diff --git a/studio/backend/core/inference/tools.py b/studio/backend/core/inference/tools.py
index 4af8b1552a..6d506eefa2 100644
--- a/studio/backend/core/inference/tools.py
+++ b/studio/backend/core/inference/tools.py
@@ -552,9 +552,13 @@ def _build_brace_re(prefix_alt: str, names: tuple[str, ...]) -> "re.Pattern[str]
         non-word -- so it cannot anchor here)."""
     return re.compile(
         _PATH_TOKEN_START
-        + r"(?:" + prefix_alt + r")"
+        + r"(?:"
+        + prefix_alt
+        + r")"
         + r"[^\s'\";&|`$]*?"
-        + r"\{[^{}]*?(?<=[,{/])(?:" + "|".join(names) + r")(?=,|\}|/)[^{}]*\}",
+        + r"\{[^{}]*?(?<=[,{/])(?:"
+        + "|".join(names)
+        + r")(?=,|\}|/)[^{}]*\}",
         re.IGNORECASE,
     )
 
@@ -568,16 +572,12 @@ _HOME_BRACE_PREFIX_ALT = (
     + r"|%USERPROFILE%/+"
     + r"|%HOMEDRIVE%%HOMEPATH%/+"
 )
-_HOME_BRACE_RE = _build_brace_re(
-    _HOME_BRACE_PREFIX_ALT, _HOME_BRACE_SENSITIVE_NAMES
-)
+_HOME_BRACE_RE = _build_brace_re(_HOME_BRACE_PREFIX_ALT, _HOME_BRACE_SENSITIVE_NAMES)
 _ETC_BRACE_RE = _build_brace_re(r"/etc/+", _ETC_BRACE_SENSITIVE_NAMES)
 _PROC_BRACE_RE = _build_brace_re(
     r"/proc/(?:self|thread-self|\d+)/+", _PROC_BRACE_SENSITIVE_NAMES
 )
-_VAR_SPOOL_BRACE_RE = _build_brace_re(
-    r"/var/spool/cron/+", (r"[\w.-]+",)
-)
+_VAR_SPOOL_BRACE_RE = _build_brace_re(r"/var/spool/cron/+", (r"[\w.-]+",))
 
 
 def _expand_brace_projections(text: str, limit: int = 1024) -> set[str]:
@@ -3248,10 +3248,7 @@ def _check_signal_escape_patterns(code: str):
             ):
                 recv = node.value.value.id
                 attr = node.value.attr
-                if (
-                    recv in self.pathlib_aliases
-                    and attr in _PATHLIB_PATH_CLASSES
-                ):
+                if recv in self.pathlib_aliases and attr in _PATHLIB_PATH_CLASSES:
                     for tgt in node.targets:
                         if isinstance(tgt, ast.Name):
                             self.path_aliases.add(tgt.id)
diff --git a/studio/backend/tests/test_sandbox_hardening.py b/studio/backend/tests/test_sandbox_hardening.py
index c38e2c3613..286becd68c 100644
--- a/studio/backend/tests/test_sandbox_hardening.py
+++ b/studio/backend/tests/test_sandbox_hardening.py
@@ -2258,7 +2258,9 @@ class TestR7_DeepPathTraversal:
         ],
     )
     def test_deep_traversal_bash_blocked(self, cmd):
-        assert _find_sensitive_paths(cmd), f"deep ~/foo/../../etc traversal leaked: {cmd!r}"
+        assert _find_sensitive_paths(
+            cmd
+        ), f"deep ~/foo/../../etc traversal leaked: {cmd!r}"
 
     @pytest.mark.parametrize(
         "code",
@@ -2280,7 +2282,9 @@ class TestR7_DeepPathTraversal:
         ],
     )
     def test_in_home_traversal_allowed(self, cmd):
-        assert not _find_sensitive_paths(cmd), f"legit in-home ../ traversal blocked: {cmd!r}"
+        assert not _find_sensitive_paths(
+            cmd
+        ), f"legit in-home ../ traversal blocked: {cmd!r}"
 
 
 class TestR7_BraceFalsePositive:
@@ -2301,7 +2305,9 @@ class TestR7_BraceFalsePositive:
         ],
     )
     def test_user_data_brace_allowed(self, cmd):
-        assert not _find_sensitive_paths(cmd), f"user-data brace falsely blocked: {cmd!r}"
+        assert not _find_sensitive_paths(
+            cmd
+        ), f"user-data brace falsely blocked: {cmd!r}"
 
     @pytest.mark.parametrize(
         "cmd",
@@ -2324,7 +2330,9 @@ class TestR7_BraceFalsePositive:
         ],
     )
     def test_home_credential_brace_blocked(self, cmd):
-        assert _find_sensitive_paths(cmd), f"home-credential brace listing leaked: {cmd!r}"
+        assert _find_sensitive_paths(
+            cmd
+        ), f"home-credential brace listing leaked: {cmd!r}"
 
 
 class TestR7_BinOpAddDepthCap:
@@ -2344,7 +2352,9 @@ class TestR7_BinOpAddDepthCap:
         parts = ["''"] * pad + [repr(c) for c in target]
         expr = " + ".join(parts)
         code = f"open({expr}).read()"
-        assert _is_blocked(code), f"long {n_parts}-operand concat leaked: open({expr!r})"
+        assert _is_blocked(
+            code
+        ), f"long {n_parts}-operand concat leaked: open({expr!r})"
 
     def test_long_concat_legit_allowed(self):
         # A long concatenation that resolves to a benign path must