from pybind11.setup_helpers import auto_cpp_level
+from pybind11.setup_helpers import ParallelCompile
+from pybind11.setup_helpers import Pybind11Extension
+from setuptools import Distribution
+from setuptools import Extension
+from setuptools.command.build_ext import build_ext as _build_ext
+
+
+DEBUG = False
+
+class PxblatExtensionBuilder(_build_ext):
+    def build_extension(self, extension: setuptools.extension.Extension) -> None:  # type: ignore
+        extension.library_dirs.append(self.build_lib)  # type: ignore
+        super().build_extension(extension)
+
+    def build_extensions(self) -> None:
+        """
+        Build extensions, injecting C++ std for Pybind11Extension if needed.
+        """
+
+        for ext in self.extensions:
+            if hasattr(ext, "_cxx_level") and ext._cxx_level == 0:
+                ext.cxx_std = auto_cpp_level(self.compiler)
+
+        super().build_extensions()
+
+
+def _get_pxblat_libname():
+    builder = setuptools.command.build_ext.build_ext(Distribution())  # type: ignore
+    full_name = builder.get_ext_filename("libpxblat")
+    without_lib = full_name.split("lib", 1)[-1]
+    without_so = without_lib.rsplit(".so", 1)[0]
+    return without_so
+
+
+def remove_env(key: str):
+    """Remove environment variable."""
+    env_cflags = os.environ.get("CFLAGS", "")
+    env_cppflags = os.environ.get("CPPFLAGS", "")
+    flags = shlex.split(env_cflags) + shlex.split(env_cppflags)
+
+    for flag in flags:
+        if flag.startswith(key):
+            raise RuntimeError(f"Please remove {key} from CFLAGS and CPPFLAGS.")
+
+
+@contextmanager
+def change_dir(path: str):
+    """Change directory."""
+    save_dir = os.getcwd()
+    os.chdir(path)
+    try:
+        yield
+    finally:
+        os.chdir(save_dir)
+
+
+def change_env(key: str, value: str):
+    """Change environment variable."""
+
+    def decorator(func):
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            old_env = os.environ.get(key, None)
+            os.environ[key] = old_env + " " + value if old_env else value
+            func(*args, **kwargs)
+            os.environ[key] = old_env if old_env else " "
+
+        return wrapper
+
+    return decorator
+
+
+def get_files_by_suffix(
+    path: typing.Union[Path, str], suffix: typing.List[str]
+) -> typing.Iterator[str]:
+    """Get bindings."""
+    if isinstance(path, str):
+        path = Path(path)
+
+    for file in path.iterdir():
+        if file.is_dir():
+            yield from get_files_by_suffix(file, suffix)
+        if file.suffix in suffix:
+            yield file.as_posix()
+
+
+def filter_files(files, exclude=None):
+    if exclude is None:
+        exclude = []
+
+    for file in files:
+        file_name = Path(file).name
+        if file_name not in exclude:
+            yield file
+
+
+# Optional multithreaded build
+def get_thread_count():
+    try:
+        import multiprocessing
+
+        return multiprocessing.cpu_count()
+    except (ImportError, NotImplementedError):
+        pass
+    return 1
+
+
+def _get_cxx_compiler():
+    cc = distutils.ccompiler.new_compiler()  # type: ignore
+    distutils.sysconfig.customize_compiler(cc)  # type: ignore
+    return cc.compiler_cxx[0]  # type: ignore
+
+
+def find_lib_in_conda(lib_name: str):
+    conda_prefix = os.environ.get("CONDA_PREFIX", None)
+    if conda_prefix is not None:
+        conda_lib_dir = Path(conda_prefix) / "lib"
+
+        if (conda_lib_dir / f"lib{lib_name}.a").exists():
+            return conda_lib_dir
+
+        if (conda_lib_dir / f"lib{lib_name}.so").exists():
+            return conda_lib_dir
+
+        if (conda_lib_dir / f"lib{lib_name}.dylib").exists():
+            return conda_lib_dir
+
+    return None
+
+
+def find_available_library(lib_name: str, *, ignores=[]):
+    lib_path = find_library(lib_name)
+
+    if lib_path is None:
+        lib_path = find_lib_in_conda(lib_name)
+
+    print(f"{lib_name} lib_path: {lib_path}")
+
+    if not lib_path:
+        if lib_name not in ignores:
+            raise RuntimeError(f"Cannot find {lib_name} library.")
+        return Path.cwd(), Path.cwd()
+
+    header_path = Path(lib_path).parent.parent / "include"
+
+    return Path(lib_path).parent, header_path
+
+
+def find_openssl_libs():
+    openssl_dir = subprocess.getoutput('openssl version -d')
+    openssl_dir = openssl_dir.replace('OPENSSLDIR: "', '').replace('"', '').strip()
+
+    lib_paths = [f"{openssl_dir}/lib"]
+
+    print(f"find openssl lib_paths: {lib_paths}")
+
+    return lib_paths
+
+def _extra_compile_args_for_libpxblat():
+    return [
+        "-D_FILE_OFFSET_BITS=64",
+        "-D_LARGEFILE_SOURCE",
+        "-D_GNU_SOURCE",
+        "-DMACHTYPE_$(MACHTYPE)",
+        "-DPXBLATLIB",
+    ]
+
+
+def _include_dirs_for_libpxblat():
+    return [
+        "src/pxblat/extc/include/core",
+        "src/pxblat/extc/include/aux",
+        "src/pxblat/extc/include/net",
+    ]
+
+
+def _include_dirs_for_pxblat():
+    return [
+        "src/pxblat/extc/bindings",
+    ]
+
+
+def _extra_compile_args_for_pxblat():
+    flag = []
+    if not DEBUG:
+        flag.append("-DDBG_MACRO_DISABLE")
+    return flag
+
+
+ParallelCompile(f"{get_thread_count()}").install()
+
+extra_compile_args = ["-pthread"]
+hidden_visibility_args = []
+include_dirs: list[str] = []
+library_dirs: list[str] = [] + find_openssl_libs()
+python_module_link_args = []
+base_library_link_args: list[str] = []
+external_libraries = [
+    "ssl",
+    "crypto",
+    "m",
+]
+
+for lib in external_libraries:
+    lib_library_dir, lib_include_dir = find_available_library(lib, ignores=["m"])
+    library_dirs.append(lib_library_dir.as_posix())
+    include_dirs.append(lib_include_dir.as_posix())
+
+if sys.platform == "win32":
+    raise RuntimeError("Windows is not supported.")
+elif sys.platform == "darwin":
+    # See https://conda-forge.org/docs/maintainer/knowledge_base.html#newer-c-features-with-old-sdk
+    extra_compile_args.append("-D_LIBCPP_DISABLE_AVAILABILITY")
+    extra_compile_args.append("-undefined dynamic_lookup")
+    hidden_visibility_args.append("-fvisibility=hidden")
+    config_vars = distutils.sysconfig.get_config_vars()  # type: ignore
+    config_vars["LDSHARED"] = config_vars["LDSHARED"].replace("-bundle", "")  # type: ignore
+    python_module_link_args.append("-bundle")
+    builder = setuptools.command.build_ext.build_ext(Distribution())  # type: ignore
+    full_name = builder.get_ext_filename("libpxblat")
+    print(f"full_name: {full_name}")
+    base_library_link_args.append(
+        f"-Wl,-dylib_install_name,@loader_path/../{full_name}"
+    )
+    base_library_link_args.append("-dynamiclib")
+else:
+    hidden_visibility_args.append("-fvisibility=hidden")
+    python_module_link_args.append("-Wl,-rpath,$ORIGIN/..")
+
+
+def get_extension_modules():
+    extension_modules = []
+
+    """
+    Extension module which is actually a plain C++ library without Python bindings
+    """
+    libpxblat_sources = (
+        list(filter_files(get_files_by_suffix("src/pxblat/extc/src/core", [".c"])))
+        + list(
+            filter_files(
+                get_files_by_suffix("src/pxblat/extc/src/aux", [".c"]),
+                exclude=["net.c"],
+            )
+        )
+        + list(filter_files(get_files_by_suffix("src/pxblat/extc/src/net", [".c"])))
+    )
+
+    pxblat_library = Extension(
+        "libpxblat",
+        language="c",
+        sources=libpxblat_sources,
+        include_dirs=include_dirs + _include_dirs_for_libpxblat(),
+        extra_compile_args=_extra_compile_args_for_libpxblat() + extra_compile_args,
+        extra_link_args=base_library_link_args,
+        libraries=external_libraries,
+        library_dirs=library_dirs,
+    )
+
+    pxblat_libs = [_get_pxblat_libname()]
+    extension_modules.append(pxblat_library)
+
+    """
+    An extension module which contains the main Python bindings for libblat
+    """
+    pxblat_python_sources = [
+        "src/pxblat/extc/bindings/faToTwoBit.cpp",
+        "src/pxblat/extc/bindings/twoBitToFa.cpp",
+        "src/pxblat/extc/bindings/gfServer.cpp",
+        "src/pxblat/extc/bindings/pygfServer.cpp",
+        "src/pxblat/extc/bindings/gfClient.cpp",
+    ] + list(
+        filter_files(get_files_by_suffix("src/pxblat/extc/bindings/binder", [".cpp"]))
+    )
+
+    pxblat_python = Pybind11Extension(
+        "pxblat._extc",
+        language="c++",
+        sources=pxblat_python_sources,
+        include_dirs=include_dirs
+        + _include_dirs_for_libpxblat()
+        + _include_dirs_for_pxblat(),
+        extra_compile_args=extra_compile_args
+        + hidden_visibility_args
+        + _extra_compile_args_for_pxblat(),
+        libraries=external_libraries + pxblat_libs,
+        extra_link_args=python_module_link_args,
+        library_dirs=library_dirs,
+    )
+
+    extension_modules.append(pxblat_python)
+    return extension_modules
+
+
+def build(setup_kwargs):
+    """Build cpp extension."""
+    ext_modules = get_extension_modules()
+    setup_kwargs.update(
+        {
+            "ext_modules": ext_modules,
+            "cmdclass": {"build_ext": PxblatExtensionBuilder},
+            "zip_safe": False,
+            "package_data": {"pxblat": ["py.typed", "*so"]},
+        }
+    )
 package_dir = {"": "src"}
 
 packages = ["pxblat", "pxblat.cli", "pxblat.extc", "pxblat.server", "pxblat.toolkit"]
@@ -52,7 +370,7 @@
     "entry_points": entry_points,
     "python_requires": ">=3.9,<3.12",
 }
-from .build import *
+
 
 build(setup_kwargs)