diff --git a/secop_psi/sea.py b/secop_psi/sea.py
index 2ad4f90..3ac2a9d 100644
--- a/secop_psi/sea.py
+++ b/secop_psi/sea.py
@@ -325,6 +325,22 @@ class SeaConfigCreator(SeaClient):
             result.append('%s: %s' % (filename, ','.join(n for n in descr)))
         raise SystemExit('; '.join(result))
 
+    @Command(StringType(), result=StringType())
+    def query(self, cmd):
+        """a request checking for errors and accepting 0 or 1 line as result"""
+        errors = []
+        reply = None
+        for line in self.request(cmd).split('\n'):
+            if line.strip().startswith('ERROR:'):
+                errors.append(line[6:].strip())
+            elif reply is None:
+                reply = line.strip()
+            else:
+                self.log.info('SEA: superfluous reply %r to %r', reply, cmd)
+        if errors:
+            raise HardwareError('; '.join(errors))
+        return reply
+
 
 SEA_TO_SECOPTYPE = {
     'float': FloatRange(),