diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 00000000..3ca8edde
Binary files /dev/null and b/.DS_Store differ
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..c45ea829
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,77 @@
+[build-system]
+requires = ["setuptools>=62.0", "setuptools-git-versioning<2"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "diffpy.srfit"
+dynamic=['version']
+authors = [
+  { name="Simon J.L. Billinge group", email="simon.billinge@gmail.com" },
+]
+maintainers = [
+  { name="Simon J.L. Billinge group", email="simon.billinge@gmail.com" },
+]
+description = "SrFit - Structure refinement from diffraction data"
+keywords = "optimization constraints restraints structure refinement complex modeling"
+readme = "README.rst"
+requires-python = ">=3.10"
+classifiers = [
+        # List of possible values at
+        # http://pypi.python.org/pypi?:action=list_classifiers
+        'Development Status :: 5 - Production/Stable',
+        'Environment :: Console',
+        'Intended Audience :: Developers',
+        'Intended Audience :: Education',
+        'Intended Audience :: Science/Research',
+        'License :: OSI Approved :: BSD License',
+        'Operating System :: MacOS',
+        'Operating System :: POSIX',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Topic :: Scientific/Engineering :: Chemistry',
+        'Topic :: Scientific/Engineering :: Physics',
+        'Topic :: Software Development :: Libraries',
+]
+
+[project.urls]
+Homepage = "https://github.com/diffpy/diffpy.srfit"
+Issues = "https://github.com/diffpy/diffpy.srfit/issues"
+
+[tool.setuptools-git-versioning]
+enabled = true
+template = "{tag}"
+dev_template = "{tag}"
+dirty_template = "{tag}"
+
+[project.scripts]
+srfit = "diffpy.srfit:main"
+
+[tool.setuptools.packages.find]
+where = ["src"]  # list of folders that contain the packages (["."] by default)
+include = ["diffpy*"]  # package names should match these glob patterns (["*"] by default)
+exclude = ["diffpy.srfit.tests*"]  # exclude packages matching these glob patterns (empty by default)
+namespaces = false  # to disable scanning PEP 420 namespaces (true by default)
+
+[tool.black]
+line-length = 115
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.git
+  | \.hg
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | _build
+  | buck-out
+  | build
+  | dist
+
+  # The following are specific to Black, you probably don't want those.
+  | blib2to3
+  | tests/data
+)/
+'''
+
diff --git a/src/diffpy/srfit/tests/__init__.py b/src/diffpy/srfit/tests/__init__.py
index 845b5c39..391786e8 100644
--- a/src/diffpy/srfit/tests/__init__.py
+++ b/src/diffpy/srfit/tests/__init__.py
@@ -16,8 +16,8 @@
 """Unit tests for diffpy.srfit.
 """
 
-import unittest
 import logging
+import unittest
 
 # create logger instance for the tests subpackage
 logging.basicConfig()
@@ -43,9 +43,9 @@ def testsuite(pattern=''):
     import re
     from os.path import dirname
     from itertools import chain
-    from pkg_resources import resource_filename
+    from importlib.resources import files
     loader = unittest.defaultTestLoader
-    thisdir = resource_filename(__name__, '')
+    thisdir = files(__name__) / ""
     depth = __name__.count('.') + 1
     topdir = thisdir
     for i in range(depth):
@@ -82,4 +82,5 @@ def test():
     return result
 
 
+
 # End of file
diff --git a/src/diffpy/srfit/version.py b/src/diffpy/srfit/version.py
index 98c20188..ebde11de 100644
--- a/src/diffpy/srfit/version.py
+++ b/src/diffpy/srfit/version.py
@@ -26,12 +26,12 @@
 
 import os.path
 
-from pkg_resources import resource_filename
+from importlib.resources import files
 
 
 # obtain version information from the version.cfg file
 cp = dict(version='', date='', commit='', timestamp='0')
-fcfg = resource_filename(__name__, 'version.cfg')
+fcfg = files(__name__) / "version.cfg"
 if not os.path.isfile(fcfg):    # pragma: no cover
     from warnings import warn
     warn('Package metadata not found, execute "./setup.py egg_info".')
@@ -47,6 +47,7 @@
 __git_commit__ = cp['commit']
 __timestamp__ = int(cp['timestamp'])
 
+
 # TODO remove deprecated __gitsha__ in version 3.1.
 __gitsha__ = __git_commit__