diff --git a/harness.R b/harness.R
new file mode 100644
index 0000000000000000000000000000000000000000..7a9a464a750245e4b4d27d270380ea9af4d1a56c
--- /dev/null
+++ b/harness.R
@@ -0,0 +1,24 @@
+arg <- commandArgs(TRUE)
+if (length(arg) < 2) {
+	stop("args")
+}
+
+conf <- arg[[1]]
+sm <- as.integer(arg[[2]])
+
+sys <- ifelse(R.Version()$major == 2L, "Renjin", "GNU R")
+
+log.result <- function(...) {
+	con <- file("results.tsv", open="at")
+	writeLines(paste(c(...), collapse="\t"), con=con)
+	close(con)
+}
+
+
+clearResultRecycler <- function() {
+	if (sys == "Renjin") {
+		import(org.renjin.compiler.pipeline.optimize.AggregationRecycler)$clear()
+		print("cleaned aggregation cache")
+	}
+}
+