diff --git a/check-linuxcnc-switchkins-remap-source-map.sh b/check-linuxcnc-switchkins-remap-source-map.sh
index 624fddb..1eb1f4f 100755
--- a/check-linuxcnc-switchkins-remap-source-map.sh
+++ b/check-linuxcnc-switchkins-remap-source-map.sh
@@ -83,11 +83,12 @@ for phrase in required_phrases:
         )
 
 case_fields = {case["field"] for case in json_cases}
-bad_fields = [field for field in case_fields if "tool" in field.lower()]
+source_only_field_re = re.compile(r"asset|metadata|tool|tooldata|tool_table|TOOL_TABLE", re.I)
+bad_fields = [field for field in case_fields if source_only_field_re.search(field)]
 if bad_fields:
-    raise SystemExit(f"generated switchkins config cases expose TOOL_TABLE fields: {bad_fields}")
-if re.search(r'\btoolTable\b|\btooltable\b|\btool_table\b|\bTOOL_TABLE\b', Path("web/src/wasm-core.js").read_text(encoding="utf-8")):
-    raise SystemExit("web/src/wasm-core.js exposes TOOL_TABLE through switchkins API")
-if re.search(r'\btoolTable\b|\btooltable\b|\btool_table\b|\bTOOL_TABLE\b', Path("web/src/index.ts").read_text(encoding="utf-8")):
-    raise SystemExit("web/src/index.ts exposes TOOL_TABLE through switchkins API")
+    raise SystemExit(f"generated switchkins config cases expose source-only fields: {bad_fields}")
+api_surface_re = re.compile(r'\b(?:asset|metadata|toolData|tooldata|toolTable|tooltable|tool_table|TOOL_TABLE)\b')
+for api_path in ["web/src/wasm-core.js", "web/src/index.ts", "core/include/cnc_sim_api.h"]:
+    if api_surface_re.search(Path(api_path).read_text(encoding="utf-8")):
+        raise SystemExit(f"{api_path} exposes source-only switchkins inputs through API surface")
 PY