diff --git a/harmony/cli.py b/harmony/cli.py
index 505ac0b..d59e42f 100644
--- a/harmony/cli.py
+++ b/harmony/cli.py
@@ -65,6 +65,8 @@ def setup_cli(parser):
     parser.add_argument('--harmony-input',
                         help=('the input data for the action provided by Harmony, required for '
                               '--harmony-action=invoke'))
+    parser.add_argument('--harmony-input-file',
+                        help=('the optional path to the input data for the action provided by Harmony'))
     parser.add_argument('--harmony-sources',
                         help=('file path that contains a STAC catalog with items and metadata to '
                               'be processed by the service.  Required for non-deprecated '
@@ -323,11 +325,16 @@ def run_cli(parser, args, AdapterClass, cfg=None):
     if args.harmony_wrap_stdout:
         setup_stdout_log_formatting(cfg)
 
+    # read in the operation file passed in with --harmony-input-file if any
+    if bool(args.harmony_input_file):
+        with open(args.harmony_input_file, 'r') as f:
+            args.harmony_input = f.read()
+
     if args.harmony_action == 'invoke':
         start_time = datetime.datetime.now()
         if not bool(args.harmony_input):
             parser.error(
-                '--harmony-input must be provided for --harmony-action=invoke')
+                '--harmony-input or --harmony-input-file must be provided for --harmony-action=invoke')
         elif not bool(args.harmony_sources):
             successful = _invoke_deprecated(AdapterClass, args.harmony_input, cfg)
             if not successful:
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 7d79297..3de52a1 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1,3 +1,4 @@
+import os
 import unittest
 from unittest.mock import patch
 
@@ -50,8 +51,11 @@ def test_when_passing_nothing_it_returns_false(self, parser):
 class TestCliInvokeAction(unittest.TestCase):
     def setUp(self):
         self.config = harmony.util.config(validate=False)
+        with open('/tmp/operation.json', 'w') as f:
+            f.write('{"test": "input"}')
 
     def tearDown(self):
+        os.remove('/tmp/operation.json')
         MockAdapter.messages = []
         MockAdapter.errors = []
         MockAdapter.cleaned_up = []
@@ -62,7 +66,7 @@ def test_when_harmony_input_is_not_provided_it_terminates_with_error(self, parse
             args = parser.parse_args()
             cli.run_cli(parser, args, MockAdapter, self.config)
             error_method.assert_called_once_with(
-                '--harmony-input must be provided for --harmony-action=invoke')
+                '--harmony-input or --harmony-input-file must be provided for --harmony-action=invoke')
 
     @cli_test('--harmony-action', 'invoke', '--harmony-input', '{"test": "input"}')
     def test_when_harmony_input_is_provided_it_creates_and_invokes_an_adapter(self, parser):
@@ -70,6 +74,13 @@ def test_when_harmony_input_is_provided_it_creates_and_invokes_an_adapter(self,
         cli.run_cli(parser, args, MockAdapter, self.config)
         self.assertListEqual([{'test': 'input'}], MockAdapter.messages)
 
+    @cli_test('--harmony-action', 'invoke', '--harmony-input-file', '/tmp/operation.json')
+    def test_when_harmony_input_file_is_provided_it_creates_and_invokes_an_adapter(self, parser):
+        args = parser.parse_args()
+
+        cli.run_cli(parser, args, MockAdapter, self.config)
+        self.assertListEqual([{'test': 'input'}], MockAdapter.messages)
+
     @cli_test('--harmony-action', 'invoke', '--harmony-input', '{"test": "input"}')
     def test_when_the_backend_service_doesnt_respond_it_responds_with_an_error(self, parser):
         class MockImpl(MockAdapter):