diff --git a/Kconfig b/Kconfig
index bf2d4a01..779dded9 100644
--- a/Kconfig
+++ b/Kconfig
@@ -33,19 +33,6 @@ config OCRE
   # Enable the WASM Micro Runtime
   select WAMR
 
-config OCRE_WAMR_HEAP_BUFFER_SIZE
-  int "WAMR heap buffer size in bytes"
-  default 32768
-  help
-    A static memory allocation for WAMR to use as a heap.
-
-config OCRE_STORAGE_HEAP_BUFFER_SIZE
-  int "Storage heap buffer size in bytes"
-  default 500000
-  depends on MEMC
-  help
-    A static memory allocation for container storage to use as a heap.
-
 config OCRE_CONTAINER_DEFAULT_HEAP_SIZE
   int "Default value for the container heap size"
   default 4096
diff --git a/boards/b_u585i_iot02a.conf b/boards/b_u585i_iot02a.conf
index 90d47674..6efe69b4 100644
--- a/boards/b_u585i_iot02a.conf
+++ b/boards/b_u585i_iot02a.conf
@@ -8,8 +8,6 @@ CONFIG_MEMC=y
 
 # Container defaults
 CONFIG_MAX_CONTAINERS=5
-CONFIG_OCRE_WAMR_HEAP_BUFFER_SIZE=6388608
-CONFIG_OCRE_STORAGE_HEAP_BUFFER_SIZE=2000000
 
 # Bus interfaces
 CONFIG_GPIO=y
diff --git a/prj.conf b/prj.conf
index 519f3f84..51e4fe66 100644
--- a/prj.conf
+++ b/prj.conf
@@ -64,7 +64,6 @@ CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=-1
 
 
 # Ocre configuration
-CONFIG_OCRE_WAMR_HEAP_BUFFER_SIZE=512000
 CONFIG_OCRE_CONTAINER_DEFAULT_HEAP_SIZE=4096
 CONFIG_OCRE_CONTAINER_DEFAULT_STACK_SIZE=4096
 CONFIG_LOG_TRACE_SHORT_TIMESTAMP=y
diff --git a/src/ocre/components/container_supervisor/cs_sm_impl.c b/src/ocre/components/container_supervisor/cs_sm_impl.c
index 04ba07ae..c4addb56 100644
--- a/src/ocre/components/container_supervisor/cs_sm_impl.c
+++ b/src/ocre/components/container_supervisor/cs_sm_impl.c
@@ -34,15 +34,6 @@ LOG_MODULE_DECLARE(ocre_cs_component, OCRE_LOG_LEVEL);
 #include "cs_sm.h"
 #include "cs_sm_impl.h"
 
-#include "ocre_psram.h"
-
-// WAMR heap buffer - uses PSRAM when available
-#if defined(CONFIG_MEMC)
-    PSRAM_SECTION_ATTR
-#endif
-static char wamr_heap_buf[CONFIG_OCRE_WAMR_HEAP_BUFFER_SIZE] = {0};
-
-
 // Thread pool for container execution
 #define CONTAINER_THREAD_POOL_SIZE 4
 static core_thread_t container_threads[CONTAINER_THREAD_POOL_SIZE];
@@ -189,7 +180,7 @@ static int load_binary_to_buffer_fs(ocre_runtime_arguments_t *container_argument
     }
 
     container_arguments->size = file_size;
-    container_arguments->buffer = storage_heap_alloc(file_size);
+    container_arguments->buffer = user_malloc(file_size);
     if (!container_arguments->buffer) {
         LOG_ERR("Failed to allocate memory for container binary from PSRAM.");
         return -ENOMEM;
@@ -200,7 +191,7 @@ static int load_binary_to_buffer_fs(ocre_runtime_arguments_t *container_argument
     ret = core_fileopen(filepath, &file_handle);
     if (ret < 0) {
         LOG_ERR("Failed to open file %s: %d", filepath, ret);
-        storage_heap_free(container_arguments->buffer);
+        user_free(container_arguments->buffer);
         return ret;
     }
 
@@ -208,14 +199,14 @@ static int load_binary_to_buffer_fs(ocre_runtime_arguments_t *container_argument
     if (ret < 0) {
         LOG_ERR("Failed to read file %s: %d", filepath, ret);
         core_fileclose(file_handle);
-        storage_heap_free(container_arguments->buffer);
+        user_free(container_arguments->buffer);
         return ret;
     }
 
     ret = core_fileclose(file_handle);
     if (ret < 0) {
         LOG_ERR("Failed to close file %s: %d", filepath, ret);
-        storage_heap_free(container_arguments->buffer);
+        user_free(container_arguments->buffer);
         return ret;
     }
     return 0;
@@ -239,12 +230,17 @@ int CS_ctx_init(ocre_cs_ctx *ctx) {
     return 0;
 }
 
+#if WASM_MEM_ALLOC_WITH_USER_DATA || WASM_MEM_ALLOC_WITH_USAGE
+#error user allocator not compatible with WASM_MEM_ALLOC_WITH_USER_DATA or WASM_MEM_ALLOC_WITH_USAGE
+#endif
+
 ocre_container_runtime_status_t CS_runtime_init(ocre_cs_ctx *ctx, ocre_container_init_arguments_t *args) {
     RuntimeInitArgs init_args;
     memset(&init_args, 0, sizeof(RuntimeInitArgs));
-    init_args.mem_alloc_type = Alloc_With_Pool;
-    init_args.mem_alloc_option.pool.heap_buf = wamr_heap_buf;
-    init_args.mem_alloc_option.pool.heap_size = sizeof(wamr_heap_buf);
+    init_args.mem_alloc_type = Alloc_With_Allocator;
+    init_args.mem_alloc_option.allocator.malloc_func = user_malloc;
+    init_args.mem_alloc_option.allocator.free_func = user_free;
+    init_args.mem_alloc_option.allocator.realloc_func = user_realloc;
     init_args.native_module_name = "env";
     init_args.n_native_symbols = ocre_api_table_size;
     init_args.native_symbols = ocre_api_table;
@@ -266,7 +262,6 @@ ocre_container_runtime_status_t CS_runtime_init(ocre_cs_ctx *ctx, ocre_container
 #ifdef CONFIG_OCRE_CONTAINER_MESSAGING
     ocre_messaging_init();
 #endif
-    storage_heap_init();
     return RUNTIME_STATUS_INITIALIZED;
 }
 
@@ -321,7 +316,7 @@ ocre_container_status_t CS_create_container(ocre_container_t *container) {
                               curr_container_arguments->error_buf, sizeof(curr_container_arguments->error_buf));
     if (!curr_container_arguments->module) {
         LOG_ERR("Failed to load WASM module: %s", curr_container_arguments->error_buf);
-        storage_heap_free(curr_container_arguments->buffer);
+        user_free(curr_container_arguments->buffer);
         return CONTAINER_STATUS_ERROR;
     }
 
@@ -380,7 +375,7 @@ ocre_container_status_t CS_run_container(ocre_container_t *container) {
             LOG_ERR("Failed to instantiate WASM module: %s, for containerID= %d", curr_container_arguments->error_buf,
                     curr_container_ID);
             wasm_runtime_unload(curr_container_arguments->module);
-            storage_heap_free(curr_container_arguments->buffer);
+            user_free(curr_container_arguments->buffer);
             return CONTAINER_STATUS_ERROR;
         }
 #if defined(CONFIG_OCRE_TIMER) || defined(CONFIG_OCRE_GPIO) || defined(CONFIG_OCRE_SENSORS) ||                         \
@@ -513,7 +508,7 @@ ocre_container_status_t CS_destroy_container(ocre_container_t *container, ocre_c
         }
 
         if (container->ocre_runtime_arguments.buffer) {
-            storage_heap_free(container->ocre_runtime_arguments.buffer);
+            user_free(container->ocre_runtime_arguments.buffer);
             container->ocre_runtime_arguments.buffer = NULL;
         }
 
diff --git a/src/shared/platform/ocre_core_external.h b/src/shared/platform/ocre_core_external.h
index 69375219..79efb20f 100644
--- a/src/shared/platform/ocre_core_external.h
+++ b/src/shared/platform/ocre_core_external.h
@@ -142,6 +142,30 @@ void *core_malloc(size_t size);
  */
 void core_free(void *ptr);
 
+/**
+ * @brief Allocate memory in application heap.
+ *
+ * @param size Number of bytes to allocate.
+ * @return Pointer to allocated memory, or NULL on failure.
+ */
+void *user_malloc(size_t size);
+
+/**
+ * @brief Free previously allocated memory in application heap.
+ *
+ * @param ptr Pointer to memory to free.
+ */
+void user_free(void *ptr);
+
+/**
+ * @brief Reallocate memory in application heap.
+ *
+ * @param ptr pointer to already allocated memory
+ * @param size Number of bytes to allocate.
+ * @return Pointer to reallocated memory, or NULL on failure.
+ */
+void *user_realloc(void *ptr, size_t size);
+
 /**
  * @brief Yield the current thread's execution.
  */
diff --git a/src/shared/platform/ocre_psram.h b/src/shared/platform/ocre_psram.h
deleted file mode 100644
index 1072b49b..00000000
--- a/src/shared/platform/ocre_psram.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#ifndef OCRE_PSRAM
-#define OCRE_PSRAM
-
-// PSRAM configuration - centralized for different platforms
-#if defined(CONFIG_MEMC)
-    // Board-specific PSRAM section attributes
-    #if defined(CONFIG_BOARD_ARDUINO_PORTENTA_H7)
-        #define PSRAM_SECTION_ATTR __attribute__((section("SDRAM1"), aligned(32)))
-    #elif defined(CONFIG_BOARD_B_U585I_IOT02A)
-        #define PSRAM_SECTION_ATTR __attribute__((section(".stm32_psram"), aligned(32)))
-    #elif defined(CONFIG_BOARD_MIMXRT1064_EVK)
-        #define PSRAM_SECTION_ATTR __attribute__((section("SDRAM"), aligned(32)))
-    #else
-        #define PSRAM_SECTION_ATTR __attribute__((aligned(32)))
-    #endif
-
-    PSRAM_SECTION_ATTR
-    static char storage_heap_buf[CONFIG_OCRE_STORAGE_HEAP_BUFFER_SIZE] = {0};
-    
-    static struct k_heap storage_heap;
-    #define storage_heap_init() k_heap_init(&storage_heap, storage_heap_buf, CONFIG_OCRE_STORAGE_HEAP_BUFFER_SIZE)
-    #define storage_heap_alloc(size) k_heap_alloc(&storage_heap, (size), K_SECONDS(1))
-    #define storage_heap_free(buffer) k_heap_free(&storage_heap, (void*)buffer)
-#else
-    // No PSRAM - use system malloc
-    #define storage_heap_init() /* No initialization needed */
-    #define storage_heap_alloc(size) malloc(size)
-    #define storage_heap_free(buffer) free(buffer)
-#endif
-
-#endif /* OCRE_PSRAM*/
diff --git a/src/shared/platform/posix/core_fs.c b/src/shared/platform/posix/core_fs.c
index 76c2fddd..fc559b14 100644
--- a/src/shared/platform/posix/core_fs.c
+++ b/src/shared/platform/posix/core_fs.c
@@ -73,11 +73,11 @@ int core_filestat(const char *path, size_t *size) {
 }
 
 int core_fileopen(const char *path, void **handle) {
-    int *fd = core_malloc(sizeof(int));
+    int *fd = user_malloc(sizeof(int));
     if (!fd) return -ENOMEM;
     *fd = open(path, O_RDONLY);
     if (*fd < 0) {
-        core_free(fd);
+        user_free(fd);
         return -errno;
     }
     *handle = fd;
@@ -95,7 +95,7 @@ int core_fileread(void *handle, void *buffer, size_t size) {
 int core_fileclose(void *handle) {
     int fd = *(int *)handle;
     int ret = close(fd);
-    core_free(handle);
+    user_free(handle);
     return ret;
 }
 
diff --git a/src/shared/platform/posix/core_memory.c b/src/shared/platform/posix/core_memory.c
index 0e13a8c0..04d0ae7d 100644
--- a/src/shared/platform/posix/core_memory.c
+++ b/src/shared/platform/posix/core_memory.c
@@ -16,3 +16,15 @@ void *core_malloc(size_t size) {
 void core_free(void *ptr) {
     free(ptr);
 }
+
+void *user_malloc(size_t size) {
+    return malloc(size);
+}
+
+void user_free(void *ptr) {
+    free(ptr);
+}
+
+void *user_realloc(void *ptr, size_t size) {
+    return realloc(ptr, size);
+}
diff --git a/src/shared/platform/zephyr/core_fs.c b/src/shared/platform/zephyr/core_fs.c
index ef08a6de..42f1d614 100644
--- a/src/shared/platform/zephyr/core_fs.c
+++ b/src/shared/platform/zephyr/core_fs.c
@@ -47,12 +47,12 @@ int core_filestat(const char *path, size_t *size) {
 }
 
 int core_fileopen(const char *path, void **handle) {
-    struct fs_file_t *file = core_malloc(sizeof(struct fs_file_t));
+    struct fs_file_t *file = user_malloc(sizeof(struct fs_file_t));
     if (!file) return -ENOMEM;
     fs_file_t_init(file);
     int ret = fs_open(file, path, FS_O_READ);
     if (ret < 0) {
-        core_free(file);
+        user_free(file);
         return ret;
     }
     *handle = file;
@@ -67,7 +67,7 @@ int core_fileread(void *handle, void *buffer, size_t size) {
 int core_fileclose(void *handle) {
     struct fs_file_t *file = (struct fs_file_t *)handle;
     int ret = fs_close(file);
-    core_free(file);
+    user_free(file);
     return ret;
 }
 
diff --git a/src/shared/platform/zephyr/core_memory.c b/src/shared/platform/zephyr/core_memory.c
index 3655ed4b..d295b32c 100644
--- a/src/shared/platform/zephyr/core_memory.c
+++ b/src/shared/platform/zephyr/core_memory.c
@@ -8,6 +8,7 @@
 #include "ocre_core_external.h"
 
 #include <zephyr/kernel.h>
+#include <zephyr/multi_heap/shared_multi_heap.h>
 
 void *core_malloc(size_t size) {
     return k_malloc(size);
@@ -16,3 +17,33 @@ void *core_malloc(size_t size) {
 void core_free(void *ptr) {
     k_free(ptr);
 }
+
+#ifdef CONFIG_SHARED_MULTI_HEAP
+void *user_malloc(size_t size) {
+    return shared_multi_heap_aligned_alloc(SMH_REG_ATTR_EXTERNAL, 32, size);
+}
+
+void user_free(void *ptr) {
+    shared_multi_heap_free(ptr);
+}
+
+void *user_realloc(void *ptr, size_t size) {
+    // TODO
+    return NULL;
+}
+
+#else
+#warning CONFIG_SHARED_MULTI_HEAP is not defined. Using internal RAM
+void *user_malloc(size_t size) {
+    return k_malloc(size);
+}
+
+void user_free(void *ptr) {
+    k_free(ptr);
+}
+
+void *user_realloc(void *ptr, size_t size) {
+    return k_realloc(ptr, size);
+}
+
+#endif