diff --git a/CMakeLists.txt b/CMakeLists.txt
index 76184672e..b82555e85 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,8 +6,8 @@ project(OMSimulator)
 
 # Options to enable/disable specific components
 option(OMS_ENABLE_OMSimulator "Enable OMSimulator component" ON)
-option(OMS_ENABLE_OMSimulatorGui "Enable OMSimulator GUI component" ON)
-option(OMS_ENABLE_PIP "Enable pip component" ON)
+option(OMS_ENABLE_OMSimulatorGui "Enable OMSimulator GUI component" OFF)
+option(OMS_ENABLE_PIP "Enable pip component" OFF)
 option(OMS_ENABLE_TESTSUITE "Enable the OMSimulator testsuite" OFF)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/config.cmake/")
diff --git a/include/OMSimulator/OMSimulator.h b/include/OMSimulator/OMSimulator.h
index 6a55662e7..632675181 100644
--- a/include/OMSimulator/OMSimulator.h
+++ b/include/OMSimulator/OMSimulator.h
@@ -159,6 +159,12 @@ OMSAPI oms_status_enu_t OMSCALL oms_simulate(const char* cref);
 OMSAPI oms_status_enu_t OMSCALL oms_stepUntil(const char* cref, double stopTime);
 OMSAPI oms_status_enu_t OMSCALL oms_terminate(const char* cref);
 
+OMSAPI oms_status_enu_t OMSCALL oms3_instantiateFromJson(char* model_json_desc, void** out_model_ptr);
+OMSAPI oms_status_enu_t OMSCALL oms3_initialize(void* model);
+OMSAPI oms_status_enu_t OMSCALL oms3_simulate(void* model);
+OMSAPI oms_status_enu_t OMSCALL oms3_stepUntil(void* model, double stopTime);
+OMSAPI oms_status_enu_t OMSCALL oms3_terminate(void* model);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/OMSimulatorLib/OMSimulator.cpp b/src/OMSimulatorLib/OMSimulator.cpp
index 6484405b4..38bab7724 100644
--- a/src/OMSimulatorLib/OMSimulator.cpp
+++ b/src/OMSimulatorLib/OMSimulator.cpp
@@ -1691,3 +1691,31 @@ oms_status_enu_t oms_setTolerance(const char* cref, double relativeTolerance)
 
   return logError_SystemNotInModel(model->getCref(), front);
 }
+
+
+oms_status_enu_t oms3_instantiateFromJson(char* model_json_desc, void** out_model_ptr)
+{
+  *out_model_ptr = nullptr;
+  logDebug(model_json_desc);
+  return oms_status_ok;
+}
+
+oms_status_enu_t oms3_initialize(void* model)
+{
+  return oms_status_error;
+}
+
+oms_status_enu_t oms3_simulate(void* model)
+{
+  return oms_status_error;
+}
+
+oms_status_enu_t oms3_stepUntil(void* model, double stopTime)
+{
+  return oms_status_error;
+}
+
+oms_status_enu_t oms3_terminate(void* model)
+{
+  return oms_status_error;
+}
diff --git a/src/OMSimulatorPython/CMakeLists.txt b/src/OMSimulatorPython/CMakeLists.txt
index 04db30bb8..d86556c27 100644
--- a/src/OMSimulatorPython/CMakeLists.txt
+++ b/src/OMSimulatorPython/CMakeLists.txt
@@ -28,12 +28,13 @@ configure_file("${CMAKE_CURRENT_SOURCE_DIR}/OMSimulatorPython3.in" "${CMAKE_CURR
 
 install(FILES "${CMAKE_CURRENT_BINARY_DIR}/__init__.py"
               "${CMAKE_CURRENT_BINARY_DIR}/capi.py"
+              "${CMAKE_CURRENT_SOURCE_DIR}/component.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/connection.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/connector.py"
-              "${CMAKE_CURRENT_SOURCE_DIR}/component.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/cref.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/elementgeometry.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/fmu.py"
+              "${CMAKE_CURRENT_SOURCE_DIR}/instantiated_model.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/namespace.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/settings.py"
               "${CMAKE_CURRENT_SOURCE_DIR}/ssd.py"
diff --git a/src/OMSimulatorPython/__init__.py b/src/OMSimulatorPython/__init__.py
index 5e1da1f72..c9af017bb 100644
--- a/src/OMSimulatorPython/__init__.py
+++ b/src/OMSimulatorPython/__init__.py
@@ -4,6 +4,7 @@
 OpenModelica FMI & SSP based simulator.
 '''
 
+from OMSimulator.capi import Capi
 from OMSimulator.connection import Connection
 from OMSimulator.connector import Connector
 from OMSimulator.cref import CRef
@@ -14,11 +15,25 @@
 from OMSimulator.ssv import SSV
 from OMSimulator.system import System
 from OMSimulator.variable import Causality, SignalType, Variable
-
-from OMSimulator import capi
+from OMSimulator.instantiated_model import InstantiatedModel
 
 # Define public API
-__all__ = ['Connection', 'Connector', 'CRef', 'FMU', 'Settings', 'SSD', 'SSP', 'SSV', 'System', 'Causality', 'SignalType', 'Variable']
+__all__ = [
+    'Capi',
+    'Causality',
+    'Connection',
+    'Connector',
+    'CRef',
+    'FMU',
+    'InstantiatedModel',
+    'Settings',
+    'SignalType',
+    'SSD',
+    'SSP',
+    'SSV',
+    'System',
+    'Variable',
+  ]
 
 __version__ = '@OMS_SHORT_VERSION_STRING@'
 __author__ = 'Open Source Modelica Consortium (OSMC)'
@@ -28,4 +43,4 @@
 c/o Linköpings universitet, Department of Computer and Information Science,
 SE-58183 Linköping, Sweden.'''
 
-version = capi.capi().getVersion()
+version = Capi.getVersion()
diff --git a/src/OMSimulatorPython/capi.py b/src/OMSimulatorPython/capi.py
index 12ebcb8b5..d503fe2d8 100644
--- a/src/OMSimulatorPython/capi.py
+++ b/src/OMSimulatorPython/capi.py
@@ -1,5 +1,17 @@
 import ctypes
 import os
+from enum import Enum
+
+
+class Status(Enum):
+  '''Enumeration for status codes (oms_status_enu_t).'''
+  ok = 0
+  warning = 1
+  discard = 2
+  error = 3
+  fatal = 4
+  pending = 5
+
 
 class capi:
   def __init__(self):
@@ -24,379 +36,50 @@ def __init__(self):
     if os.name == 'nt' and dllSearchPath: # Windows
       dllDir.close()
 
-    self.obj.oms_activateVariant.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_activateVariant.restype = ctypes.c_int
-    self.obj.oms_addBus.argtypes = [ctypes.c_char_p]
-    self.obj.oms_addBus.restype = ctypes.c_int
-    self.obj.oms_addConnection.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_bool]
-    self.obj.oms_addConnection.restype = ctypes.c_int
-    self.obj.oms_addConnector.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.c_int]
-    self.obj.oms_addConnector.restype = ctypes.c_int
-    self.obj.oms_addConnectorToBus.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_addConnectorToBus.restype = ctypes.c_int
-    self.obj.oms_addResources.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_addResources.restype = ctypes.c_int
-    self.obj.oms_addSignalsToResults.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_addSignalsToResults.restype = ctypes.c_int
-    self.obj.oms_addSubModel.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_addSubModel.restype = ctypes.c_int
-    self.obj.oms_addSystem.argtypes = [ctypes.c_char_p, ctypes.c_int]
-    self.obj.oms_addSystem.restype = ctypes.c_int
-    self.obj.oms_compareSimulationResults.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p, ctypes.c_double, ctypes.c_double]
-    self.obj.oms_compareSimulationResults.restype = ctypes.c_int
-    self.obj.oms_copySystem.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_copySystem.restype = ctypes.c_int
-    self.obj.oms_delete.argtypes = [ctypes.c_char_p]
-    self.obj.oms_delete.restype = ctypes.c_int
-    self.obj.oms_deleteConnection.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_deleteConnection.restype = ctypes.c_int
-    self.obj.oms_deleteConnectorFromBus.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_deleteConnectorFromBus.restype = ctypes.c_int
-    self.obj.oms_deleteResources.argtypes = [ctypes.c_char_p]
-    self.obj.oms_deleteResources.restype = ctypes.c_int
-    self.obj.oms_doStep.argtypes = [ctypes.c_char_p]
-    self.obj.oms_doStep.restype = ctypes.c_int
-    self.obj.oms_duplicateVariant.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_duplicateVariant.restype = ctypes.c_int
-    self.obj.oms_export.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_export.restype = ctypes.c_int
-    self.obj.oms_exportDependencyGraphs.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_exportDependencyGraphs.restype = ctypes.c_int
-    self.obj.oms_exportSnapshot.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_exportSnapshot.restype = ctypes.c_int
-    self.obj.oms_exportSSMTemplate.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_exportSSMTemplate.restype = ctypes.c_int
-    self.obj.oms_exportSSVTemplate.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_exportSSVTemplate.restype = ctypes.c_int
-    self.obj.oms_freeMemory.argtypes = [ctypes.c_void_p]
-    self.obj.oms_freeMemory.restype = None
-    self.obj.oms_getBoolean.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_bool)]
-    self.obj.oms_getBoolean.restype = ctypes.c_int
-    self.obj.oms_getDirectionalDerivative.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
-    self.obj.oms_getDirectionalDerivative.restype = ctypes.c_int
-    self.obj.oms_getFixedStepSize.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
-    self.obj.oms_getFixedStepSize.restype = ctypes.c_int
-    self.obj.oms_getInteger.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_int)]
-    self.obj.oms_getInteger.restype = ctypes.c_int
-    self.obj.oms_getModelState.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_int)]
-    self.obj.oms_getModelState.restype = ctypes.c_int
-    self.obj.oms_getReal.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
-    self.obj.oms_getReal.restype = ctypes.c_int
-    self.obj.oms_getResultFile.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p), ctypes.POINTER(ctypes.c_int)]
-    self.obj.oms_getResultFile.restype = ctypes.c_int
-    self.obj.oms_getSolver.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_int)]
-    self.obj.oms_getSolver.restype = ctypes.c_int
-    self.obj.oms_getStartTime.argtypes = [ctypes.c_char_p]
-    self.obj.oms_getStartTime.restype = ctypes.c_int
-    self.obj.oms_getStopTime.argtypes = [ctypes.c_char_p]
-    self.obj.oms_getStopTime.restype = ctypes.c_int
-    self.obj.oms_getString.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_getString.restype = ctypes.c_int
-    self.obj.oms_getSystemType.argtypes = [ctypes.c_char_p]
-    self.obj.oms_getSystemType.restype = ctypes.c_int
-    self.obj.oms_getState.argtypes = [ctypes.c_char_p]
-    self.obj.oms_getState.restype = ctypes.c_int
-    self.obj.oms_setState.argtypes = [ctypes.c_char_p]
-    self.obj.oms_setState.restype = ctypes.c_int
-    self.obj.oms_freeState.argtypes = [ctypes.c_char_p]
-    self.obj.oms_freeState.restype = ctypes.c_int
-    self.obj.oms_getTime.argtypes = [ctypes.c_char_p]
-    self.obj.oms_getTime.restype = ctypes.c_int
-    self.obj.oms_getVariableStepSize.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_double), ctypes.POINTER(ctypes.c_double), ctypes.POINTER(ctypes.c_double)]
-    self.obj.oms_getVariableStepSize.restype = ctypes.c_int
     self.obj.oms_getVersion.argtypes = None
     self.obj.oms_getVersion.restype = ctypes.c_char_p
-    self.obj.oms_importFile.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_importFile.restype = ctypes.c_int
-    self.obj.oms_importSnapshot.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_importSnapshot.restype = ctypes.c_int
-    self.obj.oms_initialize.argtypes = [ctypes.c_char_p]
-    self.obj.oms_initialize.restype = ctypes.c_int
-    self.obj.oms_instantiate.argtypes = [ctypes.c_char_p]
-    self.obj.oms_instantiate.restype = ctypes.c_int
-    self.obj.oms_list.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_list.restype = ctypes.c_int
-    self.obj.oms_listVariants.argtypes = [ctypes.c_char_p]
-    self.obj.oms_listVariants.restype = ctypes.c_int
-    self.obj.oms_listUnconnectedConnectors.argtypes = [ctypes.c_char_p]
-    self.obj.oms_listUnconnectedConnectors.restype = ctypes.c_int
-    self.obj.oms_loadSnapshot.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.POINTER(ctypes.c_char_p)]
-    self.obj.oms_loadSnapshot.restype = ctypes.c_int
-    self.obj.oms_newModel.argtypes = [ctypes.c_char_p]
-    self.obj.oms_newModel.restype = ctypes.c_int
-    self.obj.oms_newResources.argtypes = [ctypes.c_char_p]
-    self.obj.oms_newResources.restype = ctypes.c_int
-    self.obj.oms_reduceSSV.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_reduceSSV.restype = ctypes.c_int
-    self.obj.oms_referenceResources.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_referenceResources.restype = ctypes.c_int
-    self.obj.oms_removeSignalsFromResults.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_removeSignalsFromResults.restype = ctypes.c_int
-    self.obj.oms_rename.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_rename.restype = ctypes.c_int
-    self.obj.oms_replaceSubModel.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_bool, ctypes.POINTER(ctypes.c_int)]
-    self.obj.oms_replaceSubModel.restype = ctypes.c_int
-    self.obj.oms_reset.argtypes = [ctypes.c_char_p]
-    self.obj.oms_reset.restype = ctypes.c_int
-    self.obj.oms_setBoolean.argtypes = [ctypes.c_char_p, ctypes.c_bool]
-    self.obj.oms_setBoolean.restype = ctypes.c_int
-    self.obj.oms_setCommandLineOption.argtypes = [ctypes.c_char_p]
-    self.obj.oms_setCommandLineOption.restype = ctypes.c_int
-    self.obj.oms_setFixedStepSize.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setFixedStepSize.restype = ctypes.c_int
-    self.obj.oms_setInteger.argtypes = [ctypes.c_char_p, ctypes.c_int]
-    self.obj.oms_setInteger.restype = ctypes.c_int
-    self.obj.oms_setLogFile.argtypes = [ctypes.c_char_p]
-    self.obj.oms_setLogFile.restype = ctypes.c_int
-    self.obj.oms_setLoggingInterval.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setLoggingInterval.restype = ctypes.c_int
-    self.obj.oms_setLoggingLevel.argtypes = [ctypes.c_int]
-    self.obj.oms_setLoggingLevel.restype = ctypes.c_int
-    self.obj.oms_setMaxLogFileSize.argtypes = [ctypes.c_ulong]
-    self.obj.oms_setMaxLogFileSize.restype = None
-    self.obj.oms_setReal.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setReal.restype = ctypes.c_int
-    self.obj.oms_setRealInputDerivative.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setRealInputDerivative.restype = ctypes.c_int
-    self.obj.oms_setResultFile.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_int]
-    self.obj.oms_setResultFile.restype = ctypes.c_int
-    self.obj.oms_setSolver.argtypes = [ctypes.c_char_p, ctypes.c_int]
-    self.obj.oms_setSolver.restype = ctypes.c_int
-    self.obj.oms_setStartTime.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setStartTime.restype = ctypes.c_int
-    self.obj.oms_setStopTime.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_setStopTime.restype = ctypes.c_int
-    self.obj.oms_setString.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_setString.restype = ctypes.c_int
-    self.obj.oms_setTempDirectory.argtypes = [ctypes.c_char_p]
-    self.obj.oms_setTempDirectory.restype = ctypes.c_int
-    self.obj.oms_setTolerance.argtypes = [ctypes.c_char_p, ctypes.c_double, ctypes.c_double]
-    self.obj.oms_setTolerance.restype = ctypes.c_int
-    self.obj.oms_setUnit.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
-    self.obj.oms_setUnit.restype = ctypes.c_int
-    self.obj.oms_setVariableStepSize.argtypes = [ctypes.c_char_p, ctypes.c_double, ctypes.c_double, ctypes.c_double]
-    self.obj.oms_setVariableStepSize.restype = ctypes.c_int
-    self.obj.oms_setWorkingDirectory.argtypes = [ctypes.c_char_p]
-    self.obj.oms_setWorkingDirectory.restype = ctypes.c_int
-    self.obj.oms_simulate.argtypes = [ctypes.c_char_p]
-    self.obj.oms_simulate.restype = ctypes.c_int
-    self.obj.oms_stepUntil.argtypes = [ctypes.c_char_p, ctypes.c_double]
-    self.obj.oms_stepUntil.restype = ctypes.c_int
-    self.obj.oms_terminate.argtypes = [ctypes.c_char_p]
-    self.obj.oms_terminate.restype = ctypes.c_int
+    self.obj.oms3_instantiateFromJson.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_void_p)]
+    self.obj.oms3_instantiateFromJson.restype = ctypes.c_int
+    self.obj.oms3_initialize.argtypes = [ctypes.c_void_p]
+    self.obj.oms3_initialize.restype = ctypes.c_int
+    self.obj.oms3_simulate.argtypes = [ctypes.c_void_p]
+    self.obj.oms3_simulate.restype = ctypes.c_int
+    self.obj.oms3_stepUntil.argtypes = [ctypes.c_void_p, ctypes.c_double]
+    self.obj.oms3_stepUntil.restype = ctypes.c_int
+    self.obj.oms3_terminate.argtypes = [ctypes.c_void_p]
+    self.obj.oms3_terminate.restype = ctypes.c_int
 
-  def activateVariant(self, crefA, crefB):
-    return self.obj.oms_activateVariant(crefA.encode(), crefB.encode())
-  def addBus(self, crefA):
-    return self.obj.oms_addBus(crefA.encode())
-  def addConnection(self, crefA, crefB, suppressUnit=False):
-    return self.obj.oms_addConnection(crefA.encode(), crefB.encode(), suppressUnit)
-  def addConnector(self, cref, causality, type_):
-    return self.obj.oms_addConnector(cref.encode(), causality, type_)
-  def addConnectorToBus(self, busCref, connectorCref):
-    return self.obj.oms_addConnectorToBus(busCref.encode(), connectorCref.encode())
-  def addResources(self, cref, path):
-    return self.obj.oms_addResources(cref.encode(), path.encode())
-  def addSignalsToResults(self, cref, regex):
-    return self.obj.oms_addSignalsToResults(cref.encode(), regex.encode())
-  def addSubModel(self, cref, fmuPath):
-    return self.obj.oms_addSubModel(cref.encode(), fmuPath.encode())
-  def addSystem(self, ident, type_):
-    return self.obj.oms_addSystem(ident.encode(), type_)
-  def compareSimulationResults(self, filenameA, filenameB, var, relTol, absTol):
-    return self.obj.oms_compareSimulationResults(filenameA.encode(), filenameB.encode(), var.encode(), relTol, absTol)
-  def copySystem(self, source, target):
-    return self.obj.oms_copySystem(source.encode(), target.encode())
-  def delete(self, cref):
-    return self.obj.oms_delete(cref.encode())
-  def deleteConnection(self, crefA, crefB):
-    return self.obj.oms_deleteConnection(crefA.encode(), crefB.encode())
-  def deleteConnectorFromBus(self, busCref, connectorCref):
-    return self.obj.oms_deleteConnectorFromBus(busCref.encode(), connectorCref.encode())
-  def deleteResources(self, crefA):
-    return self.obj.oms_deleteResources(crefA.encode())
-  def doStep(self, cref):
-    return self.obj.oms_doStep(cref.encode())
-  def duplicateVariant(self, crefA, crefB):
-    return self.obj.oms_duplicateVariant(crefA.encode(), crefB.encode())
-  def export(self, cref, filename):
-    return self.obj.oms_export(cref.encode(), filename.encode())
-  def exportDependencyGraphs(self, cref, initialization, event, simulation):
-    return self.obj.oms_exportDependencyGraphs(cref.encode(), initialization.encode(), event.encode(), simulation.encode())
-  def exportSnapshot(self, ident):
-    contents = ctypes.c_char_p()
-    status = self.obj.oms_exportSnapshot(ident.encode(), ctypes.byref(contents))
-    contents_ = contents.value.decode('utf-8') if contents.value else None
-    self.obj.oms_freeMemory(contents)
-    return [contents_, status]
-  def exportSSMTemplate(self, ident, filename):
-    return self.obj.oms_exportSSMTemplate(ident.encode(), filename.encode())
-  def exportSSVTemplate(self, ident, filename):
-    return self.obj.oms_exportSSVTemplate(ident.encode(), filename.encode())
-  def getBoolean(self, cref):
-    value = ctypes.c_bool()
-    status = self.obj.oms_getBoolean(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getDirectionalDerivative(self, crefA, crefB=""):
-    value = ctypes.c_double()
-    status = self.obj.oms_getDirectionalDerivative(crefA.encode(), crefB.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getFixedStepSize(self, cref):
-    value = ctypes.c_double()
-    status = self.obj.oms_getFixedStepSize(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getInteger(self, cref):
-    value = ctypes.c_int()
-    status = self.obj.oms_getInteger(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getModelState(self, cref):
-    value = ctypes.c_int()
-    status = self.obj.oms_getModelState(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getReal(self, cref):
-    value = ctypes.c_double()
-    status = self.obj.oms_getReal(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getResultFile(self, cref):
-    filename = ctypes.c_char_p()
-    bufferSize = ctypes.c_int()
-    status = self.obj.oms_getResultFile(cref.encode(), ctypes.byref(filename), ctypes.byref(bufferSize))
-    return [filename.value.decode('utf-8') if filename.value else None, bufferSize.value, status]
-  def getSolver(self, cref):
-    value = ctypes.c_int()
-    status = self.obj.oms_getSolver(cref.encode(), ctypes.byref(value))
-    return [value.value, status]
-  def getStartTime(self, cref):
-    startTime = ctypes.c_double()
-    status = self.obj.oms_getStartTime(cref.encode(), ctypes.byref(startTime))
-    return [startTime.value, status]
-  def getStopTime(self, cref):
-    stopTime = ctypes.c_double()
-    status = self.obj.oms_getStopTime(cref.encode(), ctypes.byref(stopTime))
-    return [stopTime.value, status]
-  def getString(self, cref):
-    value = ctypes.c_char_p()
-    status = self.obj.oms_getString(cref.encode(), ctypes.byref(value))
-    value_ = value.value.decode('utf-8') if value.value else None
-    self.obj.oms_freeMemory(value)
-    return [value_, status]
-  def getSystemType(self, cref):
-    type_ = ctypes.c_int()
-    status = self.obj.oms_getSystemType(cref.encode(), ctypes.byref(type_))
-    return [type_.value, status]
-  def getState(self, cref):
-    return self.obj.oms_getState(cref.encode())
-  def setState(self, cref):
-    return self.obj.oms_setState(cref.encode())
-  def freeState(self, cref):
-    return self.obj.oms_freeState(cref.encode())
-  def getTime(self, cref):
-    time = ctypes.c_double()
-    status = self.obj.oms_getTime(cref.encode(), ctypes.byref(time))
-    return [time.value, status]
-  def getVariableStepSize(self, cref):
-    initialStepSize = ctypes.c_double()
-    minimumStepSize = ctypes.c_double()
-    maximumStepSize = ctypes.c_double()
-    status = self.obj.oms_getVariableStepSize(cref.encode(), ctypes.byref(initialStepSize), ctypes.byref(minimumStepSize), ctypes.byref(maximumStepSize))
-    return [initialStepSize.value, minimumStepSize.value, maximumStepSize.value, status]
   def getVersion(self):
     return self.obj.oms_getVersion().decode('utf-8')
-  def importFile(self, filename):
-    cref = ctypes.c_char_p()
-    status = self.obj.oms_importFile(filename.encode(), ctypes.byref(cref))
-    return [cref.value.decode('utf-8') if cref.value else None, status]
-  def importSnapshot(self, ident, snapshot):
-    newCref = ctypes.c_char_p()
-    status = self.obj.oms_importSnapshot(ident.encode(), snapshot.encode(), ctypes.byref(newCref))
-    return [newCref.value.decode('utf-8') if newCref.value else None, status]
-  def initialize(self, cref):
-    return self.obj.oms_initialize(cref.encode())
-  def instantiate(self, cref):
-    return self.obj.oms_instantiate(cref.encode())
-  def list(self, ident):
-    contents = ctypes.c_char_p()
-    status = self.obj.oms_list(ident.encode(), ctypes.byref(contents))
-    contents_ = contents.value.decode('utf-8') if contents.value else None
-    self.obj.oms_freeMemory(contents)
-    return [contents_, status]
-  def listVariants(self, ident):
-    contents = ctypes.c_char_p()
-    status = self.obj.oms_listVariants(ident.encode(), ctypes.byref(contents))
-    contents_ = contents.value.decode('utf-8') if contents.value else None
-    self.obj.oms_freeMemory(contents)
-    return [contents_, status]
-  def listUnconnectedConnectors(self, ident):
-    contents = ctypes.c_char_p()
-    status = self.obj.oms_listUnconnectedConnectors(ident.encode(), ctypes.byref(contents))
-    contents_ = contents.value.decode('utf-8') if contents.value else None
-    self.obj.oms_freeMemory(contents)
-    return [contents_, status]
-  def loadSnapshot(self, ident, snapshot):
-    newCref = ctypes.c_char_p()
-    status = self.obj.oms_loadSnapshot(ident.encode(), snapshot.encode(), ctypes.byref(newCref))
-    return [newCref.value.decode('utf-8') if newCref.value else None, status]
-  def newModel(self, cref):
-    return self.obj.oms_newModel(cref.encode())
-  def newResources(self, crefA):
-    return self.obj.oms_newResources(crefA.encode())
-  def reduceSSV(self, crefA, crefB, crefC, crefD=""):
-    return self.obj.oms_reduceSSV(crefA.encode(), crefB.encode(), crefC.encode(), crefD.encode())
-  def referenceResources(self, crefA, crefB=""):
-    return self.obj.oms_referenceResources(crefA.encode(), crefB.encode())
-  def removeSignalsFromResults(self, cref, regex):
-    return self.obj.oms_removeSignalsFromResults(cref.encode(), regex.encode())
-  def rename(self, cref, newcref):
-    return self.obj.oms_rename(cref.encode(), newcref.encode())
-  def replaceSubModel(self, cref, fmuPath, dryRun):
-    value = ctypes.c_int()
-    status = self.obj.oms_replaceSubModel(cref.encode(), fmuPath.encode(), dryRun, ctypes.byref(value))
-    return [value.value, status]
-  def reset(self, cref):
-    return self.obj.oms_reset(cref.encode())
-  def setBoolean(self, signal, value):
-    return self.obj.oms_setBoolean(signal.encode(), value)
-  def setCommandLineOption(self, cmd):
-    return self.obj.oms_setCommandLineOption(cmd.encode())
-  def setFixedStepSize(self, cref, stepSize):
-    return self.obj.oms_setFixedStepSize(cref.encode(), stepSize)
-  def setInteger(self, signal, value):
-    return self.obj.oms_setInteger(signal.encode(), value)
-  def setLogFile(self, filename):
-    return self.obj.oms_setLogFile(filename.encode())
-  def setLoggingInterval(self, cref, loggingInterval):
-    return self.obj.oms_setLoggingInterval(cref.encode(), loggingInterval)
-  def setLoggingLevel(self, level):
-    return self.obj.oms_setLoggingLevel(level)
-  def setMaxLogFileSize(self, size):
-    return self.obj.oms_setMaxLogFileSize(size)
-  def setReal(self, signal, value):
-    return self.obj.oms_setReal(signal.encode(), value)
-  def setRealInputDerivative(self, signal, value):
-    return self.obj.oms_setRealInputDerivative(signal.encode(), value)
-  def setResultFile(self, cref, filename, bufferSize=1):
-    return self.obj.oms_setResultFile(cref.encode(), filename.encode(), bufferSize)
-  def setSolver(self, cref, solver):
-    return self.obj.oms_setSolver(cref.encode(), solver)
-  def setStartTime(self, cref, startTime):
-    return self.obj.oms_setStartTime(cref.encode(), startTime)
-  def setStopTime(self, cref, stopTime):
-    return self.obj.oms_setStopTime(cref.encode(), stopTime)
-  def setString(self, signal, value):
-    return self.obj.oms_setString(signal.encode(), value.encode())
-  def setTempDirectory(self, newTempDir):
-    return self.obj.oms_setTempDirectory(newTempDir.encode())
-  def setTolerance(self, cref, relativeTolerance):
-    return self.obj.oms_setTolerance(cref.encode(), relativeTolerance)
-  def setUnit(self, signal, value):
-    return self.obj.oms_setUnit(signal.encode(), value.encode())
-  def setVariableStepSize(self, cref, initialStepSize, minimumStepSize, maximumStepSize):
-    return self.obj.oms_setVariableStepSize(cref.encode(), initialStepSize, minimumStepSize, maximumStepSize)
-  def setWorkingDirectory(self, path):
-    return self.obj.oms_setWorkingDirectory(path.encode())
-  def simulate(self, cref):
-    return self.obj.oms_simulate(cref.encode())
-  def stepUntil(self, cref, stopTime):
-    return self.obj.oms_stepUntil(cref.encode(), stopTime)
-  def terminate(self, cref):
-    return self.obj.oms_terminate(cref.encode())
+
+  def instantiateFromJson(self, model_json_desc) -> tuple:
+    '''Instantiate a model from a JSON description.'''
+    model_ptr = ctypes.c_void_p()
+    status = self.obj.oms3_instantiateFromJson(model_json_desc.encode('utf-8'), ctypes.byref(model_ptr))
+    if status != Status.ok:
+      return None, Status(status)
+    return model_ptr, Status(status)
+
+  def initialize(self, model) -> Status:
+    '''Enters initialization mode.'''
+    status = self.obj.oms3_initialize(model)
+    return Status(status)
+
+  def simulate(self, model) -> Status:
+    '''Exits initialization mode and runs the simulation until stopTime is reached.'''
+    status = self.obj.oms3_simulate(model)
+    return Status(status)
+
+  def stepUntil(self, model, stopTime) -> Status:
+    '''Step the simulation until the specified stop time.
+    Note: If the model is in initialization mode, this will exit initialization mode.'''
+    status = self.obj.oms3_stepUntil(model, stopTime)
+    return Status(status)
+
+  def terminate(self, model) -> Status:
+    '''Terminate the simulation and free resources.'''
+    status = self.obj.oms3_terminate(model)
+    return Status(status)
+
+
+Capi = capi()
diff --git a/src/OMSimulatorPython/instantiated_model.py b/src/OMSimulatorPython/instantiated_model.py
new file mode 100644
index 000000000..4c8323cc1
--- /dev/null
+++ b/src/OMSimulatorPython/instantiated_model.py
@@ -0,0 +1,34 @@
+from OMSimulator.capi import Capi, Status
+
+class InstantiatedModel:
+  def __init__(self, json_description):
+    print(json_description)
+    self.model, status = Capi.instantiateFromJson(json_description)
+    if status != Status.ok:
+      raise RuntimeError(f"Failed to instantiate model: {status}")
+
+  def setValues(self):
+    pass
+
+  def getValues(self):
+    pass
+
+  def initialize(self):
+    status = Capi.initialize(self.model)
+    if status != Status.ok:
+      raise RuntimeError(f"Failed to initialize model: {status}")
+
+  def simulate(self):
+    status = Capi.simulate(self.model)
+    if status != Status.ok:
+      raise RuntimeError(f"Failed to simulate model: {status}")
+
+  def stepUntil(self, stopTime):
+    status = Capi.stepUntil(self.model, stopTime)
+    if status != Status.ok:
+      raise RuntimeError(f"Failed to step until {stopTime}: {status}")
+
+  def terminate(self):
+    status = Capi.terminate(self.model)
+    if status != Status.ok:
+      raise RuntimeError(f"Failed to terminate model: {status}")
diff --git a/src/OMSimulatorPython/system.py b/src/OMSimulatorPython/system.py
index 76d599962..0c9d6fc8e 100644
--- a/src/OMSimulatorPython/system.py
+++ b/src/OMSimulatorPython/system.py
@@ -1,18 +1,18 @@
+import json
 import logging
+from collections import defaultdict
 
 from lxml import etree as ET
 from OMSimulator.component import Component
-from OMSimulator.connector import Connector
 from OMSimulator.connection import Connection
+from OMSimulator.connector import Connector
+from OMSimulator.elementgeometry import ElementGeometry
 from OMSimulator.fmu import FMU
-from OMSimulator.values import Values
+from OMSimulator.instantiated_model import InstantiatedModel
 from OMSimulator.ssv import SSV
-from OMSimulator.elementgeometry import ElementGeometry
-
-from OMSimulator import CRef, namespace, utils
+from OMSimulator.values import Values
 
-from collections import defaultdict
-import json
+from OMSimulator import Capi, CRef, namespace, utils
 
 logger = logging.getLogger(__name__)
 
@@ -268,7 +268,7 @@ def setSolver(self, cref: CRef, name: str):
         raise ValueError(f"Component '{first}' not found in {self.name}")
       self.elements[first].setSolver(name)
 
-  def instantiate(self):
+  def instantiate(self) -> InstantiatedModel:
     """Instantiates the system and its components."""
     data = {
         "simulation units": []
@@ -304,8 +304,7 @@ def instantiate(self):
 
     # Dump JSON
     json_string = json.dumps(data, indent=2)
-    print(json_string)
-
+    return InstantiatedModel(json_string)
 
   def processElements(self, elements_dict: dict, connections: list, data: dict, solver_groups : defaultdict, componentSolver : dict, solver_connections : defaultdict, systemName = None):
     """Processes the elements and connections in the system."""
diff --git a/testsuite/Makefile b/testsuite/Makefile
index 6e4a6c9e4..98e94fa3d 100644
--- a/testsuite/Makefile
+++ b/testsuite/Makefile
@@ -2,7 +2,7 @@
 
 all: difftool resources test
 
-test: api.log parker.log dcmotor.log
+test: api.log parker.log dcmotor.log simulation.log
 
 partest: difftool resources
 	cd partest && time ./runtests.pl -nocolour -with-xml
@@ -23,4 +23,8 @@ parker.log: difftool
 
 dcmotor.log: difftool
 	@$(MAKE) -C dcmotor -f Makefile test > $@
-	@grep == dcmotor.log
\ No newline at end of file
+	@grep == dcmotor.log
+
+simulation.log: difftool
+	@$(MAKE) -C simulation -f Makefile test > $@
+	@grep == simulation.log
diff --git a/testsuite/api/Makefile b/testsuite/api/Makefile
index 562ba03af..d2771609d 100644
--- a/testsuite/api/Makefile
+++ b/testsuite/api/Makefile
@@ -3,9 +3,6 @@ TEST = ../rtest -v
 TESTFILES = \
 create_ssp_file.py \
 cref.py \
-exportJson1.py \
-exportJson2.py \
-exportJson4.py \
 fmuinfo.py \
 invalidSSD.py \
 invalidSSV.py \
diff --git a/testsuite/resources/sim.json b/testsuite/resources/sim.json
new file mode 100644
index 000000000..ed463b81c
--- /dev/null
+++ b/testsuite/resources/sim.json
@@ -0,0 +1,67 @@
+{
+  "simulation units": [
+    {
+      "components": [
+        {
+          "name": "Controller",
+          "type": "FMI 2 CS",
+          "path": "resources/Controller.fmu",
+          "variables": ["output"]
+        }
+      ],
+      "solver": {
+        "type": "co-simulation"
+      },
+      "connections": []
+    },
+    {
+      "components": [
+        {
+          "name": "Plant",
+          "type": "model exchange",
+          "path": "resources/Plant.fmu",
+          "variables": ["input", "output"]
+        },
+        {
+          "name": "Sensor",
+          "type": "model exchange",
+          "path": "resources/Sensor.fmu",
+          "variables": ["output"]
+        }
+      ],
+      "solver": {
+        "type": "CVODE",
+        "stepSize": 0.01,
+        "tolerance": 1e-5
+      },
+      "connections": [
+        {
+          "start element": "Sensor",
+          "start connector": "output",
+          "end element": "Plant",
+          "end connector": "input"
+        }
+      ]
+    }
+  ],
+  "connections": [
+    {
+      "start element": "Controller",
+      "start connector": "output",
+      "end element": "Plant",
+      "end connector": "input"
+    },
+    {
+      "start element": "Sensor",
+      "start connector": "output",
+      "end element": "Controller",
+      "end connector": "input"
+    }
+  ],
+  "result file": "simulation_result.csv",
+  "simulation settings": {
+    "start time": 0.0,
+    "stop time": 10.0,
+    "tolerance": 1e-6
+  }
+}
diff --git a/testsuite/resources/sim_singleFMU.json b/testsuite/resources/sim_singleFMU.json
new file mode 100644
index 000000000..03907f429
--- /dev/null
+++ b/testsuite/resources/sim_singleFMU.json
@@ -0,0 +1,33 @@
+{
+  "temp dir": "temp",
+  "working dir": "working",
+  "simulation units": [
+    {
+      "components": [
+        {
+          "name": "",
+          "type": "FMI 2 ME",
+          "path": "resources/Controller.fmu",
+          "variables": {
+            "output": 15,
+            "state1": 0
+          }
+        }
+      ],
+      "solver": {
+        "type": "model exchange",
+        "solver": "CVODE",
+        "stepSize": 0.01,
+        "tolerance": 1e-5
+      },
+      "connections": []
+    }
+  ],
+  "connections": [],
+  "result file": "simulation_result.csv",
+  "simulation settings": {
+    "start time": 0.0,
+    "stop time": 10.0,
+    "tolerance": 1e-6
+  }
+}
diff --git a/testsuite/simulation/Makefile b/testsuite/simulation/Makefile
new file mode 100644
index 000000000..a1ce7a5e7
--- /dev/null
+++ b/testsuite/simulation/Makefile
@@ -0,0 +1,55 @@
+TEST = ../rtest -v
+
+TESTFILES = \
+exportJson1.py \
+exportJson2.py \
+exportJson3.py \
+exportJson4.py \
+SimpleSimulation.py \
+
+# Run make failingtest
+FAILINGTESTFILES = \
+
+# Dependency files that are not .lua or Makefile
+# Add them here or they will be cleaned.
+DEPENDENCIES = \
+*.lua \
+*.py \
+Makefile \
+
+CLEAN = `ls | grep -w -v -f deps.tmp`
+
+.PHONY : test clean getdeps failingtest
+
+test:
+	@echo
+	@echo Running tests...
+	@$(TEST) $(TESTFILES)
+
+baseline:
+	@echo
+	@echo Updating badelines...
+	@$(TEST) -b $(TESTFILES)
+
+# Cleans all files that are not listed as dependencies
+clean:
+	@echo $(DEPENDENCIES) | sed 's/ /\\\|/g' > deps.tmp
+	@rm -rf $(CLEAN)
+
+# Run this if you want to list out the files (dependencies).
+# do it after cleaning and updating the folder
+# then you can get a list of file names (which must be dependencies
+# since you got them from repository + your own new files)
+# then add them to the DEPENDENCIES. You can find the
+# list in deps.txt
+getdeps:
+	@echo $(DEPENDENCIES) | sed 's/ /\\\|/g' > deps.tmp
+	@echo $(CLEAN) | sed -r 's/deps.txt|deps.tmp//g' | sed 's/ / \\\n/g' > deps.txt
+	@echo Dependency list saved in deps.txt.
+	@echo Copy the list from deps.txt and add it to the Makefile @DEPENDENCIES
+
+failingtest:
+	@echo
+	@echo Running failing tests...
+	@echo
+	@$(TEST) $(FAILINGTESTFILES)
diff --git a/testsuite/simulation/SimpleSimulation.py b/testsuite/simulation/SimpleSimulation.py
new file mode 100644
index 000000000..67629d3e5
--- /dev/null
+++ b/testsuite/simulation/SimpleSimulation.py
@@ -0,0 +1,30 @@
+## status: correct
+## teardown_command:
+## linux: yes
+## ucrt64: yes
+## win: yes
+## mac: yes
+
+from OMSimulator import Capi, Settings
+
+Settings.suppressPath = True
+
+# read json object from file
+with open('../resources/sim.json', 'r') as file:
+  json_data = file.read()
+
+model, status = Capi.instantiateFromJson(json_data)
+print(f'instantiateFromJson: {status}')
+status = Capi.initialize(model)
+print(f'initialize: {status}')
+status = Capi.simulate(model)
+print(f'simulate: {status}')
+status = Capi.terminate(model)
+print(f'terminate: {status}')
+
+## Result:
+## instantiateFromJson: Status.ok
+## initialize: Status.ok
+## simulate: Status.ok
+## terminate: Status.ok
+## endResult
diff --git a/testsuite/api/exportJson1.py b/testsuite/simulation/exportJson1.py
similarity index 100%
rename from testsuite/api/exportJson1.py
rename to testsuite/simulation/exportJson1.py
diff --git a/testsuite/api/exportJson2.py b/testsuite/simulation/exportJson2.py
similarity index 100%
rename from testsuite/api/exportJson2.py
rename to testsuite/simulation/exportJson2.py
diff --git a/testsuite/api/exportJson3.py b/testsuite/simulation/exportJson3.py
similarity index 100%
rename from testsuite/api/exportJson3.py
rename to testsuite/simulation/exportJson3.py
diff --git a/testsuite/api/exportJson4.py b/testsuite/simulation/exportJson4.py
similarity index 100%
rename from testsuite/api/exportJson4.py
rename to testsuite/simulation/exportJson4.py