diff --git a/lib/grading/rpc.c b/lib/grading/rpc.c
index 2890653..5857677 100644
--- a/lib/grading/rpc.c
+++ b/lib/grading/rpc.c
@@ -18,12 +18,12 @@ void grading_rpc_handler_string(const char* string)
 
 void grading_rpc_handler_serial_getchar(void)
 {
-  DEBUG_PRINTF("grading_rpc_handler_serial_getchar()\n");
+  // DEBUG_PRINTF("grading_rpc_handler_serial_getchar()\n");
 }
 
 void grading_rpc_handler_serial_putchar(char c)
 {
-  DEBUG_PRINTF("grading_rpc_handler_serial_putchar(0x%"PRIx8")\n", c);
+  // DEBUG_PRINTF("grading_rpc_handler_serial_putchar(0x%"PRIx8")\n", c);
 }
 
 void grading_rpc_handler_ram_cap(size_t bytes, size_t alignment)
diff --git a/usr/hello/hello.c b/usr/hello/hello.c
index 2801872..f17d1d3 100644
--- a/usr/hello/hello.c
+++ b/usr/hello/hello.c
@@ -185,14 +185,18 @@ int main(int argc, char *argv[])
     }
 
     if (argc > 1 && !strncmp(argv[1], HELLO_CMD_IO, sizeof(HELLO_CMD_IO))) {
-        int testInteger;
-        printf("Hi! Please enter an integer: ");
-        scanf("%d", &testInteger);  
-        printf("number = %d",testInteger);
-        char name_input[20];
-        printf("Please enter your name: ");
-        scanf("%s", name_input);
-        printf("why hello there, %s", name_input);
+        char input[256];
+        printf("Hi! Please enter an input: \n\r");
+        fflush(stdout);
+        input[0] = fgetc(stdin);
+        fflush(stdin);
+        printf("input = %s\n\r", input);
+        printf("Please enter your name: \n\r");
+        fflush(stdout);
+        input[1] = fgetc(stdin);
+        fflush(stdin);
+        printf("why hello there, %s\n\r", input);
+        fflush(stdout);
     }
 
     return EXIT_SUCCESS;
diff --git a/usr/shelly/Hakefile b/usr/shelly/Hakefile
index 773fa4b..2cf94c6 100644
--- a/usr/shelly/Hakefile
+++ b/usr/shelly/Hakefile
@@ -14,6 +14,6 @@
   { 
     target = "shelly",
     cFiles = [ "shelly.c" ],
-    addLibraries = [ "lpuart", "gic_dist", "fs" ]
+    addLibraries = [ "lpuart", "gic_dist", "fs", "grading" ]
   }
 ]
diff --git a/usr/shelly/shelly.c b/usr/shelly/shelly.c
index 66fdba3..62531fc 100644
--- a/usr/shelly/shelly.c
+++ b/usr/shelly/shelly.c
@@ -17,6 +17,7 @@
 #include <aos/shelly_client.h>
 #include <aos/aos_rpc.h>
 #include <fs/fs.h>
+#include <grading.h>
 
 #include "shelly.h"
 
@@ -91,18 +92,6 @@ static void handle_lpuart_interrupt(void * arg) {
             if (err_is_fail(err)) USER_PANIC_ERR(err, "while trying to put character");
         }
 
-        if (global_state->current_getchar_request != NULL) {
-            // a client is waiting for a getchar request, forward it.
-            if (is_newline(input_char)) {
-                input_char = '\0';
-            }
-            send_response(global_state->current_getchar_request, SYS_ERR_OK, input_char, 0, NULL);
-            global_state->current_getchar_request = NULL;
-            continue;
-        }
-
-        assert(global_state->current_getchar_request == NULL);
-        //handle as shell input
         if (is_newline(input_char)) {
             global_state->buf[global_state->buffer_i] = '\0';
             global_state->buffer_i += 1;
@@ -110,13 +99,23 @@ static void handle_lpuart_interrupt(void * arg) {
             err = shelly_write_str("\n\r");
             if (err_is_fail(err)) USER_PANIC_ERR(err, "while trying to write string");
 
-            err = handle_shelly_cmd(global_state->buf, global_state->buffer_i);
-            if (err_is_fail(err)) shelly_write_str("failed to run command :(\n\r");
+            if (global_state->current_getchar_request != NULL) {
+                //send to client
+                for (int i = 0; i < global_state->buffer_i; ++i) {
+                    send_response(global_state->current_getchar_request, SYS_ERR_OK, global_state->buf[i], 0, NULL);
+                }
+                global_state->current_getchar_request = NULL;
+                shelly_reset_buffer();
+            } else {
+                //treat as command
+                err = handle_shelly_cmd(global_state->buf, global_state->buffer_i);
+                if (err_is_fail(err)) shelly_write_str("failed to run command :(\n\r");
 
-            shelly_reset_buffer();
+                shelly_reset_buffer();
 
-            err = shelly_write_str("\n\ryou@windows me > ");
-            if (err_is_fail(err)) USER_PANIC_ERR(err, "while trying to write string");
+                err = shelly_write_str("\n\ryou@windows me > ");
+                if (err_is_fail(err)) USER_PANIC_ERR(err, "while trying to write string");
+            }
         } else {
             err = shelly_buffer_append(input_char);
             if (err_is_fail(err)) {
@@ -179,8 +178,11 @@ static void handle_client_request(void *arg, size_t header_size, void *header_bu
     struct shelly_header * header = (struct shelly_header *) header_buf;
 
     if (header->type == SHELLY_MSG_GETCHAR) {
+        grading_rpc_handler_serial_getchar();
+        shelly_reset_buffer();
         global_state->current_getchar_request = local_state;
     } else if (header->type == SHELLY_MSG_PUTCHAR) {
+        grading_rpc_handler_serial_putchar(header->character);
         err = lpuart_putchar(global_state->uart_s, header->character);
         if (err_is_fail(err)) USER_PANIC_ERR(err, "while trying to put character");
         if (is_newline(header->character)) {