diff --git a/core/setup.py b/core/setup.py
index 296ea562..5208d919 100644
--- a/core/setup.py
+++ b/core/setup.py
@@ -151,6 +151,7 @@ def get_long_description(package_dir):
 }
 META_FILE = read(META_PATH)
 INSTALL_REQUIRES = [
+    "apache-beam[gcp]",
     "click",
     "glom",
     "google-api-python-client",
diff --git a/core/src/klio_core/config/_io.py b/core/src/klio_core/config/_io.py
index a964b2b4..302e5286 100644
--- a/core/src/klio_core/config/_io.py
+++ b/core/src/klio_core/config/_io.py
@@ -18,8 +18,9 @@
 import json
 import logging
 
-
 import attr
+from apache_beam.io.filesystem import CompressionTypes
+
 
 logger = logging.getLogger("klio")
 
@@ -255,6 +256,7 @@ def from_dict(cls, config_dict, *args, **kwargs):
 
 class KlioFileConfig(object):
     name = "file"
+    compression_type = attr.attrib(type=str, default=CompressionTypes.AUTO)
 
 
 @attr.attrs(frozen=True)
@@ -286,6 +288,11 @@ def as_dict(self):
 @attr.attrs(frozen=True)
 class KlioWriteFileConfig(KlioEventOutput, KlioFileConfig):
     file_path_prefix = attr.attrib(type=str)
+    file_name_suffix = attr.attrib(type=str, default="")
+    append_trailing_newlines = attr.attrib(type=bool, default=True)
+    num_shards = attr.attrib(type=int, default=0)
+    shard_name_template = attr.attrib(type=str, default=None)
+    header = attr.attrib(type=str, default=None)
 
     @classmethod
     def from_dict(cls, config_dict, *args, **kwargs):
diff --git a/core/tests/config/test_config.py b/core/tests/config/test_config.py
index 6d300185..b254f96b 100644
--- a/core/tests/config/test_config.py
+++ b/core/tests/config/test_config.py
@@ -432,17 +432,33 @@ def test_klio_read_file_config():
     assert config_dict["location"] == klio_read_file_config.file_pattern
 
 
-def test_klio_write_file_config():
-    config_dict = {
-        "type": "GCS",
-        "location": "gs://sigint-output/test-parent-job-out",
-    }
+@pytest.mark.parametrize(
+    "config_dict",
+    (
+        # The minimum inputs
+        {"type": "GCS", "location": "gs://sigint-output/test-parent-job-out"},
+        # Other fields configured
+        {
+            "type": "GCS",
+            "location": "gs://sigint-output/test-parent-job-out",
+            "file_name_suffix": ".txt",
+            "num_shards": 3,
+            "append_trailing_newlines": True,
+        },
+    ),
+)
+def test_klio_write_file_config(config_dict):
     klio_write_file_config = io.KlioWriteFileConfig.from_dict(
         config_dict, io.KlioIOType.DATA, io.KlioIODirection.OUTPUT
     )
 
+    config_dict.pop("type")
     assert "file" == klio_write_file_config.name
-    assert config_dict["location"] == klio_write_file_config.file_path_prefix
+    for k, v in config_dict.items():
+        if k == "location":
+            assert v == klio_write_file_config.file_path_prefix
+        else:
+            assert v == getattr(klio_write_file_config, k)
 
 
 def test_klio_write_bigquery_config():
diff --git a/core/tox.ini b/core/tox.ini
index 99cf367b..5c436f26 100644
--- a/core/tox.ini
+++ b/core/tox.ini
@@ -1,9 +1,15 @@
 [tox]
-envlist = py36,py37,py38,docs,manifest,check-formatting,lint
+envlist = {py36,py37,py38}-beam{26,27,28},docs,manifest,check-formatting,lint
 
 [testenv]
 install_command = python -m pip install {opts} {packages}
 extras = tests
+deps =
+    {toxinidir}/../core
+    beam26: apache-beam[gcp]>=2.26.0,<2.27.0
+    beam27: apache-beam[gcp]>=2.27.0,<2.28.0
+    beam28: apache-beam[gcp]>=2.28.0,<2.29.0
+
 commands =
     coverage run -m pytest {posargs}
     ; assert that protos are compiled
@@ -85,6 +91,8 @@ filterwarnings =
     ignore:invalid escape sequence:DeprecationWarning
     ; 3rd party libraries haven't updated their use of collections.abc (py37+)
     ignore:Using or importing the ABCs from:DeprecationWarning
+    ; Apache Beam-related warnings
+    ignore:Running the Apache Beam SDK on Python 3:UserWarning
 
 ; required for mapping envs -> github runtimes
 [gh-actions]