Document Zarr encoding options

doc/user-guide/io.rst

@@ -1105,6 +1105,13 @@ For example:
     compressor = BloscCodec(cname="zstd", clevel=3, shuffle="shuffle")
     ds.to_zarr(zarr_filename, consolidated=False, encoding={"foo": {"compressors": [compressor]}})
 
+For Zarr v3, xarray forwards codec configuration in each variable's
+``encoding`` dictionary to zarr-python. Use ``compressors`` for bytes-to-bytes
+codecs and ``serializer`` for array-to-bytes codecs, with codec objects and
+configuration following zarr-python. Other Zarr v3 metadata options accepted by
+xarray include ``filters``, ``shards``, ``fill_value``, and
+``chunk_key_encoding``.
+
 .. note::
 
     Not all native zarr compression and filtering options have been tested with

xarray/core/dataset.py

@@ -2263,6 +2263,10 @@ def to_zarr(
             Nested dictionary with variable names as keys and dictionaries of
             variable specific encodings as values, e.g.,
             ``{"my_variable": {"dtype": "int16", "scale_factor": 0.1,}, ...}``
+            Zarr-specific options such as ``chunks``, ``compressor``,
+            ``compressors``, ``filters``, ``serializer``, ``shards``, and
+            ``chunk_key_encoding`` may also be provided. See the Zarr encoding
+            section in the I/O user guide for details.
         compute : bool, default: True
             If True write array data immediately, otherwise return a
             ``dask.delayed.Delayed`` object that can be computed to write