diff --git a/func_in_breakpoint/coreneuron/func_in_breakpoint.cpp b/func_in_breakpoint/coreneuron/func_in_breakpoint.cpp
new file mode 100644
index 0000000..49876b4
--- /dev/null
+++ b/func_in_breakpoint/coreneuron/func_in_breakpoint.cpp
@@ -0,0 +1,343 @@
+/*********************************************************
+Model Name      : func_in_breakpoint
+Filename        : func_in_breakpoint.mod
+NMODL Version   : 7.7.0
+Vectorized      : true
+Threadsafe      : true
+Created         : DATE
+Simulator       : CoreNEURON
+Backend         : C++ (api-compatibility)
+NMODL Compiler  : VERSION
+*********************************************************/
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <coreneuron/gpu/nrn_acc_manager.hpp>
+#include <coreneuron/mechanism/mech/mod2c_core_thread.hpp>
+#include <coreneuron/mechanism/register_mech.hpp>
+#include <coreneuron/nrnconf.h>
+#include <coreneuron/nrniv/nrniv_decl.h>
+#include <coreneuron/sim/multicore.hpp>
+#include <coreneuron/sim/scopmath/newton_thread.hpp>
+#include <coreneuron/utils/ivocvect.hpp>
+#include <coreneuron/utils/nrnoc_aux.hpp>
+#include <coreneuron/utils/randoms/nrnran123.h>
+
+
+namespace coreneuron {
+    #ifndef NRN_PRCELLSTATE
+    #define NRN_PRCELLSTATE 0
+    #endif
+
+
+    /** channel information */
+    static const char *mechanism_info[] = {
+        "7.7.0",
+        "func_in_breakpoint",
+        0,
+        "il_func_in_breakpoint",
+        0,
+        0,
+        0
+    };
+
+
+    /** all global variables */
+    struct func_in_breakpoint_Store {
+        int reset{};
+        int mech_type{};
+        double c{1};
+    };
+    static_assert(std::is_trivially_copy_constructible_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_move_constructible_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_copy_assignable_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_move_assignable_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_destructible_v<func_in_breakpoint_Store>);
+    func_in_breakpoint_Store func_in_breakpoint_global;
+
+
+    /** all mechanism instance variables and global variables */
+    struct func_in_breakpoint_Instance  {
+        double* il{};
+        double* v_unused{};
+        double* g_unused{};
+        func_in_breakpoint_Store* global{&func_in_breakpoint_global};
+    };
+
+
+    /** connect global (scalar) variables to hoc -- */
+    static DoubScal hoc_scalar_double[] = {
+        {"c_func_in_breakpoint", &func_in_breakpoint_global.c},
+        {nullptr, nullptr}
+    };
+
+
+    /** connect global (array) variables to hoc -- */
+    static DoubVec hoc_vector_double[] = {
+        {nullptr, nullptr, 0}
+    };
+
+
+    static inline int first_pointer_var_index() {
+        return -1;
+    }
+
+
+    static inline int first_random_var_index() {
+        return -1;
+    }
+
+
+    static inline int float_variables_size() {
+        return 3;
+    }
+
+
+    static inline int int_variables_size() {
+        return 0;
+    }
+
+
+    static inline int get_mech_type() {
+        return func_in_breakpoint_global.mech_type;
+    }
+
+
+    static inline Memb_list* get_memb_list(NrnThread* nt) {
+        if (!nt->_ml_list) {
+            return nullptr;
+        }
+        return nt->_ml_list[get_mech_type()];
+    }
+
+
+    static inline void* mem_alloc(size_t num, size_t size, size_t alignment = 16) {
+        void* ptr;
+        posix_memalign(&ptr, alignment, num*size);
+        memset(ptr, 0, size);
+        return ptr;
+    }
+
+
+    static inline void mem_free(void* ptr) {
+        free(ptr);
+    }
+
+
+    static inline void coreneuron_abort() {
+        abort();
+    }
+
+    // Allocate instance structure
+    static void nrn_private_constructor_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        assert(!ml->instance);
+        assert(!ml->global_variables);
+        assert(ml->global_variables_size == 0);
+        auto* const inst = new func_in_breakpoint_Instance{};
+        assert(inst->global == &func_in_breakpoint_global);
+        ml->instance = inst;
+        ml->global_variables = inst->global;
+        ml->global_variables_size = sizeof(func_in_breakpoint_Store);
+    }
+
+    // Deallocate the instance structure
+    static void nrn_private_destructor_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+        assert(inst);
+        assert(inst->global);
+        assert(inst->global == &func_in_breakpoint_global);
+        assert(inst->global == ml->global_variables);
+        assert(ml->global_variables_size == sizeof(func_in_breakpoint_Store));
+        delete inst;
+        ml->instance = nullptr;
+        ml->global_variables = nullptr;
+        ml->global_variables_size = 0;
+    }
+
+    /** initialize mechanism instance variables */
+    static inline void setup_instance(NrnThread* nt, Memb_list* ml) {
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+        assert(inst);
+        assert(inst->global);
+        assert(inst->global == &func_in_breakpoint_global);
+        assert(inst->global == ml->global_variables);
+        assert(ml->global_variables_size == sizeof(func_in_breakpoint_Store));
+        int pnodecount = ml->_nodecount_padded;
+        Datum* indexes = ml->pdata;
+        inst->il = ml->data+0*pnodecount;
+        inst->v_unused = ml->data+1*pnodecount;
+        inst->g_unused = ml->data+2*pnodecount;
+    }
+
+
+
+    static void nrn_alloc_func_in_breakpoint(double* data, Datum* indexes, int type) {
+        // do nothing
+    }
+
+
+    void nrn_constructor_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        #ifndef CORENEURON_BUILD
+        int nodecount = ml->nodecount;
+        int pnodecount = ml->_nodecount_padded;
+        const int* node_index = ml->nodeindices;
+        double* data = ml->data;
+        const double* voltage = nt->_actual_v;
+        Datum* indexes = ml->pdata;
+        ThreadDatum* thread = ml->_thread;
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+
+        #endif
+    }
+
+
+    void nrn_destructor_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        #ifndef CORENEURON_BUILD
+        int nodecount = ml->nodecount;
+        int pnodecount = ml->_nodecount_padded;
+        const int* node_index = ml->nodeindices;
+        double* data = ml->data;
+        const double* voltage = nt->_actual_v;
+        Datum* indexes = ml->pdata;
+        ThreadDatum* thread = ml->_thread;
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+
+        #endif
+    }
+
+
+    inline int func_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v);
+    inline int func_with_v_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v, double arg_v);
+    inline int func_with_other_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v, double q);
+
+
+    inline int func_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v) {
+        int ret_func = 0;
+        return ret_func;
+    }
+
+
+    inline int func_with_v_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v, double arg_v) {
+        int ret_func_with_v = 0;
+        return ret_func_with_v;
+    }
+
+
+    inline int func_with_other_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v, double q) {
+        int ret_func_with_other = 0;
+        return ret_func_with_other;
+    }
+
+
+    /** initialize channel */
+    void nrn_init_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        int nodecount = ml->nodecount;
+        int pnodecount = ml->_nodecount_padded;
+        const int* node_index = ml->nodeindices;
+        double* data = ml->data;
+        const double* voltage = nt->_actual_v;
+        Datum* indexes = ml->pdata;
+        ThreadDatum* thread = ml->_thread;
+
+        setup_instance(nt, ml);
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+
+        if (_nrn_skip_initmodel == 0) {
+            #pragma omp simd
+            #pragma ivdep
+            for (int id = 0; id < nodecount; id++) {
+                int node_id = node_index[id];
+                double v = voltage[node_id];
+                #if NRN_PRCELLSTATE
+                inst->v_unused[id] = v;
+                #endif
+            }
+        }
+    }
+
+
+    inline double nrn_current_func_in_breakpoint(int id, int pnodecount, func_in_breakpoint_Instance* inst, double* data, const Datum* indexes, ThreadDatum* thread, NrnThread* nt, double v) {
+        double current = 0.0;
+        func_func_in_breakpoint(id, pnodecount, inst, data, indexes, thread, nt, v);
+        func_with_v_func_in_breakpoint(id, pnodecount, inst, data, indexes, thread, nt, v, v);
+        func_with_other_func_in_breakpoint(id, pnodecount, inst, data, indexes, thread, nt, v, inst->global->c);
+        current += inst->il[id];
+        return current;
+    }
+
+
+    /** update current */
+    void nrn_cur_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        int nodecount = ml->nodecount;
+        int pnodecount = ml->_nodecount_padded;
+        const int* node_index = ml->nodeindices;
+        double* data = ml->data;
+        const double* voltage = nt->_actual_v;
+        double* vec_rhs = nt->_actual_rhs;
+        double* vec_d = nt->_actual_d;
+        Datum* indexes = ml->pdata;
+        ThreadDatum* thread = ml->_thread;
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+
+        #pragma omp simd
+        #pragma ivdep
+        for (int id = 0; id < nodecount; id++) {
+            int node_id = node_index[id];
+            double v = voltage[node_id];
+            #if NRN_PRCELLSTATE
+            inst->v_unused[id] = v;
+            #endif
+            double g = nrn_current_func_in_breakpoint(id, pnodecount, inst, data, indexes, thread, nt, v+0.001);
+            double rhs = nrn_current_func_in_breakpoint(id, pnodecount, inst, data, indexes, thread, nt, v);
+            g = (g-rhs)/0.001;
+            #if NRN_PRCELLSTATE
+            inst->g_unused[id] = g;
+            #endif
+            vec_rhs[node_id] -= rhs;
+            vec_d[node_id] += g;
+        }
+    }
+
+
+    /** update state */
+    void nrn_state_func_in_breakpoint(NrnThread* nt, Memb_list* ml, int type) {
+        int nodecount = ml->nodecount;
+        int pnodecount = ml->_nodecount_padded;
+        const int* node_index = ml->nodeindices;
+        double* data = ml->data;
+        const double* voltage = nt->_actual_v;
+        Datum* indexes = ml->pdata;
+        ThreadDatum* thread = ml->_thread;
+        auto* const inst = static_cast<func_in_breakpoint_Instance*>(ml->instance);
+
+        #pragma omp simd
+        #pragma ivdep
+        for (int id = 0; id < nodecount; id++) {
+            int node_id = node_index[id];
+            double v = voltage[node_id];
+            #if NRN_PRCELLSTATE
+            inst->v_unused[id] = v;
+            #endif
+        }
+    }
+
+
+    /** register channel with the simulator */
+    void _func_in_breakpoint_reg() {
+
+        int mech_type = nrn_get_mechtype("func_in_breakpoint");
+        func_in_breakpoint_global.mech_type = mech_type;
+        if (mech_type == -1) {
+            return;
+        }
+
+        _nrn_layout_reg(mech_type, 0);
+        register_mech(mechanism_info, nrn_alloc_func_in_breakpoint, nrn_cur_func_in_breakpoint, nullptr, nrn_state_func_in_breakpoint, nrn_init_func_in_breakpoint, nrn_private_constructor_func_in_breakpoint, nrn_private_destructor_func_in_breakpoint, first_pointer_var_index(), 1);
+
+        hoc_register_prop_size(mech_type, float_variables_size(), int_variables_size());
+        hoc_register_var(hoc_scalar_double, hoc_vector_double, NULL);
+    }
+}
diff --git a/func_in_breakpoint/neuron/func_in_breakpoint.cpp b/func_in_breakpoint/neuron/func_in_breakpoint.cpp
new file mode 100644
index 0000000..b1395cd
--- /dev/null
+++ b/func_in_breakpoint/neuron/func_in_breakpoint.cpp
@@ -0,0 +1,411 @@
+/*********************************************************
+Model Name      : func_in_breakpoint
+Filename        : func_in_breakpoint.mod
+NMODL Version   : 7.7.0
+Vectorized      : true
+Threadsafe      : true
+Created         : DATE
+Simulator       : NEURON
+Backend         : C++ (api-compatibility)
+NMODL Compiler  : VERSION
+*********************************************************/
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "mech_api.h"
+#include "neuron/cache/mechanism_range.hpp"
+#include "nrniv_mf.h"
+#include "section_fwd.hpp"
+
+/* NEURON global macro definitions */
+/* VECTORIZED */
+#define NRN_VECTORIZED 1
+
+static constexpr auto number_of_datum_variables = 0;
+static constexpr auto number_of_floating_point_variables = 3;
+
+namespace {
+template <typename T>
+using _nrn_mechanism_std_vector = std::vector<T>;
+using _nrn_model_sorted_token = neuron::model_sorted_token;
+using _nrn_mechanism_cache_range = neuron::cache::MechanismRange<number_of_floating_point_variables, number_of_datum_variables>;
+using _nrn_mechanism_cache_instance = neuron::cache::MechanismInstance<number_of_floating_point_variables, number_of_datum_variables>;
+using _nrn_non_owning_id_without_container = neuron::container::non_owning_identifier_without_container;
+template <typename T>
+using _nrn_mechanism_field = neuron::mechanism::field<T>;
+template <typename... Args>
+void _nrn_mechanism_register_data_fields(Args&&... args) {
+    neuron::mechanism::register_data_fields(std::forward<Args>(args)...);
+}
+}  // namespace
+
+Prop* hoc_getdata_range(int type);
+
+
+namespace neuron {
+    #ifndef NRN_PRCELLSTATE
+    #define NRN_PRCELLSTATE 0
+    #endif
+
+
+    /** channel information */
+    static const char *mechanism_info[] = {
+        "7.7.0",
+        "func_in_breakpoint",
+        0,
+        "il_func_in_breakpoint",
+        0,
+        0,
+        0
+    };
+
+
+    /* NEURON global variables */
+    static int mech_type;
+    static Prop* _extcall_prop;
+    /* _prop_id kind of shadows _extcall_prop to allow validity checking. */
+    static _nrn_non_owning_id_without_container _prop_id{};
+    static int hoc_nrnpointerindex = -1;
+    static _nrn_mechanism_std_vector<Datum> _extcall_thread;
+
+
+    /** all global variables */
+    struct func_in_breakpoint_Store {
+        double c{1};
+    };
+    static_assert(std::is_trivially_copy_constructible_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_move_constructible_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_copy_assignable_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_move_assignable_v<func_in_breakpoint_Store>);
+    static_assert(std::is_trivially_destructible_v<func_in_breakpoint_Store>);
+    func_in_breakpoint_Store func_in_breakpoint_global;
+
+
+    /** all mechanism instance variables and global variables */
+    struct func_in_breakpoint_Instance  {
+        double* il{};
+        double* v_unused{};
+        double* g_unused{};
+        func_in_breakpoint_Store* global{&func_in_breakpoint_global};
+    };
+
+
+    struct func_in_breakpoint_NodeData  {
+        int const * nodeindices;
+        double const * node_voltages;
+        double * node_diagonal;
+        double * node_rhs;
+        int nodecount;
+    };
+
+
+    static func_in_breakpoint_Instance make_instance_func_in_breakpoint(_nrn_mechanism_cache_range& _ml) {
+        return func_in_breakpoint_Instance {
+            _ml.template fpfield_ptr<0>(),
+            _ml.template fpfield_ptr<1>(),
+            _ml.template fpfield_ptr<2>()
+        };
+    }
+
+
+    static func_in_breakpoint_NodeData make_node_data_func_in_breakpoint(NrnThread& _nt, Memb_list& _ml_arg) {
+        return func_in_breakpoint_NodeData {
+            _ml_arg.nodeindices,
+            _nt.node_voltage_storage(),
+            _nt.node_d_storage(),
+            _nt.node_rhs_storage(),
+            _ml_arg.nodecount
+        };
+    }
+
+
+    static void nrn_alloc_func_in_breakpoint(Prop* _prop) {
+        Prop *prop_ion{};
+        Datum *_ppvar{};
+        _nrn_mechanism_cache_instance _ml_real{_prop};
+        auto* const _ml = &_ml_real;
+        size_t const _iml{};
+        assert(_nrn_mechanism_get_num_vars(_prop) == 3);
+        /*initialize range parameters*/
+    }
+
+
+    /* Neuron setdata functions */
+    extern void _nrn_setdata_reg(int, void(*)(Prop*));
+    static void _setdata(Prop* _prop) {
+        _extcall_prop = _prop;
+        _prop_id = _nrn_get_prop_id(_prop);
+    }
+    static void _hoc_setdata() {
+        Prop *_prop = hoc_getdata_range(mech_type);
+        _setdata(_prop);
+        hoc_retpushx(1.);
+    }
+    /* Mechanism procedures and functions */
+    inline int func_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt);
+    inline int func_with_v_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt, double v);
+    inline int func_with_other_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt, double q);
+
+
+    /** connect global (scalar) variables to hoc -- */
+    static DoubScal hoc_scalar_double[] = {
+        {"c_func_in_breakpoint", &func_in_breakpoint_global.c},
+        {nullptr, nullptr}
+    };
+
+
+    /** connect global (array) variables to hoc -- */
+    static DoubVec hoc_vector_double[] = {
+        {nullptr, nullptr, 0}
+    };
+
+
+    /* declaration of user functions */
+    static void _hoc_func(void);
+    static void _hoc_func_with_v(void);
+    static void _hoc_func_with_other(void);
+    static double _npy_func(Prop*);
+    static double _npy_func_with_v(Prop*);
+    static double _npy_func_with_other(Prop*);
+
+
+    /* connect user functions to hoc names */
+    static VoidFunc hoc_intfunc[] = {
+        {"setdata_func_in_breakpoint", _hoc_setdata},
+        {"func_func_in_breakpoint", _hoc_func},
+        {"func_with_v_func_in_breakpoint", _hoc_func_with_v},
+        {"func_with_other_func_in_breakpoint", _hoc_func_with_other},
+        {0, 0}
+    };
+    static NPyDirectMechFunc npy_direct_func_proc[] = {
+        {"func", _npy_func},
+        {"func_with_v", _npy_func_with_v},
+        {"func_with_other", _npy_func_with_other},
+    };
+    static void _hoc_func(void) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        Prop* _local_prop = _prop_id ? _extcall_prop : nullptr;
+        _nrn_mechanism_cache_instance _ml_real{_local_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _local_prop ? _nrn_mechanism_access_dparam(_local_prop) : nullptr;
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt);
+        hoc_retpushx(_r);
+    }
+    static double _npy_func(Prop* _prop) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        _nrn_mechanism_cache_instance _ml_real{_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _nrn_mechanism_access_dparam(_prop);
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt);
+        return(_r);
+    }
+    static void _hoc_func_with_v(void) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        Prop* _local_prop = _prop_id ? _extcall_prop : nullptr;
+        _nrn_mechanism_cache_instance _ml_real{_local_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _local_prop ? _nrn_mechanism_access_dparam(_local_prop) : nullptr;
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_with_v_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, *getarg(1));
+        hoc_retpushx(_r);
+    }
+    static double _npy_func_with_v(Prop* _prop) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        _nrn_mechanism_cache_instance _ml_real{_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _nrn_mechanism_access_dparam(_prop);
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_with_v_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, *getarg(1));
+        return(_r);
+    }
+    static void _hoc_func_with_other(void) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        Prop* _local_prop = _prop_id ? _extcall_prop : nullptr;
+        _nrn_mechanism_cache_instance _ml_real{_local_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _local_prop ? _nrn_mechanism_access_dparam(_local_prop) : nullptr;
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_with_other_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, *getarg(1));
+        hoc_retpushx(_r);
+    }
+    static double _npy_func_with_other(Prop* _prop) {
+        double _r{};
+        Datum* _ppvar;
+        Datum* _thread;
+        NrnThread* _nt;
+        _nrn_mechanism_cache_instance _ml_real{_prop};
+        auto* const _ml = &_ml_real;
+        size_t const id{};
+        _ppvar = _nrn_mechanism_access_dparam(_prop);
+        _thread = _extcall_thread.data();
+        _nt = nrn_threads;
+        auto inst = make_instance_func_in_breakpoint(_ml_real);
+        _r = 1.;
+        func_with_other_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, *getarg(1));
+        return(_r);
+    }
+
+
+    inline int func_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt) {
+        int ret_func = 0;
+        auto v = inst.v_unused[id];
+        return ret_func;
+    }
+
+
+    inline int func_with_v_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt, double v) {
+        int ret_func_with_v = 0;
+        return ret_func_with_v;
+    }
+
+
+    inline int func_with_other_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, func_in_breakpoint_Instance& inst, size_t id, Datum* _ppvar, Datum* _thread, NrnThread* _nt, double q) {
+        int ret_func_with_other = 0;
+        auto v = inst.v_unused[id];
+        return ret_func_with_other;
+    }
+
+
+    void nrn_init_func_in_breakpoint(_nrn_model_sorted_token const& _sorted_token, NrnThread* _nt, Memb_list* _ml_arg, int _type) {
+        _nrn_mechanism_cache_range _lmr{_sorted_token, *_nt, *_ml_arg, _type};
+        auto inst = make_instance_func_in_breakpoint(_lmr);
+        auto node_data = make_node_data_func_in_breakpoint(*_nt, *_ml_arg);
+        auto nodecount = _ml_arg->nodecount;
+        auto* const _ml = &_lmr;
+        auto* _thread = _ml_arg->_thread;
+        for (int id = 0; id < nodecount; id++) {
+            
+            int node_id = node_data.nodeindices[id];
+            auto* _ppvar = _ml_arg->pdata[id];
+            auto v = node_data.node_voltages[node_id];
+            inst.v_unused[id] = v;
+        }
+    }
+
+
+    inline double nrn_current_func_in_breakpoint(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, func_in_breakpoint_Instance& inst, func_in_breakpoint_NodeData& node_data, double v) {
+        double current = 0.0;
+        func_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt);
+        func_with_v_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, v);
+        func_with_other_func_in_breakpoint(_ml, inst, id, _ppvar, _thread, _nt, inst.global->c);
+        current += inst.il[id];
+        return current;
+    }
+
+
+    /** update current */
+    void nrn_cur_func_in_breakpoint(_nrn_model_sorted_token const& _sorted_token, NrnThread* _nt, Memb_list* _ml_arg, int _type) {
+        _nrn_mechanism_cache_range _lmr{_sorted_token, *_nt, *_ml_arg, _type};
+        auto inst = make_instance_func_in_breakpoint(_lmr);
+        auto node_data = make_node_data_func_in_breakpoint(*_nt, *_ml_arg);
+        auto nodecount = _ml_arg->nodecount;
+        auto* const _ml = &_lmr;
+        auto* _thread = _ml_arg->_thread;
+        for (int id = 0; id < nodecount; id++) {
+            int node_id = node_data.nodeindices[id];
+            double v = node_data.node_voltages[node_id];
+            auto* _ppvar = _ml_arg->pdata[id];
+            double I1 = nrn_current_func_in_breakpoint(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
+            double I0 = nrn_current_func_in_breakpoint(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
+            double rhs = I0;
+            double g = (I1-I0)/0.001;
+            node_data.node_rhs[node_id] -= rhs;
+            // remember the conductances so we can set them later
+            inst.g_unused[id] = g;
+        }
+    }
+
+
+    void nrn_state_func_in_breakpoint(_nrn_model_sorted_token const& _sorted_token, NrnThread* _nt, Memb_list* _ml_arg, int _type) {
+        _nrn_mechanism_cache_range _lmr{_sorted_token, *_nt, *_ml_arg, _type};
+        auto inst = make_instance_func_in_breakpoint(_lmr);
+        auto node_data = make_node_data_func_in_breakpoint(*_nt, *_ml_arg);
+        auto nodecount = _ml_arg->nodecount;
+        auto* const _ml = &_lmr;
+        auto* _thread = _ml_arg->_thread;
+        for (int id = 0; id < nodecount; id++) {
+            
+            int node_id = node_data.nodeindices[id];
+            auto* _ppvar = _ml_arg->pdata[id];
+            auto v = node_data.node_voltages[node_id];
+        }
+    }
+
+
+    /** nrn_jacob function */
+    static void nrn_jacob_func_in_breakpoint(_nrn_model_sorted_token const& _sorted_token, NrnThread* _nt, Memb_list* _ml_arg, int _type) {
+        _nrn_mechanism_cache_range _lmr{_sorted_token, *_nt, *_ml_arg, _type};
+        auto inst = make_instance_func_in_breakpoint(_lmr);
+        auto node_data = make_node_data_func_in_breakpoint(*_nt, *_ml_arg);
+        auto nodecount = _ml_arg->nodecount;
+        for (int id = 0; id < nodecount; id++) {
+            // set conductances properly
+            int node_id = node_data.nodeindices[id];
+            node_data.node_diagonal[node_id] += inst.g_unused[id];
+        }
+    }
+
+
+    static void _initlists() {
+    }
+
+
+    /** register channel with the simulator */
+    extern "C" void _func_in_breakpoint_reg() {
+        _initlists();
+
+
+
+        register_mech(mechanism_info, nrn_alloc_func_in_breakpoint, nrn_cur_func_in_breakpoint, nrn_jacob_func_in_breakpoint, nrn_state_func_in_breakpoint, nrn_init_func_in_breakpoint, hoc_nrnpointerindex, 1);
+
+        mech_type = nrn_get_mechtype(mechanism_info[1]);
+        _nrn_mechanism_register_data_fields(mech_type,
+            _nrn_mechanism_field<double>{"il"} /* 0 */,
+            _nrn_mechanism_field<double>{"v_unused"} /* 1 */,
+            _nrn_mechanism_field<double>{"g_unused"} /* 2 */
+        );
+
+        hoc_register_prop_size(mech_type, 3, 0);
+        hoc_register_var(hoc_scalar_double, hoc_vector_double, hoc_intfunc);
+        hoc_register_npy_direct(mech_type, npy_direct_func_proc);
+    }
+}
diff --git a/hodgkin_huxley/neuron/hodhux.cpp b/hodgkin_huxley/neuron/hodhux.cpp
index 05b2831..e317f10 100644
--- a/hodgkin_huxley/neuron/hodhux.cpp
+++ b/hodgkin_huxley/neuron/hodhux.cpp
@@ -447,7 +447,7 @@ namespace neuron {
     }
 
 
-    inline double nrn_current_hodhux(size_t id, hodhux_Instance& inst, hodhux_NodeData& node_data, double v) {
+    inline double nrn_current_hodhux(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, hodhux_Instance& inst, hodhux_NodeData& node_data, double v) {
         double current = 0.0;
         inst.ina[id] = inst.gnabar[id] * inst.m[id] * inst.m[id] * inst.m[id] * inst.h[id] * (v - inst.ena[id]);
         inst.ik[id] = inst.gkbar[id] * inst.n[id] * inst.n[id] * inst.n[id] * inst.n[id] * (v - inst.ek[id]);
@@ -470,12 +470,13 @@ namespace neuron {
         for (int id = 0; id < nodecount; id++) {
             int node_id = node_data.nodeindices[id];
             double v = node_data.node_voltages[node_id];
+            auto* _ppvar = _ml_arg->pdata[id];
             inst.ena[id] = (*inst.ion_ena[id]);
             inst.ek[id] = (*inst.ion_ek[id]);
-            double I1 = nrn_current_hodhux(id, inst, node_data, v+0.001);
+            double I1 = nrn_current_hodhux(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
             double dina = inst.ina[id];
             double dik = inst.ik[id];
-            double I0 = nrn_current_hodhux(id, inst, node_data, v);
+            double I0 = nrn_current_hodhux(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
             double rhs = I0;
             double g = (I1-I0)/0.001;
             (*inst.ion_dinadv[id]) += (dina-inst.ina[id])/0.001;
diff --git a/net_receive/neuron/snapsyn.cpp b/net_receive/neuron/snapsyn.cpp
index f355835..c3a1e6c 100644
--- a/net_receive/neuron/snapsyn.cpp
+++ b/net_receive/neuron/snapsyn.cpp
@@ -220,7 +220,7 @@ namespace neuron {
     }
 
 
-    inline double nrn_current_SnapSyn(size_t id, SnapSyn_Instance& inst, SnapSyn_NodeData& node_data, double v) {
+    inline double nrn_current_SnapSyn(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, SnapSyn_Instance& inst, SnapSyn_NodeData& node_data, double v) {
         double current = 0.0;
         inst.i[id] = inst.g[id] * (v - inst.e[id]);
         current += inst.i[id];
@@ -239,8 +239,9 @@ namespace neuron {
         for (int id = 0; id < nodecount; id++) {
             int node_id = node_data.nodeindices[id];
             double v = node_data.node_voltages[node_id];
-            double I1 = nrn_current_SnapSyn(id, inst, node_data, v+0.001);
-            double I0 = nrn_current_SnapSyn(id, inst, node_data, v);
+            auto* _ppvar = _ml_arg->pdata[id];
+            double I1 = nrn_current_SnapSyn(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
+            double I0 = nrn_current_SnapSyn(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
             double rhs = I0;
             double g = (I1-I0)/0.001;
             double mfactor = 1.e2/(*inst.node_area[id]);
diff --git a/nonspecific_current/neuron/leonhard.cpp b/nonspecific_current/neuron/leonhard.cpp
index df3cc28..b4fbbc7 100644
--- a/nonspecific_current/neuron/leonhard.cpp
+++ b/nonspecific_current/neuron/leonhard.cpp
@@ -190,7 +190,7 @@ namespace neuron {
     }
 
 
-    inline double nrn_current_leonhard(size_t id, leonhard_Instance& inst, leonhard_NodeData& node_data, double v) {
+    inline double nrn_current_leonhard(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, leonhard_Instance& inst, leonhard_NodeData& node_data, double v) {
         double current = 0.0;
         inst.il[id] = inst.c[id] * (v - 1.5);
         current += inst.il[id];
@@ -209,8 +209,9 @@ namespace neuron {
         for (int id = 0; id < nodecount; id++) {
             int node_id = node_data.nodeindices[id];
             double v = node_data.node_voltages[node_id];
-            double I1 = nrn_current_leonhard(id, inst, node_data, v+0.001);
-            double I0 = nrn_current_leonhard(id, inst, node_data, v);
+            auto* _ppvar = _ml_arg->pdata[id];
+            double I1 = nrn_current_leonhard(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
+            double I0 = nrn_current_leonhard(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
             double rhs = I0;
             double g = (I1-I0)/0.001;
             node_data.node_rhs[node_id] -= rhs;
diff --git a/spike_travel/neuron/expsyn2.cpp b/spike_travel/neuron/expsyn2.cpp
index 74b73c8..8e038ea 100644
--- a/spike_travel/neuron/expsyn2.cpp
+++ b/spike_travel/neuron/expsyn2.cpp
@@ -229,7 +229,7 @@ namespace neuron {
     }
 
 
-    inline double nrn_current_ExpSyn2(size_t id, ExpSyn2_Instance& inst, ExpSyn2_NodeData& node_data, double v) {
+    inline double nrn_current_ExpSyn2(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, ExpSyn2_Instance& inst, ExpSyn2_NodeData& node_data, double v) {
         double current = 0.0;
         inst.i[id] = inst.g[id] * (v - inst.e[id]);
         current += inst.i[id];
@@ -248,8 +248,9 @@ namespace neuron {
         for (int id = 0; id < nodecount; id++) {
             int node_id = node_data.nodeindices[id];
             double v = node_data.node_voltages[node_id];
-            double I1 = nrn_current_ExpSyn2(id, inst, node_data, v+0.001);
-            double I0 = nrn_current_ExpSyn2(id, inst, node_data, v);
+            auto* _ppvar = _ml_arg->pdata[id];
+            double I1 = nrn_current_ExpSyn2(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
+            double I0 = nrn_current_ExpSyn2(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
             double rhs = I0;
             double g = (I1-I0)/0.001;
             double mfactor = 1.e2/(*inst.node_area[id]);
diff --git a/spike_travel/neuron/hodhux.cpp b/spike_travel/neuron/hodhux.cpp
index 05b2831..e317f10 100644
--- a/spike_travel/neuron/hodhux.cpp
+++ b/spike_travel/neuron/hodhux.cpp
@@ -447,7 +447,7 @@ namespace neuron {
     }
 
 
-    inline double nrn_current_hodhux(size_t id, hodhux_Instance& inst, hodhux_NodeData& node_data, double v) {
+    inline double nrn_current_hodhux(_nrn_mechanism_cache_range* _ml, NrnThread* _nt, Datum* _ppvar, Datum* _thread, size_t id, hodhux_Instance& inst, hodhux_NodeData& node_data, double v) {
         double current = 0.0;
         inst.ina[id] = inst.gnabar[id] * inst.m[id] * inst.m[id] * inst.m[id] * inst.h[id] * (v - inst.ena[id]);
         inst.ik[id] = inst.gkbar[id] * inst.n[id] * inst.n[id] * inst.n[id] * inst.n[id] * (v - inst.ek[id]);
@@ -470,12 +470,13 @@ namespace neuron {
         for (int id = 0; id < nodecount; id++) {
             int node_id = node_data.nodeindices[id];
             double v = node_data.node_voltages[node_id];
+            auto* _ppvar = _ml_arg->pdata[id];
             inst.ena[id] = (*inst.ion_ena[id]);
             inst.ek[id] = (*inst.ion_ek[id]);
-            double I1 = nrn_current_hodhux(id, inst, node_data, v+0.001);
+            double I1 = nrn_current_hodhux(_ml, _nt, _ppvar, _thread, id, inst, node_data, v+0.001);
             double dina = inst.ina[id];
             double dik = inst.ik[id];
-            double I0 = nrn_current_hodhux(id, inst, node_data, v);
+            double I0 = nrn_current_hodhux(_ml, _nt, _ppvar, _thread, id, inst, node_data, v);
             double rhs = I0;
             double g = (I1-I0)/0.001;
             (*inst.ion_dinadv[id]) += (dina-inst.ina[id])/0.001;