Using files from the SDK/lib_standard_app

diff --git a/Makefile b/Makefile
index 229d39e..cbe63d0 100644
--- a/Makefile
+++ b/Makefile
@@ -175,9 +175,18 @@ endif
 
 # Needed to be able to include the definition of G_cx
 INCLUDES_PATH += $(BOLOS_SDK)/lib_cxng/src
+INCLUDES_PATH += $(BOLOS_SDK)/lib_standard_app
 
 # Application source files
 APP_SOURCE_PATH += src
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/base58.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/bip32.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/buffer.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/format.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/parser.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/read.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/varint.c
+APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/write.c
 
 # Allow usage of function from lib_standard_app/crypto_helpers.c
 APP_SOURCE_FILES += ${BOLOS_SDK}/lib_standard_app/crypto_helpers.c
diff --git a/src/boilerplate/apdu_parser.c b/src/boilerplate/apdu_parser.c
deleted file mode 100644
index 2ad3869..0000000
--- a/src/boilerplate/apdu_parser.c
+++ /dev/null
@@ -1,39 +0,0 @@
-/*****************************************************************************
- *   Ledger App Bitcoin.
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <stdbool.h>  // bool
-
-#include "apdu_parser.h"
-#include "offsets.h"
-
-bool apdu_parser(command_t *cmd, uint8_t *buf, size_t buf_len) {
-    // Check minimum length and Lc field of APDU command
-    if (buf_len < OFFSET_CDATA || buf_len - OFFSET_CDATA != buf[OFFSET_LC]) {
-        return false;
-    }
-
-    cmd->cla = buf[OFFSET_CLA];
-    cmd->ins = buf[OFFSET_INS];
-    cmd->p1 = buf[OFFSET_P1];
-    cmd->p2 = buf[OFFSET_P2];
-    cmd->lc = buf[OFFSET_LC];
-    cmd->data = (buf[OFFSET_LC] > 0) ? buf + OFFSET_CDATA : NULL;
-
-    return true;
-}
diff --git a/src/boilerplate/apdu_parser.h b/src/boilerplate/apdu_parser.h
deleted file mode 100644
index 4d002dd..0000000
--- a/src/boilerplate/apdu_parser.h
+++ /dev/null
@@ -1,32 +0,0 @@
-#pragma once
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <stdbool.h>  // bool
-
-/**
- * Structure with fields of APDU command.
- */
-typedef struct {
-    uint8_t cla;    /// Instruction class
-    uint8_t ins;    /// Instruction code
-    uint8_t p1;     /// Instruction parameter 1
-    uint8_t p2;     /// Instruction parameter 2
-    uint8_t lc;     /// Length of command data
-    uint8_t *data;  /// Command data
-} command_t;
-
-/**
- * Parse APDU command from byte buffer.
- *
- * @param[out] cmd
- *   Structured APDU command (CLA, INS, P1, P2, Lc, Command data).
- * @param[in]  buf
- *   Byte buffer with raw APDU command.
- * @param[in]  buf_len
- *   Length of byte buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool apdu_parser(command_t *cmd, uint8_t *buf, size_t buf_len);
diff --git a/src/boilerplate/constants.h b/src/boilerplate/constants.h
deleted file mode 100644
index e9c390f..0000000
--- a/src/boilerplate/constants.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#pragma once
-
-/**
- * APDU instruction class for command defined by the framework.
- */
-#define CLA_FRAMEWORK 0xF8
-
-/**
- * Framework instruction to continue execution after an interruption.
- */
-#define INS_CONTINUE 0x01
diff --git a/src/boilerplate/dispatcher.c b/src/boilerplate/dispatcher.c
index b307d75..405e863 100644
--- a/src/boilerplate/dispatcher.c
+++ b/src/boilerplate/dispatcher.c
@@ -15,17 +15,21 @@
  *  limitations under the License.
  *****************************************************************************/
 
-#include <stdint.h>
 #include <stdbool.h>
+#include <stdint.h>
 
 #include "dispatcher.h"
+
+/* SDK headers */
+#include "buffer.h"
+
+/* Local headers */
+#include "buffer_ext.h"
 #include "constants.h"
 #include "globals.h"
-#include "io.h"
+#include "io_ext.h"
 #include "sw.h"
 
-#include "common/buffer.h"
-
 extern dispatcher_context_t G_dispatcher_context;
 
 extern bool G_was_processing_screen_shown;
diff --git a/src/boilerplate/dispatcher.h b/src/boilerplate/dispatcher.h
index 8a36dfe..b30a44c 100644
--- a/src/boilerplate/dispatcher.h
+++ b/src/boilerplate/dispatcher.h
@@ -1,10 +1,11 @@
 #pragma once
 
+/* SDK headers */
+#include "buffer.h"
 #include "os.h"
 
-#include "apdu_parser.h"
-
-#include "common/buffer.h"
+/* Local headers */
+#include "parser.h"
 
 // Forward declaration
 struct dispatcher_context_s;
diff --git a/src/boilerplate/io.c b/src/boilerplate/io.c
deleted file mode 100644
index f671e1b..0000000
--- a/src/boilerplate/io.c
+++ /dev/null
@@ -1,217 +0,0 @@
-/*****************************************************************************
- *   Ledger App Bitcoin.
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdint.h>
-#include <string.h>
-
-#include "os.h"
-#include "ux.h"
-#include "nbgl_touch.h"
-#include "nbgl_use_case.h"
-
-#include "io.h"
-#include "globals.h"
-#include "sw.h"
-#include "common/buffer.h"
-#include "common/write.h"
-
-#include "dispatcher.h"
-#include "../swap/swap_globals.h"
-#include "../ui/display.h"
-
-uint16_t G_output_len = 0;
-
-// Counter incremented at every tick
-// The initial value does not matter, as only the difference between timeframes is used.
-uint16_t G_ticks;
-
-struct {
-    bool interruption : 1;
-    bool processing : 1;
-} G_is_timeout_active;
-
-// set to true when the "Processing..." screen is shown, in order for the dispatcher to know if the
-// UX is not in idle state at the end of a command handler.
-bool G_was_processing_screen_shown;
-
-uint16_t G_interruption_timeout_start_tick;
-uint16_t G_processing_timeout_start_tick;
-
-void io_start_interruption_timeout() {
-    G_interruption_timeout_start_tick = G_ticks;
-    G_is_timeout_active.interruption = true;
-}
-
-void io_clear_interruption_timeout() {
-    G_is_timeout_active.interruption = false;
-}
-
-void io_start_processing_timeout() {
-    G_processing_timeout_start_tick = G_ticks;
-    G_is_timeout_active.processing = true;
-}
-
-void io_clear_processing_timeout() {
-    G_is_timeout_active.processing = false;
-}
-
-void io_reset_timeouts() {
-    io_clear_interruption_timeout();
-    io_clear_processing_timeout();
-    G_was_processing_screen_shown = false;
-}
-
-void io_show_processing_screen() {
-    if (!G_was_processing_screen_shown) {
-        G_was_processing_screen_shown = true;
-        if (!G_swap_state.called_from_swap) {
-            nbgl_useCaseSpinner(ui_get_processing_screen_text());
-        }
-    }
-}
-
-uint8_t io_event(uint8_t channel) {
-    UNUSED(channel);
-
-    switch (G_io_seproxyhal_spi_buffer[0]) {
-        case SEPROXYHAL_TAG_BUTTON_PUSH_EVENT:
-            UX_BUTTON_PUSH_EVENT(G_io_seproxyhal_spi_buffer);
-            break;
-        case SEPROXYHAL_TAG_STATUS_EVENT:
-            if (G_io_apdu_media == IO_APDU_MEDIA_USB_HID &&  //
-                !(U4BE(G_io_seproxyhal_spi_buffer, 3) &      //
-                  SEPROXYHAL_TAG_STATUS_EVENT_FLAG_USB_POWERED)) {
-                THROW(EXCEPTION_IO_RESET);
-            }
-            __attribute__((fallthrough));
-        case SEPROXYHAL_TAG_DISPLAY_PROCESSED_EVENT:
-            UX_DEFAULT_EVENT();
-            break;
-#ifdef SCREEN_SIZE_WALLET
-        case SEPROXYHAL_TAG_FINGER_EVENT:
-            UX_FINGER_EVENT(G_io_seproxyhal_spi_buffer);
-            break;
-#endif  // SCREEN_SIZE_WALLET
-        case SEPROXYHAL_TAG_TICKER_EVENT:
-            ++G_ticks;
-
-            if (G_is_timeout_active.processing &&
-                G_ticks - G_processing_timeout_start_tick >= PROCESSING_TIMEOUT_TICKS) {
-                io_clear_processing_timeout();
-
-                io_show_processing_screen();
-            }
-
-            if (G_is_timeout_active.interruption &&
-                G_ticks - G_interruption_timeout_start_tick >= INTERRUPTION_TIMEOUT_TICKS) {
-                io_clear_interruption_timeout();
-
-                // TODO: It would be better to have the dispatcher be notified somehow.
-                //       This would require some tampering with the io_exchange in
-                //       process_interruption.
-                THROW(EXCEPTION_IO_RESET);
-            }
-
-            UX_TICKER_EVENT(G_io_seproxyhal_spi_buffer, {});
-            break;
-        default:
-            UX_DEFAULT_EVENT();
-            break;
-    }
-
-    if (!io_seproxyhal_spi_is_status_sent()) {
-        io_seproxyhal_general_status();
-    }
-
-    return 1;
-}
-
-uint16_t io_exchange_al(uint8_t channel, uint16_t tx_len) {
-    switch (channel & ~(IO_FLAGS)) {
-        case CHANNEL_KEYBOARD:
-            break;
-        case CHANNEL_SPI:
-            if (tx_len) {
-                io_seproxyhal_spi_send(G_io_apdu_buffer, tx_len);
-
-                if (channel & IO_RESET_AFTER_REPLIED) {
-                    halt();
-                }
-
-                return 0;
-            } else {
-                return io_seproxyhal_spi_recv(G_io_apdu_buffer, sizeof(G_io_apdu_buffer), 0);
-            }
-        default:
-            THROW(INVALID_PARAMETER);
-    }
-
-    return 0;
-}
-
-void io_add_to_response(const void *rdata, size_t rdata_len) {
-    if (G_output_len >= IO_APDU_BUFFER_SIZE - 2) {
-        G_output_len = IO_APDU_BUFFER_SIZE;
-        write_u16_be(G_io_apdu_buffer, IO_APDU_BUFFER_SIZE - 2, SW_WRONG_RESPONSE_LENGTH);
-    } else if (G_output_len + rdata_len > IO_APDU_BUFFER_SIZE - 2) {
-        io_add_to_response(rdata, IO_APDU_BUFFER_SIZE - 2 - rdata_len);
-        io_finalize_response(SW_WRONG_RESPONSE_LENGTH);
-    } else {
-        memmove(G_io_apdu_buffer + G_output_len, rdata, rdata_len);
-        G_output_len += rdata_len;
-    }
-}
-
-void io_finalize_response(uint16_t sw) {
-    if (G_output_len >= IO_APDU_BUFFER_SIZE - 2) {
-        G_output_len = IO_APDU_BUFFER_SIZE;
-        write_u16_be(G_io_apdu_buffer, IO_APDU_BUFFER_SIZE - 2, SW_WRONG_RESPONSE_LENGTH);
-    } else {
-        write_u16_be(G_io_apdu_buffer, G_output_len, sw);
-        G_output_len += 2;
-    }
-}
-
-void io_reset_response() {
-    G_output_len = 0;
-}
-
-void io_set_response(const void *rdata, size_t rdata_len, uint16_t sw) {
-    io_reset_response();
-    if (rdata != NULL) {
-        io_add_to_response(rdata, rdata_len);
-    }
-    io_finalize_response(sw);
-}
-
-int io_confirm_response() {
-    int ret;
-
-    ret = io_exchange(CHANNEL_APDU | IO_RETURN_AFTER_TX, G_output_len);
-    G_output_len = 0;
-
-    return ret;
-}
-
-int io_send_response(void *rdata, size_t rdata_len, uint16_t sw) {
-    io_set_response(rdata, rdata_len, sw);
-    return io_confirm_response();
-}
-
-int io_send_sw(uint16_t sw) {
-    return io_send_response(NULL, 0, sw);
-}
diff --git a/src/boilerplate/io.h b/src/boilerplate/io.h
deleted file mode 100644
index e2ba520..0000000
--- a/src/boilerplate/io.h
+++ /dev/null
@@ -1,103 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-#include "ux.h"
-#include "os_io_seproxyhal.h"
-
-#include "common/buffer.h"
-
-/**
- * IO callback called when an interrupt based channel has received
- * data to be processed.
- *
- * @return 1 if success, 0 otherwise.
- *
- */
-uint8_t io_event(uint8_t channel);
-
-uint16_t io_exchange_al(uint8_t channel, uint16_t tx_len);
-
-#define INTERRUPTION_TIMEOUT_TICKS 50
-#define PROCESSING_TIMEOUT_TICKS   10
-
-/**
- * Instructs io_event to reset the app if INTERRUPTION_TIMEOUT_TICKS tick events are received before
- * io_clear_interruption_timeout is called. Used to cause an app reset if the client stop responding
- * while an APDU is being processed.
- */
-void io_start_interruption_timeout();
-
-/**
- * Removes the timeout started from io_start_interruption_timeout.
- */
-void io_clear_interruption_timeout();
-
-/**
- * Instructs io_event to show the "Processing..." screen if PROCESSING_TIMEOUT_TICKS tick events are
- * received before io_clear_interruption_timeout is called.
- */
-void io_start_processing_timeout();
-
-/**
- * Removes the timeout started from io_start_processing_timeout.
- */
-void io_clear_processing_timeout();
-
-/**
- * Clears both the interruption and processing timeouts, and sets G_was_processing_screen_shown to
- * false.
- */
-void io_reset_timeouts();
-
-/**
- * Shows the "Processing..." screen.
- */
-void io_show_processing_screen();
-
-/**
- * TODO: docs
- */
-void io_reset_response();
-
-/**
- * TODO: docs
- */
-void io_add_to_response(const void *rdata, size_t rdata_len);
-
-/**
- * TODO: docs
- */
-void io_finalize_response(uint16_t sw);
-
-/* TODO: docs */
-void io_set_response(const void *rdata, size_t rdata_len, uint16_t sw);
-
-/* TODO: docs */
-int io_confirm_response(void);
-
-/**
- * Send APDU response (response data + status word) by filling G_io_apdu_buffer.
- *
- * @param[in] rdata
- *   Pointer to the response.
- * @param[in] rdata_len
- *   Length of response.
- * @param[in] sw
- *   Status word of APDU response.
- *
- * @return zero or positive integer if success, -1 otherwise.
- *
- */
-int io_send_response(void *rdata, size_t rdata_len, uint16_t sw);
-
-/**
- * Send APDU response (only status word) by filling G_io_apdu_buffer.
- *
- * @param[in] sw
- *   Status word of APDU response.
- *
- * @return zero or positive integer if success, -1 otherwise.
- *
- */
-int io_send_sw(uint16_t sw);
diff --git a/src/boilerplate/io_ext.c b/src/boilerplate/io_ext.c
new file mode 100644
index 0000000..1f14db4
--- /dev/null
+++ b/src/boilerplate/io_ext.c
@@ -0,0 +1,219 @@
+/*****************************************************************************
+ *   Ledger App Bitcoin.
+ *   (c) 2025 Ledger SAS.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *****************************************************************************/
+
+#include <stdint.h>
+#include <string.h>
+
+#include "io_ext.h"
+
+/* SDK headers */
+#include "buffer.h"
+#include "nbgl_touch.h"
+#include "nbgl_use_case.h"
+#include "os.h"
+#include "ux.h"
+#include "write.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "display.h"
+#include "globals.h"
+#include "sw.h"
+#include "swap_globals.h"
+
+uint16_t G_output_len = 0;
+
+// Counter incremented at every tick
+// The initial value does not matter, as only the difference between timeframes is used.
+uint16_t G_ticks;
+
+struct {
+    bool interruption : 1;
+    bool processing : 1;
+} G_is_timeout_active;
+
+// set to true when the "Processing..." screen is shown, in order for the dispatcher to know if the
+// UX is not in idle state at the end of a command handler.
+bool G_was_processing_screen_shown;
+
+uint16_t G_interruption_timeout_start_tick;
+uint16_t G_processing_timeout_start_tick;
+
+void io_start_interruption_timeout() {
+    G_interruption_timeout_start_tick = G_ticks;
+    G_is_timeout_active.interruption = true;
+}
+
+void io_clear_interruption_timeout() {
+    G_is_timeout_active.interruption = false;
+}
+
+void io_start_processing_timeout() {
+    G_processing_timeout_start_tick = G_ticks;
+    G_is_timeout_active.processing = true;
+}
+
+void io_clear_processing_timeout() {
+    G_is_timeout_active.processing = false;
+}
+
+void io_reset_timeouts() {
+    io_clear_interruption_timeout();
+    io_clear_processing_timeout();
+    G_was_processing_screen_shown = false;
+}
+
+void io_show_processing_screen() {
+    if (!G_was_processing_screen_shown) {
+        G_was_processing_screen_shown = true;
+        if (!G_swap_state.called_from_swap) {
+            nbgl_useCaseSpinner(ui_get_processing_screen_text());
+        }
+    }
+}
+
+uint8_t io_event(uint8_t channel) {
+    UNUSED(channel);
+
+    switch (G_io_seproxyhal_spi_buffer[0]) {
+        case SEPROXYHAL_TAG_BUTTON_PUSH_EVENT:
+            UX_BUTTON_PUSH_EVENT(G_io_seproxyhal_spi_buffer);
+            break;
+        case SEPROXYHAL_TAG_STATUS_EVENT:
+            if (G_io_apdu_media == IO_APDU_MEDIA_USB_HID &&  //
+                !(U4BE(G_io_seproxyhal_spi_buffer, 3) &      //
+                  SEPROXYHAL_TAG_STATUS_EVENT_FLAG_USB_POWERED)) {
+                THROW(EXCEPTION_IO_RESET);
+            }
+            __attribute__((fallthrough));
+        case SEPROXYHAL_TAG_DISPLAY_PROCESSED_EVENT:
+            UX_DEFAULT_EVENT();
+            break;
+#ifdef SCREEN_SIZE_WALLET
+        case SEPROXYHAL_TAG_FINGER_EVENT:
+            UX_FINGER_EVENT(G_io_seproxyhal_spi_buffer);
+            break;
+#endif  // SCREEN_SIZE_WALLET
+        case SEPROXYHAL_TAG_TICKER_EVENT:
+            ++G_ticks;
+
+            if (G_is_timeout_active.processing &&
+                G_ticks - G_processing_timeout_start_tick >= PROCESSING_TIMEOUT_TICKS) {
+                io_clear_processing_timeout();
+
+                io_show_processing_screen();
+            }
+
+            if (G_is_timeout_active.interruption &&
+                G_ticks - G_interruption_timeout_start_tick >= INTERRUPTION_TIMEOUT_TICKS) {
+                io_clear_interruption_timeout();
+
+                // TODO: It would be better to have the dispatcher be notified somehow.
+                //       This would require some tampering with the io_exchange in
+                //       process_interruption.
+                THROW(EXCEPTION_IO_RESET);
+            }
+
+            UX_TICKER_EVENT(G_io_seproxyhal_spi_buffer, {});
+            break;
+        default:
+            UX_DEFAULT_EVENT();
+            break;
+    }
+
+    if (!io_seproxyhal_spi_is_status_sent()) {
+        io_seproxyhal_general_status();
+    }
+
+    return 1;
+}
+
+uint16_t io_exchange_al(uint8_t channel, uint16_t tx_len) {
+    switch (channel & ~(IO_FLAGS)) {
+        case CHANNEL_KEYBOARD:
+            break;
+        case CHANNEL_SPI:
+            if (tx_len) {
+                io_seproxyhal_spi_send(G_io_apdu_buffer, tx_len);
+
+                if (channel & IO_RESET_AFTER_REPLIED) {
+                    halt();
+                }
+
+                return 0;
+            } else {
+                return io_seproxyhal_spi_recv(G_io_apdu_buffer, sizeof(G_io_apdu_buffer), 0);
+            }
+        default:
+            THROW(INVALID_PARAMETER);
+    }
+
+    return 0;
+}
+
+void io_add_to_response(const void *rdata, size_t rdata_len) {
+    if (G_output_len >= IO_APDU_BUFFER_SIZE - 2) {
+        G_output_len = IO_APDU_BUFFER_SIZE;
+        write_u16_be(G_io_apdu_buffer, IO_APDU_BUFFER_SIZE - 2, SW_WRONG_RESPONSE_LENGTH);
+    } else if (G_output_len + rdata_len > IO_APDU_BUFFER_SIZE - 2) {
+        io_add_to_response(rdata, IO_APDU_BUFFER_SIZE - 2 - rdata_len);
+        io_finalize_response(SW_WRONG_RESPONSE_LENGTH);
+    } else {
+        memmove(G_io_apdu_buffer + G_output_len, rdata, rdata_len);
+        G_output_len += rdata_len;
+    }
+}
+
+void io_finalize_response(uint16_t sw) {
+    if (G_output_len >= IO_APDU_BUFFER_SIZE - 2) {
+        G_output_len = IO_APDU_BUFFER_SIZE;
+        write_u16_be(G_io_apdu_buffer, IO_APDU_BUFFER_SIZE - 2, SW_WRONG_RESPONSE_LENGTH);
+    } else {
+        write_u16_be(G_io_apdu_buffer, G_output_len, sw);
+        G_output_len += 2;
+    }
+}
+
+void io_reset_response() {
+    G_output_len = 0;
+}
+
+void io_set_response(const void *rdata, size_t rdata_len, uint16_t sw) {
+    io_reset_response();
+    if (rdata != NULL) {
+        io_add_to_response(rdata, rdata_len);
+    }
+    io_finalize_response(sw);
+}
+
+int io_confirm_response() {
+    int ret;
+
+    ret = io_exchange(CHANNEL_APDU | IO_RETURN_AFTER_TX, G_output_len);
+    G_output_len = 0;
+
+    return ret;
+}
+
+int io_send_response(void *rdata, size_t rdata_len, uint16_t sw) {
+    io_set_response(rdata, rdata_len, sw);
+    return io_confirm_response();
+}
+
+int io_send_sw(uint16_t sw) {
+    return io_send_response(NULL, 0, sw);
+}
diff --git a/src/boilerplate/io_ext.h b/src/boilerplate/io_ext.h
new file mode 100644
index 0000000..d4ab46b
--- /dev/null
+++ b/src/boilerplate/io_ext.h
@@ -0,0 +1,105 @@
+#pragma once
+
+#include <stdint.h>
+
+/* SDK headers */
+#include "buffer.h"
+#include "ux.h"
+
+/* Local headers */
+#include "os_io_seproxyhal.h"
+
+/**
+ * IO callback called when an interrupt based channel has received
+ * data to be processed.
+ *
+ * @return 1 if success, 0 otherwise.
+ *
+ */
+uint8_t io_event(uint8_t channel);
+
+uint16_t io_exchange_al(uint8_t channel, uint16_t tx_len);
+
+#define INTERRUPTION_TIMEOUT_TICKS 50
+#define PROCESSING_TIMEOUT_TICKS   10
+
+/**
+ * Instructs io_event to reset the app if INTERRUPTION_TIMEOUT_TICKS tick events are received before
+ * io_clear_interruption_timeout is called. Used to cause an app reset if the client stop responding
+ * while an APDU is being processed.
+ */
+void io_start_interruption_timeout();
+
+/**
+ * Removes the timeout started from io_start_interruption_timeout.
+ */
+void io_clear_interruption_timeout();
+
+/**
+ * Instructs io_event to show the "Processing..." screen if PROCESSING_TIMEOUT_TICKS tick events are
+ * received before io_clear_interruption_timeout is called.
+ */
+void io_start_processing_timeout();
+
+/**
+ * Removes the timeout started from io_start_processing_timeout.
+ */
+void io_clear_processing_timeout();
+
+/**
+ * Clears both the interruption and processing timeouts, and sets G_was_processing_screen_shown to
+ * false.
+ */
+void io_reset_timeouts();
+
+/**
+ * Shows the "Processing..." screen.
+ */
+void io_show_processing_screen();
+
+/**
+ * TODO: docs
+ */
+void io_reset_response();
+
+/**
+ * TODO: docs
+ */
+void io_add_to_response(const void *rdata, size_t rdata_len);
+
+/**
+ * TODO: docs
+ */
+void io_finalize_response(uint16_t sw);
+
+/* TODO: docs */
+void io_set_response(const void *rdata, size_t rdata_len, uint16_t sw);
+
+/* TODO: docs */
+int io_confirm_response(void);
+
+/**
+ * Send APDU response (response data + status word) by filling G_io_apdu_buffer.
+ *
+ * @param[in] rdata
+ *   Pointer to the response.
+ * @param[in] rdata_len
+ *   Length of response.
+ * @param[in] sw
+ *   Status word of APDU response.
+ *
+ * @return zero or positive integer if success, -1 otherwise.
+ *
+ */
+int io_send_response(void *rdata, size_t rdata_len, uint16_t sw);
+
+/**
+ * Send APDU response (only status word) by filling G_io_apdu_buffer.
+ *
+ * @param[in] sw
+ *   Status word of APDU response.
+ *
+ * @return zero or positive integer if success, -1 otherwise.
+ *
+ */
+int io_send_sw(uint16_t sw);
diff --git a/src/boilerplate/offsets.h b/src/boilerplate/offsets.h
deleted file mode 100644
index 3db4bc1..0000000
--- a/src/boilerplate/offsets.h
+++ /dev/null
@@ -1,26 +0,0 @@
-#pragma once
-
-/**
- * Offset of instruction class.
- */
-#define OFFSET_CLA 0
-/**
- * Offset of instruction code.
- */
-#define OFFSET_INS 1
-/**
- * Offset of instruction parameter 1.
- */
-#define OFFSET_P1 2
-/**
- * Offset of instruction parameter 2.
- */
-#define OFFSET_P2 3
-/**
- * Offset of command data length.
- */
-#define OFFSET_LC 4
-/**
- * Offset of command data.
- */
-#define OFFSET_CDATA 5
diff --git a/src/common/base58.c b/src/common/base58.c
deleted file mode 100644
index 5db60c3..0000000
--- a/src/common/base58.c
+++ /dev/null
@@ -1,159 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <string.h>   // memmove, memset
-#include <stdbool.h>  // bool
-
-#include "base58.h"
-
-uint8_t const BASE58_TABLE[] = {
-    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  //
-    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  //
-    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  //
-    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  //
-    0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0xFF, 0xFF,  //
-    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,  //
-    0x10, 0xFF, 0x11, 0x12, 0x13, 0x14, 0x15, 0xFF, 0x16, 0x17, 0x18, 0x19,  //
-    0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  //
-    0xFF, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B,  //
-    0xFF, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36,  //
-    0x37, 0x38, 0x39, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF                           //
-};
-
-char const BASE58_ALPHABET[] = {
-    '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',  //
-    'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',  //
-    'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm',  //
-    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'             //
-};
-
-int base58_decode(const char *in, size_t in_len, uint8_t *out, size_t out_len) {
-    uint8_t tmp[MAX_DEC_INPUT_SIZE] = {0};
-    uint8_t buffer[MAX_DEC_INPUT_SIZE] = {0};
-
-    memset(tmp, 0, MAX_DEC_INPUT_SIZE);
-    memset(buffer, 0, MAX_DEC_INPUT_SIZE);
-
-    uint8_t j;
-    uint8_t start_at;
-    uint8_t zero_count = 0;
-
-    if (in_len > MAX_DEC_INPUT_SIZE || in_len < 2) {
-        return -1;
-    }
-
-    memmove(tmp, in, in_len);
-
-    for (uint8_t i = 0; i < in_len; i++) {
-        if (in[i] >= sizeof(BASE58_TABLE)) {
-            return -1;
-        }
-
-        tmp[i] = BASE58_TABLE[(int) in[i]];
-
-        if (tmp[i] == 0xFF) {
-            return -1;
-        }
-    }
-
-    while ((zero_count < in_len) && (tmp[zero_count] == 0)) {
-        ++zero_count;
-    }
-
-    j = in_len;
-    start_at = zero_count;
-    while (start_at < in_len) {
-        uint16_t remainder = 0;
-        for (uint8_t div_loop = start_at; div_loop < in_len; div_loop++) {
-            uint16_t digit256 = (uint16_t) (tmp[div_loop] & 0xFF);
-            uint16_t tmp_div = remainder * 58 + digit256;
-            tmp[div_loop] = (uint8_t) (tmp_div / 256);
-            remainder = tmp_div % 256;
-        }
-
-        if (tmp[start_at] == 0) {
-            ++start_at;
-        }
-
-        buffer[--j] = (uint8_t) remainder;
-    }
-
-    while ((j < in_len) && (buffer[j] == 0)) {
-        ++j;
-    }
-
-    int length = in_len - (j - zero_count);
-
-    if ((int) out_len < length) {
-        return -1;
-    }
-
-    memmove(out, buffer + j - zero_count, length);
-
-    return length;
-}
-
-int base58_encode(const uint8_t *in, size_t in_len, char *out, size_t out_len) {
-    uint8_t buffer[MAX_ENC_INPUT_SIZE * 138 / 100 + 1] = {0};
-    size_t i, j;
-    size_t stop_at;
-    size_t zero_count = 0;
-    size_t output_size;
-
-    if (in_len > MAX_ENC_INPUT_SIZE) {
-        return -1;
-    }
-
-    while ((zero_count < in_len) && (in[zero_count] == 0)) {
-        ++zero_count;
-    }
-
-    output_size = (in_len - zero_count) * 138 / 100 + 1;
-    stop_at = output_size - 1;
-    for (size_t start_at = zero_count; start_at < in_len; start_at++) {
-        unsigned int carry = in[start_at];
-        for (j = output_size - 1; (int) j >= 0; j--) {
-            carry += 256 * buffer[j];
-            buffer[j] = carry % 58;
-            carry /= 58;
-
-            if (j <= stop_at - 1 && carry == 0) {
-                break;
-            }
-        }
-        stop_at = j;
-    }
-
-    j = 0;
-    while (j < output_size && buffer[j] == 0) {
-        j += 1;
-    }
-
-    if (out_len < zero_count + output_size - j) {
-        return -1;
-    }
-
-    memset(out, BASE58_ALPHABET[0], zero_count);
-
-    i = zero_count;
-    while (j < output_size) {
-        out[i++] = BASE58_ALPHABET[buffer[j++]];
-    }
-
-    return i;
-}
diff --git a/src/common/base58.h b/src/common/base58.h
deleted file mode 100644
index f214afd..0000000
--- a/src/common/base58.h
+++ /dev/null
@@ -1,52 +0,0 @@
-#pragma once
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <stdbool.h>  // bool
-
-/**
- * Maximum length of input when decoding in base 58.
- */
-#define MAX_DEC_INPUT_SIZE 164
-/**
- * Maximum length of input when encoding in base 58.
- */
-#define MAX_ENC_INPUT_SIZE 120
-
-/**
- * Decode input string in base 58.
- *
- * @see https://tools.ietf.org/html/draft-msporny-base58-02
- *
- * @param[in]  in
- *   Pointer to input string buffer.
- * @param[in]  in_len
- *   Length of the input string buffer.
- * @param[out] out
- *   Pointer to output byte buffer.
- * @param[in]  out_len
- *   Maximum length to write in output byte buffer.
- *
- * @return number of bytes decoded, -1 otherwise.
- *
- */
-int base58_decode(const char *in, size_t in_len, uint8_t *out, size_t out_len);
-
-/**
- * Encode input bytes in base 58.
- *
- * @see https://tools.ietf.org/html/draft-msporny-base58-02
- *
- * @param[in]  in
- *   Pointer to input byte buffer.
- * @param[in]  in_len
- *   Length of the input byte buffer.
- * @param[out] out
- *   Pointer to output string buffer.
- * @param[in]  out_len
- *   Maximum length to write in output byte buffer.
- *
- * @return number of bytes encoded, -1 otherwise.
- *
- */
-int base58_encode(const uint8_t *in, size_t in_len, char *out, size_t out_len);
diff --git a/src/common/bip32.c b/src/common/bip32.c
deleted file mode 100644
index 8cec65f..0000000
--- a/src/common/bip32.c
+++ /dev/null
@@ -1,143 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdio.h>    // snprintf
-#include <string.h>   // memset, strlen
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <stdbool.h>  // bool
-
-#include "bip32.h"
-#include "base58.h"
-#include "read.h"
-#include "write.h"
-
-// shortcut for convenience
-#define H BIP32_FIRST_HARDENED_CHILD
-
-bool bip32_path_read(const uint8_t *in, size_t in_len, uint32_t *out, size_t out_len) {
-    if (out_len > MAX_BIP32_PATH_STEPS) {
-        return false;
-    }
-
-    size_t offset = 0;
-
-    for (size_t i = 0; i < out_len; i++) {
-        if (offset > in_len) {
-            return false;
-        }
-        out[i] = read_u32_be(in, offset);
-        offset += 4;
-    }
-
-    return true;
-}
-
-bool bip32_path_format(const uint32_t *bip32_path,
-                       size_t bip32_path_len,
-                       char *out,
-                       size_t out_len) {
-    if (bip32_path_len > MAX_BIP32_PATH_STEPS || out_len < 1) {
-        return false;
-    }
-    if (bip32_path_len == 0) {
-        out[0] = '\0';
-    }
-
-    size_t offset = 0;
-
-    for (uint16_t i = 0; i < bip32_path_len; i++) {
-        size_t written;
-
-        snprintf(out + offset, out_len - offset, "%d", bip32_path[i] & 0x7FFFFFFFu);
-        written = strlen(out + offset);
-        if (written == 0 || written >= out_len - offset) {
-            memset(out, 0, out_len);
-            return false;
-        }
-        offset += written;
-
-        if ((bip32_path[i] & H) != 0) {
-            snprintf(out + offset, out_len - offset, "'");
-            written = strlen(out + offset);
-            if (written == 0 || written >= out_len - offset) {
-                memset(out, 0, out_len);
-                return false;
-            }
-            offset += written;
-        }
-
-        if (i != bip32_path_len - 1) {
-            snprintf(out + offset, out_len - offset, "/");
-            written = strlen(out + offset);
-            if (written == 0 || written >= out_len - offset) {
-                memset(out, 0, out_len);
-                return false;
-            }
-            offset += written;
-        }
-    }
-
-    return true;
-}
-
-bool is_pubkey_path_standard(const uint32_t *bip32_path,
-                             size_t bip32_path_len,
-                             uint32_t expected_purpose,
-                             const uint32_t expected_coin_types[],
-                             size_t expected_coin_types_len) {
-    // if exporting the pubkey, should specify _at least_ until the coin type,
-    // and not deeper than the account (therefore 2 or 3 steps)
-    if (bip32_path_len < 2 || bip32_path_len > 3) {
-        return false;
-    }
-
-    uint32_t purpose = bip32_path[BIP44_PURPOSE_OFFSET];
-    if (purpose != (expected_purpose ^ H)) {  // the purpose should be hardened
-        return false;
-    }
-
-    uint32_t coin_type = bip32_path[BIP44_COIN_TYPE_OFFSET];
-    if (coin_type < H) {
-        return false;  // the coin_type should be hardened
-    }
-
-    if (expected_coin_types_len > 0) {
-        // make sure that the coin_type is in the given list
-        bool is_coin_type_valid = false;
-        for (unsigned int i = 0; i < expected_coin_types_len; i++) {
-            if (coin_type == (expected_coin_types[i] ^ H)) {
-                is_coin_type_valid = true;
-                break;
-            }
-        }
-        if (!is_coin_type_valid) {
-            return false;
-        }
-    }
-
-    if (bip32_path_len == 2) {
-        return true;  // nothing else to check
-    }
-
-    uint32_t account_number = bip32_path[BIP44_ACCOUNT_OFFSET];
-    if ((account_number ^ H) >
-        MAX_BIP44_ACCOUNT_RECOMMENDED) {  // should be hardened, and not too large
-        return false;
-    }
-
-    return true;
-}
diff --git a/src/common/bip32.h b/src/common/bip32.h
deleted file mode 100644
index cd6707e..0000000
--- a/src/common/bip32.h
+++ /dev/null
@@ -1,116 +0,0 @@
-#pragma once
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // uint*_t
-#include <stdbool.h>  // bool
-
-/**
- * Maximum length of BIP32 path supported.
- * Note: BIP32 allows up to 256 derivation steps - but only 5 or 6 are used in most cases.
- */
-#define MAX_BIP32_PATH_STEPS 8
-
-/**
- * Maximum length of a string representing a BIP32 derivation path.
- * Each step is up to 11 characters (10 decimal digits, plus the "hardened" symbol),
- * and there is 1 separator before each step.
- */
-#define MAX_SERIALIZED_BIP32_PATH_LENGTH (12 * MAX_BIP32_PATH_STEPS)
-
-/**
- * Index of first hardened child according to BIP32; it can also be used as the bitmask for hardened
- * children.
- */
-#define BIP32_FIRST_HARDENED_CHILD 0x80000000
-
-#define BIP44_PURPOSE_OFFSET                0
-#define BIP44_COIN_TYPE_OFFSET              1
-#define BIP44_ACCOUNT_OFFSET                2
-#define BIP44_CHANGE_OFFSET                 3
-#define BIP44_ADDRESS_INDEX_OFFSET          4
-#define MAX_BIP44_ACCOUNT_RECOMMENDED       100
-#define MAX_BIP44_ADDRESS_INDEX_RECOMMENDED 50000
-
-// Address types
-// Legacy address. P2PKH for single sig, P2SH for scripts.
-#define ADDRESS_TYPE_LEGACY 1
-// Native segwit. P2WPKH for single sig, P2WPSH for scripts.
-#define ADDRESS_TYPE_WIT 2
-// Nested segwit. P2SH-P2WPKH for single sig, P2SH-P2WPSH for scripts.
-#define ADDRESS_TYPE_SH_WIT 3
-// Taproot P2TR
-#define ADDRESS_TYPE_TR 4
-
-/**
- * Read BIP32 path from byte buffer.
- *
- * @param[in]  in
- *   Pointer to input byte buffer.
- * @param[in]  in_len
- *   Length of input byte buffer.
- * @param[out] out
- *   Pointer to output 32-bit integer buffer.
- * @param[in]  out_len
- *   Number of BIP32 paths read in the output buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool bip32_path_read(const uint8_t *in, size_t in_len, uint32_t *out, size_t out_len);
-
-/**
- * Format BIP32 path as string.
- *
- * @param[in]  bip32_path
- *   Pointer to 32-bit integer input buffer.
- * @param[in]  bip32_path_len
- *   Maximum number of BIP32 paths in the input buffer.
- * @param[out] out string
- *   Pointer to output string.
- * @param[in]  out_len
- *   Length of the output string.
- *
- * @return true if success, false otherwise.
- *
- */
-bool bip32_path_format(const uint32_t *bip32_path,
-                       size_t bip32_path_len,
-                       char *out,
-                       size_t out_len);
-
-/**
- * Verifies if a given path is standard according to BIP44 or derived standards, and it is
- * reasonable to export its pubkey. Should not export paths that are too short to specify the coin
- * type (it would expose other coins' keys), but also not deeper than the standard account number
- * (third level of derivation), since no standard currently defines deeper hardened derivations.
- *
- * Returns false if any of the following conditions is not satisfied by the given bip32_path:
- * - the bip32_path has 2 or 3 steps;
- * - purpose, coin_type and account_number (if given) are hardened;
- * - purpose is not hardened, or it does not match expected_purpose;
- * - coin_type is in the expected_coin_types array (if given);
- * - account_number (if given) at most MAX_BIP44_ACCOUNT_RECOMMENDED.
- *
- * @param[in]  bip32_path
- *   Pointer to 32-bit integer input buffer.
- * @param[in]  bip32_path_len
- *   Maximum number of BIP32 paths in the input buffer.
- * @param[in]  expected_purpose
- *   The purpose that should be in the derivation (e.g. 44 for BIP44).
- * @param[in]  expected_coin_types
- *   Pointer to an array with the coin types that are considered acceptable. The
- *   elements of the array should be given as simple numbers (not their hardened version);
- *   for example, the coin type for Bitcoin is 0.
- *   Ignored if expected_coin_types_len is 0; in that case, it is only checked
- *   that the coin_type is hardened, as expected in the standard.
- * @param[in]  expected_coin_types_len
- *   The length of expected_coin_types.
- *
- * @return true if the given address is standard, false otherwise.
- *
- */
-bool is_pubkey_path_standard(const uint32_t *bip32_path,
-                             size_t bip32_path_len,
-                             uint32_t expected_purpose,
-                             const uint32_t expected_coin_types[],
-                             size_t expected_coin_types_len);
diff --git a/src/common/bitvector.h b/src/common/bitvector.h
index 4be97c0..037fb78 100644
--- a/src/common/bitvector.h
+++ b/src/common/bitvector.h
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <stdint.h>
 #include <stdbool.h>
+#include <stdint.h>
 
 /**
  * Returns the size in bytes of a bitvector that can contain n bits.
diff --git a/src/common/buffer.c b/src/common/buffer.c
deleted file mode 100644
index b5ce2ff..0000000
--- a/src/common/buffer.c
+++ /dev/null
@@ -1,257 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdint.h>   // uint*_t
-#include <stddef.h>   // size_t
-#include <stdbool.h>  // bool
-#include <string.h>   // memmove
-
-#include "buffer.h"
-#include "read.h"
-#include "write.h"
-#include "varint.h"
-#include "bip32.h"
-
-bool buffer_can_read(const buffer_t *buffer, size_t n) {
-    return buffer->size - buffer->offset >= n;
-}
-
-bool buffer_seek_set(buffer_t *buffer, size_t offset) {
-    if (offset > buffer->size) {
-        return false;
-    }
-
-    buffer->offset = offset;
-
-    return true;
-}
-
-bool buffer_seek_cur(buffer_t *buffer, size_t offset) {
-    if (buffer->offset + offset < buffer->offset ||  // overflow
-        buffer->offset + offset > buffer->size) {    // exceed buffer size
-        return false;
-    }
-
-    buffer->offset += offset;
-
-    return true;
-}
-
-bool buffer_seek_end(buffer_t *buffer, size_t offset) {
-    if (offset > buffer->size) {
-        return false;
-    }
-
-    buffer->offset = buffer->size - offset;
-
-    return true;
-}
-
-bool buffer_read_u8(buffer_t *buffer, uint8_t *value) {
-    if (!buffer_can_read(buffer, 1)) {
-        *value = 0;
-
-        return false;
-    }
-
-    *value = buffer->ptr[buffer->offset];
-    buffer_seek_cur(buffer, 1);
-
-    return true;
-}
-
-bool buffer_peek(const buffer_t *buffer, uint8_t *value) {
-    return buffer_peek_n(buffer, 0, value);
-}
-
-bool buffer_peek_n(const buffer_t *buffer, size_t n, uint8_t *value) {
-    if (!buffer_can_read(buffer, n + 1)) {
-        return false;
-    }
-
-    *value = buffer->ptr[buffer->offset + n];
-
-    return true;
-}
-
-bool buffer_read_u16(buffer_t *buffer, uint16_t *value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 2)) {
-        *value = 0;
-
-        return false;
-    }
-
-    *value = ((endianness == BE) ? read_u16_be(buffer->ptr, buffer->offset)
-                                 : read_u16_le(buffer->ptr, buffer->offset));
-
-    buffer_seek_cur(buffer, 2);
-
-    return true;
-}
-
-bool buffer_read_u32(buffer_t *buffer, uint32_t *value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 4)) {
-        *value = 0;
-
-        return false;
-    }
-
-    *value = ((endianness == BE) ? read_u32_be(buffer->ptr, buffer->offset)
-                                 : read_u32_le(buffer->ptr, buffer->offset));
-
-    buffer_seek_cur(buffer, 4);
-
-    return true;
-}
-
-bool buffer_read_u64(buffer_t *buffer, uint64_t *value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 8)) {
-        *value = 0;
-
-        return false;
-    }
-
-    *value = ((endianness == BE) ? read_u64_be(buffer->ptr, buffer->offset)
-                                 : read_u64_le(buffer->ptr, buffer->offset));
-
-    buffer_seek_cur(buffer, 8);
-
-    return true;
-}
-
-bool buffer_read_varint(buffer_t *buffer, uint64_t *value) {
-    int length = varint_read(buffer->ptr + buffer->offset, buffer->size - buffer->offset, value);
-
-    if (length < 0) {
-        *value = 0;
-
-        return false;
-    }
-
-    buffer_seek_cur(buffer, (size_t) length);
-
-    return true;
-}
-
-bool buffer_read_bip32_path(buffer_t *buffer, uint32_t *out, size_t out_len) {
-    if (!bip32_path_read(buffer->ptr + buffer->offset,
-                         buffer->size - buffer->offset,
-                         out,
-                         out_len)) {
-        return false;
-    }
-
-    buffer_seek_cur(buffer, sizeof(*out) * out_len);
-
-    return true;
-}
-
-bool buffer_read_bytes(buffer_t *buffer, uint8_t *out, size_t n) {
-    if (buffer->size - buffer->offset < n) {
-        return false;
-    }
-
-    memmove(out, buffer->ptr + buffer->offset, n);
-    buffer_seek_cur(buffer, n);
-
-    return true;
-}
-
-bool buffer_write_u8(buffer_t *buffer, uint8_t value) {
-    if (!buffer_can_read(buffer, 1)) {
-        return false;
-    }
-
-    buffer->ptr[buffer->offset] = value;
-    buffer_seek_cur(buffer, 1);
-
-    return true;
-}
-
-bool buffer_write_u16(buffer_t *buffer, uint16_t value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 2)) {
-        return false;
-    }
-
-    if (endianness == BE) {
-        write_u16_be(buffer->ptr, buffer->offset, value);
-    } else {
-        write_u16_le(buffer->ptr, buffer->offset, value);
-    }
-    buffer_seek_cur(buffer, 2);
-
-    return true;
-}
-
-bool buffer_write_u32(buffer_t *buffer, uint32_t value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 4)) {
-        return false;
-    }
-
-    if (endianness == BE) {
-        write_u32_be(buffer->ptr, buffer->offset, value);
-    } else {
-        write_u32_le(buffer->ptr, buffer->offset, value);
-    }
-    buffer_seek_cur(buffer, 4);
-
-    return true;
-}
-
-bool buffer_write_u64(buffer_t *buffer, uint64_t value, endianness_t endianness) {
-    if (!buffer_can_read(buffer, 8)) {
-        return false;
-    }
-
-    if (endianness == BE) {
-        write_u64_be(buffer->ptr, buffer->offset, value);
-    } else {
-        write_u64_le(buffer->ptr, buffer->offset, value);
-    }
-
-    buffer_seek_cur(buffer, 8);
-
-    return true;
-}
-
-bool buffer_write_bytes(buffer_t *buffer, const uint8_t *data, size_t n) {
-    if (!buffer_can_read(buffer, n)) {
-        return false;
-    }
-
-    memmove(buffer->ptr + buffer->offset, data, n);
-    buffer_seek_cur(buffer, n);
-    return true;
-}
-
-void *buffer_alloc(buffer_t *buffer, size_t size, bool aligned) {
-    size_t padding_size = 0;
-
-    if (aligned) {
-        uint32_t d = (uint32_t) (buffer->ptr + buffer->offset) % 4;
-        if (d != 0) {
-            padding_size = 4 - d;
-        }
-    }
-
-    if (!buffer_can_read(buffer, padding_size + size)) {
-        return NULL;
-    }
-
-    void *result = buffer->ptr + buffer->offset + padding_size;
-    buffer_seek_cur(buffer, padding_size + size);
-    return result;
-}
diff --git a/src/common/buffer.h b/src/common/buffer.h
deleted file mode 100644
index 3f3539f..0000000
--- a/src/common/buffer.h
+++ /dev/null
@@ -1,358 +0,0 @@
-#pragma once
-
-#include <stdint.h>   // uint*_t
-#include <stddef.h>   // size_t
-#include <stdbool.h>  // bool
-
-/**
- * Enumeration for endianness.
- */
-typedef enum {
-    BE,  /// Big Endian
-    LE   /// Little Endian
-} endianness_t;
-
-typedef size_t buffer_snapshot_t;
-
-/**
- * Struct for buffer with size and offset.
- */
-typedef struct {
-    uint8_t *ptr;   /// Pointer to byte buffer
-    size_t size;    /// Size of byte buffer
-    size_t offset;  /// Offset in byte buffer
-} buffer_t;
-
-/**
- * Tell whether buffer can read bytes or not.
- *
- * @param[in] buffer
- *   Pointer to input buffer struct.
- * @param[in] n
- *   Number of bytes to read in buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_can_read(const buffer_t *buffer, size_t n);
-
-/**
- * Seek the buffer to specific offset.
- *
- * @param[in,out] buffer
- *   Pointer to input buffer struct.
- * @param[in]     offset
- *   Specific offset to seek.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_seek_set(buffer_t *buffer, size_t offset);
-
-/**
- * Seek buffer relatively to current offset.
- *
- * @param[in,out] buffer
- *   Pointer to input buffer struct.
- * @param[in]     offset
- *   Offset to seek relatively to `buffer->offset`.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_seek_cur(buffer_t *buffer, size_t offset);
-
-/**
- * Seek the buffer relatively to the end.
- *
- * @param[in,out] buffer
- *   Pointer to input buffer struct.
- * @param[in]     offset
- *   Offset to seek relatively to `buffer->size`.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_seek_end(buffer_t *buffer, size_t offset);
-
-/**
- * Returns the pointer to byte in the current position of the buffer.
- *
- * @param[in] buffer
- *   Pointer to input buffer struct.
- *
- * @return the pointer to the current position.
- *
- */
-static inline uint8_t *buffer_get_cur(const buffer_t *buffer) {
-    return buffer->ptr + buffer->offset;
-}
-
-/**
- * Read 1 byte from buffer into uint8_t.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     value
- *   Pointer to 8-bit unsigned integer read from buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_u8(buffer_t *buffer, uint8_t *value);
-
-/**
- * Read 1 byte from buffer into uint8_t without advancing the current position in the buffer.
- * Returns `true` on success, `false` if the buffer was empty; `value` is not changed in case of
- * failure.
- *
- * @param[in]  buffer
- *   Pointer to input buffer struct.
- * @param[out]  value
- *   Pointer to 8-bit unsigned integer read from buffer.
- *
- * @return true if success, false otherwise.
- */
-bool buffer_peek(const buffer_t *buffer, uint8_t *value);
-
-/**
- * Read 1 byte at position `n` from buffer into uint8_t without advancing the current position in
- * the buffer. Returns `true` on success, `false` if the buffer is not large enough; `value` is not
- * changed in case of failure.
- *
- * @param[in]  buffer
- *   Pointer to input buffer struct.
- * @param[out]  n
- *   Index of the byte to read, where the immediate next byte has index 0.
- * @param[out]  value
- *   Pointer to 8-bit unsigned integer read from buffer.
- *
- * @return true if success, false otherwise.
- */
-bool buffer_peek_n(const buffer_t *buffer, size_t n, uint8_t *value);
-
-/**
- * Read 2 bytes from buffer into uint16_t.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     value
- *   Pointer to 16-bit unsigned integer read from buffer.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_u16(buffer_t *buffer, uint16_t *value, endianness_t endianness);
-
-/**
- * Read 4 bytes from buffer into uint32_t.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     value
- *   Pointer to 32-bit unsigned integer read from buffer.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_u32(buffer_t *buffer, uint32_t *value, endianness_t endianness);
-
-/**
- * Read 8 bytes from buffer into uint64_t.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     value
- *   Pointer to 64-bit unsigned integer read from buffer.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_u64(buffer_t *buffer, uint64_t *value, endianness_t endianness);
-
-/**
- * Read Bitcoin-like varint from buffer into uint64_t.
- *
- * @see https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     value
- *   Pointer to 64-bit unsigned integer read from buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_varint(buffer_t *buffer, uint64_t *value);
-
-/**
- * Read BIP32 path from buffer.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     out
- *   Pointer to output 32-bit integer buffer.
- * @param[in]      out_len
- *   Number of BIP32 paths read in the output buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_bip32_path(buffer_t *buffer, uint32_t *out, size_t out_len);
-
-/**
- * Read n bytes from buffer, and stores them in out.
- *
- * @param[in,out]  buffer
- *   Pointer to input buffer struct.
- * @param[out]     out
- *   Pointer to output buffer. It is the responsibility of the caller to make sure that the output
- * buffer is at least n bytes long.
- * @param[in]      n
- *   Number of bytes to read from buffer.
- *
- * @return true if success, false otherwise.
- *
- */
-bool buffer_read_bytes(buffer_t *buffer, uint8_t *out, size_t n);
-
-/**
- * Write a uint8_t into a buffer.
- *
- * @param[in,out]  buffer
- *   Pointer to output buffer struct.
- * @param[out]     value
- *   Value to be written.
- *
- * @return true if success, false if not enough space left in the buffer.
- *
- */
-bool buffer_write_u8(buffer_t *buffer, uint8_t value);
-
-/**
- * Write a uint16_t into the buffer as 2 bytes, with the given endianness.
- *
- * @param[in,out]  buffer
- *   Pointer to output buffer struct.
- * @param[out]     value
- *   Value to be written.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false if not enough space left in the buffer.
- *
- */
-bool buffer_write_u16(buffer_t *buffer, uint16_t value, endianness_t endianness);
-
-/**
- * Write a uint32_t into the buffer as 4 bytes, with the given endianness.
- *
- * @param[in,out]  buffer
- *   Pointer to output buffer struct.
- * @param[out]     value
- *   Value to be written.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false if not enough space left in the buffer.
- *
- */
-bool buffer_write_u32(buffer_t *buffer, uint32_t value, endianness_t endianness);
-
-/**
- * Write a uint64_t into the buffer as 8 bytes, with the given endianness.
- *
- * @param[in,out]  buffer
- *   Pointer to output buffer struct.
- * @param[out]     value
- *   Value to be written.
- * @param[in]      endianness
- *   Either BE (Big Endian) or LE (Little Endian).
- *
- * @return true if success, false if not enough space left in the buffer.
- *
- */
-bool buffer_write_u64(buffer_t *buffer, uint64_t value, endianness_t endianness);
-
-/**
- * Write a number of bytes to a buffer.
- *
- * @param[in,out]  buffer
- *   Pointer to output buffer struct.
- * @param[in]      data
- *   Pointer to bytes to be written.
- * @param[in]      n
- *   Size of bytes to be written.
- *
- * @return true if success, false if not enough space left in the buffer.
- *
- */
-bool buffer_write_bytes(buffer_t *buffer, const uint8_t *data, size_t n);
-
-/**
- * Creates a buffer pointing at ptr and with the given size; the initial offset is 0.
- *
- * @param[in,out]  ptr
- *   Pointer to the buffer's data.
- * @param[in]  size
- *   Size of the buffer.
- *
- * @return the new buffer with the given pointer and size.
- *
- */
-static inline buffer_t buffer_create(void *ptr, size_t size) {
-    return (buffer_t){.ptr = ptr, .size = size, .offset = 0};
-}
-
-/**
- * Returns a pointer to the current position in the buffer if at least `size` bytes are available in
- * the buffer (possibly after skipping some bytes to guarantee alignment), or NULL otherwise. On
- * success, the buffer is advanced by `size` bytes. If `aligned == true`, the returned pointer is
- * 32-bit aligned (adding up to three padding bytes if necessary). The buffer is not advanced in
- * case of failure.
- *
- * @param[in,out]  buffer The buffer in which the memory is to be allocated.
- * @param[in]  size The number of bytes allocated within `buffer`.
- * @param[in]  aligned If `true`, makes sure that the returned pointer is 32-bit aligned.
- *
- * @return a pointer to the allocated memory within the buffer.
- */
-void *buffer_alloc(buffer_t *buffer, size_t size, bool aligned);
-
-/**
- * Checks if the current position in the buffer is aligned in memory to a 4-byte boundary.
- *
- * @param[in]  buffer Pointer to a buffer struct.
- *
- * @return `true` if the current position in the buffer is aligned, `false` otherwise.
- */
-static inline bool buffer_is_cur_aligned(const buffer_t *buffer) {
-    return (size_t) (buffer->ptr + buffer->offset) % 4 == 0;
-}
-
-/**
- * Saves a snapshot of the current position within the buffer.
- *
- * @param[in] buffer The buffer whose position is saved.
- *
- * @return a snapshot that can be restored with `buffer_restore`.
- */
-static inline buffer_snapshot_t buffer_snapshot(const buffer_t *buffer) {
-    return buffer->offset;
-}
-
-/**
- * Restores a previously taken snapshot of the buffer.
- *
- * @param[in,out] snapshot The snapshot previously returned by a call to `buffer_snapshot` on the
- * same buffer. The behavior is undefined if any other value is passed as `snapshot`.
- */
-static inline void buffer_restore(buffer_t *buffer, buffer_snapshot_t snapshot) {
-    buffer->offset = snapshot;
-}
diff --git a/src/common/buffer_ext.c b/src/common/buffer_ext.c
new file mode 100644
index 0000000..05211f7
--- /dev/null
+++ b/src/common/buffer_ext.c
@@ -0,0 +1,140 @@
+/*****************************************************************************
+ *   (c) 2026 Ledger SAS.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *****************************************************************************/
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "buffer_ext.h"
+
+/* SDK headers */
+#include "bip32.h"
+#include "buffer.h"
+#include "read.h"
+#include "varint.h"
+#include "write.h"
+
+bool buffer_peek(const buffer_t *buffer, uint8_t *value) {
+    return buffer_peek_n(buffer, 0, value);
+}
+
+bool buffer_peek_n(const buffer_t *buffer, size_t n, uint8_t *value) {
+    if (!buffer_can_read(buffer, n + 1)) {
+        return false;
+    }
+
+    *value = buffer->ptr[buffer->offset + n];
+
+    return true;
+}
+
+bool buffer_read_bytes(buffer_t *buffer, uint8_t *out, size_t n) {
+    if (buffer->size - buffer->offset < n) {
+        return false;
+    }
+
+    memmove(out, buffer->ptr + buffer->offset, n);
+    buffer_seek_cur(buffer, n);
+
+    return true;
+}
+
+bool buffer_write_u8(buffer_t *buffer, uint8_t value) {
+    if (!buffer_can_read(buffer, 1)) {
+        return false;
+    }
+
+    ((uint8_t *) buffer->ptr)[buffer->offset] = value;
+    buffer_seek_cur(buffer, 1);
+
+    return true;
+}
+
+bool buffer_write_u16(buffer_t *buffer, uint16_t value, endianness_t endianness) {
+    if (!buffer_can_read(buffer, 2)) {
+        return false;
+    }
+
+    if (endianness == BE) {
+        write_u16_be((uint8_t *) buffer->ptr, buffer->offset, value);
+    } else {
+        write_u16_le((uint8_t *) buffer->ptr, buffer->offset, value);
+    }
+    buffer_seek_cur(buffer, 2);
+
+    return true;
+}
+
+bool buffer_write_u32(buffer_t *buffer, uint32_t value, endianness_t endianness) {
+    if (!buffer_can_read(buffer, 4)) {
+        return false;
+    }
+
+    if (endianness == BE) {
+        write_u32_be((uint8_t *) buffer->ptr, buffer->offset, value);
+    } else {
+        write_u32_le((uint8_t *) buffer->ptr, buffer->offset, value);
+    }
+    buffer_seek_cur(buffer, 4);
+
+    return true;
+}
+
+bool buffer_write_u64(buffer_t *buffer, uint64_t value, endianness_t endianness) {
+    if (!buffer_can_read(buffer, 8)) {
+        return false;
+    }
+
+    if (endianness == BE) {
+        write_u64_be((uint8_t *) buffer->ptr, buffer->offset, value);
+    } else {
+        write_u64_le((uint8_t *) buffer->ptr, buffer->offset, value);
+    }
+
+    buffer_seek_cur(buffer, 8);
+
+    return true;
+}
+
+bool buffer_write_bytes(buffer_t *buffer, const uint8_t *data, size_t n) {
+    if (!buffer_can_read(buffer, n)) {
+        return false;
+    }
+
+    memmove((uint8_t *) (buffer->ptr + buffer->offset), data, n);
+    buffer_seek_cur(buffer, n);
+    return true;
+}
+
+void *buffer_alloc(buffer_t *buffer, size_t size, bool aligned) {
+    size_t padding_size = 0;
+
+    if (aligned) {
+        uint32_t d = (uint32_t) (buffer->ptr + buffer->offset) % 4;
+        if (d != 0) {
+            padding_size = 4 - d;
+        }
+    }
+
+    if (!buffer_can_read(buffer, padding_size + size)) {
+        return NULL;
+    }
+
+    void *result = (uint8_t *) (buffer->ptr + buffer->offset) + padding_size;
+    buffer_seek_cur(buffer, padding_size + size);
+    return result;
+}
diff --git a/src/common/buffer_ext.h b/src/common/buffer_ext.h
new file mode 100644
index 0000000..19ccf66
--- /dev/null
+++ b/src/common/buffer_ext.h
@@ -0,0 +1,217 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/* SDK headers */
+#include "buffer.h"
+
+typedef size_t buffer_snapshot_t;
+
+/**
+ * Returns the pointer to byte in the current position of the buffer.
+ *
+ * @param[in] buffer
+ *   Pointer to input buffer struct.
+ *
+ * @return the pointer to the current position.
+ *
+ */
+static inline uint8_t *buffer_get_cur(const buffer_t *buffer) {
+    return (uint8_t *) (buffer->ptr + buffer->offset);
+}
+
+/**
+ * Read 1 byte from buffer into uint8_t.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to input buffer struct.
+ * @param[out]     value
+ *   Pointer to 8-bit unsigned integer read from buffer.
+ *
+ * @return true if success, false otherwise.
+ *
+ */
+bool buffer_read_u8(buffer_t *buffer, uint8_t *value);
+
+/**
+ * Read 1 byte from buffer into uint8_t without advancing the current position in the buffer.
+ * Returns `true` on success, `false` if the buffer was empty; `value` is not changed in case of
+ * failure.
+ *
+ * @param[in]  buffer
+ *   Pointer to input buffer struct.
+ * @param[out]  value
+ *   Pointer to 8-bit unsigned integer read from buffer.
+ *
+ * @return true if success, false otherwise.
+ */
+bool buffer_peek(const buffer_t *buffer, uint8_t *value);
+
+/**
+ * Read 1 byte at position `n` from buffer into uint8_t without advancing the current position in
+ * the buffer. Returns `true` on success, `false` if the buffer is not large enough; `value` is not
+ * changed in case of failure.
+ *
+ * @param[in]  buffer
+ *   Pointer to input buffer struct.
+ * @param[out]  n
+ *   Index of the byte to read, where the immediate next byte has index 0.
+ * @param[out]  value
+ *   Pointer to 8-bit unsigned integer read from buffer.
+ *
+ * @return true if success, false otherwise.
+ */
+bool buffer_peek_n(const buffer_t *buffer, size_t n, uint8_t *value);
+
+/**
+ * Read n bytes from buffer, and stores them in out.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to input buffer struct.
+ * @param[out]     out
+ *   Pointer to output buffer. It is the responsibility of the caller to make sure that the output
+ * buffer is at least n bytes long.
+ * @param[in]      n
+ *   Number of bytes to read from buffer.
+ *
+ * @return true if success, false otherwise.
+ *
+ */
+bool buffer_read_bytes(buffer_t *buffer, uint8_t *out, size_t n);
+
+/**
+ * Write a uint8_t into a buffer.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to output buffer struct.
+ * @param[out]     value
+ *   Value to be written.
+ *
+ * @return true if success, false if not enough space left in the buffer.
+ *
+ */
+bool buffer_write_u8(buffer_t *buffer, uint8_t value);
+
+/**
+ * Write a uint16_t into the buffer as 2 bytes, with the given endianness.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to output buffer struct.
+ * @param[out]     value
+ *   Value to be written.
+ * @param[in]      endianness
+ *   Either BE (Big Endian) or LE (Little Endian).
+ *
+ * @return true if success, false if not enough space left in the buffer.
+ *
+ */
+bool buffer_write_u16(buffer_t *buffer, uint16_t value, endianness_t endianness);
+
+/**
+ * Write a uint32_t into the buffer as 4 bytes, with the given endianness.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to output buffer struct.
+ * @param[out]     value
+ *   Value to be written.
+ * @param[in]      endianness
+ *   Either BE (Big Endian) or LE (Little Endian).
+ *
+ * @return true if success, false if not enough space left in the buffer.
+ *
+ */
+bool buffer_write_u32(buffer_t *buffer, uint32_t value, endianness_t endianness);
+
+/**
+ * Write a uint64_t into the buffer as 8 bytes, with the given endianness.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to output buffer struct.
+ * @param[out]     value
+ *   Value to be written.
+ * @param[in]      endianness
+ *   Either BE (Big Endian) or LE (Little Endian).
+ *
+ * @return true if success, false if not enough space left in the buffer.
+ *
+ */
+bool buffer_write_u64(buffer_t *buffer, uint64_t value, endianness_t endianness);
+
+/**
+ * Write a number of bytes to a buffer.
+ *
+ * @param[in,out]  buffer
+ *   Pointer to output buffer struct.
+ * @param[in]      data
+ *   Pointer to bytes to be written.
+ * @param[in]      n
+ *   Size of bytes to be written.
+ *
+ * @return true if success, false if not enough space left in the buffer.
+ *
+ */
+bool buffer_write_bytes(buffer_t *buffer, const uint8_t *data, size_t n);
+
+/**
+ * Creates a buffer pointing at ptr and with the given size; the initial offset is 0.
+ *
+ * @param[in,out]  ptr
+ *   Pointer to the buffer's data.
+ * @param[in]  size
+ *   Size of the buffer.
+ *
+ * @return the new buffer with the given pointer and size.
+ *
+ */
+static inline buffer_t buffer_create(void *ptr, size_t size) {
+    return (buffer_t){.ptr = ptr, .size = size, .offset = 0};
+}
+
+/**
+ * Returns a pointer to the current position in the buffer if at least `size` bytes are available in
+ * the buffer (possibly after skipping some bytes to guarantee alignment), or NULL otherwise. On
+ * success, the buffer is advanced by `size` bytes. If `aligned == true`, the returned pointer is
+ * 32-bit aligned (adding up to three padding bytes if necessary). The buffer is not advanced in
+ * case of failure.
+ *
+ * @param[in,out]  buffer The buffer in which the memory is to be allocated.
+ * @param[in]  size The number of bytes allocated within `buffer`.
+ * @param[in]  aligned If `true`, makes sure that the returned pointer is 32-bit aligned.
+ *
+ * @return a pointer to the allocated memory within the buffer.
+ */
+void *buffer_alloc(buffer_t *buffer, size_t size, bool aligned);
+
+/**
+ * Checks if the current position in the buffer is aligned in memory to a 4-byte boundary.
+ *
+ * @param[in]  buffer Pointer to a buffer struct.
+ *
+ * @return `true` if the current position in the buffer is aligned, `false` otherwise.
+ */
+static inline bool buffer_is_cur_aligned(const buffer_t *buffer) {
+    return (size_t) (buffer->ptr + buffer->offset) % 4 == 0;
+}
+
+/**
+ * Saves a snapshot of the current position within the buffer.
+ *
+ * @param[in] buffer The buffer whose position is saved.
+ *
+ * @return a snapshot that can be restored with `buffer_restore`.
+ */
+static inline buffer_snapshot_t buffer_snapshot(const buffer_t *buffer) {
+    return buffer->offset;
+}
+
+/**
+ * Restores a previously taken snapshot of the buffer.
+ *
+ * @param[in,out] snapshot The snapshot previously returned by a call to `buffer_snapshot` on the
+ * same buffer. The behavior is undefined if any other value is passed as `snapshot`.
+ */
+static inline void buffer_restore(buffer_t *buffer, buffer_snapshot_t snapshot) {
+    buffer->offset = snapshot;
+}
diff --git a/src/common/format.c b/src/common/format.c
deleted file mode 100644
index 8433806..0000000
--- a/src/common/format.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // int*_t, uint*_t
-#include <string.h>   // strncpy, memmove
-#include <stdbool.h>  // bool
-
-#include "format.h"
-
-bool format_i64(char *dst, size_t dst_len, const int64_t value) {
-    char temp[] = "-9223372036854775808";
-
-    char *ptr = temp;
-    int64_t num = value;
-    int sign = 1;
-
-    if (value < 0) {
-        sign = -1;
-    }
-
-    while (num != 0) {
-        *ptr++ = '0' + (num % 10) * sign;
-        num /= 10;
-    }
-
-    if (value < 0) {
-        *ptr++ = '-';
-    } else if (value == 0) {
-        *ptr++ = '0';
-    }
-
-    int distance = (ptr - temp) + 1;
-
-    if ((int) dst_len < distance) {
-        return false;
-    }
-
-    size_t index = 0;
-
-    while (--ptr >= temp) {
-        dst[index++] = *ptr;
-    }
-
-    dst[index] = '\0';
-
-    return true;
-}
-
-bool format_u64(char *out, size_t outLen, uint64_t in) {
-    uint8_t i = 0;
-
-    if (outLen == 0) {
-        return false;
-    }
-    outLen--;
-
-    while (in > 9) {
-        out[i] = in % 10 + '0';
-        in /= 10;
-        i++;
-        if (i + 1 > outLen) {
-            return false;
-        }
-    }
-    out[i] = in + '0';
-    out[i + 1] = '\0';
-
-    uint8_t j = 0;
-    char tmp;
-
-    // revert the string
-    while (j < i) {
-        // swap out[j] and out[i]
-        tmp = out[j];
-        out[j] = out[i];
-        out[i] = tmp;
-
-        i--;
-        j++;
-    }
-    return true;
-}
-
-bool format_fpu64(char *dst, size_t dst_len, const uint64_t value, uint8_t decimals) {
-    char buffer[21] = {0};
-
-    if (!format_u64(buffer, sizeof(buffer), value)) {
-        return false;
-    }
-
-    size_t digits = strlen(buffer);
-
-    if (digits <= decimals) {
-        if (dst_len <= 2 + decimals - digits) {
-            return false;
-        }
-        *dst++ = '0';
-        *dst++ = '.';
-        for (uint16_t i = 0; i < decimals - digits; i++, dst++) {
-            *dst = '0';
-        }
-        dst_len -= 2 + decimals - digits;
-        strncpy(dst, buffer, dst_len);
-    } else {
-        if (dst_len <= digits + 1 + decimals) {
-            return false;
-        }
-
-        const size_t shift = digits - decimals;
-        memmove(dst, buffer, shift);
-        dst[shift] = '.';
-        strncpy(dst + shift + 1, buffer + shift, decimals);
-    }
-
-    return true;
-}
-
-int format_hex(const uint8_t *in, size_t in_len, char *out, size_t out_len) {
-    if (out_len < 2 * in_len + 1) {
-        return -1;
-    }
-
-    const char hex[] = "0123456789abcdef";
-    size_t i = 0;
-    int written = 0;
-
-    while (i < in_len && (i * 2 + (2 + 1)) <= out_len) {
-        uint8_t high_nibble = (in[i] & 0xF0) >> 4;
-        *out = hex[high_nibble];
-        out++;
-
-        uint8_t low_nibble = in[i] & 0x0F;
-        *out = hex[low_nibble];
-        out++;
-
-        i++;
-        written += 2;
-    }
-
-    *out = '\0';
-
-    return written + 1;
-}
diff --git a/src/common/format.h b/src/common/format.h
deleted file mode 100644
index f145748..0000000
--- a/src/common/format.h
+++ /dev/null
@@ -1,69 +0,0 @@
-#pragma once
-
-#include <stddef.h>   // size_t
-#include <stdint.h>   // int*_t, uint*_t
-#include <stdbool.h>  // bool
-
-/**
- * Format 64-bit signed integer as string.
- *
- * @param[out] dst
- *   Pointer to output string.
- * @param[in]  dst_len
- *   Length of output string.
- * @param[in]  value
- *   64-bit signed integer to format.
- *
- * @return true if success, false otherwise.
- *
- */
-bool format_i64(char *dst, size_t dst_len, const int64_t value);
-
-/**
- * Format 64-bit unsigned integer as string.
- *
- * @param[out] dst
- *   Pointer to output string.
- * @param[in]  dst_len
- *   Length of output string.
- * @param[in]  value
- *   64-bit unsigned integer to format.
- *
- * @return true if success, false otherwise.
- *
- */
-bool format_u64(char *dst, size_t dst_len, uint64_t value);
-
-/**
- * Format 64-bit unsigned integer as string with decimals.
- *
- * @param[out] dst
- *   Pointer to output string.
- * @param[in]  dst_len
- *   Length of output string.
- * @param[in]  value
- *   64-bit unsigned integer to format.
- * @param[in]  decimals
- *   Number of digits after decimal separator.
- *
- * @return true if success, false otherwise.
- *
- */
-bool format_fpu64(char *dst, size_t dst_len, const uint64_t value, uint8_t decimals);
-
-/**
- * Format byte buffer to uppercase hexadecimal string.
- *
- * @param[in]  in
- *   Pointer to input byte buffer.
- * @param[in]  in_len
- *   Length of input byte buffer.
- * @param[out] out
- *   Pointer to output string.
- * @param[in]  out_len
- *   Length of output string.
- *
- * @return number of bytes written if success, -1 otherwise.
- *
- */
-int format_hex(const uint8_t *in, size_t in_len, char *out, size_t out_len);
diff --git a/src/common/merkle.c b/src/common/merkle.c
index fa6c507..20a8770 100644
--- a/src/common/merkle.c
+++ b/src/common/merkle.c
@@ -15,19 +15,20 @@
  *  limitations under the License.
  *****************************************************************************/
 
-#include <stdint.h>   // uint*_t
-#include <string.h>   // memset, explicit_bzero
-#include <stdbool.h>  // bool
-
-#include "buffer.h"
-#include "../crypto.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
 
 #include "merkle.h"
 
-#include "../debug-helpers/debug.h"
-
+/* SDK headers */
+#include "buffer.h"
 #include "ledger_assert.h"
 
+/* Local headers */
+#include "crypto.h"
+#include "debug.h"
+
 void merkle_compute_element_hash(const uint8_t *in,
                                  size_t in_len,
                                  uint8_t out[static CX_SHA256_SIZE]) {
diff --git a/src/common/parser.c b/src/common/parser.c
deleted file mode 100644
index 02913a7..0000000
--- a/src/common/parser.c
+++ /dev/null
@@ -1,144 +0,0 @@
-#include <stdio.h>
-
-#include "parser.h"
-
-#include "read.h"
-
-size_t dbuffer_get_length(buffer_t *buffers[2]) {
-    return (buffers[0]->size - buffers[0]->offset) + (buffers[1]->size - buffers[1]->offset);
-}
-
-bool dbuffer_can_read(buffer_t *buffers[2], size_t n) {
-    return dbuffer_get_length(buffers) >= n;
-}
-
-bool dbuffer_read_bytes(buffer_t *buffers[2], uint8_t *out, size_t n) {
-    size_t length0 = buffers[0]->size - buffers[0]->offset;
-    size_t length1 = buffers[1]->size - buffers[1]->offset;
-    if (n > length0 + length1) {
-        return false;
-    }
-
-    size_t n0 = (length0 >= n) ? n : length0;  // bytes to read from first buffer
-    size_t n1 = n - n0;                        // bytes to read from second buffer
-
-    if (n0 > 0) {
-        buffer_read_bytes(buffers[0], out, n0);
-    }
-    if (n1 > 0) {
-        buffer_read_bytes(buffers[1], out + n0, n1);
-    }
-    return true;
-}
-
-bool dbuffer_read_u8(buffer_t *buffers[2], uint8_t *out) {
-    return dbuffer_read_bytes(buffers, out, 1);
-}
-
-bool dbuffer_read_u16(buffer_t *buffers[2], uint16_t *out, endianness_t endianness) {
-    if (!dbuffer_can_read(buffers, 2)) {
-        return false;
-    }
-
-    uint8_t tmp[2];
-    dbuffer_read_bytes(buffers, tmp, 2);
-    if (endianness == BE)
-        *out = read_u16_be(tmp, 0);
-    else
-        *out = read_u16_le(tmp, 0);
-    return true;
-}
-
-bool dbuffer_read_u32(buffer_t *buffers[2], uint32_t *out, endianness_t endianness) {
-    if (!dbuffer_can_read(buffers, 4)) {
-        return false;
-    }
-
-    uint8_t tmp[4];
-    dbuffer_read_bytes(buffers, tmp, 4);
-    if (endianness == BE)
-        *out = read_u32_be(tmp, 0);
-    else
-        *out = read_u32_le(tmp, 0);
-    return true;
-}
-
-bool dbuffer_read_varint(buffer_t *buffers[2], uint64_t *out) {
-    if (!dbuffer_can_read(buffers, 1)) {
-        return false;
-    }
-
-    // peek the first byte without changing the offsets
-    uint8_t first_byte = buffer_can_read(buffers[0], 1) ? buffers[0]->ptr[buffers[0]->offset]
-                                                        : buffers[1]->ptr[buffers[1]->offset];
-    uint8_t len;  // length excluding the prefix
-    switch (first_byte) {
-        case 0xfd:
-            len = 2;
-            break;
-        case 0xfe:
-            len = 4;
-            break;
-        case 0xff:
-            len = 8;
-            break;
-        default:
-            len = 0;
-            break;
-    }
-
-    if (!dbuffer_can_read(buffers, 1 + len)) {
-        return false;
-    }
-
-    dbuffer_read_u8(buffers, &first_byte);  // redundant, just to skip 1 byte
-
-    if (first_byte <= 0xfc) {
-        *out = first_byte;
-        return true;
-    }
-
-    uint8_t data[8] = {0};
-    dbuffer_read_bytes(buffers, data, len);
-
-    // Since data was zeroed, parsing the entire array as a little-endian works for any size
-    *out = read_u64_le(data, 0);
-    return true;
-}
-
-bool parser_consolidate_buffers(buffer_t *buffers[2], size_t max_size) {
-    size_t length0 = buffers[0]->size - buffers[0]->offset;
-    size_t length1 = buffers[1]->size - buffers[1]->offset;
-    if (length0 + length1 > max_size) {
-        return false;
-    }
-
-    memmove(buffers[0]->ptr, buffers[0]->ptr + buffers[0]->offset, length0);
-    memmove(buffers[0]->ptr + length0, buffers[1]->ptr + buffers[1]->offset, length1);
-    buffers[0]->offset = 0;
-    buffers[0]->size = length0 + length1;
-    return true;
-}
-
-int parser_run(const parsing_step_t *parsing_steps,
-               size_t n_steps,
-               parser_context_t *parser_context,
-               buffer_t *buffers[2],
-               void *(*pic_fn)(void *) ) {
-    while (parser_context->cur_step < n_steps) {
-        parsing_step_t step_fn =
-            pic_fn != NULL ? (parsing_step_t) pic_fn(parsing_steps[parser_context->cur_step])
-                           : parsing_steps[parser_context->cur_step];
-
-        int step_result = step_fn(parser_context->state, buffers);
-
-        if (step_result <= 0) {
-            // Either error, or parsing incomplete and more data is needed
-            return step_result;
-        } else {
-            // continue with the next step
-            ++parser_context->cur_step;
-        }
-    }
-    return 1;
-}
diff --git a/src/common/parser.h b/src/common/parser.h
deleted file mode 100644
index f6aebea..0000000
--- a/src/common/parser.h
+++ /dev/null
@@ -1,86 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-#include <string.h>
-#include "buffer.h"
-
-typedef struct {
-    size_t cur_step;
-    void *state;  // subtyped for each specific parser
-} parser_context_t;
-
-/**
- * A parsing step gets a pointer to the parser's state, and an array of two pointers to buffers. The
- * concatenation o the two buffer is the (possibly incomplete) data to be parsed. The parsing step
- * returns -1 in case of parsing error (e.g.: invalid value was parsed); 1 if the parsing step is
- * completed successfully, 0 if more data is expected.
- * Any remaining data in the concatenation of the two buffers' remaining content must be passed in
- * the next call to the parser, that will continue from the same parsing step.
- */
-typedef int (*parsing_step_t)(void *, buffer_t *[2]);
-
-// Convenience functions to handle reading from the concatenation of two buffers.
-// All these functions are analogous to the corresponding buffer_read_X functions, but they exhaust
-// the first buffer before reading from the second buffer.
-
-/**
- * Get the total remaining length readable from this pair of buffers.
- * TODO: finish docs
- */
-size_t dbuffer_get_length(buffer_t *buffers[2]);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_can_read(buffer_t *buffers[2], size_t n);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_read_bytes(buffer_t *buffers[2], uint8_t *out, size_t n);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_read_u8(buffer_t *buffers[2], uint8_t *out);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_read_u16(buffer_t *buffers[2], uint16_t *out, endianness_t endianness);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_read_u32(buffer_t *buffers[2], uint32_t *out, endianness_t endianness);
-
-/**
- * TODO: docs.
- */
-bool dbuffer_read_varint(buffer_t *buffers[2], uint64_t *out);
-
-/**
- * TODO: docs.
- */
-static inline void parser_init_context(parser_context_t *parser_context, void *state) {
-    parser_context->cur_step = 0;
-    parser_context->state = state;
-}
-
-/**
- * Moves the concatenation of all the remaining bytes in the two buffers into the memory pointed by
- * the first buffer, as long as the number of remaining bytes is at most max_byte. The offset of the
- * first buffer is set to 0, and the new size reflects the total size
- *
- * Returns true on success; false if the total number of remaining bytes is larger than max_size.
- */
-bool parser_consolidate_buffers(buffer_t *buffers[2], size_t max_size);
-
-/**
- * TODO: docs
- */
-int parser_run(const parsing_step_t *parsing_steps,
-               size_t n_steps,
-               parser_context_t *parser_context,
-               buffer_t *buffers[2],
-               void *(*pic_fn)(void *) );
diff --git a/src/common/parser_ext.c b/src/common/parser_ext.c
new file mode 100644
index 0000000..0f54bab
--- /dev/null
+++ b/src/common/parser_ext.c
@@ -0,0 +1,148 @@
+#include <stdio.h>
+
+#include "parser_ext.h"
+
+/* SDK headers */
+#include "read.h"
+
+/* Local headers */
+#include "buffer_ext.h"
+
+size_t dbuffer_get_length(buffer_t *buffers[2]) {
+    return (buffers[0]->size - buffers[0]->offset) + (buffers[1]->size - buffers[1]->offset);
+}
+
+bool dbuffer_can_read(buffer_t *buffers[2], size_t n) {
+    return dbuffer_get_length(buffers) >= n;
+}
+
+bool dbuffer_read_bytes(buffer_t *buffers[2], uint8_t *out, size_t n) {
+    size_t length0 = buffers[0]->size - buffers[0]->offset;
+    size_t length1 = buffers[1]->size - buffers[1]->offset;
+    if (n > length0 + length1) {
+        return false;
+    }
+
+    size_t n0 = (length0 >= n) ? n : length0;  // bytes to read from first buffer
+    size_t n1 = n - n0;                        // bytes to read from second buffer
+
+    if (n0 > 0) {
+        buffer_read_bytes(buffers[0], out, n0);
+    }
+    if (n1 > 0) {
+        buffer_read_bytes(buffers[1], out + n0, n1);
+    }
+    return true;
+}
+
+bool dbuffer_read_u8(buffer_t *buffers[2], uint8_t *out) {
+    return dbuffer_read_bytes(buffers, out, 1);
+}
+
+bool dbuffer_read_u16(buffer_t *buffers[2], uint16_t *out, endianness_t endianness) {
+    if (!dbuffer_can_read(buffers, 2)) {
+        return false;
+    }
+
+    uint8_t tmp[2];
+    dbuffer_read_bytes(buffers, tmp, 2);
+    if (endianness == BE)
+        *out = read_u16_be(tmp, 0);
+    else
+        *out = read_u16_le(tmp, 0);
+    return true;
+}
+
+bool dbuffer_read_u32(buffer_t *buffers[2], uint32_t *out, endianness_t endianness) {
+    if (!dbuffer_can_read(buffers, 4)) {
+        return false;
+    }
+
+    uint8_t tmp[4];
+    dbuffer_read_bytes(buffers, tmp, 4);
+    if (endianness == BE)
+        *out = read_u32_be(tmp, 0);
+    else
+        *out = read_u32_le(tmp, 0);
+    return true;
+}
+
+bool dbuffer_read_varint(buffer_t *buffers[2], uint64_t *out) {
+    if (!dbuffer_can_read(buffers, 1)) {
+        return false;
+    }
+
+    // peek the first byte without changing the offsets
+    uint8_t first_byte = buffer_can_read(buffers[0], 1) ? buffers[0]->ptr[buffers[0]->offset]
+                                                        : buffers[1]->ptr[buffers[1]->offset];
+    uint8_t len;  // length excluding the prefix
+    switch (first_byte) {
+        case 0xfd:
+            len = 2;
+            break;
+        case 0xfe:
+            len = 4;
+            break;
+        case 0xff:
+            len = 8;
+            break;
+        default:
+            len = 0;
+            break;
+    }
+
+    if (!dbuffer_can_read(buffers, 1 + len)) {
+        return false;
+    }
+
+    dbuffer_read_u8(buffers, &first_byte);  // redundant, just to skip 1 byte
+
+    if (first_byte <= 0xfc) {
+        *out = first_byte;
+        return true;
+    }
+
+    uint8_t data[8] = {0};
+    dbuffer_read_bytes(buffers, data, len);
+
+    // Since data was zeroed, parsing the entire array as a little-endian works for any size
+    *out = read_u64_le(data, 0);
+    return true;
+}
+
+bool parser_consolidate_buffers(buffer_t *buffers[2], size_t max_size) {
+    size_t length0 = buffers[0]->size - buffers[0]->offset;
+    size_t length1 = buffers[1]->size - buffers[1]->offset;
+    if (length0 + length1 > max_size) {
+        return false;
+    }
+
+    memmove((uint8_t *) buffers[0]->ptr, buffers[0]->ptr + buffers[0]->offset, length0);
+    memmove((uint8_t *) buffers[0]->ptr + length0, buffers[1]->ptr + buffers[1]->offset, length1);
+    buffers[0]->offset = 0;
+    buffers[0]->size = length0 + length1;
+    return true;
+}
+
+int parser_run(const parsing_step_t *parsing_steps,
+               size_t n_steps,
+               parser_context_t *parser_context,
+               buffer_t *buffers[2],
+               void *(*pic_fn)(void *) ) {
+    while (parser_context->cur_step < n_steps) {
+        parsing_step_t step_fn =
+            pic_fn != NULL ? (parsing_step_t) pic_fn(parsing_steps[parser_context->cur_step])
+                           : parsing_steps[parser_context->cur_step];
+
+        int step_result = step_fn(parser_context->state, buffers);
+
+        if (step_result <= 0) {
+            // Either error, or parsing incomplete and more data is needed
+            return step_result;
+        } else {
+            // continue with the next step
+            ++parser_context->cur_step;
+        }
+    }
+    return 1;
+}
diff --git a/src/common/parser_ext.h b/src/common/parser_ext.h
new file mode 100644
index 0000000..d7f6b94
--- /dev/null
+++ b/src/common/parser_ext.h
@@ -0,0 +1,88 @@
+#pragma once
+
+#include <stdint.h>
+#include <string.h>
+
+/* SDK headers */
+#include "buffer.h"
+
+typedef struct {
+    size_t cur_step;
+    void *state;  // subtyped for each specific parser
+} parser_context_t;
+
+/**
+ * A parsing step gets a pointer to the parser's state, and an array of two pointers to buffers. The
+ * concatenation o the two buffer is the (possibly incomplete) data to be parsed. The parsing step
+ * returns -1 in case of parsing error (e.g.: invalid value was parsed); 1 if the parsing step is
+ * completed successfully, 0 if more data is expected.
+ * Any remaining data in the concatenation of the two buffers' remaining content must be passed in
+ * the next call to the parser, that will continue from the same parsing step.
+ */
+typedef int (*parsing_step_t)(void *, buffer_t *[2]);
+
+// Convenience functions to handle reading from the concatenation of two buffers.
+// All these functions are analogous to the corresponding buffer_read_X functions, but they exhaust
+// the first buffer before reading from the second buffer.
+
+/**
+ * Get the total remaining length readable from this pair of buffers.
+ * TODO: finish docs
+ */
+size_t dbuffer_get_length(buffer_t *buffers[2]);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_can_read(buffer_t *buffers[2], size_t n);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_read_bytes(buffer_t *buffers[2], uint8_t *out, size_t n);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_read_u8(buffer_t *buffers[2], uint8_t *out);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_read_u16(buffer_t *buffers[2], uint16_t *out, endianness_t endianness);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_read_u32(buffer_t *buffers[2], uint32_t *out, endianness_t endianness);
+
+/**
+ * TODO: docs.
+ */
+bool dbuffer_read_varint(buffer_t *buffers[2], uint64_t *out);
+
+/**
+ * TODO: docs.
+ */
+static inline void parser_init_context(parser_context_t *parser_context, void *state) {
+    parser_context->cur_step = 0;
+    parser_context->state = state;
+}
+
+/**
+ * Moves the concatenation of all the remaining bytes in the two buffers into the memory pointed by
+ * the first buffer, as long as the number of remaining bytes is at most max_byte. The offset of the
+ * first buffer is set to 0, and the new size reflects the total size
+ *
+ * Returns true on success; false if the total number of remaining bytes is larger than max_size.
+ */
+bool parser_consolidate_buffers(buffer_t *buffers[2], size_t max_size);
+
+/**
+ * TODO: docs
+ */
+int parser_run(const parsing_step_t *parsing_steps,
+               size_t n_steps,
+               parser_context_t *parser_context,
+               buffer_t *buffers[2],
+               void *(*pic_fn)(void *) );
diff --git a/src/common/read.c b/src/common/read.c
deleted file mode 100644
index d170f37..0000000
--- a/src/common/read.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdint.h>  // uint*_t
-#include <stddef.h>  // size_t
-
-uint16_t read_u16_be(const uint8_t *ptr, size_t offset) {
-    return (uint16_t) ptr[offset + 0] << 8 |  //
-           (uint16_t) ptr[offset + 1] << 0;
-}
-
-uint32_t read_u32_be(const uint8_t *ptr, size_t offset) {
-    return (uint32_t) ptr[offset + 0] << 24 |  //
-           (uint32_t) ptr[offset + 1] << 16 |  //
-           (uint32_t) ptr[offset + 2] << 8 |   //
-           (uint32_t) ptr[offset + 3] << 0;
-}
-
-uint64_t read_u64_be(const uint8_t *ptr, size_t offset) {
-    return (uint64_t) ptr[offset + 0] << 56 |  //
-           (uint64_t) ptr[offset + 1] << 48 |  //
-           (uint64_t) ptr[offset + 2] << 40 |  //
-           (uint64_t) ptr[offset + 3] << 32 |  //
-           (uint64_t) ptr[offset + 4] << 24 |  //
-           (uint64_t) ptr[offset + 5] << 16 |  //
-           (uint64_t) ptr[offset + 6] << 8 |   //
-           (uint64_t) ptr[offset + 7] << 0;
-}
-
-uint16_t read_u16_le(const uint8_t *ptr, size_t offset) {
-    return (uint16_t) ptr[offset + 0] << 0 |  //
-           (uint16_t) ptr[offset + 1] << 8;
-}
-
-uint32_t read_u32_le(const uint8_t *ptr, size_t offset) {
-    return (uint32_t) ptr[offset + 0] << 0 |   //
-           (uint32_t) ptr[offset + 1] << 8 |   //
-           (uint32_t) ptr[offset + 2] << 16 |  //
-           (uint32_t) ptr[offset + 3] << 24;
-}
-
-uint64_t read_u64_le(const uint8_t *ptr, size_t offset) {
-    return (uint64_t) ptr[offset + 0] << 0 |   //
-           (uint64_t) ptr[offset + 1] << 8 |   //
-           (uint64_t) ptr[offset + 2] << 16 |  //
-           (uint64_t) ptr[offset + 3] << 24 |  //
-           (uint64_t) ptr[offset + 4] << 32 |  //
-           (uint64_t) ptr[offset + 5] << 40 |  //
-           (uint64_t) ptr[offset + 6] << 48 |  //
-           (uint64_t) ptr[offset + 7] << 56;
-}
diff --git a/src/common/read.h b/src/common/read.h
deleted file mode 100644
index 61cfa8c..0000000
--- a/src/common/read.h
+++ /dev/null
@@ -1,82 +0,0 @@
-#pragma once
-
-#include <stdint.h>  // uint*_t
-#include <stddef.h>  // size_t
-
-/**
- * Read 2 bytes as Big Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 2 bytes value read from buffer.
- *
- */
-uint16_t read_u16_be(const uint8_t *ptr, size_t offset);
-
-/**
- * Read 4 bytes as Big Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 4 bytes value read from buffer.
- *
- */
-uint32_t read_u32_be(const uint8_t *ptr, size_t offset);
-
-/**
- * Read 8 bytes as Big Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 8 bytes value read from buffer.
- *
- */
-uint64_t read_u64_be(const uint8_t *ptr, size_t offset);
-
-/**
- * Read 2 bytes as Little Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 2 bytes value read from buffer.
- *
- */
-uint16_t read_u16_le(const uint8_t *ptr, size_t offset);
-
-/**
- * Read 4 bytes as Little Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 4 bytes value read from buffer.
- *
- */
-uint32_t read_u32_le(const uint8_t *ptr, size_t offset);
-
-/**
- * Read 8 bytes as Little Endian from byte buffer.
- *
- * @param[in] ptr
- *   Pointer to byte buffer.
- * @param[in] offset
- *   Offset in the byte buffer.
- *
- * @return 8 bytes value read from buffer.
- *
- */
-uint64_t read_u64_le(const uint8_t *ptr, size_t offset);
diff --git a/src/common/script.c b/src/common/script.c
index ffcc8f1..cdac1c1 100644
--- a/src/common/script.c
+++ b/src/common/script.c
@@ -1,13 +1,17 @@
+#include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-#include <limits.h>
 
-#include "../common/bip32.h"
-#include "../common/buffer.h"
-#include "../common/read.h"
-#include "../common/script.h"
-#include "../common/segwit_addr.h"
+#include "script.h"
+
+/* SDK headers */
+#include "bip32.h"
+#include "buffer.h"
+#include "read.h"
+
+/* Local headers */
+#include "segwit_addr.h"
 
 #ifndef SKIP_FOR_CMOCKA
 #include "../crypto.h"
@@ -239,4 +243,4 @@ bool format_script(const uint8_t script[],
     return true;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/common/script.h b/src/common/script.h
index 793a942..0360098 100644
--- a/src/common/script.h
+++ b/src/common/script.h
@@ -1,8 +1,12 @@
 #pragma once
 
+#include <stdbool.h>
+
+/* SDK headers */
 #include "os.h"
 
-#include "../constants.h"
+/* Local headers */
+#include "constants.h"
 
 /** Script opcodes */
 // from bitcoin-core
@@ -255,4 +259,4 @@ int format_opscript_script(const uint8_t script[],
  */
 bool format_script(const uint8_t script[],
                    size_t script_len,
-                   char out[static MAX_OUTPUT_SCRIPT_DESC_SIZE]);
\ No newline at end of file
+                   char out[static MAX_OUTPUT_SCRIPT_DESC_SIZE]);
diff --git a/src/common/segwit_addr.c b/src/common/segwit_addr.c
index d54f59e..35ac18f 100644
--- a/src/common/segwit_addr.c
+++ b/src/common/segwit_addr.c
@@ -21,8 +21,8 @@
  * THE SOFTWARE.
  */
 #include <assert.h>
-#include <stdlib.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "segwit_addr.h"
diff --git a/src/common/varint.c b/src/common/varint.c
deleted file mode 100644
index 7087fb0..0000000
--- a/src/common/varint.c
+++ /dev/null
@@ -1,101 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdint.h>   // uint*_t
-#include <stddef.h>   // size_t
-#include <stdbool.h>  // bool
-
-#include "varint.h"
-#include "write.h"
-#include "read.h"
-
-uint8_t varint_size(uint64_t value) {
-    if (value <= 0xFC) {
-        return 1;
-    }
-
-    if (value <= UINT16_MAX) {
-        return 3;
-    }
-
-    if (value <= UINT32_MAX) {
-        return 5;
-    }
-
-    return 9;  // <= UINT64_MAX
-}
-
-int varint_read(const uint8_t *in, size_t in_len, uint64_t *value) {
-    if (in_len < 1) {
-        return -1;
-    }
-
-    uint8_t prefix = in[0];
-
-    if (prefix == 0xFD) {
-        if (in_len < 3) {
-            return -1;
-        }
-        *value = (uint64_t) read_u16_le(in, 1);
-        return 3;
-    }
-
-    if (prefix == 0xFE) {
-        if (in_len < 5) {
-            return -1;
-        }
-        *value = (uint64_t) read_u32_le(in, 1);
-        return 5;
-    }
-
-    if (prefix == 0xFF) {
-        if (in_len < 9) {
-            return -1;
-        }
-        *value = (uint64_t) read_u64_le(in, 1);
-        return 9;
-    }
-
-    *value = (uint64_t) prefix;  // prefix <= 0xFC
-
-    return 1;
-}
-
-int varint_write(uint8_t *out, size_t offset, uint64_t value) {
-    uint8_t varint_len = varint_size(value);
-
-    switch (varint_len) {
-        case 1:
-            out[offset] = (uint8_t) value;
-            break;
-        case 3:
-            out[offset++] = 0xFD;
-            write_u16_le(out, offset, (uint16_t) value);
-            break;
-        case 5:
-            out[offset++] = 0xFE;
-            write_u32_le(out, offset, (uint32_t) value);
-            break;
-        case 9:
-            out[offset++] = 0xFF;
-            write_u64_le(out, offset, (uint64_t) value);
-            break;
-        default:
-            return -1;
-    }
-
-    return varint_len;
-}
diff --git a/src/common/varint.h b/src/common/varint.h
deleted file mode 100644
index 6cb263d..0000000
--- a/src/common/varint.h
+++ /dev/null
@@ -1,54 +0,0 @@
-#pragma once
-
-#include <stdint.h>   // uint*_t
-#include <stddef.h>   // size_t
-#include <stdbool.h>  // bool
-
-// TODO: write unit tests
-
-/**
- * Size of value represented as Bitcoin-like varint.
- *
- * @see https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer
- *
- * @param[in] value
- *   64-bit unsigned integer to compute varint size.
- *
- * @return number of bytes to write value as varint (1, 3, 5 or 9 bytes).
- *
- */
-uint8_t varint_size(uint64_t value);
-
-/**
- * Read Bitcoin-like varint from byte buffer.
- *
- * @see https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer
- *
- * @param[in]  in
- *   Pointer to input byte buffer.
- * @param[in]  in_len
- *   Length of the input byte buffer.
- * @param[out] value
- *   Pointer to 64-bit unsigned integer to output varint.
- *
- * @return number of bytes read (1, 3, 5 or 9 bytes), -1 otherwise.
- *
- */
-int varint_read(const uint8_t *in, size_t in_len, uint64_t *value);
-
-/**
- * Write Bitcoin-like varint to byte buffer.
- *
- * @see https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer
- *
- * @param[out] out
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   64-bit unsigned integer to write as varint.
- *
- * @return number of bytes written (1, 3, 5 or 9 bytes), -1 otherwise.
- *
- */
-int varint_write(uint8_t *out, size_t offset, uint64_t value);
diff --git a/src/common/wallet.c b/src/common/wallet.c
index 1f9434d..56a9f63 100644
--- a/src/common/wallet.c
+++ b/src/common/wallet.c
@@ -1,17 +1,20 @@
+#include <limits.h>
 #include <stdint.h>
 #include <string.h>
-#include <limits.h>
 
-#include "../common/base58.h"
-#include "../common/bip32.h"
-#include "../common/buffer.h"
-#include "../common/script.h"
-#include "../common/segwit_addr.h"
-#include "../common/wallet.h"
+#include "wallet.h"
 
-#include "../boilerplate/sw.h"
+/* SDK headers */
+#include "base58.h"
+#include "bip32.h"
+#include "buffer.h"
 
-#include "../debug-helpers/debug.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "debug.h"
+#include "script.h"
+#include "segwit_addr.h"
+#include "sw.h"
 
 #ifndef SKIP_FOR_CMOCKA
 #include "../crypto.h"
diff --git a/src/common/wallet.h b/src/common/wallet.h
index 77b389f..605bcd0 100644
--- a/src/common/wallet.h
+++ b/src/common/wallet.h
@@ -1,14 +1,16 @@
 #pragma once
 
-#include <stdint.h>
 #include <assert.h>
+#include <stdint.h>
 
+/* SDK headers */
+#include "bip32.h"
+#include "buffer.h"
 #include "ledger_assert.h"
 
-#include "common/bip32.h"
-#include "common/buffer.h"
-#include "../constants.h"
-#include "../crypto.h"
+/* Local headers */
+#include "constants.h"
+#include "crypto.h"
 
 #ifndef SKIP_FOR_CMOCKA
 #include "os.h"
diff --git a/src/common/write.c b/src/common/write.c
deleted file mode 100644
index 3ab47d8..0000000
--- a/src/common/write.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/*****************************************************************************
- *   (c) 2025 Ledger SAS.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *****************************************************************************/
-
-#include <stdint.h>  // uint*_t
-#include <stddef.h>  // size_t
-
-void write_u16_be(uint8_t *ptr, size_t offset, uint16_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 8);
-    ptr[offset + 1] = (uint8_t) (value >> 0);
-}
-
-void write_u32_be(uint8_t *ptr, size_t offset, uint32_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 24);
-    ptr[offset + 1] = (uint8_t) (value >> 16);
-    ptr[offset + 2] = (uint8_t) (value >> 8);
-    ptr[offset + 3] = (uint8_t) (value >> 0);
-}
-
-void write_u64_be(uint8_t *ptr, size_t offset, uint64_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 56);
-    ptr[offset + 1] = (uint8_t) (value >> 48);
-    ptr[offset + 2] = (uint8_t) (value >> 40);
-    ptr[offset + 3] = (uint8_t) (value >> 32);
-    ptr[offset + 4] = (uint8_t) (value >> 24);
-    ptr[offset + 5] = (uint8_t) (value >> 16);
-    ptr[offset + 6] = (uint8_t) (value >> 8);
-    ptr[offset + 7] = (uint8_t) (value >> 0);
-}
-
-void write_u16_le(uint8_t *ptr, size_t offset, uint16_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 0);
-    ptr[offset + 1] = (uint8_t) (value >> 8);
-}
-
-void write_u32_le(uint8_t *ptr, size_t offset, uint32_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 0);
-    ptr[offset + 1] = (uint8_t) (value >> 8);
-    ptr[offset + 2] = (uint8_t) (value >> 16);
-    ptr[offset + 3] = (uint8_t) (value >> 24);
-}
-
-void write_u64_le(uint8_t *ptr, size_t offset, uint64_t value) {
-    ptr[offset + 0] = (uint8_t) (value >> 0);
-    ptr[offset + 1] = (uint8_t) (value >> 8);
-    ptr[offset + 2] = (uint8_t) (value >> 16);
-    ptr[offset + 3] = (uint8_t) (value >> 24);
-    ptr[offset + 4] = (uint8_t) (value >> 32);
-    ptr[offset + 5] = (uint8_t) (value >> 40);
-    ptr[offset + 6] = (uint8_t) (value >> 48);
-    ptr[offset + 7] = (uint8_t) (value >> 56);
-}
diff --git a/src/common/write.h b/src/common/write.h
deleted file mode 100644
index 0418f5c..0000000
--- a/src/common/write.h
+++ /dev/null
@@ -1,82 +0,0 @@
-#pragma once
-
-#include <stdint.h>  // uint*_t
-#include <stddef.h>  // size_t
-
-/**
- * Write 16-bit unsigned integer value as Big Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   16-bit unsigned integer to write in output byte buffer as Big Endian.
- *
- */
-void write_u16_be(const uint8_t *ptr, size_t offset, uint16_t value);
-
-/**
- * Write 32-bit unsigned integer value as Big Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   32-bit unsigned integer to write in output byte buffer as Big Endian.
- *
- */
-void write_u32_be(uint8_t *ptr, size_t offset, uint32_t value);
-
-/**
- * Write 64-bit unsigned integer value as Big Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   64-bit unsigned integer to write in output byte buffer as Big Endian.
- *
- */
-void write_u64_be(uint8_t *ptr, size_t offset, uint64_t value);
-
-/**
- * Write 16-bit unsigned integer value as Little Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   16-bit unsigned integer to write in output byte buffer as Little Endian.
- *
- */
-void write_u16_le(uint8_t *ptr, size_t offset, uint16_t value);
-
-/**
- * Write 32-bit unsigned integer value as Little Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   32-bit unsigned integer to write in output byte buffer as Little Endian.
- *
- */
-void write_u32_le(uint8_t *ptr, size_t offset, uint32_t value);
-
-/**
- * Write 64-bit unsigned integer value as Little Endian.
- *
- * @param[out] ptr
- *   Pointer to output byte buffer.
- * @param[in]  offset
- *   Offset in the output byte buffer.
- * @param[in]  value
- *   64-bit unsigned integer to write in output byte buffer as Little Endian.
- *
- */
-void write_u64_le(uint8_t *ptr, size_t offset, uint64_t value);
diff --git a/src/constants.h b/src/constants.h
index ad9aa0a..352be68 100644
--- a/src/constants.h
+++ b/src/constants.h
@@ -1,10 +1,23 @@
 #pragma once
 
+/* SDK headers */
+#include "bip32.h"
+
 /**
  * Instruction class of the Bitcoin application.
  */
 #define CLA_APP 0xE1
 
+/**
+ * APDU instruction class for command defined by the framework.
+ */
+#define CLA_FRAMEWORK 0xF8
+
+/**
+ * Framework instruction to continue execution after an interruption.
+ */
+#define INS_CONTINUE 0x01
+
 /**
  * Encodes the protocol version, which is passed in the p2 field of APDUs.
  */
@@ -81,3 +94,30 @@
 #define MAX_STANDARD_P2WSH_STACK_ITEMS 100U
 #define MAX_STANDARD_P2WSH_SCRIPT_SIZE 3600U
 #define MAX_OPS_PER_SCRIPT             201U
+
+
+/* BIP-32, BIP-44 and BIP-388 constants */
+/**
+ * Maximum length of BIP32 path supported.
+ * Note: BIP32 allows up to 256 derivation steps - but only 5 or 6 are used in most cases.
+ */
+#define MAX_BIP32_PATH_STEPS MAX_BIP32_PATH
+//#define MAX_BIP388_XPUB_DERIVATION_STEPS 8
+//#define MAX_BIP32_PATH_STEPS (MAX_BIP388_XPUB_DERIVATION_STEPS + 2)
+
+
+/**
+ * Maximum length of a string representing a BIP32 derivation path.
+ * Each step is up to 11 characters (10 decimal digits, plus the "hardened" symbol),
+ * and there is 1 separator before each step.
+ */
+#define MAX_SERIALIZED_BIP32_PATH_LENGTH (12 * MAX_BIP32_PATH_STEPS)
+
+/**
+ * Index of first hardened child according to BIP32; it can also be used as the bitmask for hardened
+ * children.
+ */
+#define BIP32_FIRST_HARDENED_CHILD 0x80000000
+
+#define MAX_BIP44_ACCOUNT_RECOMMENDED       100
+#define MAX_BIP44_ADDRESS_INDEX_RECOMMENDED 50000
diff --git a/src/crypto.c b/src/crypto.c
index fcca770..22b7b11 100644
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -15,32 +15,33 @@
  *  limitations under the License.
  *****************************************************************************/
 
-#include <stdint.h>   // uint*_t
-#include <string.h>   // memset, explicit_bzero
-#include <stdbool.h>  // bool
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
 
-#include "os.h"
+#include "crypto.h"
+
+/* SDK headers */
+#include "base58.h"
+#include "bip32.h"
+#include "crypto_helpers.h"
 #include "cx.h"
-#include "cx_stubs.h"
 #include "cx_ecfp.h"
-#include "ox_ec.h"
 #include "cx_ram.h"
-#include "lcx_ripemd160.h"
 #include "cx_ripemd160.h"
-#include "lib_standard_app/crypto_helpers.h"
-
-#include "common/base58.h"
-#include "common/bip32.h"
-#include "common/format.h"
-#include "common/read.h"
-#include "common/write.h"
-
-#include "../boilerplate/sw.h"
-#include "../debug-helpers/debug.h"
-
-#include "crypto.h"
+#include "cx_stubs.h"
+#include "format.h"
+#include "lcx_ripemd160.h"
+#include "os.h"
+#include "ox_ec.h"
+#include "read.h"
+#include "write.h"
 
+/* Local headers */
+#include "constants.h"
+#include "debug.h"
 #include "secp256k1.h"
+#include "sw.h"
 
 /* BIP0341 tags for computing the tagged hashes when tweaking public keys */
 const uint8_t BIP0341_taptweak_tag[] = {'T', 'a', 'p', 'T', 'w', 'e', 'a', 'k'};
diff --git a/src/crypto.h b/src/crypto.h
index 9e24aee..4c41df0 100644
--- a/src/crypto.h
+++ b/src/crypto.h
@@ -4,13 +4,15 @@
 #include <stdint.h>
 #include <string.h>
 
-#include "os.h"
+/* SDK headers */
+#include "bip32.h"
 #include "cx.h"
-#include "constants.h"
+#include "os.h"
+#include "varint.h"
+#include "write.h"
 
-#include "./common/bip32.h"
-#include "./common/varint.h"
-#include "./common/write.h"
+/* Local headers */
+#include "constants.h"
 
 /**
  * A serialized extended pubkey according to BIP32 specifications.
diff --git a/src/debug-helpers/debug.c b/src/debug-helpers/debug.c
index d01f243..95db14d 100644
--- a/src/debug-helpers/debug.c
+++ b/src/debug-helpers/debug.c
@@ -1,5 +1,8 @@
-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
+
+
+/* Local headers */
 #include "printf.h"
 
 #pragma GCC diagnostic ignored "-Wunused-function"
diff --git a/src/debug-helpers/debug.h b/src/debug-helpers/debug.h
index 9966fbe..f327ee5 100644
--- a/src/debug-helpers/debug.h
+++ b/src/debug-helpers/debug.h
@@ -1,5 +1,6 @@
 #pragma once
 
+/* SDK headers */
 #include "os.h"
 
 void debug_write(const char *buf);
diff --git a/src/globals.h b/src/globals.h
index ede4e83..34e1b79 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -2,11 +2,13 @@
 
 #include <stdint.h>
 
+/* SDK headers */
 #include "ux.h"
 
-#include "boilerplate/io.h"
+/* Local headers */
 #include "commands.h"
 #include "constants.h"
+#include "io_ext.h"
 
 /**
  * Global buffer for interactions between SE and MCU.
diff --git a/src/handler/get_extended_pubkey.c b/src/handler/get_extended_pubkey.c
index 143ce98..9025cea 100644
--- a/src/handler/get_extended_pubkey.c
+++ b/src/handler/get_extended_pubkey.c
@@ -17,16 +17,19 @@
 
 #include <stdint.h>
 
-#include "boilerplate/io.h"
-#include "boilerplate/dispatcher.h"
-#include "boilerplate/sw.h"
-#include "../common/base58.h"
-#include "../common/bip32.h"
-#include "../commands.h"
-#include "../constants.h"
-#include "../crypto.h"
-#include "../ui/display.h"
-#include "../ui/menu.h"
+/* SDK headers */
+#include "base58.h"
+#include "bip32.h"
+
+/* Local headers */
+#include "commands.h"
+#include "constants.h"
+#include "crypto.h"
+#include "dispatcher.h"
+#include "display.h"
+#include "io_ext.h"
+#include "menu.h"
+#include "sw.h"
 
 #define H 0x80000000ul
 
@@ -124,9 +127,11 @@ void handler_get_extended_pubkey(dispatcher_context_t *dc, uint8_t protocol_vers
     }
 
     uint32_t bip32_path[MAX_BIP32_PATH_STEPS];
-    if (!buffer_read_bip32_path(&dc->read_buffer, bip32_path, bip32_path_len)) {
-        SEND_SW(dc, SW_WRONG_DATA_LENGTH);
-        return;
+    if (bip32_path_len > 0) {
+        if (!buffer_read_bip32_path(&dc->read_buffer, bip32_path, bip32_path_len)) {
+            SEND_SW(dc, SW_WRONG_DATA_LENGTH);
+            return;
+        }
     }
 
     bool is_safe = is_path_safe_for_pubkey_export(bip32_path, bip32_path_len);
diff --git a/src/handler/get_master_fingerprint.c b/src/handler/get_master_fingerprint.c
index 1a32842..2e18acc 100644
--- a/src/handler/get_master_fingerprint.c
+++ b/src/handler/get_master_fingerprint.c
@@ -17,14 +17,14 @@
 
 #include <stdint.h>
 
-#include "os_seed.h"
-
-#include "boilerplate/dispatcher.h"
-#include "boilerplate/sw.h"
-#include "../commands.h"
-#include "../crypto.h"
 
+/* Local headers */
+#include "commands.h"
+#include "crypto.h"
+#include "dispatcher.h"
 #include "handlers.h"
+#include "os_seed.h"
+#include "sw.h"
 
 void handler_get_master_fingerprint(dispatcher_context_t *dc, uint8_t protocol_version) {
     (void) protocol_version;
diff --git a/src/handler/get_wallet_address.c b/src/handler/get_wallet_address.c
index 7f7bb55..a9aeb65 100644
--- a/src/handler/get_wallet_address.c
+++ b/src/handler/get_wallet_address.c
@@ -17,32 +17,33 @@
 
 #include <stdint.h>
 
-#include "boilerplate/io.h"
-#include "boilerplate/sw.h"
-#include "../common/base58.h"
-#include "../common/bip32.h"
-#include "../common/buffer.h"
-#include "../common/merkle.h"
-#include "../common/read.h"
-#include "../common/script.h"
-#include "../common/segwit_addr.h"
-#include "../common/wallet.h"
-#include "../commands.h"
-#include "../constants.h"
-#include "../crypto.h"
-#include "../error_codes.h"
-#include "../ui/display.h"
-#include "../ui/menu.h"
-
-#include "../swap/swap_globals.h"
-#include "../swap/handle_swap_sign_transaction.h"
-
-#include "lib/policy.h"
-#include "lib/get_preimage.h"
-#include "lib/get_merkle_leaf_element.h"
-
-#include "handlers.h"
+/* SDK headers */
+#include "base58.h"
+#include "bip32.h"
+#include "buffer.h"
+#include "read.h"
+
+/* Local headers */
+#include "buffer_ext.h"
 #include "client_commands.h"
+#include "commands.h"
+#include "constants.h"
+#include "crypto.h"
+#include "display.h"
+#include "error_codes.h"
+#include "get_merkle_leaf_element.h"
+#include "get_preimage.h"
+#include "handle_swap_sign_transaction.h"
+#include "handlers.h"
+#include "io_ext.h"
+#include "menu.h"
+#include "merkle.h"
+#include "policy.h"
+#include "script.h"
+#include "segwit_addr.h"
+#include "sw.h"
+#include "swap_globals.h"
+#include "wallet.h"
 
 void handler_get_wallet_address(dispatcher_context_t *dc, uint8_t protocol_version) {
     UNUSED(protocol_version);
diff --git a/src/handler/handlers.h b/src/handler/handlers.h
index ad3d28d..5dbb536 100644
--- a/src/handler/handlers.h
+++ b/src/handler/handlers.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 void handler_get_extended_pubkey(dispatcher_context_t *dispatcher_context, uint8_t p2);
 void handler_get_master_fingerprint(dispatcher_context_t *dispatcher_context, uint8_t p2);
diff --git a/src/handler/lib/check_merkle_tree_sorted.c b/src/handler/lib/check_merkle_tree_sorted.c
index 3c1f16f..550dcb4 100644
--- a/src/handler/lib/check_merkle_tree_sorted.c
+++ b/src/handler/lib/check_merkle_tree_sorted.c
@@ -1,9 +1,11 @@
 #include <string.h>
 
 #include "check_merkle_tree_sorted.h"
-#include "get_merkle_leaf_element.h"
 
-#include "../../common/merkle.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "get_merkle_leaf_element.h"
+#include "merkle.h"
 
 static int compare_byte_arrays(const uint8_t array1[],
                                size_t array1_len,
@@ -76,4 +78,4 @@ static int compare_byte_arrays(const uint8_t array1[],
     }
 
     return memcmp_result;
-}
\ No newline at end of file
+}
diff --git a/src/handler/lib/check_merkle_tree_sorted.h b/src/handler/lib/check_merkle_tree_sorted.h
index 23f28d5..38a79ca 100644
--- a/src/handler/lib/check_merkle_tree_sorted.h
+++ b/src/handler/lib/check_merkle_tree_sorted.h
@@ -1,8 +1,10 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
-#include "../../common/wallet.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
+#include "wallet.h"
 
 // this flow aborts if any element is larger than this size
 // TODO: we might remove this limitation altogether with a more careful implementation.
diff --git a/src/handler/lib/get_merkle_leaf_element.c b/src/handler/lib/get_merkle_leaf_element.c
index 5ab4b04..f29dcb5 100644
--- a/src/handler/lib/get_merkle_leaf_element.c
+++ b/src/handler/lib/get_merkle_leaf_element.c
@@ -1,5 +1,6 @@
 #include "get_merkle_leaf_element.h"
 
+/* Local headers */
 #include "get_merkle_leaf_hash.h"
 #include "get_merkle_preimage.h"
 
diff --git a/src/handler/lib/get_merkle_leaf_element.h b/src/handler/lib/get_merkle_leaf_element.h
index f11429a..4979e7e 100644
--- a/src/handler/lib/get_merkle_leaf_element.h
+++ b/src/handler/lib/get_merkle_leaf_element.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * TODO: docs
diff --git a/src/handler/lib/get_merkle_leaf_hash.c b/src/handler/lib/get_merkle_leaf_hash.c
index ca7acfd..183e14d 100644
--- a/src/handler/lib/get_merkle_leaf_hash.c
+++ b/src/handler/lib/get_merkle_leaf_hash.c
@@ -2,14 +2,17 @@
 
 #include "get_merkle_leaf_hash.h"
 
-#include "../../common/buffer.h"
-#include "../../common/write.h"
-#include "../../common/merkle.h"
-#include "../../common/varint.h"
-#include "../../boilerplate/sw.h"
-#include "../client_commands.h"
-
-#include "../../debug-helpers/debug.h"
+/* SDK headers */
+#include "buffer.h"
+#include "varint.h"
+#include "write.h"
+
+/* Local headers */
+#include "buffer_ext.h"
+#include "client_commands.h"
+#include "debug.h"
+#include "merkle.h"
+#include "sw.h"
 
 // Reads the inputs and sends the GET_MERKLE_LEAF_PROOF request.
 int call_get_merkle_leaf_hash(dispatcher_context_t *dc,
diff --git a/src/handler/lib/get_merkle_leaf_hash.h b/src/handler/lib/get_merkle_leaf_hash.h
index 9a92e86..f6f6962 100644
--- a/src/handler/lib/get_merkle_leaf_hash.h
+++ b/src/handler/lib/get_merkle_leaf_hash.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * TODO: docs
diff --git a/src/handler/lib/get_merkle_leaf_index.c b/src/handler/lib/get_merkle_leaf_index.c
index 6689778..c9086e9 100644
--- a/src/handler/lib/get_merkle_leaf_index.c
+++ b/src/handler/lib/get_merkle_leaf_index.c
@@ -1,9 +1,10 @@
 #include <string.h>
 
-#include "../../boilerplate/sw.h"
-#include "get_merkle_leaf_hash.h"
 
-#include "../client_commands.h"
+/* Local headers */
+#include "client_commands.h"
+#include "get_merkle_leaf_hash.h"
+#include "sw.h"
 
 int call_get_merkle_leaf_index(dispatcher_context_t *dispatcher_context,
                                size_t size,
diff --git a/src/handler/lib/get_merkle_leaf_index.h b/src/handler/lib/get_merkle_leaf_index.h
index 64fa329..808e228 100644
--- a/src/handler/lib/get_merkle_leaf_index.h
+++ b/src/handler/lib/get_merkle_leaf_index.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * TODO: docs
diff --git a/src/handler/lib/get_merkle_preimage.c b/src/handler/lib/get_merkle_preimage.c
index 6795208..2f03645 100644
--- a/src/handler/lib/get_merkle_preimage.c
+++ b/src/handler/lib/get_merkle_preimage.c
@@ -2,12 +2,15 @@
 
 #include "get_merkle_preimage.h"
 
-#include "../../boilerplate/sw.h"
-#include "../../common/buffer.h"
-#include "../../crypto.h"
-#include "../client_commands.h"
+/* SDK headers */
+#include "buffer.h"
 
-#include "../../debug-helpers/debug.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "client_commands.h"
+#include "crypto.h"
+#include "debug.h"
+#include "sw.h"
 
 // TODO: refactor common code with stream_preimage.c
 
@@ -56,7 +59,7 @@ int call_get_merkle_preimage(dispatcher_context_t *dispatcher_context,
     }
 
     uint8_t *data_ptr =
-        dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        (uint8_t *) (dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset);
 
     cx_sha256_t hash_context;
 
@@ -97,7 +100,8 @@ int call_get_merkle_preimage(dispatcher_context_t *dispatcher_context,
             return -9;
         }
 
-        data_ptr = dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        data_ptr = (uint8_t *) dispatcher_context->read_buffer.ptr +
+                   dispatcher_context->read_buffer.offset;
 
         // update hash
         crypto_hash_update(&hash_context.header, data_ptr, n_bytes);
@@ -118,4 +122,4 @@ int call_get_merkle_preimage(dispatcher_context_t *dispatcher_context,
     }
 
     return (int) (preimage_len - 1);
-}
\ No newline at end of file
+}
diff --git a/src/handler/lib/get_merkle_preimage.h b/src/handler/lib/get_merkle_preimage.h
index 0ba7ea2..c1d3519 100644
--- a/src/handler/lib/get_merkle_preimage.h
+++ b/src/handler/lib/get_merkle_preimage.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * In this flow, the HWW sends a CCMD_GET_PREIMAGE command with a SHA256 hash.
diff --git a/src/handler/lib/get_merkleized_map.c b/src/handler/lib/get_merkleized_map.c
index 1e6e7a9..f11ae5b 100644
--- a/src/handler/lib/get_merkleized_map.c
+++ b/src/handler/lib/get_merkleized_map.c
@@ -2,10 +2,13 @@
 
 #include "get_merkleized_map.h"
 
-#include "get_merkle_leaf_element.h"
-#include "check_merkle_tree_sorted.h"
+/* SDK headers */
+#include "buffer.h"
 
-#include "../../common/buffer.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "check_merkle_tree_sorted.h"
+#include "get_merkle_leaf_element.h"
 
 int call_get_merkleized_map_with_callback(dispatcher_context_t *dispatcher_context,
                                           void *callback_state,
@@ -42,4 +45,4 @@ int call_get_merkleized_map_with_callback(dispatcher_context_t *dispatcher_conte
                                                        out_ptr->size,
                                                        callback,
                                                        out_ptr);
-}
\ No newline at end of file
+}
diff --git a/src/handler/lib/get_merkleized_map.h b/src/handler/lib/get_merkleized_map.h
index c3ed69e..6e4119f 100644
--- a/src/handler/lib/get_merkleized_map.h
+++ b/src/handler/lib/get_merkleized_map.h
@@ -1,9 +1,10 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
 
+/* Local headers */
 #include "check_merkle_tree_sorted.h"
+#include "dispatcher.h"
+#include "merkle.h"
 
 /**
  * TODO: docs
diff --git a/src/handler/lib/get_merkleized_map_value.c b/src/handler/lib/get_merkleized_map_value.c
index f9baf2f..039c2e5 100644
--- a/src/handler/lib/get_merkleized_map_value.c
+++ b/src/handler/lib/get_merkleized_map_value.c
@@ -2,8 +2,9 @@
 
 #include "get_merkleized_map_value.h"
 
-#include "get_merkle_leaf_index.h"
+/* Local headers */
 #include "get_merkle_leaf_element.h"
+#include "get_merkle_leaf_index.h"
 
 int call_get_merkleized_map_value(dispatcher_context_t *dispatcher_context,
                                   const merkleized_map_commitment_t *map,
diff --git a/src/handler/lib/get_merkleized_map_value.h b/src/handler/lib/get_merkleized_map_value.h
index b7a6aa0..68d5dd4 100644
--- a/src/handler/lib/get_merkleized_map_value.h
+++ b/src/handler/lib/get_merkleized_map_value.h
@@ -1,8 +1,11 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
-#include "../../common/read.h"
+/* SDK headers */
+#include "read.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
 
 /**
  * Given a commitment to a merkleized key-value map, this flow finds out the index of the element
@@ -42,4 +45,4 @@ static inline int call_get_merkleized_map_value_u32_le(dispatcher_context_t *dis
     *out = read_u32_le(result_raw, 0);
 
     return 4;
-}
\ No newline at end of file
+}
diff --git a/src/handler/lib/get_merkleized_map_value_hash.c b/src/handler/lib/get_merkleized_map_value_hash.c
index 29ee4b0..ea1881f 100644
--- a/src/handler/lib/get_merkleized_map_value_hash.c
+++ b/src/handler/lib/get_merkleized_map_value_hash.c
@@ -2,6 +2,7 @@
 
 #include "get_merkleized_map_value_hash.h"
 
+/* Local headers */
 #include "get_merkle_leaf_hash.h"
 #include "get_merkle_leaf_index.h"
 
diff --git a/src/handler/lib/get_merkleized_map_value_hash.h b/src/handler/lib/get_merkleized_map_value_hash.h
index db1ca4c..3213413 100644
--- a/src/handler/lib/get_merkleized_map_value_hash.h
+++ b/src/handler/lib/get_merkleized_map_value_hash.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
 
 /**
  * Given a commitment to a merkleized key-value map, this flow finds out the index of the element
diff --git a/src/handler/lib/get_preimage.c b/src/handler/lib/get_preimage.c
index b5f5f5c..733a7ae 100644
--- a/src/handler/lib/get_preimage.c
+++ b/src/handler/lib/get_preimage.c
@@ -1,10 +1,12 @@
 #include <string.h>
 
-#include "../../boilerplate/sw.h"
-#include "stream_preimage.h"
 
-#include "../../crypto.h"
-#include "../client_commands.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "client_commands.h"
+#include "crypto.h"
+#include "stream_preimage.h"
+#include "sw.h"
 
 int call_get_preimage(dispatcher_context_t *dispatcher_context,
                       const uint8_t hash[static 32],
@@ -46,7 +48,7 @@ int call_get_preimage(dispatcher_context_t *dispatcher_context,
     buffer_t buffer_out = buffer_create(out, out_len);
 
     uint8_t *data_ptr =
-        dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        (uint8_t *) (dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset);
 
     cx_sha256_t hash_context;
     cx_sha256_init(&hash_context);
@@ -86,7 +88,8 @@ int call_get_preimage(dispatcher_context_t *dispatcher_context,
             return -8;
         }
 
-        data_ptr = dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        data_ptr = (uint8_t *) (dispatcher_context->read_buffer.ptr +
+                                dispatcher_context->read_buffer.offset);
 
         // update hash
         crypto_hash_update(&hash_context.header, data_ptr, n_bytes);
diff --git a/src/handler/lib/get_preimage.h b/src/handler/lib/get_preimage.h
index f748c1c..627a5b4 100644
--- a/src/handler/lib/get_preimage.h
+++ b/src/handler/lib/get_preimage.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * Given a sha256 hash, requests the corresponding pre-image to the host.
diff --git a/src/handler/lib/policy.c b/src/handler/lib/policy.c
index cc93be6..5e3eaac 100644
--- a/src/handler/lib/policy.c
+++ b/src/handler/lib/policy.c
@@ -2,20 +2,22 @@
 
 #include "policy.h"
 
-#include "../lib/get_merkle_leaf_element.h"
-#include "../lib/get_preimage.h"
-#include "../../crypto.h"
-#include "../../musig/musig.h"
-#include "../../common/base58.h"
-#include "../../common/bitvector.h"
-#include "../../common/read.h"
-#include "../../common/script.h"
-#include "../../common/segwit_addr.h"
-#include "../../common/wallet.h"
-
-#include "../../debug-helpers/debug.h"
-
+/* SDK headers */
+#include "base58.h"
 #include "ledger_assert.h"
+#include "read.h"
+
+/* Local headers */
+#include "bitvector.h"
+#include "buffer_ext.h"
+#include "crypto.h"
+#include "debug.h"
+#include "get_merkle_leaf_element.h"
+#include "get_preimage.h"
+#include "musig.h"
+#include "script.h"
+#include "segwit_addr.h"
+#include "wallet.h"
 
 #define MAX_POLICY_DEPTH 10
 
diff --git a/src/handler/lib/policy.h b/src/handler/lib/policy.h
index e5cd241..b1c5a22 100644
--- a/src/handler/lib/policy.h
+++ b/src/handler/lib/policy.h
@@ -1,8 +1,10 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/wallet.h"
-#include "../../handler/sign_psbt/sign_psbt_cache.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "sign_psbt_cache.h"
+#include "wallet.h"
 
 /**
  * Parses a serialized wallet policy, saving the wallet header, the policy map descriptor and the
diff --git a/src/handler/lib/psbt_parse_rawtx.c b/src/handler/lib/psbt_parse_rawtx.c
index d0c0ee4..05808eb 100644
--- a/src/handler/lib/psbt_parse_rawtx.c
+++ b/src/handler/lib/psbt_parse_rawtx.c
@@ -1,21 +1,22 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "cx.h"
-
 #include "psbt_parse_rawtx.h"
 
+/* SDK headers */
+#include "buffer.h"
+#include "cx.h"
+#include "read.h"
+#include "varint.h"
+
+/* Local headers */
+#include "buffer_ext.h"
+#include "crypto.h"
+#include "dispatcher.h"
 #include "get_merkleized_map_value_hash.h"
+#include "parser_ext.h"
 #include "stream_preimage.h"
-
-#include "../../boilerplate/dispatcher.h"
-#include "../../boilerplate/sw.h"
-
-#include "../../common/buffer.h"
-#include "../../common/parser.h"
-#include "../../common/read.h"
-#include "../../common/varint.h"
-#include "../../crypto.h"
+#include "sw.h"
 
 struct parse_rawtx_state_s;  // forward declaration
 
diff --git a/src/handler/lib/psbt_parse_rawtx.h b/src/handler/lib/psbt_parse_rawtx.h
index 21082ae..daeb92f 100644
--- a/src/handler/lib/psbt_parse_rawtx.h
+++ b/src/handler/lib/psbt_parse_rawtx.h
@@ -1,8 +1,10 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
-#include "../../constants.h"
+
+/* Local headers */
+#include "constants.h"
+#include "dispatcher.h"
+#include "merkle.h"
 
 typedef struct {
     uint64_t vout_value;                 // will contain the value of the requested output
diff --git a/src/handler/lib/stream_merkle_leaf_element.c b/src/handler/lib/stream_merkle_leaf_element.c
index 751e0b0..ce21ced 100644
--- a/src/handler/lib/stream_merkle_leaf_element.c
+++ b/src/handler/lib/stream_merkle_leaf_element.c
@@ -1,6 +1,7 @@
 
 #include "stream_merkle_leaf_element.h"
 
+/* Local headers */
 #include "get_merkle_leaf_hash.h"
 #include "stream_preimage.h"
 
diff --git a/src/handler/lib/stream_merkle_leaf_element.h b/src/handler/lib/stream_merkle_leaf_element.h
index 638650e..ba2872a 100644
--- a/src/handler/lib/stream_merkle_leaf_element.h
+++ b/src/handler/lib/stream_merkle_leaf_element.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
 
 /**
  * This flow obtains and streams to the callback the preimage of a leaf of a Merkle tree, specified
diff --git a/src/handler/lib/stream_merkleized_map_value.c b/src/handler/lib/stream_merkleized_map_value.c
index 0c7c44a..f5d79b5 100644
--- a/src/handler/lib/stream_merkleized_map_value.c
+++ b/src/handler/lib/stream_merkleized_map_value.c
@@ -1,4 +1,6 @@
 #include "stream_merkleized_map_value.h"
+
+/* Local headers */
 #include "get_merkle_leaf_index.h"
 #include "stream_merkle_leaf_element.h"
 
diff --git a/src/handler/lib/stream_merkleized_map_value.h b/src/handler/lib/stream_merkleized_map_value.h
index b1f6f6f..4c77954 100644
--- a/src/handler/lib/stream_merkleized_map_value.h
+++ b/src/handler/lib/stream_merkleized_map_value.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
 
 /**
  * Given a commitment to a merkleized key-value map, this flow find out the index of the
diff --git a/src/handler/lib/stream_preimage.c b/src/handler/lib/stream_preimage.c
index cd6a0c7..09f8990 100644
--- a/src/handler/lib/stream_preimage.c
+++ b/src/handler/lib/stream_preimage.c
@@ -1,10 +1,12 @@
 #include <string.h>
 
-#include "../../boilerplate/sw.h"
 #include "stream_preimage.h"
 
-#include "../../crypto.h"
-#include "../client_commands.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "client_commands.h"
+#include "crypto.h"
+#include "sw.h"
 
 int call_stream_preimage(dispatcher_context_t *dispatcher_context,
                          const uint8_t hash[static 32],
@@ -49,7 +51,7 @@ int call_stream_preimage(dispatcher_context_t *dispatcher_context,
     }
 
     uint8_t *data_ptr =
-        dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        (uint8_t *) (dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset);
 
     cx_sha256_t hash_context;
     cx_sha256_init(&hash_context);
@@ -90,7 +92,8 @@ int call_stream_preimage(dispatcher_context_t *dispatcher_context,
             return -8;
         }
 
-        data_ptr = dispatcher_context->read_buffer.ptr + dispatcher_context->read_buffer.offset;
+        data_ptr = (uint8_t *) dispatcher_context->read_buffer.ptr +
+                   dispatcher_context->read_buffer.offset;
 
         // update hash
         crypto_hash_update(&hash_context.header, data_ptr, n_bytes);
diff --git a/src/handler/lib/stream_preimage.h b/src/handler/lib/stream_preimage.h
index 8f57115..fb9b28f 100644
--- a/src/handler/lib/stream_preimage.h
+++ b/src/handler/lib/stream_preimage.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
+
+/* Local headers */
+#include "dispatcher.h"
 
 /**
  * Given the hash of a leaf of a Merkle tree, requests the corresponding pre-image to the host. The
diff --git a/src/handler/register_wallet.c b/src/handler/register_wallet.c
index 3339fc4..5a7b5d1 100644
--- a/src/handler/register_wallet.c
+++ b/src/handler/register_wallet.c
@@ -18,31 +18,30 @@
 #include <stdint.h>
 #include <string.h>
 
-#include "os.h"
+/* SDK headers */
+#include "bip32.h"
 #include "cx.h"
+#include "os.h"
+#include "read.h"
+#include "write.h"
 
-#include "../boilerplate/dispatcher.h"
-#include "../boilerplate/sw.h"
-#include "../common/bip32.h"
-#include "../common/merkle.h"
-#include "../common/read.h"
-#include "../common/wallet.h"
-#include "../common/write.h"
-
-#include "../commands.h"
-#include "../constants.h"
-#include "../crypto.h"
-#include "../error_codes.h"
-#include "../ui/display.h"
-#include "../ui/menu.h"
-
-#include "lib/get_merkle_leaf_element.h"
-#include "lib/get_preimage.h"
-#include "lib/policy.h"
-
+/* Local headers */
+#include "buffer_ext.h"
 #include "client_commands.h"
-
+#include "commands.h"
+#include "constants.h"
+#include "crypto.h"
+#include "dispatcher.h"
+#include "display.h"
+#include "error_codes.h"
+#include "get_merkle_leaf_element.h"
+#include "get_preimage.h"
 #include "handlers.h"
+#include "menu.h"
+#include "merkle.h"
+#include "policy.h"
+#include "sw.h"
+#include "wallet.h"
 
 static bool is_policy_acceptable(const policy_node_t *policy);
 static bool is_policy_name_acceptable(const char *name, size_t name_len);
diff --git a/src/handler/sign_message.c b/src/handler/sign_message.c
index 159f9a4..d4e4786 100644
--- a/src/handler/sign_message.c
+++ b/src/handler/sign_message.c
@@ -17,18 +17,21 @@
 
 #include <stdint.h>
 
-#include "boilerplate/io.h"
-#include "boilerplate/dispatcher.h"
-#include "boilerplate/sw.h"
-#include "../common/bip32.h"
-#include "../commands.h"
-#include "../constants.h"
-#include "../crypto.h"
-#include "../ui/display.h"
-#include "../ui/menu.h"
-#include "lib/get_merkle_leaf_element.h"
-
+/* SDK headers */
+#include "bip32.h"
+
+/* Local headers */
+#include "buffer_ext.h"
+#include "commands.h"
+#include "constants.h"
+#include "crypto.h"
+#include "dispatcher.h"
+#include "display.h"
+#include "get_merkle_leaf_element.h"
 #include "handlers.h"
+#include "io_ext.h"
+#include "menu.h"
+#include "sw.h"
 
 extern const char GA_LOADING_MESSAGE[];
 
diff --git a/src/handler/sign_psbt.c b/src/handler/sign_psbt.c
index 865d41f..3cad8be 100644
--- a/src/handler/sign_psbt.c
+++ b/src/handler/sign_psbt.c
@@ -18,50 +18,48 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-#include "lib_standard_app/crypto_helpers.h"
-
-#include "../boilerplate/dispatcher.h"
-#include "../boilerplate/sw.h"
-#include "../common/bitvector.h"
-#include "../common/merkle.h"
-#include "../common/psbt.h"
-#include "../common/read.h"
-#include "../common/script.h"
-#include "../common/varint.h"
-#include "../common/wallet.h"
-#include "../common/write.h"
-
-#include "../commands.h"
-#include "../constants.h"
-#include "../crypto.h"
-#include "../error_codes.h"
-#include "../ui/display.h"
-#include "../ui/menu.h"
+#include "sign_psbt.h"
 
+/* SDK headers */
+#include "crypto_helpers.h"
+#include "read.h"
+#include "varint.h"
+#include "write.h"
+
+/* Local headers */
+#include "amount_from_psbt.h"
+#include "bitvector.h"
+#include "buffer_ext.h"
+#include "check_merkle_tree_sorted.h"
 #include "client_commands.h"
-
-#include "lib/policy.h"
-#include "lib/check_merkle_tree_sorted.h"
-#include "lib/get_preimage.h"
-#include "lib/get_merkleized_map.h"
-#include "lib/get_merkleized_map_value.h"
-#include "lib/get_merkle_leaf_element.h"
-#include "lib/psbt_parse_rawtx.h"
-
+#include "commands.h"
+#include "compare_wallet_script_at_path.h"
+#include "constants.h"
+#include "crypto.h"
+#include "dispatcher.h"
+#include "display.h"
+#include "error_codes.h"
+#include "extract_bip32_derivation.h"
+#include "get_merkle_leaf_element.h"
+#include "get_merkleized_map.h"
+#include "get_merkleized_map_value.h"
+#include "get_preimage.h"
+#include "handle_swap_sign_transaction.h"
 #include "handlers.h"
-#include "sign_psbt.h"
-
-#include "sign_psbt/amount_from_psbt.h"
-#include "sign_psbt/compare_wallet_script_at_path.h"
-#include "sign_psbt/extract_bip32_derivation.h"
-#include "sign_psbt/musig_signing.h"
-#include "sign_psbt/txhashes.h"
-#include "sign_psbt/sign_psbt_cache.h"
-
-#include "../swap/swap_globals.h"
-#include "../swap/handle_swap_sign_transaction.h"
-#include "../musig/musig.h"
-#include "../musig/musig_sessions.h"
+#include "menu.h"
+#include "merkle.h"
+#include "musig.h"
+#include "musig_sessions.h"
+#include "musig_signing.h"
+#include "policy.h"
+#include "psbt.h"
+#include "psbt_parse_rawtx.h"
+#include "script.h"
+#include "sign_psbt_cache.h"
+#include "sw.h"
+#include "swap_globals.h"
+#include "txhashes.h"
+#include "wallet.h"
 
 /*
 Current assumptions during signing:
diff --git a/src/handler/sign_psbt.h b/src/handler/sign_psbt.h
index 7373b50..7ef9d00 100644
--- a/src/handler/sign_psbt.h
+++ b/src/handler/sign_psbt.h
@@ -1,8 +1,10 @@
 #pragma once
 
-#include "../musig/musig_sessions.h"
-#include "../common/merkle.h"
-#include "../ui/display.h"
+
+/* Local headers */
+#include "display.h"
+#include "merkle.h"
+#include "musig_sessions.h"
 
 // common info that applies to either the current input or the current output
 typedef struct {
diff --git a/src/handler/sign_psbt/amount_from_psbt.c b/src/handler/sign_psbt/amount_from_psbt.c
index 15ae007..3b6ebcc 100644
--- a/src/handler/sign_psbt/amount_from_psbt.c
+++ b/src/handler/sign_psbt/amount_from_psbt.c
@@ -1,9 +1,9 @@
 #include "amount_from_psbt.h"
 
-#include "../../common/psbt.h"
-
-#include "../lib/get_merkleized_map_value.h"
-#include "../lib/psbt_parse_rawtx.h"
+/* Local headers */
+#include "get_merkleized_map_value.h"
+#include "psbt.h"
+#include "psbt_parse_rawtx.h"
 
 /*
  Convenience function to get the amount and scriptpubkey from the non-witness-utxo of a certain
diff --git a/src/handler/sign_psbt/amount_from_psbt.h b/src/handler/sign_psbt/amount_from_psbt.h
index 873b2a6..aa578f3 100644
--- a/src/handler/sign_psbt/amount_from_psbt.h
+++ b/src/handler/sign_psbt/amount_from_psbt.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../boilerplate/dispatcher.h"
-#include "../sign_psbt.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "sign_psbt.h"
 
 // These functions are used to extract the amount and scriptPubKey of an input from the witness-utxo
 // or the non-witness-utxo of a PSBTv2.
diff --git a/src/handler/sign_psbt/compare_wallet_script_at_path.c b/src/handler/sign_psbt/compare_wallet_script_at_path.c
index fffc008..2fa12e7 100644
--- a/src/handler/sign_psbt/compare_wallet_script_at_path.c
+++ b/src/handler/sign_psbt/compare_wallet_script_at_path.c
@@ -3,10 +3,12 @@
 
 #include "compare_wallet_script_at_path.h"
 
-#include "../lib/get_merkleized_map_value.h"
-#include "../lib/policy.h"
+/* SDK headers */
+#include "read.h"
 
-#include "../../common/read.h"
+/* Local headers */
+#include "get_merkleized_map_value.h"
+#include "policy.h"
 
 int compare_wallet_script_at_path(dispatcher_context_t *dispatcher_context,
                                   sign_psbt_cache_t *sign_psbt_cache,
diff --git a/src/handler/sign_psbt/compare_wallet_script_at_path.h b/src/handler/sign_psbt/compare_wallet_script_at_path.h
index 2940ebf..5b02ac3 100644
--- a/src/handler/sign_psbt/compare_wallet_script_at_path.h
+++ b/src/handler/sign_psbt/compare_wallet_script_at_path.h
@@ -1,9 +1,11 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/merkle.h"
-#include "../../common/wallet.h"
-#include "../../handler/sign_psbt/sign_psbt_cache.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "merkle.h"
+#include "sign_psbt_cache.h"
+#include "wallet.h"
 
 /**
  * TODO
diff --git a/src/handler/sign_psbt/extract_bip32_derivation.c b/src/handler/sign_psbt/extract_bip32_derivation.c
index 496a381..b17739a 100644
--- a/src/handler/sign_psbt/extract_bip32_derivation.c
+++ b/src/handler/sign_psbt/extract_bip32_derivation.c
@@ -1,12 +1,16 @@
 #include <stdint.h>
 #include <string.h>
 
-#include "./extract_bip32_derivation.h"
+#include "extract_bip32_derivation.h"
 
-#include "../lib/stream_merkle_leaf_element.h"
+/* SDK headers */
+#include "read.h"
+#include "varint.h"
 
-#include "../../common/psbt.h"
-#include "../../common/read.h"
+/* Local headers */
+#include "buffer_ext.h"
+#include "psbt.h"
+#include "stream_merkle_leaf_element.h"
 
 typedef struct {
     int psbt_key_type;
@@ -129,4 +133,4 @@ int extract_bip32_derivation(dispatcher_context_t *dc,
     }
 
     return (callback_state.out_data_length / 4) - 1;
-}
\ No newline at end of file
+}
diff --git a/src/handler/sign_psbt/extract_bip32_derivation.h b/src/handler/sign_psbt/extract_bip32_derivation.h
index 2fbda42..4b87869 100644
--- a/src/handler/sign_psbt/extract_bip32_derivation.h
+++ b/src/handler/sign_psbt/extract_bip32_derivation.h
@@ -1,7 +1,11 @@
 #pragma once
 
-#include "../../boilerplate/dispatcher.h"
-#include "../../common/bip32.h"
+/* SDK headers */
+#include "bip32.h"
+
+/* Local headers */
+#include "constants.h"
+#include "dispatcher.h"
 
 /**
  * Convenience function to extract the BIP32 derivation part from a PSBT field key type
@@ -14,4 +18,4 @@ int extract_bip32_derivation(dispatcher_context_t *dc,
                              const uint8_t values_root[static 32],
                              uint32_t merkle_tree_size,
                              int index,
-                             uint32_t out[static 1 + MAX_BIP32_PATH_STEPS]);
\ No newline at end of file
+                             uint32_t out[static 1 + MAX_BIP32_PATH_STEPS]);
diff --git a/src/handler/sign_psbt/musig_signing.c b/src/handler/sign_psbt/musig_signing.c
index 4ae706e..896d1bc 100644
--- a/src/handler/sign_psbt/musig_signing.c
+++ b/src/handler/sign_psbt/musig_signing.c
@@ -1,12 +1,16 @@
 #include <stdlib.h>
 
 #include "musig_signing.h"
-#include "lib_standard_app/crypto_helpers.h"
-#include "../boilerplate/sw.h"
-#include "../common/psbt.h"
-#include "../client_commands.h"
-#include "../lib/get_merkleized_map_value.h"
-#include "../lib/policy.h"
+
+/* SDK headers */
+#include "crypto_helpers.h"
+
+/* Local headers */
+#include "client_commands.h"
+#include "get_merkleized_map_value.h"
+#include "policy.h"
+#include "psbt.h"
+#include "sw.h"
 
 bool compute_musig_per_input_info(dispatcher_context_t *dc,
                                   sign_psbt_state_t *st,
diff --git a/src/handler/sign_psbt/musig_signing.h b/src/handler/sign_psbt/musig_signing.h
index ae20c48..281be19 100644
--- a/src/handler/sign_psbt/musig_signing.h
+++ b/src/handler/sign_psbt/musig_signing.h
@@ -1,8 +1,11 @@
 #include <stdint.h>
-#include "../common/wallet.h"
-#include "../musig/musig.h"
-#include "../boilerplate/dispatcher.h"
-#include "../sign_psbt.h"
+
+
+/* Local headers */
+#include "dispatcher.h"
+#include "musig.h"
+#include "sign_psbt.h"
+#include "wallet.h"
 
 // Struct to hold the info computed for a given input in either of the two rounds
 typedef struct {
diff --git a/src/handler/sign_psbt/sign_psbt_cache.h b/src/handler/sign_psbt/sign_psbt_cache.h
index fb87c73..b022a3e 100644
--- a/src/handler/sign_psbt/sign_psbt_cache.h
+++ b/src/handler/sign_psbt/sign_psbt_cache.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../crypto.h"
-#include "../common/wallet.h"
+
+/* Local headers */
+#include "crypto.h"
+#include "wallet.h"
 
 // This allows to keep the cache size small, while only paying a performance hit for any extremely
 // complicated policy with more than 16 key expressions in total (should that occur in practice).
diff --git a/src/handler/sign_psbt/txhashes.c b/src/handler/sign_psbt/txhashes.c
index dbfb5ec..a3f9e11 100644
--- a/src/handler/sign_psbt/txhashes.c
+++ b/src/handler/sign_psbt/txhashes.c
@@ -1,12 +1,12 @@
 #include "txhashes.h"
-#include "amount_from_psbt.h"
-
-#include "../../common/psbt.h"
-#include "../../error_codes.h"
 
-#include "../lib/get_merkleized_map.h"
-#include "../lib/get_merkleized_map_value.h"
-#include "../lib/stream_merkleized_map_value.h"
+/* Local headers */
+#include "amount_from_psbt.h"
+#include "error_codes.h"
+#include "get_merkleized_map.h"
+#include "get_merkleized_map_value.h"
+#include "psbt.h"
+#include "stream_merkleized_map_value.h"
 
 /* BIP0341 tags for computing the tagged hashes when computing he sighash */
 static const uint8_t BIP0341_sighash_tag[] = {'T', 'a', 'p', 'S', 'i', 'g', 'h', 'a', 's', 'h'};
@@ -28,7 +28,7 @@ static void cb_process_data(buffer_t *data, void *cb_state) {
     callback_state_t *state = (callback_state_t *) cb_state;
 
     size_t data_len = data->size - data->offset;
-    uint8_t *data_start_ptr = data->ptr + data->offset;
+    uint8_t *data_start_ptr = (uint8_t *) data->ptr + data->offset;
 
     if (state->hash_prefixed != NULL) {
         crypto_hash_update(state->hash_prefixed, data_start_ptr, data_len);
diff --git a/src/handler/sign_psbt/txhashes.h b/src/handler/sign_psbt/txhashes.h
index e4b2833..61c5aec 100644
--- a/src/handler/sign_psbt/txhashes.h
+++ b/src/handler/sign_psbt/txhashes.h
@@ -1,7 +1,9 @@
 #pragma once
 
-#include "../boilerplate/dispatcher.h"
-#include "../sign_psbt.h"
+
+/* Local headers */
+#include "dispatcher.h"
+#include "sign_psbt.h"
 
 /**
  * @brief Computes the transaction hashes required for signing.
diff --git a/src/main.c b/src/main.c
index 158365f..b00e16b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -15,37 +15,32 @@
  *  limitations under the License.
  *****************************************************************************/
 
-#include <stdint.h>  // uint*_t
-#include <string.h>  // memset, explicit_bzero
-
 #include <assert.h>
+#include <stdint.h>
+#include <string.h>
 
+/* SDK headers */
+#include "nbgl_use_case.h"
 #include "os.h"
 #include "ux.h"
 
+/* Local headers */
+#include "commands.h"
+#include "constants.h"
+#include "debug.h"
+#include "dispatcher.h"
 #include "globals.h"
-#include "io.h"
+#include "handle_check_address.h"
+#include "handle_get_printable_amount.h"
+#include "handle_swap_sign_transaction.h"
+#include "handlers.h"
+#include "io_ext.h"
+#include "menu.h"
+#include "parser.h"
 #include "sw.h"
-#include "ui/menu.h"
-#include "boilerplate/apdu_parser.h"
-#include "boilerplate/constants.h"
-#include "boilerplate/dispatcher.h"
-
-#include "../debug-helpers/debug.h"
-
-#include "handler/handlers.h"
-#include "commands.h"
-
-#include "common/wallet.h"
-
-// common declarations between legacy and new code; will refactor it out later
-#include "swap/swap_lib_calls.h"
-#include "swap/swap_globals.h"
-#include "swap/handle_swap_sign_transaction.h"
-#include "swap/handle_get_printable_amount.h"
-#include "swap/handle_check_address.h"
-
-#include "nbgl_use_case.h"
+#include "swap_globals.h"
+#include "swap_lib_calls.h"
+#include "wallet.h"
 
 #ifdef HAVE_BOLOS_APP_STACK_CANARY
 extern unsigned int app_stack_canary;
diff --git a/src/musig/musig.c b/src/musig/musig.c
index f6ea51a..48982f2 100644
--- a/src/musig/musig.c
+++ b/src/musig/musig.c
@@ -1,11 +1,13 @@
 #include <stdbool.h>
 
-#include "cx_errors.h"
-
 #include "musig.h"
 
-#include "../crypto.h"
-#include "../secp256k1.h"
+/* SDK headers */
+#include "cx_errors.h"
+
+/* Local headers */
+#include "crypto.h"
+#include "secp256k1.h"
 
 static const uint8_t BIP0327_keyagg_coeff_tag[] =
     {'K', 'e', 'y', 'A', 'g', 'g', ' ', 'c', 'o', 'e', 'f', 'f', 'i', 'c', 'i', 'e', 'n', 't'};
diff --git a/src/musig/musig.h b/src/musig/musig.h
index 76e7030..e0fe8e9 100644
--- a/src/musig/musig.h
+++ b/src/musig/musig.h
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <stdint.h>
 #include <stddef.h>
+#include <stdint.h>
 
 #define MUSIG_PUBNONCE_SIZE 66
 
diff --git a/src/musig/musig_sessions.c b/src/musig/musig_sessions.c
index 33f24b3..9561da8 100644
--- a/src/musig/musig_sessions.c
+++ b/src/musig/musig_sessions.c
@@ -1,9 +1,12 @@
 #include <string.h>
 
+#include "musig_sessions.h"
+
+/* SDK headers */
 #include "cx.h"
 
-#include "musig_sessions.h"
-#include "../crypto.h"
+/* Local headers */
+#include "crypto.h"
 
 typedef struct {
     // Aligning by 4 is necessary due to platform limitations.
diff --git a/src/musig/musig_sessions.h b/src/musig/musig_sessions.h
index 01b6b3c..1ce3466 100644
--- a/src/musig/musig_sessions.h
+++ b/src/musig/musig_sessions.h
@@ -1,6 +1,9 @@
 #pragma once
 
 #include <stdbool.h>
+
+
+/* Local headers */
 #include "musig.h"
 
 /**
diff --git a/src/swap/bip32_path.c b/src/swap/bip32_path.c
index be272f4..64ed79d 100644
--- a/src/swap/bip32_path.c
+++ b/src/swap/bip32_path.c
@@ -1,7 +1,8 @@
 
 #include "bip32_path.h"
 
-#include "../common/read.h"
+/* SDK headers */
+#include "read.h"
 
 bool parse_serialized_path(bip32_path_t* path,
                            unsigned char* serialized_path,
diff --git a/src/swap/bip32_path.h b/src/swap/bip32_path.h
index 05a5b89..6e1b421 100644
--- a/src/swap/bip32_path.h
+++ b/src/swap/bip32_path.h
@@ -1,8 +1,10 @@
 #pragma once
 
-#include "stdbool.h"
+#include <stdbool.h>
+
+/* SDK headers */
+#include "bip32.h"
 
-#define MAX_BIP32_PATH        10
 #define MAX_BIP32_PATH_LENGTH (4 * MAX_BIP32_PATH) + 1
 
 typedef struct bip32_path {
diff --git a/src/swap/handle_check_address.c b/src/swap/handle_check_address.c
index 21f23d2..733c2ed 100644
--- a/src/swap/handle_check_address.c
+++ b/src/swap/handle_check_address.c
@@ -1,12 +1,14 @@
 #include <string.h>
 
-#include "os.h"
-
 #include "handle_check_address.h"
+
+/* SDK headers */
 #include "bip32_path.h"
+#include "os.h"
 
-#include "../common/segwit_addr.h"
-#include "../crypto.h"
+/* Local headers */
+#include "crypto.h"
+#include "segwit_addr.h"
 
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 
diff --git a/src/swap/handle_check_address.h b/src/swap/handle_check_address.h
index ef717e9..457e763 100644
--- a/src/swap/handle_check_address.h
+++ b/src/swap/handle_check_address.h
@@ -1,5 +1,7 @@
 #pragma once
 
+
+/* Local headers */
 #include "swap_lib_calls.h"
 
 int handle_check_address(check_address_parameters_t* check_address_params);
diff --git a/src/swap/handle_get_printable_amount.c b/src/swap/handle_get_printable_amount.c
index f77a1c7..75ca90b 100644
--- a/src/swap/handle_get_printable_amount.c
+++ b/src/swap/handle_get_printable_amount.c
@@ -1,7 +1,10 @@
+#include "handle_get_printable_amount.h"
+
+/* SDK headers */
 #include "read.h"
 
+/* Local headers */
 #include "display_utils.h"
-#include "handle_get_printable_amount.h"
 
 #define MAX_NON_PRINTABLE_AMOUNT_LEN 8
 
diff --git a/src/swap/handle_get_printable_amount.h b/src/swap/handle_get_printable_amount.h
index a1a23f3..03b0e70 100644
--- a/src/swap/handle_get_printable_amount.h
+++ b/src/swap/handle_get_printable_amount.h
@@ -1,5 +1,7 @@
 #pragma once
 
+
+/* Local headers */
 #include "swap_lib_calls.h"
 
 int handle_get_printable_amount(get_printable_amount_parameters_t* get_printable_amount_params);
\ No newline at end of file
diff --git a/src/swap/handle_swap_sign_transaction.c b/src/swap/handle_swap_sign_transaction.c
index f439ed5..cf5e134 100644
--- a/src/swap/handle_swap_sign_transaction.c
+++ b/src/swap/handle_swap_sign_transaction.c
@@ -1,15 +1,17 @@
 #include <assert.h>
 
-#include "ux.h"
-#include "usbd_core.h"
-#include "os_io_seproxyhal.h"
-#include "os.h"
-
 #include "handle_swap_sign_transaction.h"
 
-#include "../globals.h"
-#include "../swap/swap_globals.h"
-#include "../common/read.h"
+/* SDK headers */
+#include "os.h"
+#include "read.h"
+#include "ux.h"
+
+/* Local headers */
+#include "globals.h"
+#include "os_io_seproxyhal.h"
+#include "swap_globals.h"
+#include "usbd_core.h"
 
 // Save the BSS address where we will write the return value when finished
 static uint8_t* G_swap_sign_return_value_address;
diff --git a/src/swap/handle_swap_sign_transaction.h b/src/swap/handle_swap_sign_transaction.h
index bbd82b2..97e53ae 100644
--- a/src/swap/handle_swap_sign_transaction.h
+++ b/src/swap/handle_swap_sign_transaction.h
@@ -1,5 +1,7 @@
 #pragma once
 
+
+/* Local headers */
 #include "swap_lib_calls.h"
 
 bool copy_transaction_parameters(create_transaction_parameters_t* sign_transaction_params);
diff --git a/src/swap/swap_lib_calls.h b/src/swap/swap_lib_calls.h
deleted file mode 100644
index dc88417..0000000
--- a/src/swap/swap_lib_calls.h
+++ /dev/null
@@ -1,80 +0,0 @@
-#pragma once
-
-/* This file is the shared API between Exchange and the apps started in Library mode for Exchange
- *
- * DO NOT MODIFY THIS FILE IN APPLICATIONS OTHER THAN EXCHANGE
- * On modification in Exchange, forward the changes to all applications supporting Exchange
- */
-
-#include "stdbool.h"
-#include "stdint.h"
-
-#define RUN_APPLICATION 1
-
-#define SIGN_TRANSACTION 2
-
-#define CHECK_ADDRESS 3
-
-#define GET_PRINTABLE_AMOUNT 4
-
-/*
- * Amounts are stored as bytes, with a max size of 16 (see protobuf
- * specifications). Max 16B integer is 340282366920938463463374607431768211455
- * in decimal, which is a 32-long char string.
- * The printable amount also contains spaces, the ticker symbol (with variable
- * size, up to 12 in Ethereum for instance) and a terminating null byte, so 50
- * bytes total should be a fair maximum.
- */
-#define MAX_PRINTABLE_AMOUNT_SIZE 50
-
-// structure that should be send to specific coin application to get address
-typedef struct check_address_parameters_s {
-    // IN
-    uint8_t *coin_configuration;
-    uint8_t coin_configuration_length;
-    // serialized path, segwit, version prefix, hash used, dictionary etc.
-    // fields and serialization format depends on spesific coin app
-    uint8_t *address_parameters;
-    uint8_t address_parameters_length;
-    char *address_to_check;
-    char *extra_id_to_check;
-    // OUT
-    int result;
-} check_address_parameters_t;
-
-// structure that should be send to specific coin application to get printable amount
-typedef struct get_printable_amount_parameters_s {
-    // IN
-    uint8_t *coin_configuration;
-    uint8_t coin_configuration_length;
-    uint8_t *amount;
-    uint8_t amount_length;
-    bool is_fee;
-    // OUT
-    char printable_amount[MAX_PRINTABLE_AMOUNT_SIZE];
-} get_printable_amount_parameters_t;
-
-typedef struct create_transaction_parameters_s {
-    // IN
-    uint8_t *coin_configuration;
-    uint8_t coin_configuration_length;
-    uint8_t *amount;
-    uint8_t amount_length;
-    uint8_t *fee_amount;
-    uint8_t fee_amount_length;
-    char *destination_address;
-    char *destination_address_extra_id;
-    // OUT
-    uint8_t result;
-} create_transaction_parameters_t;
-
-typedef struct libargs_s {
-    unsigned int id;
-    unsigned int command;
-    unsigned int unused;
-    union {
-        check_address_parameters_t *check_address;
-        create_transaction_parameters_t *create_transaction;
-        get_printable_amount_parameters_t *get_printable_amount;
-    };
-} libargs_t;
diff --git a/src/types.h b/src/types.h
index de3cbdc..6095dda 100644
--- a/src/types.h
+++ b/src/types.h
@@ -1,8 +1,11 @@
 #pragma once
 
-#include <stddef.h>  // size_t
-#include <stdint.h>  // uint*_t
+#include <stddef.h>
+#include <stdint.h>
 
-#include "constants.h"
-#include "common/bip32.h"
+/* SDK headers */
+#include "bip32.h"
+
+/* Local headers */
 #include "commands.h"
+#include "constants.h"
diff --git a/src/ui/display.c b/src/ui/display.c
index a00ba65..9feb7f5 100644
--- a/src/ui/display.c
+++ b/src/ui/display.c
@@ -1,16 +1,17 @@
 #pragma GCC diagnostic ignored "-Wformat-invalid-specifier"  // snprintf
 #pragma GCC diagnostic ignored "-Wformat-extra-args"         // snprintf
 
-#include <stdbool.h>  // bool
-#include <stdio.h>    // snprintf
-#include <string.h>   // memset
+#include <stdbool.h>
 #include <stdint.h>
+#include <stdio.h>
+#include <string.h>
 
+#include "display.h"
+
+/* SDK headers */
 #include "os.h"
 #include "ux.h"
 
-#include "./display.h"
-
 // These globals are a workaround for a limitation of the UX library that
 // does not allow to pass proper callbacks and context.
 
diff --git a/src/ui/display.h b/src/ui/display.h
index 0cbdc9b..c063af4 100644
--- a/src/ui/display.h
+++ b/src/ui/display.h
@@ -1,19 +1,21 @@
 #pragma once
 
-#include <stdbool.h>  // bool
-#include "../boilerplate/dispatcher.h"
-
-#include "../common/wallet.h"
-#include "./display.h"
-#include "./display_utils.h"
-#include "../constants.h"
-#include "../globals.h"
-#include "../boilerplate/io.h"
-#include "../boilerplate/sw.h"
-#include "../common/bip32.h"
-#include "../common/format.h"
-#include "../common/script.h"
-#include "../constants.h"
+#include <stdbool.h>
+
+/* SDK headers */
+#include "bip32.h"
+#include "format.h"
+
+/* Local headers */
+#include "constants.h"
+#include "dispatcher.h"
+#include "display.h"
+#include "display_utils.h"
+#include "globals.h"
+#include "io_ext.h"
+#include "script.h"
+#include "sw.h"
+#include "wallet.h"
 
 #define MESSAGE_CHUNK_SIZE 64  // Protocol specific
 // Displayed message length - if the message is too long we will not display it
diff --git a/src/ui/display_nbgl.c b/src/ui/display_nbgl.c
index c6f188e..00da4c1 100644
--- a/src/ui/display_nbgl.c
+++ b/src/ui/display_nbgl.c
@@ -1,11 +1,13 @@
+#include <assert.h>
 #include <stdint.h>
 
+/* SDK headers */
 #include "nbgl_use_case.h"
-#include "./display.h"
-#include "./menu.h"
-#include "io.h"
 
-#include <assert.h>
+/* Local headers */
+#include "display.h"
+#include "io_ext.h"
+#include "menu.h"
 
 #define REVIEW_CONFIRM FIRST_USER_TOKEN + 1
 
diff --git a/src/ui/display_utils.c b/src/ui/display_utils.c
index b422153..2e4cc28 100644
--- a/src/ui/display_utils.c
+++ b/src/ui/display_utils.c
@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "./display_utils.h"
+#include "display_utils.h"
 
 static size_t n_digits(uint64_t number) {
     size_t count = 0;
diff --git a/src/ui/display_utils.h b/src/ui/display_utils.h
index 4beb3bf..6d0da09 100644
--- a/src/ui/display_utils.h
+++ b/src/ui/display_utils.h
@@ -2,7 +2,9 @@
 
 #include <stdint.h>
 
-#include "../constants.h"
+
+/* Local headers */
+#include "constants.h"
 
 // up to 5 chars for ticker, 1 space, up to 20 digits (20 = digits of 2^64), + 1 decimal separator
 #define MAX_AMOUNT_LENGTH (5 + 1 + 20 + 1)
diff --git a/src/ui/menu_nbgl.c b/src/ui/menu_nbgl.c
index f249a35..0e1d175 100644
--- a/src/ui/menu_nbgl.c
+++ b/src/ui/menu_nbgl.c
@@ -15,10 +15,13 @@
  *  limitations under the License.
  *****************************************************************************/
 
+/* SDK headers */
+/* SDK headers */
 #include "nbgl_use_case.h"
 
-#include "../globals.h"
-#include "./display.h"
+/* Local headers */
+#include "display.h"
+#include "globals.h"
 #include "menu.h"
 
 #define SETTING_INFO_NB 3