diff --git a/include/fusion.hpp b/include/fusion.hpp
new file mode 100644
index 0000000..9443c03
--- /dev/null
+++ b/include/fusion.hpp
@@ -0,0 +1,8 @@
+#pragma once
+#include "reading.hpp"
+#include <optional>
+
+enum class FusionState { Nominal, Degraded, Conflict, Unavailable };
+struct FusionResult { FusionState state; std::optional<double> celsius; std::string source; };
+FusionResult fuse(const ChannelAssessment& primary, const ChannelAssessment& secondary);
+const char* state_name(FusionState state);