diff --git a/api/onnx_web/serve.py b/api/onnx_web/serve.py
index 2048f54f..e5904f08 100644
--- a/api/onnx_web/serve.py
+++ b/api/onnx_web/serve.py
@@ -320,9 +320,11 @@ def load_platforms():
                         'device_id': i,
                     }))
             else:
-                available_platforms.append(DeviceParams(potential, platform_providers[potential]))
+                available_platforms.append(DeviceParams(
+                    potential, platform_providers[potential]))
 
-    logger.info('available acceleration platforms: %s', ', '.join([str(p) for p in available_platforms]))
+    logger.info('available acceleration platforms: %s',
+                ', '.join([str(p) for p in available_platforms]))
 
 
 context = ServerContext.from_environ()
@@ -603,6 +605,26 @@ def chain():
             upscale = UpscaleParams(kwargs.get('upscale'), params.provider)
             kwargs['upscale'] = upscale
 
+        stage_source_name = 'source:%s' % (stage.name)
+        stage_mask_name = 'mask:%s' % (stage.name)
+
+        if stage_source_name in request.files:
+            logger.debug('loading source image %s for pipeline stage %s',
+                         stage_source_name, stage.name)
+            source_file = request.files.get('source')
+            source_image = Image.open(
+                BytesIO(source_file.read())).convert('RGB')
+            source_image = source_image.thumbnail((512, 512))
+            kwargs['source_image'] = source_image
+
+        if stage_mask_name in request.files:
+            logger.debug('loading mask image %s for pipeline stage %s',
+                         stage_mask_name, stage.name)
+            mask_file = request.files.get('source')
+            mask_image = Image.open(BytesIO(mask_file.read())).convert('RGB')
+            mask_image = mask_image.thumbnail((512, 512))
+            kwargs['mask_image'] = mask_image
+
         pipeline.append((callback, stage, kwargs))
 
     logger.info('running chain pipeline with %s stages', len(pipeline.stages))