diff --git a/studio/backend/core/inference/sd_cpp_backend.py b/studio/backend/core/inference/sd_cpp_backend.py
index 6a52fc9ec9..642310b6fd 100644
--- a/studio/backend/core/inference/sd_cpp_backend.py
+++ b/studio/backend/core/inference/sd_cpp_backend.py
@@ -707,7 +707,6 @@ class SdCppDiffusionBackend:
         out: dict[tuple[str, str], int] = {}
         try:
             from huggingface_hub import HfApi
-
             api = HfApi(token = hf_token)
         except Exception:  # noqa: BLE001 -- sizes are best-effort
             return out
diff --git a/studio/backend/routes/inference.py b/studio/backend/routes/inference.py
index 4701610bf3..8c82cd17e2 100644
--- a/studio/backend/routes/inference.py
+++ b/studio/backend/routes/inference.py
@@ -16097,7 +16097,6 @@ async def diffusion_download_plan(
         planner = backend
         if fam is not None and predict_engine(fam, model_kind = kind) == ENGINE_SD_CPP:
             from core.inference.sd_cpp_backend import get_sd_cpp_backend
-
             planner = get_sd_cpp_backend()
         plan = await asyncio.to_thread(
             planner.download_plan,
diff --git a/studio/backend/tests/test_diffusion_engine_router.py b/studio/backend/tests/test_diffusion_engine_router.py
index 09ac9e8398..cabee43b2a 100644
--- a/studio/backend/tests/test_diffusion_engine_router.py
+++ b/studio/backend/tests/test_diffusion_engine_router.py
@@ -408,9 +408,9 @@ def test_predict_engine_falls_back_when_install_is_disabled_and_nothing_is_insta
 @pytest.mark.parametrize(
     "kwargs, device",
     [
-        ({"model_kind": "pipeline"}, "cpu"),   # native is GGUF-only
+        ({"model_kind": "pipeline"}, "cpu"),  # native is GGUF-only
         ({"model_kind": "single_file"}, "cpu"),
-        ({"model_kind": "gguf"}, "cuda"),      # a usable GPU always means diffusers
+        ({"model_kind": "gguf"}, "cuda"),  # a usable GPU always means diffusers
     ],
 )
 def test_predict_engine_returns_diffusers_where_the_load_would(monkeypatch, kwargs, device):
diff --git a/studio/backend/tests/test_diffusion_routes.py b/studio/backend/tests/test_diffusion_routes.py
index 477e772be6..3e772eeaaf 100644
--- a/studio/backend/tests/test_diffusion_routes.py
+++ b/studio/backend/tests/test_diffusion_routes.py
@@ -1082,8 +1082,14 @@ def test_download_plan_uses_the_engine_the_load_will_pick(client, monkeypatch):
 
     monkeypatch.setattr(router, "predict_engine", lambda fam, **_: ENGINE_SD_CPP)
     native_plan = {
-        "entries": [{"repo_id": "Comfy-Org/z_image_turbo", "files": ["ae.safetensors"],
-                     "bytes": 7, "gguf_filename": None}],
+        "entries": [
+            {
+                "repo_id": "Comfy-Org/z_image_turbo",
+                "files": ["ae.safetensors"],
+                "bytes": 7,
+                "gguf_filename": None,
+            }
+        ],
         "total_bytes": 7,
     }
     seen: dict = {}
diff --git a/studio/backend/tests/test_sd_cpp_backend.py b/studio/backend/tests/test_sd_cpp_backend.py
index 2460986aec..4c1e6934dd 100644
--- a/studio/backend/tests/test_sd_cpp_backend.py
+++ b/studio/backend/tests/test_sd_cpp_backend.py
@@ -240,9 +240,12 @@ def test_download_plan_stages_exactly_what_sd_cli_opens(monkeypatch):
     )
 
     fam = detect_family("z-image")
-    expected = {(r, f) for r, f, _k in b._asset_specs(
-        "unsloth/Z-Image-Turbo-GGUF", "z-image-turbo-Q4_K_M.gguf", fam
-    )}
+    expected = {
+        (r, f)
+        for r, f, _k in b._asset_specs(
+            "unsloth/Z-Image-Turbo-GGUF", "z-image-turbo-Q4_K_M.gguf", fam
+        )
+    }
     listed = {(e["repo_id"], f) for e in plan["entries"] for f in e["files"]}
     assert listed == expected
     assert plan["total_bytes"] == 12_300