diff --git a/src/dps_stac_item_generator/generator.py b/src/dps_stac_item_generator/generator.py
index f1a90fa..fb76f47 100644
--- a/src/dps_stac_item_generator/generator.py
+++ b/src/dps_stac_item_generator/generator.py
@@ -368,6 +368,7 @@ def run(
                 source=href,
                 id=item_id,
                 asset_name=asset_key,
+                asset_href=href,
                 with_proj=True,
                 with_raster=True,
                 asset_media_type=media_type_for_extension(suffix, is_cog=is_cog),
@@ -401,6 +402,7 @@ def run(
             source_item = create_stac_item(
                 source=href,
                 id=item_id,
+                asset_href=href,
                 with_proj=True,
                 with_raster=True,
                 asset_name=asset_key,
diff --git a/tests/test_s3_asset_hrefs.py b/tests/test_s3_asset_hrefs.py
new file mode 100644
index 0000000..3738253
--- /dev/null
+++ b/tests/test_s3_asset_hrefs.py
@@ -0,0 +1,100 @@
+"""Regression tests for preserving canonical remote raster asset hrefs."""
+
+import json
+from pathlib import Path
+from urllib.parse import urlsplit
+
+import numpy as np
+import pytest
+import rasterio
+from pystac import Catalog
+from rasterio.transform import from_origin
+from rio_stac import create_stac_item
+
+from dps_stac_item_generator import generator
+
+
+def write_raster(path: Path) -> None:
+    """Write a tiny real GeoTIFF used for rio-stac metadata extraction."""
+    path.parent.mkdir(parents=True, exist_ok=True)
+    with rasterio.open(
+        path,
+        "w",
+        driver="GTiff",
+        height=1,
+        width=1,
+        count=1,
+        dtype="uint16",
+        crs="EPSG:4326",
+        transform=from_origin(0, 1, 1, 1),
+    ) as dataset:
+        dataset.write(np.ones((1, 1, 1), dtype="uint16"))
+
+
+@pytest.mark.parametrize("grouped", [False, True], ids=["default", "grouped"])
+def test_catalog_publication_preserves_canonical_s3_asset_hrefs(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path, grouped: bool
+) -> None:
+    """Raster hrefs survive rio-stac creation and PySTAC href resolution unchanged."""
+    source = "s3://maap-ops-workspace/shared/henrydevseed/happy-face"
+    relative_paths = ["right/red.tif"]
+    keys = ["asset"]
+    config_json = None
+    if grouped:
+        relative_paths = [
+            "right/red.tif",
+            "right/green.tif",
+            "right/blue.tif",
+        ]
+        keys = ["red", "green", "blue"]
+        config_json = json.dumps(
+            {
+                "path_pattern": r"right/(?P<color>red|green|blue)\.tif",
+                "item_id_template": "happy-face-right",
+                "asset_key_template": "{color}",
+                "datetime_template": "2026-01-01T00:00:00Z",
+                "reference_asset": "red",
+                "required_assets": keys,
+            }
+        )
+
+    local_sources = {}
+    for relative_path in relative_paths:
+        local_path = tmp_path / "rasters" / relative_path
+        write_raster(local_path)
+        local_sources[f"{source}/{relative_path}"] = local_path
+
+    monkeypatch.setattr(generator, "from_url", lambda *_args, **_kwargs: "fake-store")
+    monkeypatch.setattr(
+        generator.obstore,
+        "list",
+        lambda _store: [[{"path": path} for path in relative_paths]],
+    )
+    monkeypatch.setattr(generator, "is_cloud_optimized_geotiff", lambda _href: False)
+
+    def create_from_local_raster(**kwargs):
+        # The dataset name is a local path, deliberately unlike its canonical S3 URL.
+        with rasterio.open(local_sources[kwargs["source"]]) as dataset:
+            return create_stac_item(
+                source=dataset,
+                **{key: value for key, value in kwargs.items() if key != "source"},
+            )
+
+    monkeypatch.setattr(generator, "create_stac_item", create_from_local_raster)
+    output = tmp_path / "catalog"
+    generator.run(
+        source=source,
+        output_dir=output,
+        config_json=config_json,
+    )
+
+    catalog = Catalog.from_file(str(output / "catalog.json"))
+    catalog.make_all_asset_hrefs_absolute()
+    items = list(catalog.get_items())
+    assert len(items) == 1
+    assert set(items[0].assets) == set(keys)
+    for key, relative_path in zip(keys, relative_paths, strict=True):
+        expected_href = f"{source}/{relative_path}"
+        assert items[0].assets[key].href == expected_href
+        assert urlsplit(items[0].assets[key].href).scheme == "s3"
+        assert items[0].assets[key].href.startswith("s3://")