diff --git a/web_api/app/alignment.py b/web_api/app/alignment.py
index fa72588eb..15f5454e8 100644
--- a/web_api/app/alignment.py
+++ b/web_api/app/alignment.py
@@ -68,6 +68,16 @@ class ApplyCorrespondencesRequest(BaseModel):
         description="Mask interpretation: 'tissue' (1=tissue, 0=non-tissue) or "
         "'defect' (1=defect, 0=non-defect). Defect masks are inverted internally.",
     )
+    tgt_image: list[list[list[list[float]]]] | None = Field(
+        None,
+        description="Target section image tensor (C, H, W, 1). When provided with "
+        "mse_weight > 0, enables image-based MSE optimization.",
+    )
+    mse_weight: float = Field(
+        0.0,
+        description="Weight for MSE loss between warped source and target images. "
+        "Only used when tgt_image is provided.",
+    )
 
 
 class ApplyCorrespondencesResponse(BaseModel):
@@ -105,6 +115,7 @@ def _parse_json_request(body: dict, device: torch.device):
 
     src_mask_tensor = None
     tgt_mask_tensor = None
+    tgt_image_tensor = None
 
     if req.src_mask is not None:
         src_mask_tensor = torch.tensor(req.src_mask, dtype=torch.float32, device=device)
@@ -116,12 +127,20 @@ def _parse_json_request(body: dict, device: torch.device):
         if req.mask_type == "defect":
             tgt_mask_tensor = 1.0 - tgt_mask_tensor
 
-    return correspondences_dict, image_tensor, src_mask_tensor, tgt_mask_tensor, {
+    if req.tgt_image is not None:
+        tgt_image_tensor = torch.tensor(req.tgt_image, dtype=torch.float32, device=device)
+
+    params = {
         "num_iter": req.num_iter,
         "rig": req.rig,
         "lr": req.lr,
         "optimizer_type": req.optimizer_type,
+        "mse_weight": req.mse_weight,
     }
+    return (
+        correspondences_dict, image_tensor, src_mask_tensor,
+        tgt_mask_tensor, tgt_image_tensor, params,
+    )
 
 
 async def _read_form_field_bytes(form, field_name: str) -> bytes:
@@ -219,12 +238,30 @@ async def _parse_multipart_request(request: Request, device: torch.device):
         if mask_type == "defect":
             tgt_mask_tensor = 1.0 - tgt_mask_tensor
 
-    return correspondences_dict, image_tensor, src_mask_tensor, tgt_mask_tensor, {
+    tgt_image_tensor = None
+    if "tgt-image-data" in form:
+        if "tgt_image_shape" not in metadata:
+            raise HTTPException(
+                status_code=400,
+                detail="'tgt_image_shape' required in metadata when 'tgt-image-data' is provided",
+            )
+        tgt_img_bytes = await _read_form_field_bytes(form, "tgt-image-data")
+        tgt_img_np = _read_tensor_from_bytes(
+            tgt_img_bytes, metadata["tgt_image_shape"], "tgt-image-data"
+        )
+        tgt_image_tensor = torch.tensor(tgt_img_np, dtype=torch.float32, device=device)
+
+    params = {
         "num_iter": metadata.get("num_iter", 200),
         "rig": metadata.get("rig", 1000),
         "lr": metadata.get("lr", 1e-3),
         "optimizer_type": metadata.get("optimizer_type", "adam"),
+        "mse_weight": metadata.get("mse_weight", 1.0),
     }
+    return (
+        correspondences_dict, image_tensor, src_mask_tensor,
+        tgt_mask_tensor, tgt_image_tensor, params,
+    )
 
 
 def _build_json_response(relaxed_field_np: np.ndarray, warped_image_np: np.ndarray):
@@ -306,20 +343,36 @@ async def apply_correspondences(request: Request):
 
     content_type = request.headers.get("content-type", "")
     if "multipart/form-data" in content_type:
-        correspondences_dict, image_tensor, src_mask_tensor, tgt_mask_tensor, params = (
-            await _parse_multipart_request(request, device)
-        )
+        (
+            correspondences_dict, image_tensor, src_mask_tensor,
+            tgt_mask_tensor, tgt_image_tensor, params,
+        ) = await _parse_multipart_request(request, device)
     else:
         body = await request.json()
-        correspondences_dict, image_tensor, src_mask_tensor, tgt_mask_tensor, params = (
-            _parse_json_request(body, device)
-        )
+        (
+            correspondences_dict, image_tensor, src_mask_tensor,
+            tgt_mask_tensor, tgt_image_tensor, params,
+        ) = _parse_json_request(body, device)
+
+    print(f"[apply_correspondences] tgt_image_tensor is None: "
+          f"{tgt_image_tensor is None}")
+    if tgt_image_tensor is not None:
+        print(f"[apply_correspondences] tgt_image_tensor "
+              f"shape: {tgt_image_tensor.shape}, "
+              f"min: {tgt_image_tensor.min().item():.4f}, "
+              f"max: {tgt_image_tensor.max().item():.4f}")
+    print(f"[apply_correspondences] image_tensor "
+          f"shape: {image_tensor.shape}, "
+          f"min: {image_tensor.min().item():.4f}, "
+          f"max: {image_tensor.max().item():.4f}")
+    print(f"[apply_correspondences] params: {params}")
 
     relaxed_field, warped_image = apply_correspondences_to_image(
         correspondences_dict=correspondences_dict,
         image=image_tensor,
         src_mask=src_mask_tensor,
         tgt_mask=tgt_mask_tensor,
+        tgt_image=tgt_image_tensor,
         **params,
     )