diff --git a/pkgs/clan-cli/clan_cli/inventory/__init__.py b/pkgs/clan-cli/clan_cli/inventory/__init__.py
index a2cb05af1..18f743e8f 100644
--- a/pkgs/clan-cli/clan_cli/inventory/__init__.py
+++ b/pkgs/clan-cli/clan_cli/inventory/__init__.py
@@ -119,6 +119,37 @@ def load_inventory_json(
     return inventory
 
 
+def patch(d: dict[str, Any], path: str, content: Any) -> None:
+    """
+    Update the value at a specific dot-separated path in a nested dictionary.
+
+    :param d: The dictionary to update.
+    :param path: The dot-separated path to the key (e.g., 'foo.bar').
+    :param content: The new value to set.
+    """
+    keys = path.split(".")
+    current = d
+    for key in keys[:-1]:
+        current = current.setdefault(key, {})
+    current[keys[-1]] = content
+
+
+@API.register
+def patch_inventory_with(base_dir: Path, section: str, content: dict[str, Any]) -> None:
+    inventory_file = get_path(base_dir)
+
+    curr_inventory = {}
+    with inventory_file.open("r") as f:
+        curr_inventory = json.load(f)
+
+    patch(curr_inventory, section, content)
+
+    with inventory_file.open("w") as f:
+        json.dump(curr_inventory, f, indent=2)
+
+    commit_file(inventory_file, base_dir, commit_message=f"inventory.{section}: Update")
+
+
 @API.register
 def set_inventory(
     inventory: Inventory | dict[str, Any], flake_dir: str | Path, message: str
diff --git a/pkgs/clan-cli/tests/test_patch_inventory.py b/pkgs/clan-cli/tests/test_patch_inventory.py
new file mode 100644
index 000000000..c788288bb
--- /dev/null
+++ b/pkgs/clan-cli/tests/test_patch_inventory.py
@@ -0,0 +1,36 @@
+# Functions to test
+from clan_cli.inventory import patch
+
+
+def test_patch_nested() -> None:
+    orig = {"a": 1, "b": {"a": 2.1, "b": 2.2}, "c": 3}
+
+    patch(orig, "b.b", "foo")
+
+    # Should only update the nested value
+    assert orig == {"a": 1, "b": {"a": 2.1, "b": "foo"}, "c": 3}
+
+
+def test_patch_nested_dict() -> None:
+    orig = {"a": 1, "b": {"a": 2.1, "b": 2.2}, "c": 3}
+
+    # This should update the whole "b" dict
+    # Which also removes all other keys
+    patch(orig, "b", {"b": "foo"})
+
+    # Should only update the nested value
+    assert orig == {"a": 1, "b": {"b": "foo"}, "c": 3}
+
+
+def test_create_missing_paths() -> None:
+    orig = {"a": 1}
+
+    patch(orig, "b.c", "foo")
+
+    # Should only update the nested value
+    assert orig == {"a": 1, "b": {"c": "foo"}}
+
+    orig = {}
+    patch(orig, "a.b.c", "foo")
+
+    assert orig == {"a": {"b": {"c": "foo"}}}