diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2492df6d5..7f56c7b10 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,13 +36,37 @@ jobs:
       - name: ruff format check
         run: ruff format --check src tests
 
+  typecheck:
+    name: Typecheck (pyright strict — public API)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install package and pyright
+        run: |
+          python -m pip install --upgrade pip pyright
+          python -m pip install -e .
+      # ---public-API surface: pptx/__init__.py is the literal entrypoint
+      # ---resolved by `from pptx import Presentation`, plus the modules
+      # ---it pulls in (api, presentation, util, exc, types).
+      # ---Strict-mode pyright on the broader codebase still surfaces several
+      # ---thousand findings (reportUnknownMemberType-heavy in chart and
+      # ---oxml.simpletypes); those are tracked as future work, not this gate.
+      - name: pyright (public-API entry points)
+        run: |
+          pyright src/pptx/__init__.py src/pptx/api.py src/pptx/presentation.py \
+                  src/pptx/util.py src/pptx/exc.py src/pptx/types.py
+
   test:
     name: Test (Python ${{ matrix.python-version }})
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
diff --git a/pyproject.toml b/pyproject.toml
index 2da7a2681..b19d84595 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,11 +14,11 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
     "Topic :: Office/Business :: Office Suites",
     "Topic :: Software Development :: Libraries",
 ]
@@ -33,7 +33,7 @@ dynamic = ["version"]
 keywords = ["powerpoint", "ppt", "pptx", "openxml", "office"]
 license = { text = "MIT" }
 readme = "README.rst"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 
 [project.urls]
 Changelog = "https://github.com/MHoroszowski/python-pptx/blob/master/HISTORY.rst"
@@ -42,9 +42,6 @@ Homepage = "https://github.com/MHoroszowski/python-pptx"
 Repository = "https://github.com/MHoroszowski/python-pptx"
 Upstream = "https://github.com/scanny/python-pptx"
 
-[tool.black]
-line-length = 100
-
 [tool.pyright]
 exclude = [
     "**/__pycache__",
diff --git a/src/pptx/api.py b/src/pptx/api.py
index daa3e8410..69269ea33 100644
--- a/src/pptx/api.py
+++ b/src/pptx/api.py
@@ -27,18 +27,21 @@ def Presentation(
     |pathlib.Path|) or a file-like object. If *pptx* is missing or ``None``,
     the built-in default presentation "template" is loaded.
     """
+    # ---accept os.PathLike (pathlib.Path, etc.) by coercing to str at the
+    # ---boundary; collapse the union to (str | IO[bytes]) for downstream---
+    pkg_file: str | IO[bytes]
     if pptx is None:
-        pptx = _default_pptx_path()
+        pkg_file = _default_pptx_path()
+    elif isinstance(pptx, os.PathLike):
+        pkg_file = os.fspath(pptx)
+    else:
+        pkg_file = pptx
 
-    # ---accept os.PathLike (pathlib.Path, etc.) by coercing to str at the boundary---
-    if hasattr(pptx, "__fspath__"):
-        pptx = os.fspath(pptx)
-
-    presentation_part = Package.open(pptx).main_document_part
+    presentation_part = Package.open(pkg_file).main_document_part
 
     if not _is_pptx_package(presentation_part):
         tmpl = "file '%s' is not a PowerPoint file, content type is '%s'"
-        raise ValueError(tmpl % (pptx, presentation_part.content_type))
+        raise ValueError(tmpl % (pkg_file, presentation_part.content_type))
 
     return presentation_part.presentation
 
diff --git a/src/pptx/presentation.py b/src/pptx/presentation.py
index 426a50fd2..44db95f9e 100644
--- a/src/pptx/presentation.py
+++ b/src/pptx/presentation.py
@@ -73,10 +73,10 @@ def save(self, file: str | os.PathLike[str] | IO[bytes]):
         `file` can be a file-path (|str| or any |os.PathLike| object such as
         |pathlib.Path|) or a file-like object open for writing bytes.
         """
-        # ---accept os.PathLike (pathlib.Path etc.) by coercing to str---
-        if hasattr(file, "__fspath__"):
-            file = os.fspath(file)
-        self.part.save(file)
+        # ---accept os.PathLike (pathlib.Path etc.) by coercing to str at the
+        # ---boundary; collapse the union to (str | IO[bytes]) for downstream---
+        pkg_file: str | IO[bytes] = os.fspath(file) if isinstance(file, os.PathLike) else file
+        self.part.save(pkg_file)
 
     @property
     def slide_height(self) -> Length | None:
@@ -157,7 +157,7 @@ def sections(self):
         elements into existence; the wrapping XML is created on the first
         ``add_section`` call.
         """
-        from pptx.sections import _Sections
+        from pptx.sections import _Sections  # pyright: ignore[reportPrivateUsage]
 
         return _Sections(self)
 
@@ -202,7 +202,7 @@ def append_from(
         Raises |IndexError| if any value in `slide_indexes` is out of
         range for ``other_pres.slides``.
         """
-        from pptx.parts.slide import _PortContext, duplicate_notes_slide_for  # noqa: F401
+        from pptx.parts.slide import _PortContext  # pyright: ignore[reportPrivateUsage]
 
         if slide_indexes is None:
             source_slides = list(other_pres.slides)