diff --git a/ai_models/__init__.py b/ai_models/__init__.py
index a9f10ab..c51499b 100644
--- a/ai_models/__init__.py
+++ b/ai_models/__init__.py
@@ -5,4 +5,4 @@
 # granted to it by virtue of its status as an intergovernmental organisation
 # nor does it submit to any jurisdiction.
 
-__version__ = "0.3.5"
+__version__ = "0.3.6"
diff --git a/ai_models/model.py b/ai_models/model.py
index 1ec5e1e..25ce083 100644
--- a/ai_models/model.py
+++ b/ai_models/model.py
@@ -319,10 +319,10 @@ def print_assets_list(self):
 
     def _print_request(self, verb, request, file=sys.stdout):
         r = [verb]
-        for k, v in request.items():
+        for k, v in sorted(request.items()):
             if not isinstance(v, (list, tuple, set)):
                 v = [v]
-            v = [str(_) for _ in v]
+            v = [str(_) for _ in sorted(v)]
             v = "/".join(v)
             r.append(f"{k}={v}")
 
@@ -428,6 +428,49 @@ def gridpoints(self):
     def start_datetime(self):
         return self.all_fields.order_by(valid_datetime="ascending")[-1].datetime()
 
+    def write_input_fields(
+        self,
+        fields,
+        accumulations=None,
+        accumulations_template=None,
+        accumulations_shape=None,
+        ignore=None,
+    ):
+        if ignore is None:
+            ignore = []
+
+        with self.timer("Writing step 0"):
+            for field in fields:
+                if field.metadata("shortName") in ignore:
+                    continue
+
+                if field.valid_datetime() == self.start_datetime:
+                    self.write(
+                        None,
+                        template=field,
+                        step=0,
+                    )
+
+            if accumulations is not None:
+                if accumulations_template is None:
+                    accumulations_template = fields.sel(param="2t")[0]
+
+                if accumulations_shape is None:
+                    accumulations_shape = accumulations_template.shape
+
+                for param in accumulations:
+                    self.write(
+                        np.zeros(accumulations_shape, dtype=np.float32),
+                        stepType="accum",
+                        template=accumulations_template,
+                        param=param,
+                        startStep=0,
+                        endStep=0,
+                        date=int(self.start_datetime.strftime("%Y%m%d")),
+                        time=int(self.start_datetime.strftime("%H%M")),
+                        check=True,
+                    )
+
 
 def load_model(name, **kwargs):
     return available_models()[name].load()(**kwargs)
diff --git a/ai_models/outputs/__init__.py b/ai_models/outputs/__init__.py
index 377a54a..bc9dcc9 100644
--- a/ai_models/outputs/__init__.py
+++ b/ai_models/outputs/__init__.py
@@ -17,6 +17,7 @@
 class FileOutput:
     def __init__(self, owner, path, metadata, **kwargs):
         self._first = True
+        metadata.setdefault("stream", "oper")
         metadata.setdefault("expver", owner.expver)
         metadata.setdefault("class", "ml")
 
@@ -27,7 +28,8 @@ def __init__(self, owner, path, metadata, **kwargs):
         edition = metadata.pop("edition", 2)
 
         self.grib_keys = dict(
-            edition=edition, generatingProcessIdentifier=self.owner.version
+            edition=edition,
+            generatingProcessIdentifier=self.owner.version,
         )
         self.grib_keys.update(metadata)
 
@@ -37,9 +39,10 @@ def __init__(self, owner, path, metadata, **kwargs):
             **self.grib_keys,
         )
 
-    def write(self, data, *args, **kwargs):
+    def write(self, data, *args, check=False, **kwargs):
         try:
-            return self.output.write(data, *args, **kwargs)
+            handle, path = self.output.write(data, *args, **kwargs)
+
         except Exception:
             if np.isnan(data).any():
                 raise ValueError(
@@ -51,6 +54,23 @@ def write(self, data, *args, **kwargs):
                 )
             raise
 
+        if check:
+            # Check that the GRIB keys are as expected
+            for key, value in itertools.chain(self.grib_keys.items(), kwargs.items()):
+                if key in ("template",):
+                    continue
+
+                # If "param" is a string, we what to compare it to the shortName
+                if key == "param":
+                    try:
+                        float(value)
+                    except ValueError:
+                        key = "shortName"
+
+                assert str(handle.get(key)) == str(value), (key, handle.get(key), value)
+
+        return handle, path
+
 
 class HindcastReLabel:
     def __init__(self, owner, output, hindcast_reference_year, **kwargs):
@@ -81,25 +101,7 @@ def write(self, *args, **kwargs):
             kwargs["referenceDate"] = referenceDate
             kwargs["hdate"] = date
 
-        handle, path = self.output.write(*args, **kwargs)
-
-        # Check that the GRIB keys are as expected
-        for key, value in itertools.chain(
-            self.output.grib_keys.items(), kwargs.items()
-        ):
-            if key in ("template",):
-                continue
-
-            # If "param" is a string, we what to compare it to the shortName
-            if key == "param":
-                try:
-                    float(value)
-                except ValueError:
-                    key = "shortName"
-
-            assert str(handle.get(key)) == str(value), (key, handle.get(key), value)
-
-        return handle, path
+        return self.output.write(*args, check=True, **kwargs)
 
 
 class NoneOutput:
diff --git a/setup.py b/setup.py
index c5329f9..2cc71d9 100644
--- a/setup.py
+++ b/setup.py
@@ -47,6 +47,7 @@ def read(fname):
         "multiurl",
         "ecmwflibs>=0.6.1",
         "gputil",
+        "earthkit-meteo",
     ],
     extras_require={
         "provenance": [