diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9673a5b7..fc60e61d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -104,7 +104,7 @@ ecbuild_add_option( FEATURE OUTPUT_MANAGER
 
 ecbuild_add_option( FEATURE OUTPUT_MANAGER_ENCODER_REPORT
                     CONDITION HAVE_OUTPUT_MANAGER
-		                DEFAULT OFF
+		    DEFAULT OFF
                     DESCRIPTION "Enable generation of the encoding report" )
 
 ecbuild_add_option( FEATURE OUTPUT_MANAGER_TOOL
diff --git a/src/multiom/CMakeLists.txt b/src/multiom/CMakeLists.txt
index 123360cf..c0d117c3 100644
--- a/src/multiom/CMakeLists.txt
+++ b/src/multiom/CMakeLists.txt
@@ -1,5 +1,3 @@
-
-
 if ( HAVE_OUTPUT_MANAGER )
 
 # Update on new big features
diff --git a/src/multiom/common/general_utils_mod.F90 b/src/multiom/common/general_utils_mod.F90
index e7daf5ba..8a9523b9 100644
--- a/src/multiom/common/general_utils_mod.F90
+++ b/src/multiom/common/general_utils_mod.F90
@@ -10,12 +10,44 @@
 #define PP_SECTION_NAME 'GENERAL_UTILS_MOD'
 MODULE GENERAL_UTILS_MOD
 
+  ! Symbolds imported from intrinsic modules
+  USE, INTRINSIC :: ISO_FORTRAN_ENV, ONLY: ERROR_UNIT
+  USE, INTRINSIC :: ISO_FORTRAN_ENV, ONLY: OUTPUT_UNIT
+
+  ! Symbols imported from other modules within the project.
+  USE :: DATAKINDS_DEF_MOD, ONLY: JPIB_K
+
 IMPLICIT NONE
 
 !> Default visibility of the module
 PRIVATE
 
-! Whitelist of public symbols
+!> Dr Hook interface for tracing forwarding
+INTERFACE
+  SUBROUTINE DR_HOOK_DEFAULT8_IF(CDNAME,KSWITCH,PKEY)
+    USE :: DATAKINDS_DEF_MOD, ONLY: JPIM_K
+    USE :: DATAKINDS_DEF_MOD, ONLY: JPTR_K
+  IMPLICIT NONE
+    CHARACTER(LEN=*),     INTENT(IN)    :: CDNAME
+    INTEGER(KIND=JPIM_K), INTENT(IN)    :: KSWITCH
+    REAL(KIND=JPTR_K),    INTENT(INOUT) :: PKEY
+  END SUBROUTINE DR_HOOK_DEFAULT8_IF
+END INTERFACE
+
+!> Tracing variables
+PROCEDURE(DR_HOOK_DEFAULT8_IF), POINTER :: DR_HOOK => NULL()
+LOGICAL :: LHOOK_ = .FALSE.
+
+!> Default error unit
+INTEGER(KIND=JPIB_K) :: JPERR_UNIT=ERROR_UNIT
+INTEGER(KIND=JPIB_K) :: JPOUT_UNIT=OUTPUT_UNIT
+
+!> Whitelist of public symbols (Interfaces)
+PUBLIC :: DR_HOOK_DEFAULT8_IF
+
+!> Whitelist of public symbols (Procedures)
+PUBLIC :: SET_CUSTOM_UNITS
+PUBLIC :: SET_DR_HOOK
 PUBLIC :: ENVVAR_IS_DEFINED
 PUBLIC :: READ_ENVVAR
 PUBLIC :: REPLACE_ENVVAR_IN_STRING
@@ -28,6 +60,42 @@ MODULE GENERAL_UTILS_MOD
 
 CONTAINS
 
+#define PP_PROCEDURE_TYPE 'SUBROUTINE'
+#define PP_PROCEDURE_NAME 'SET_DR_HOOK'
+SUBROUTINE SET_DR_HOOK( LHOOK, DR_HOOK_PROCEDURE )
+IMPLICIT NONE
+
+  ! Dummy arguments
+  LOGICAL,                                 INTENT(IN) :: LHOOK
+  PROCEDURE(DR_HOOK_DEFAULT8_IF), POINTER, INTENT(IN) :: DR_HOOK_PROCEDURE
+
+  !> Set the hook
+  LHOOK_  = LHOOK
+  DR_HOOK => DR_HOOK_PROCEDURE
+
+END SUBROUTINE SET_DR_HOOK
+#undef PP_PROCEDURE_NAME
+#undef PP_PROCEDURE_TYPE
+
+#define PP_PROCEDURE_TYPE 'SUBROUTINE'
+#define PP_PROCEDURE_NAME 'SET_CUSTOM_UNITS'
+SUBROUTINE SET_CUSTOM_UNITS( CUSTOM_OUTPUT_UNIT, CUSTOM_ERROR_UNIT )
+
+  ! Symbols imported from other modules within the project.
+  USE :: DATAKINDS_DEF_MOD, ONLY: JPIM_K
+
+IMPLICIT NONE
+
+  ! Dummy arguments
+  INTEGER(KIND=JPIM_K), INTENT(IN) :: CUSTOM_OUTPUT_UNIT
+  INTEGER(KIND=JPIM_K), INTENT(IN) :: CUSTOM_ERROR_UNIT
+
+  JPERR_UNIT = CUSTOM_ERROR_UNIT
+  JPOUT_UNIT = CUSTOM_OUTPUT_UNIT
+
+END SUBROUTINE SET_CUSTOM_UNITS
+#undef PP_PROCEDURE_NAME
+#undef PP_PROCEDURE_TYPE
 
 #define PP_PROCEDURE_TYPE 'FUNCTION'
 #define PP_PROCEDURE_NAME 'NEED_FIT_SPECTRUM'
diff --git a/src/multiom/hooks/debug/debug_mod.F90 b/src/multiom/hooks/debug/debug_mod.F90
index 94efdd92..d083ee7e 100644
--- a/src/multiom/hooks/debug/debug_mod.F90
+++ b/src/multiom/hooks/debug/debug_mod.F90
@@ -104,7 +104,10 @@ MODULE DEBUG_MOD
     !> TODO: Add more options to add messages to the frame (i.e. int message, float messge, etc.)
 
     !> Print all error frames and their messages
-    PROCEDURE, PUBLIC, PASS, NON_OVERRIDABLE :: PRINT_ERROR_STACK => DEBUG_PRINT_ERROR_STACK
+    PROCEDURE, PUBLIC, PASS, NON_OVERRIDABLE :: PRINT_ERROR_STACK_I64 => DEBUG_PRINT_ERROR_STACK_I64
+    PROCEDURE, PUBLIC, PASS, NON_OVERRIDABLE :: PRINT_ERROR_STACK_I32 => DEBUG_PRINT_ERROR_STACK_I32
+
+    GENERIC, PUBLIC :: PRINT_ERROR_STACK => PRINT_ERROR_STACK_I64, PRINT_ERROR_STACK_I32
 
   END TYPE
 
@@ -360,7 +363,7 @@ END SUBROUTINE DEBUG_PUSH_ERROR_MSG
 !> @param [in] THIS The `DEBUG_T` object containing the error stack to be printed.
 !> @param [in] UNIT The output unit where the error stack will be printed.
 !>                  This can be a file unit or the standard output.
-SUBROUTINE DEBUG_PRINT_ERROR_STACK( THIS, UNIT )
+SUBROUTINE DEBUG_PRINT_ERROR_STACK_I64( THIS, UNIT )
 
   ! Symbols imported from other modules within the project.
   USE :: DATAKINDS_DEF_MOD, ONLY: JPIB_K
@@ -506,6 +509,40 @@ SUBROUTINE DEBUG_PRINT_ERROR_STACK( THIS, UNIT )
   !> Exit point
   RETURN
 
-END SUBROUTINE DEBUG_PRINT_ERROR_STACK
+END SUBROUTINE DEBUG_PRINT_ERROR_STACK_I64
+
+!>
+!> @brief Prints all error frames and their associated messages in the `DEBUG_T` structure.
+!>
+!> This subroutine traverses the error stack in the `DEBUG_T` object and prints
+!> each error frame along with its corresponding error messages to the specified
+!> output unit. This is useful for debugging purposes, as it provides a complete
+!> overview of all recorded errors.
+!>
+!> @param [in] THIS The `DEBUG_T` object containing the error stack to be printed.
+!> @param [in] UNIT The output unit where the error stack will be printed.
+!>                  This can be a file unit or the standard output.
+SUBROUTINE DEBUG_PRINT_ERROR_STACK_I32( THIS, UNIT )
+
+  ! Symbols imported from other modules within the project.
+  USE :: DATAKINDS_DEF_MOD, ONLY: JPIM_K
+  USE :: DATAKINDS_DEF_MOD, ONLY: JPIB_K
+
+IMPLICIT NONE
+
+  !> Dummy arguments
+  CLASS(DEBUG_T),       INTENT(IN) :: THIS
+  INTEGER(KIND=JPIM_K), INTENT(IN) :: UNIT
+
+  !> Local variables
+  INTEGER(KIND=JPIB_K) :: LOC_UNIT
+
+  !> Convert the integer unit to the default kind
+  LOC_UNIT = INT(UNIT, KIND=JPIB_K)
+
+  !> Call the I64 version of the subroutine
+  CALL THIS%PRINT_ERROR_STACK_I64( LOC_UNIT )
+
+END SUBROUTINE DEBUG_PRINT_ERROR_STACK_I32
 
 END MODULE DEBUG_MOD
diff --git a/src/multiom/ifs-interface/ifs_msg_mod.F90 b/src/multiom/ifs-interface/ifs_msg_mod.F90
index e723603a..19b5478f 100644
--- a/src/multiom/ifs-interface/ifs_msg_mod.F90
+++ b/src/multiom/ifs-interface/ifs_msg_mod.F90
@@ -97,6 +97,8 @@ MODULE IFS_MSG_MOD
   INTEGER (KIND=JPIB_K) :: KLEV
   INTEGER (KIND=JPIB_K) :: IFCST
   INTEGER (KIND=JPIB_K) :: NSTEP
+  INTEGER (KIND=JPIB_K) :: ITMAX
+  INTEGER (KIND=JPIB_K) :: ITMIN
   CHARACTER(LEN=2)      :: MARSTYPE
   CHARACTER(LEN=14)     :: CDATE  !> @brief true if there are missing values in the message
 END TYPE
@@ -1909,6 +1911,12 @@ PP_THREAD_SAFE FUNCTION WRITE_WAM( DATA, UNIT, HOOKS ) RESULT(RET)
   WRITE(UNIT,IOSTAT=STAT) INT( DATA%NSTEP, INT64 )
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_WRITE_WAM )
 
+  WRITE(UNIT,IOSTAT=STAT) INT( DATA%ITMIN, INT64 )
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_WRITE_WAM )
+
+  WRITE(UNIT,IOSTAT=STAT) INT( DATA%ITMAX, INT64 )
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_WRITE_WAM )
+
   WRITE(UNIT,IOSTAT=STAT) DATA%LRSTST0
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_WRITE_WAM )
 
@@ -2171,6 +2179,20 @@ PP_THREAD_SAFE FUNCTION READ_WAM(DATA, UNIT, VERBOSE, HOOKS ) RESULT(RET)
     WRITE(ERROR_UNIT,*) ' + MSG_WAM%NSTEP................. :: ', DATA%NSTEP
   ENDIF
 
+  READ(UNIT,IOSTAT=STAT) ITMP
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_READ_WAM )
+  DATA%ITMIN = INT( ITMP, KIND(DATA%ITMIN) )
+  IF ( VERBOSE ) THEN
+    WRITE(ERROR_UNIT,*) ' + MSG_WAM%ITMIN................. :: ', DATA%ITMIN
+  ENDIF
+
+  READ(UNIT,IOSTAT=STAT) ITMP
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_READ_WAM )
+  DATA%ITMAX = INT( ITMP, KIND(DATA%ITMAX) )
+  IF ( VERBOSE ) THEN
+    WRITE(ERROR_UNIT,*) ' + MSG_WAM%ITMAX................. :: ', DATA%ITMAX
+  ENDIF
+
   READ(UNIT,IOSTAT=STAT) DATA%LRSTST0
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_READ_WAM )
   IF ( VERBOSE ) THEN
@@ -2354,6 +2376,10 @@ PP_THREAD_SAFE FUNCTION PRINT_WAM( DATA, UNIT, HOOKS ) RESULT(RET)
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_PRINT_WAM )
   WRITE(UNIT,*,IOSTAT=STAT) ' + MSG_WAM%NSTEP................. :: ', DATA%NSTEP
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_PRINT_WAM )
+  WRITE(UNIT,*,IOSTAT=STAT) ' + MSG_WAM%ITMIN................. :: ', DATA%ITMIN
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_PRINT_WAM )
+  WRITE(UNIT,*,IOSTAT=STAT) ' + MSG_WAM%ITMAX................. :: ', DATA%ITMAX
+  PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_PRINT_WAM )
   WRITE(UNIT,*,IOSTAT=STAT) ' + MSG_WAM%LRSTST0............... :: ', DATA%LRSTST0
   PP_DEBUG_DEVELOP_COND_THROW( STAT.NE.0, ERRFLAG_UNABLE_TO_PRINT_WAM )
   WRITE(UNIT,*,IOSTAT=STAT) ' + MSG_WAM%MARSTYPE.............. :: ', DATA%MARSTYPE
diff --git a/src/multiom/multiom_api.F90 b/src/multiom/multiom_api.F90
index 8c2052da..60dcf8da 100644
--- a/src/multiom/multiom_api.F90
+++ b/src/multiom/multiom_api.F90
@@ -97,6 +97,9 @@ MODULE MULTIOM_API
   USE :: GENERAL_UTILS_MOD, ONLY: READ_TYPE_FROM_ENV
   USE :: GENERAL_UTILS_MOD, ONLY: READ_YAML_FROM_ENV
   USE :: GENERAL_UTILS_MOD, ONLY: NEED_FIT_SPECTRUM
+  USE :: GENERAL_UTILS_MOD, ONLY: SET_CUSTOM_UNITS
+  USE :: GENERAL_UTILS_MOD, ONLY: SET_DR_HOOK
+  USE :: GENERAL_UTILS_MOD, ONLY: DR_HOOK_DEFAULT8_IF
 
 IMPLICIT NONE
 
@@ -116,12 +119,23 @@ MODULE MULTIOM_API
 PUBLIC :: JPRM_K
 PUBLIC :: JPRD_K
 
+! Serialization helpers
+PUBLIC :: MODEL_PAR_SERIAL_T
+PUBLIC :: PAR_SERIALIZE
+PUBLIC :: PAR_DESERIALIZE
+
 ! Enumerators
+PUBLIC :: CPREFIX2IPREFIX
+PUBLIC :: IPREFIX2IMSGTYPE
 PUBLIC :: IPREFIX2ILEVTYPE
 PUBLIC :: ILEVTYPE2CLEVTYPE
 PUBLIC :: IREPRES2CREPRES
 PUBLIC :: VALUES_SP_E
 PUBLIC :: VALUES_DP_E
+PUBLIC :: ATM_MSG_E
+PUBLIC :: WAM_MSG_E
+PUBLIC :: REPRES_GAUSSIANGRID_E
+PUBLIC :: REPRES_SPHERICALHARMONICS_E
 
 ! ifs interface
 PUBLIC :: OM_ATM_MSG_T
@@ -165,6 +179,14 @@ MODULE MULTIOM_API
 PUBLIC :: MAKE_OUTPUT_MANAGER
 PUBLIC :: DESTROY_OUTPUT_MANAGER
 
+! General utils
+PUBLIC :: READ_TYPE_FROM_ENV
+PUBLIC :: READ_YAML_FROM_ENV
+PUBLIC :: NEED_FIT_SPECTRUM
+PUBLIC :: SET_CUSTOM_UNITS
+PUBLIC :: SET_DR_HOOK
+PUBLIC :: DR_HOOK_DEFAULT8_IF
+
 END MODULE MULTIOM_API
 #undef PP_SECTION_NAME
 #undef PP_SECTION_TYPE