diff --git a/tests/test_decoder.py b/tests/test_decoder.py
index a57ab3e..f870f8a 100644
--- a/tests/test_decoder.py
+++ b/tests/test_decoder.py
@@ -261,20 +261,20 @@ def test_get_workflow_inputs_for_step_with_name_step1():
     # Arrange
 
     # Act
-    inputs = decoder.get_workflow_input_names_for_step(
+    inputs = decoder.get_workflow_job_input_names_for_step(
         _SIMPLE_PYTHON_MOLPROPS_WITH_OPTIONS_WORKFLOW, "step1"
     )
 
     # Assert
     assert len(inputs) == 1
-    assert "candidateMolecules" in inputs
+    assert "inputFile" in inputs
 
 
 def test_get_workflow_inputs_for_step_with_name_step2():
     # Arrange
 
     # Act
-    inputs = decoder.get_workflow_input_names_for_step(
+    inputs = decoder.get_workflow_job_input_names_for_step(
         _SIMPLE_PYTHON_MOLPROPS_WITH_OPTIONS_WORKFLOW, "step2"
     )
 
@@ -286,7 +286,7 @@ def test_get_workflow_inputs_for_step_with_unkown_step_name():
     # Arrange
 
     # Act
-    inputs = decoder.get_workflow_input_names_for_step(
+    inputs = decoder.get_workflow_job_input_names_for_step(
         _SIMPLE_PYTHON_MOLPROPS_WITH_OPTIONS_WORKFLOW, "unknown"
     )
 
diff --git a/workflow/decoder.py b/workflow/decoder.py
index 5aeb8c6..9e75133 100644
--- a/workflow/decoder.py
+++ b/workflow/decoder.py
@@ -82,15 +82,12 @@ def get_variable_names(definition: dict[str, Any]) -> list[str]:
     return wf_variable_names
 
 
-def get_workflow_input_names_for_step(
+def get_workflow_job_input_names_for_step(
     definition: dict[str, Any], name: str
 ) -> list[str]:
-    """Given a Workflow definition and a step name we return a list of workflow
-    input variable names the step expects. To do this we iterate through the step's
-    inputs to find those that are declared 'from->workflow-input'.
-
-    To get the input (a filename) the caller simply looks these names up
-    in the variable map."""
+    """Given a Workflow definition and a step name we return a list of step Job input
+    variable names the step expects. To do this we iterate through the step's
+    inputs to find those that are declared 'from->workflow-input'."""
     inputs: list[str] = []
     for step in definition.get("steps", {}):
         if step["name"] == name and "inputs" in step:
@@ -98,7 +95,7 @@ def get_workflow_input_names_for_step(
             # This gives us the name of the workflow input variable
             # and the name of the step input (Job) variable.
             inputs.extend(
-                step_input["from"]["workflow-input"]
+                step_input["input"]
                 for step_input in step["inputs"]
                 if "from" in step_input and "workflow-input" in step_input["from"]
             )
diff --git a/workflow/workflow_abc.py b/workflow/workflow_abc.py
index 2e7c263..12e3251 100644
--- a/workflow/workflow_abc.py
+++ b/workflow/workflow_abc.py
@@ -49,14 +49,14 @@ class LaunchParameters:
     #
     #   ["r-workflow-step-a04d", "r-workflow-step-d904"]
     running_workflow_step_prior_steps: list[str] | None = None
-    # Workflow inputs (for this step Instance). These Workflow Inputs (files) are
-    # expected to be present in the Project directory. It is simply a list of files
-    # with the ability to rename them. For example, if the step requires "a.sdf"
-    # from the Project directory (and renamed as 'input.sdf" in the step's
-    # instance directory) the engine would provide the following list: -
+    # Workflow step Job inputs (for this step Instance). These Workflow Inputs (files)
+    # are a list of Job input variable names for file variables where the
+    # file is expected to be present in the Project directory. It is simply a list of
+    # Job variable names. The launcher is expected to find the 'value' of these
+    # variables and then move the file to the instance directory.
     #
-    #   [("a.sdf", "input.sdf")]
-    running_workflow_step_inputs: list[tuple[str, str]] | None = None
+    #   ["inputFile"]
+    running_workflow_step_inputs: list[str] | None = None
     # The application ID (a custom resource name)
     # used to identify the 'type' of Instance to create.
     # For DM Jobs this will be 'datamanagerjobs.squonk.it'
diff --git a/workflow/workflow_engine.py b/workflow/workflow_engine.py
index 8d0e35a..85f57b4 100644
--- a/workflow/workflow_engine.py
+++ b/workflow/workflow_engine.py
@@ -39,7 +39,7 @@
 )
 
 from .decoder import (
-    get_workflow_input_names_for_step,
+    get_workflow_job_input_names_for_step,
     get_workflow_output_values_for_step,
     set_step_variables,
 )
@@ -571,18 +571,15 @@ def _launch(
         # We must also identify workflow inputs that are required by the step we are
         # about to launch and pass those using a launch parameter. The launcher
         # will ensure these are copied into out instance directory before we are run.
+        # We cannot provide the variable values (even though we have them) because
+        # the DM passes input through 'InputHandlers', which may translate the value.
+        # So we have to pass the name and let the DM move the files after
+        # the InputHandler has run.
         #
         #   'running_workflow_step_inputs'
-        #       A list of string pairs (input/Project filename and output/Instance filename)
-        #       (with relative paths if appropriate.
-        inputs: list[tuple[str, str]] = []
-        for wf_input_name in get_workflow_input_names_for_step(wf, step_name):
-            # The variable must be known.
-            # It should have been checked by the time we get here!
-            assert wf_input_name in variables
-            # No name change of inputs in this version
-            inputs.append((variables[wf_input_name], variables[wf_input_name]))
-
+        #       A list of Job input variable names
+        inputs: list[str] = []
+        inputs.extend(iter(get_workflow_job_input_names_for_step(wf, step_name)))
         lp: LaunchParameters = LaunchParameters(
             project_id=project_id,
             name=step_name,