diff --git a/pyinfra/rest.py b/pyinfra/rest.py
index 624b6dd..3591fd3 100644
--- a/pyinfra/rest.py
+++ b/pyinfra/rest.py
@@ -1,8 +1,6 @@
-from collections import deque
 from operator import itemgetter
 
-import flask
-from funcy import repeatedly, lmap, compose
+from funcy import compose
 
 from pyinfra.utils.func import star
 from test.utils.server import bytes_to_string, string_to_bytes
@@ -25,24 +23,3 @@ def bundle(data: bytes, metadata: dict):
 
 def wrap_operation(operation):
     return compose(star(pack), star(operation), unpack)
-
-
-def make_processor(operation, buffer_size=3):
-    def processor_fn(request: flask.Request, final=False):
-        buffer.append(request.json)
-        response_payload = lmap(operation, repeatedly(buffer.popleft, n_items_to_pop(buffer, final)))
-        return response_payload
-
-    def buffer_full(current_buffer_size):
-        assert current_buffer_size <= buffer_size
-        return current_buffer_size == buffer_size
-
-    def n_items_to_pop(buffer, final):
-        current_buffer_size = len(buffer)
-        return (final or buffer_full(current_buffer_size)) * current_buffer_size
-
-    operation = wrap_operation(operation)
-
-    buffer = deque()
-
-    return processor_fn
diff --git a/pyinfra/utils/buffer.py b/pyinfra/utils/buffer.py
new file mode 100644
index 0000000..030f290
--- /dev/null
+++ b/pyinfra/utils/buffer.py
@@ -0,0 +1,23 @@
+from collections import deque
+from typing import Any
+
+from funcy import lmap, repeatedly
+
+
+def bufferize(fn, buffer_size=3, persist_fn=lambda x: x):
+    def buffered_fn(item: Any, final=False):
+        buffer.append(persist_fn(item))
+        response_payload = lmap(fn, repeatedly(buffer.popleft, n_items_to_pop(buffer, final)))
+        return response_payload
+
+    def buffer_full(current_buffer_size):
+        assert current_buffer_size <= buffer_size
+        return current_buffer_size == buffer_size
+
+    def n_items_to_pop(buffer, final):
+        current_buffer_size = len(buffer)
+        return (final or buffer_full(current_buffer_size)) * current_buffer_size
+
+    buffer = deque()
+
+    return buffered_fn
diff --git a/test/fixtures/server.py b/test/fixtures/server.py
index 006e9d5..6a7b6a8 100644
--- a/test/fixtures/server.py
+++ b/test/fixtures/server.py
@@ -1,6 +1,7 @@
 import io
 import socket
 from multiprocessing import Process
+from operator import attrgetter
 
 import fitz
 import pytest
@@ -9,7 +10,8 @@ from PIL import Image
 from funcy import retry
 from waitress import serve
 
-from pyinfra.rest import make_processor
+from pyinfra.rest import wrap_operation
+from pyinfra.utils.buffer import bufferize
 from test.server import set_up_processing_server
 from test.utils.image import image_to_bytes
 
@@ -42,7 +44,7 @@ def server(processor_fn):
 
 @pytest.fixture
 def processor_fn(operation, buffer_size):
-    return make_processor(operation, buffer_size=buffer_size)
+    return bufferize(wrap_operation(operation), buffer_size=buffer_size, persist_fn=attrgetter("json"))
 
 
 @pytest.fixture