diff --git a/.claude/sweep-api-consistency-state.csv b/.claude/sweep-api-consistency-state.csv
index 85ee7521..f922f9be 100644
--- a/.claude/sweep-api-consistency-state.csv
+++ b/.claude/sweep-api-consistency-state.csv
@@ -1,3 +1,3 @@
 module,last_inspected,issue,severity_max,categories_found,notes
-geotiff,2026-05-15,1922,MEDIUM,1,"Sweep 2026-05-15 (deep-sweep-api-consistency-geotiff-2026-05-15-1778854324). 1 MEDIUM Cat 1 finding fixed in this branch: write_geotiff_gpu and to_geotiff disagreed on order of max_z_error / streaming_buffer_bytes kwargs. Both kwargs are keyword-only so no functional break; drift surfaced in inspect.signature, IDE autocomplete, and Sphinx docs against the writers' explicit-parity promise. Fix reorders write_geotiff_gpu to match to_geotiff (streaming_buffer_bytes before max_z_error) and updates the docstring; gpu is the only kwarg to_geotiff has that write_geotiff_gpu does not, so the gap stays. Regression test in test_writer_kwarg_order_1922.py pins kwarg order parity and default-value parity. Prior findings (#1654 #1683 #1684 #1685 #1705 #1715 #1754 #1775 #1810 #1845-followup) all confirmed fixed. Cross-sibling return-type drift (Cat 2): write_vrt returns str while to_geotiff and write_geotiff_gpu return None -- still deferred (LOW, callers do not substitute these writers). Cross-cutting cross-module drift (chunk_size in reproject vs chunks in geotiff; target_crs vs crs) documented but not filed per sweep template (cross-cutting). cuda-validated."
+geotiff,2026-05-18,2106,MEDIUM,3,"Sweep 2026-05-18 (deep-sweep-api-consistency-geotiff-2026-05-18-1779164255). 1 MEDIUM Cat 3 finding fixed in this branch: open_geotiff(max_cloud_bytes=...) was the only kwarg on the public reader/writer surface without a Python type annotation. Docstring already declared ``int or None``; the surface and the docs disagreed. Fix adds ``int | None`` to the annotation; default stays the module-internal _MAX_CLOUD_BYTES_SENTINEL. Regression test in test_open_geotiff_max_cloud_bytes_annot_2106.py pins the immediate gap and parametrises over every public reader/writer to catch future ungenerated annotations. Prior sweep findings (#1922/#1935 kwarg ordering, #2052 mask_nodata parity, #2097 GPU MinIsWhite, #2095 zero-band 3D writes, #1946 write_vrt path/vrt_path shim) all confirmed fixed. Cross-sibling return-type drift (Cat 2): write_vrt returns str while to_geotiff and write_geotiff_gpu return path which is str | BinaryIO -- inspected and still LOW (callers do not substitute writers; the return-type drift is documented in each writer's docstring). Cross-cutting cross-module drift (chunk_size in reproject vs chunks in geotiff; target_crs vs crs) documented but not filed per sweep template (cross-cutting). cuda-validated."
 reproject,2026-05-10,1570,HIGH,2;5,"Filed cross-module attrs['vertical_crs'] type collision (string vs EPSG int) vs xrspatial.geotiff. Fixed in PR (TBD): reproject now writes EPSG int and preserves friendly token under vertical_datum. MEDIUM kwarg-order drift (transform_precision vs chunk_size) and missing type hints vs geotiff documented but not fixed (cosmetic, kwarg-only)."
diff --git a/xrspatial/geotiff/__init__.py b/xrspatial/geotiff/__init__.py
index 215fa354..6fe74d17 100644
--- a/xrspatial/geotiff/__init__.py
+++ b/xrspatial/geotiff/__init__.py
@@ -249,7 +249,7 @@ def open_geotiff(source: str | BinaryIO, *,
                  chunks: int | tuple | None = None,
                  gpu: bool = False,
                  max_pixels: int | None = None,
-                 max_cloud_bytes=_MAX_CLOUD_BYTES_SENTINEL,
+                 max_cloud_bytes: int | None = _MAX_CLOUD_BYTES_SENTINEL,  # type: ignore[assignment]
                  on_gpu_failure: str = _ON_GPU_FAILURE_SENTINEL,
                  missing_sources: str = _MISSING_SOURCES_SENTINEL,
                  allow_rotated: bool = False,
diff --git a/xrspatial/geotiff/tests/test_open_geotiff_max_cloud_bytes_annot_2106.py b/xrspatial/geotiff/tests/test_open_geotiff_max_cloud_bytes_annot_2106.py
new file mode 100644
index 00000000..3bc61344
--- /dev/null
+++ b/xrspatial/geotiff/tests/test_open_geotiff_max_cloud_bytes_annot_2106.py
@@ -0,0 +1,83 @@
+"""Regression test for #2106: every kwarg on the public read/write
+entry points carries a type annotation.
+
+The original gap: ``open_geotiff(max_cloud_bytes=...)`` had no annotation
+on its kwarg, while every other kwarg on the function -- and every kwarg
+on every other public reader and writer in ``xrspatial.geotiff`` -- did.
+``inspect.signature``, IDE autocomplete, Sphinx, and ``mypy --strict`` all
+saw a bare parameter for the only fsspec-related kwarg on the public
+read entry point, despite the docstring declaring ``int or None``.
+
+This test fixes the immediate gap (``max_cloud_bytes``) and pins every
+other public reader/writer kwarg to a non-empty annotation so a future
+addition cannot reopen the surface without surfacing in CI.
+"""
+from __future__ import annotations
+
+import inspect
+
+import pytest
+
+from xrspatial.geotiff import (
+    open_geotiff,
+    read_geotiff_dask,
+    read_geotiff_gpu,
+    read_vrt,
+    to_geotiff,
+    write_geotiff_gpu,
+    write_vrt,
+)
+
+
+PUBLIC_ENTRY_POINTS = (
+    open_geotiff,
+    read_geotiff_gpu,
+    read_geotiff_dask,
+    read_vrt,
+    to_geotiff,
+    write_geotiff_gpu,
+    write_vrt,
+)
+
+
+def test_open_geotiff_max_cloud_bytes_has_type_annotation():
+    """Pin the #2106 fix: the kwarg the bug named carries ``int | None``."""
+    sig = inspect.signature(open_geotiff)
+    param = sig.parameters["max_cloud_bytes"]
+    assert param.annotation is not inspect.Parameter.empty, (
+        "open_geotiff(max_cloud_bytes=...) is missing a type annotation; "
+        "the docstring declares ``int or None`` so the surface should match."
+    )
+    # ``xrspatial.geotiff.__init__`` uses ``from __future__ import
+    # annotations``, so ``param.annotation`` comes back as the source
+    # string. Pin the exact PEP 604 form rather than ``"int" in s and
+    # "None" in s`` -- the looser check would also pass on something
+    # like ``Mapping[int, None]``.
+    annotation_repr = str(param.annotation)
+    assert annotation_repr == "int | None", (
+        f"open_geotiff(max_cloud_bytes=...) annotation should be exactly "
+        f"``int | None`` to match the docstring; got {annotation_repr!r}"
+    )
+
+
+@pytest.mark.parametrize("fn", PUBLIC_ENTRY_POINTS, ids=lambda f: f.__name__)
+def test_public_entry_point_kwargs_have_type_annotations(fn):
+    """Every kwarg on the public read/write surface carries an annotation.
+
+    Catches future regressions of the same class as #2106: a kwarg added
+    to one entry point without an annotation while the rest of the
+    signature has them.
+    """
+    sig = inspect.signature(fn)
+    missing = [
+        name
+        for name, param in sig.parameters.items()
+        if param.annotation is inspect.Parameter.empty
+    ]
+    assert missing == [], (
+        f"{fn.__name__} has kwargs without type annotations: {missing}. "
+        f"Add ``annotation`` to each so inspect.signature, IDE "
+        f"autocomplete, Sphinx, and mypy --strict all see the declared "
+        f"type. The docstring already declares the type for the kwargs "
+        f"in question (#2106 raised this for max_cloud_bytes)."
+    )