diff --git a/src/config_updater.c b/src/config_updater.c
index 13e62df4..c8da33f4 100644
--- a/src/config_updater.c
+++ b/src/config_updater.c
@@ -222,20 +222,34 @@ static int insert_or_replace_option(char **buf, size_t *buf_len, size_t *buf_cap
 int config_ensure_keys_and_node_id(const char *filename) {
     // ── Read config file into memory (single open) ──
     FILE *fp = fopen(filename, "rb");
-    if (!fp) {
-        DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "Failed to open config file: %s (errno=%d)", filename, errno);
-        return -1;
+    char *file_buf = NULL;
+    size_t file_size = 0;
+    struct utun_config *config = NULL;
+
+    if (fp) {
+        fseek(fp, 0, SEEK_END); long fsz = ftell(fp); fseek(fp, 0, SEEK_SET);
+        if (fsz < 0) { fclose(fp); return -1; }
+        file_size = (size_t)fsz;
+        file_buf = u_malloc(file_size + 1);
+        if (!file_buf || fread(file_buf, 1, file_size, fp) != file_size) { u_free(file_buf); fclose(fp); return -1; }
+        file_buf[file_size] = '\0';
+        fclose(fp);
+        config = parse_config_from_buf(file_buf, file_size, filename);
+        if (!config) { DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "Failed to parse config from buffer: %s", filename); u_free(file_buf); return -1; }
+    } else {
+        // No file — create minimal config
+        DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Config file not found, creating new: %s (errno=%d)", filename, errno);
+        config = u_calloc(1, sizeof(struct utun_config));
+        if (!config) return -1;
+        config->global.my_node_id = 0;
+        config->global.my_private_key_hex[0] = '\0';
+        config->global.my_public_key_hex[0] = '\0';
+        config->global.name[0] = '\0';
+        config->global.keepalive_timeout = 2000;
+        config->global.keepalive_interval = 200;
+        config->global.keepalive_adaptive = 1;
+        config->global.bbr_max_cwnd = 1048576;
     }
-    fseek(fp, 0, SEEK_END); long fsz = ftell(fp); fseek(fp, 0, SEEK_SET);
-    if (fsz < 0) { fclose(fp); return -1; }
-    size_t file_size = (size_t)fsz;
-    char *file_buf = u_malloc(file_size + 1);
-    if (!file_buf || fread(file_buf, 1, file_size, fp) != file_size) { u_free(file_buf); fclose(fp); return -1; }
-    file_buf[file_size] = '\0';
-    fclose(fp);
-
-    struct utun_config *config = parse_config_from_buf(file_buf, file_size, filename);
-    if (!config) { DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "Failed to parse config from buffer: %s", filename); u_free(file_buf); return -1; }
 
     struct global_config *global = &config->global;
 
@@ -294,34 +308,54 @@ int config_ensure_keys_and_node_id(const char *filename) {
 
     if (!need_priv_key && !need_pub_key && !need_node_id) { free_config(config); u_free(file_buf); return 0; }
 
+    char cfg_name[16]; snprintf(cfg_name, sizeof(cfg_name), "%s", global->name[0] ? global->name : "utun");
+
     free_config(config);
 
-    // ── Modify file buffer in place ──
-    size_t buf_capacity = file_size + 1024;
-    char *work_buf = u_malloc(buf_capacity);
-    if (!work_buf) { u_free(file_buf); return -1; }
-    memcpy(work_buf, file_buf, file_size);
-    u_free(file_buf);
-    size_t work_len = file_size;
+    char node_id_hex[HEXNODEID_LEN + 1];
+    snprintf(node_id_hex, sizeof(node_id_hex), "%016llx", (unsigned long long)new_node_id);
+
+    // ── Modify/create config buffer ──
+    char *work_buf = NULL; size_t work_len = 0; size_t buf_capacity = 0;
+    int is_new_file = (!file_buf || !file_size);
+
+    if (is_new_file) {
+        buf_capacity = 2048;
+        work_buf = u_malloc(buf_capacity);
+        if (!work_buf) { u_free(file_buf); return -1; }
+        work_len = (size_t)snprintf(work_buf, buf_capacity,
+            "[global]\nmy_node_name=%s\nmy_private_key=%s\nmy_public_key=%s\nmy_node_id=%s\n",
+            cfg_name, new_priv_key, new_pub_key, node_id_hex);
+        u_free(file_buf); file_buf = NULL;
+    } else {
+        buf_capacity = file_size + 1024;
+        work_buf = u_malloc(buf_capacity);
+        if (!work_buf) { u_free(file_buf); return -1; }
+        memcpy(work_buf, file_buf, file_size);
+        work_len = file_size;
+        u_free(file_buf); file_buf = NULL;
+    }
+
     int ret = 0;
-    int write_keys = (need_priv_key || need_pub_key || need_node_id);
 
-    if (need_node_id) {
-        char node_id_hex[HEXNODEID_LEN + 1];
-        snprintf(node_id_hex, sizeof(node_id_hex), "%016llx", (unsigned long long)new_node_id);
-        DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_node_id=%s to %s", node_id_hex, filename);
-        if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_node_id", node_id_hex) < 0) ret = -1;
-    }
-    if (write_keys && ret == 0) {
-        DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_private_key to %s", filename);
-        if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_private_key", new_priv_key) < 0) ret = -1;
-    }
-    if (write_keys && ret == 0) {
-        DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_public_key to %s", filename);
-        if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_public_key", new_pub_key) < 0) ret = -1;
+    if (!is_new_file) {
+        int write_keys = (need_priv_key || need_pub_key || need_node_id);
+
+        if (need_node_id) {
+            DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_node_id=%s to %s", node_id_hex, filename);
+            if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_node_id", node_id_hex) < 0) ret = -1;
+        }
+        if (write_keys && ret == 0) {
+            DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_private_key to %s", filename);
+            if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_private_key", new_priv_key) < 0) ret = -1;
+        }
+        if (write_keys && ret == 0) {
+            DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "Writing my_public_key to %s", filename);
+            if (insert_or_replace_option(&work_buf, &work_len, &buf_capacity, "my_public_key", new_pub_key) < 0) ret = -1;
+        }
     }
 
-    if (ret == 0) {
+    if (ret == 0 && work_buf) {
         if (write_mem_to_file(filename, work_buf, work_len) < 0) {
             DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "Failed to write updated config file: %s", filename);
             ret = -1;