diff --git a/src/benchmark_api_internal.h b/src/benchmark_api_internal.h
new file mode 100644
index 0000000..0524a85
--- /dev/null
+++ b/src/benchmark_api_internal.h
@@ -0,0 +1,52 @@
+#ifndef BENCHMARK_API_INTERNAL_H
+#define BENCHMARK_API_INTERNAL_H
+
+#include "benchmark/benchmark.h"
+#include "commandlineflags.h"
+
+#include <cmath>
+#include <iosfwd>
+#include <limits>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace benchmark {
+namespace internal {
+
+// Information kept per benchmark we may want to run
+struct BenchmarkInstance {
+  std::string name;
+  Benchmark* benchmark;
+  AggregationReportMode aggregation_report_mode;
+  std::vector<int64_t> arg;
+  TimeUnit time_unit;
+  int range_multiplier;
+  bool use_real_time;
+  bool use_manual_time;
+  BigO complexity;
+  BigOFunc* complexity_lambda;
+  UserCounters counters;
+  const std::vector<Statistics>* statistics;
+  bool last_benchmark_instance;
+  int repetitions;
+  double min_time;
+  size_t iterations;
+  int threads;  // Number of concurrent threads to us
+
+  State Run(size_t iters, int thread_id, internal::ThreadTimer* timer,
+            internal::ThreadManager* manager) const;
+};
+
+bool FindBenchmarksInternal(const std::string& re,
+                            std::vector<BenchmarkInstance>* benchmarks,
+                            std::ostream* Err);
+
+bool IsZero(double n);
+
+ConsoleReporter::OutputOptions GetOutputOptions(bool force_no_color = false);
+
+}  // end namespace internal
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_API_INTERNAL_H