Index: MessagePayloads.h
===================================================================
diff -u -rdfdb72696ea34b33fdf79d3f89f3a49dd053b3ac -r97ee6a80d6bbd4193fd1aa29e5c07b04f8a4b4d1
--- MessagePayloads.h	(.../MessagePayloads.h)	(revision dfdb72696ea34b33fdf79d3f89f3a49dd053b3ac)
+++ MessagePayloads.h	(.../MessagePayloads.h)	(revision 97ee6a80d6bbd4193fd1aa29e5c07b04f8a4b4d1)
@@ -7,8 +7,8 @@
 *
 * @file    MessagePayloads.h
 *
-* @author  (last)      Raghu Kallala
-* @date    (last)      04-May-2026
+* @author  (last)      Sameer Kalliadan Poyil
+* @date    (last)      15-Jun-2026
 *
 * @author  (original)  Sean Nash
 * @date    (original)  07-Nov-2024
@@ -46,6 +46,7 @@
     F32  bicarbConvFactor;                              ///< Conversion factor of bicarbonate.
     U32  sodium;                                        ///< Set sodium being used to make dialysate.
     U32  bicarbonate;                                   ///< Set bicarbonate being used to make dialysate.
+    F32  substitutionRate;                              ///< Set HDF rate ( mL/min).
 } DIALYSATE_DELIVERY_REQ_PAYLOAD_T;
 
 /// Payload record structure for requesting pre generate dialysate.