diff --git a/main/cli/serial_cli.c b/main/cli/serial_cli.c
new file mode 100644
index 0000000..97287fd
--- /dev/null
+++ b/main/cli/serial_cli.c
@@ -0,0 +1,307 @@
+#include "serial_cli.h"
+#include "mimi_config.h"
+#include "wifi/wifi_manager.h"
+#include "telegram/telegram_bot.h"
+#include "llm/llm_proxy.h"
+#include "memory/memory_store.h"
+#include "memory/session_mgr.h"
+
+#include <string.h>
+#include <stdio.h>
+#include "esp_log.h"
+#include "esp_console.h"
+#include "esp_system.h"
+#include "esp_heap_caps.h"
+#include "argtable3/argtable3.h"
+
+static const char *TAG = "cli";
+
+/* --- wifi_set command --- */
+static struct {
+    struct arg_str *ssid;
+    struct arg_str *password;
+    struct arg_end *end;
+} wifi_set_args;
+
+static int cmd_wifi_set(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&wifi_set_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, wifi_set_args.end, argv[0]);
+        return 1;
+    }
+    wifi_manager_set_credentials(wifi_set_args.ssid->sval[0],
+                                  wifi_set_args.password->sval[0]);
+    printf("WiFi credentials saved. Restart to apply.\n");
+    return 0;
+}
+
+/* --- wifi_status command --- */
+static int cmd_wifi_status(int argc, char **argv)
+{
+    printf("WiFi connected: %s\n", wifi_manager_is_connected() ? "yes" : "no");
+    printf("IP: %s\n", wifi_manager_get_ip());
+    return 0;
+}
+
+/* --- set_tg_token command --- */
+static struct {
+    struct arg_str *token;
+    struct arg_end *end;
+} tg_token_args;
+
+static int cmd_set_tg_token(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&tg_token_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, tg_token_args.end, argv[0]);
+        return 1;
+    }
+    telegram_set_token(tg_token_args.token->sval[0]);
+    printf("Telegram bot token saved.\n");
+    return 0;
+}
+
+/* --- set_api_key command --- */
+static struct {
+    struct arg_str *key;
+    struct arg_end *end;
+} api_key_args;
+
+static int cmd_set_api_key(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&api_key_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, api_key_args.end, argv[0]);
+        return 1;
+    }
+    llm_set_api_key(api_key_args.key->sval[0]);
+    printf("API key saved.\n");
+    return 0;
+}
+
+/* --- set_model command --- */
+static struct {
+    struct arg_str *model;
+    struct arg_end *end;
+} model_args;
+
+static int cmd_set_model(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&model_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, model_args.end, argv[0]);
+        return 1;
+    }
+    llm_set_model(model_args.model->sval[0]);
+    printf("Model set.\n");
+    return 0;
+}
+
+/* --- memory_read command --- */
+static int cmd_memory_read(int argc, char **argv)
+{
+    char buf[4096];
+    if (memory_read_long_term(buf, sizeof(buf)) == ESP_OK && buf[0]) {
+        printf("=== MEMORY.md ===\n%s\n=================\n", buf);
+    } else {
+        printf("MEMORY.md is empty or not found.\n");
+    }
+    return 0;
+}
+
+/* --- memory_write command --- */
+static struct {
+    struct arg_str *content;
+    struct arg_end *end;
+} memory_write_args;
+
+static int cmd_memory_write(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&memory_write_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, memory_write_args.end, argv[0]);
+        return 1;
+    }
+    memory_write_long_term(memory_write_args.content->sval[0]);
+    printf("MEMORY.md updated.\n");
+    return 0;
+}
+
+/* --- session_list command --- */
+static int cmd_session_list(int argc, char **argv)
+{
+    printf("Sessions:\n");
+    session_list();
+    return 0;
+}
+
+/* --- session_clear command --- */
+static struct {
+    struct arg_str *chat_id;
+    struct arg_end *end;
+} session_clear_args;
+
+static int cmd_session_clear(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&session_clear_args);
+    if (nerrors != 0) {
+        arg_print_errors(stderr, session_clear_args.end, argv[0]);
+        return 1;
+    }
+    if (session_clear(session_clear_args.chat_id->sval[0]) == ESP_OK) {
+        printf("Session cleared.\n");
+    } else {
+        printf("Session not found.\n");
+    }
+    return 0;
+}
+
+/* --- heap_info command --- */
+static int cmd_heap_info(int argc, char **argv)
+{
+    printf("Internal free: %d bytes\n",
+           (int)heap_caps_get_free_size(MALLOC_CAP_INTERNAL));
+    printf("PSRAM free:    %d bytes\n",
+           (int)heap_caps_get_free_size(MALLOC_CAP_SPIRAM));
+    printf("Total free:    %d bytes\n",
+           (int)esp_get_free_heap_size());
+    return 0;
+}
+
+/* --- restart command --- */
+static int cmd_restart(int argc, char **argv)
+{
+    printf("Restarting...\n");
+    esp_restart();
+    return 0;  /* unreachable */
+}
+
+esp_err_t serial_cli_init(void)
+{
+    esp_console_repl_t *repl = NULL;
+    esp_console_repl_config_t repl_config = ESP_CONSOLE_REPL_CONFIG_DEFAULT();
+    repl_config.prompt = "mimi> ";
+    repl_config.max_cmdline_length = 256;
+
+    /* USB Serial JTAG */
+    esp_console_dev_usb_serial_jtag_config_t hw_config =
+        ESP_CONSOLE_DEV_USB_SERIAL_JTAG_CONFIG_DEFAULT();
+
+    ESP_ERROR_CHECK(esp_console_new_repl_usb_serial_jtag(&hw_config, &repl_config, &repl));
+
+    /* Register commands */
+
+    /* wifi_set */
+    wifi_set_args.ssid = arg_str1(NULL, NULL, "<ssid>", "WiFi SSID");
+    wifi_set_args.password = arg_str1(NULL, NULL, "<password>", "WiFi password");
+    wifi_set_args.end = arg_end(2);
+    esp_console_cmd_t wifi_set_cmd = {
+        .command = "wifi_set",
+        .help = "Set WiFi SSID and password",
+        .func = &cmd_wifi_set,
+        .argtable = &wifi_set_args,
+    };
+    esp_console_cmd_register(&wifi_set_cmd);
+
+    /* wifi_status */
+    esp_console_cmd_t wifi_status_cmd = {
+        .command = "wifi_status",
+        .help = "Show WiFi connection status",
+        .func = &cmd_wifi_status,
+    };
+    esp_console_cmd_register(&wifi_status_cmd);
+
+    /* set_tg_token */
+    tg_token_args.token = arg_str1(NULL, NULL, "<token>", "Telegram bot token");
+    tg_token_args.end = arg_end(1);
+    esp_console_cmd_t tg_token_cmd = {
+        .command = "set_tg_token",
+        .help = "Set Telegram bot token",
+        .func = &cmd_set_tg_token,
+        .argtable = &tg_token_args,
+    };
+    esp_console_cmd_register(&tg_token_cmd);
+
+    /* set_api_key */
+    api_key_args.key = arg_str1(NULL, NULL, "<key>", "Anthropic API key");
+    api_key_args.end = arg_end(1);
+    esp_console_cmd_t api_key_cmd = {
+        .command = "set_api_key",
+        .help = "Set Claude API key",
+        .func = &cmd_set_api_key,
+        .argtable = &api_key_args,
+    };
+    esp_console_cmd_register(&api_key_cmd);
+
+    /* set_model */
+    model_args.model = arg_str1(NULL, NULL, "<model>", "Model identifier");
+    model_args.end = arg_end(1);
+    esp_console_cmd_t model_cmd = {
+        .command = "set_model",
+        .help = "Set LLM model (default: " MIMI_LLM_DEFAULT_MODEL ")",
+        .func = &cmd_set_model,
+        .argtable = &model_args,
+    };
+    esp_console_cmd_register(&model_cmd);
+
+    /* memory_read */
+    esp_console_cmd_t mem_read_cmd = {
+        .command = "memory_read",
+        .help = "Read MEMORY.md",
+        .func = &cmd_memory_read,
+    };
+    esp_console_cmd_register(&mem_read_cmd);
+
+    /* memory_write */
+    memory_write_args.content = arg_str1(NULL, NULL, "<content>", "Content to write");
+    memory_write_args.end = arg_end(1);
+    esp_console_cmd_t mem_write_cmd = {
+        .command = "memory_write",
+        .help = "Write to MEMORY.md",
+        .func = &cmd_memory_write,
+        .argtable = &memory_write_args,
+    };
+    esp_console_cmd_register(&mem_write_cmd);
+
+    /* session_list */
+    esp_console_cmd_t sess_list_cmd = {
+        .command = "session_list",
+        .help = "List all sessions",
+        .func = &cmd_session_list,
+    };
+    esp_console_cmd_register(&sess_list_cmd);
+
+    /* session_clear */
+    session_clear_args.chat_id = arg_str1(NULL, NULL, "<chat_id>", "Chat ID to clear");
+    session_clear_args.end = arg_end(1);
+    esp_console_cmd_t sess_clear_cmd = {
+        .command = "session_clear",
+        .help = "Clear a session",
+        .func = &cmd_session_clear,
+        .argtable = &session_clear_args,
+    };
+    esp_console_cmd_register(&sess_clear_cmd);
+
+    /* heap_info */
+    esp_console_cmd_t heap_cmd = {
+        .command = "heap_info",
+        .help = "Show heap memory usage",
+        .func = &cmd_heap_info,
+    };
+    esp_console_cmd_register(&heap_cmd);
+
+    /* restart */
+    esp_console_cmd_t restart_cmd = {
+        .command = "restart",
+        .help = "Restart the device",
+        .func = &cmd_restart,
+    };
+    esp_console_cmd_register(&restart_cmd);
+
+    /* Start REPL */
+    ESP_ERROR_CHECK(esp_console_start_repl(repl));
+    ESP_LOGI(TAG, "Serial CLI started");
+
+    return ESP_OK;
+}
diff --git a/main/cli/serial_cli.h b/main/cli/serial_cli.h
new file mode 100644
index 0000000..9498d3f
--- /dev/null
+++ b/main/cli/serial_cli.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include "esp_err.h"
+
+/**
+ * Initialize and start the serial CLI (esp_console based).
+ * Registers all commands and starts the REPL on USB-JTAG serial.
+ */
+esp_err_t serial_cli_init(void);