+#ifndef TDB_TEST_EXTERNAL_TRANSACTION_H
+#define TDB_TEST_EXTERNAL_TRANSACTION_H
+#include <stdbool.h>
+
+/* Do this before doing any tdb stuff. Return handle, or -1. */
+int prepare_external_agent(void);
+
+/* Ask the external agent to try to do a transaction. */
+bool external_agent_transaction(int handle, const char *tdbname);
+
+#endif /* TDB_TEST_EXTERNAL_TRANSACTION_H */