diff --git a/src/main.c b/src/main.c
index 0cf69e8..21719b6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -503,8 +503,8 @@ int socket_name_random(char *out, size_t out_len);
 /* Version information (auto-updated by build/version tooling) */
 #define NSIGNER_VERSION_MAJOR 0
 #define NSIGNER_VERSION_MINOR 0
-#define NSIGNER_VERSION_PATCH 39
-#define NSIGNER_VERSION "v0.0.39"
+#define NSIGNER_VERSION_PATCH 40
+#define NSIGNER_VERSION "v0.0.40"
 
 
 /* NSIGNER_HEADERLESS_DECLS_END */
@@ -1671,6 +1671,59 @@ static int prompt_transport_selection(void) {
     return selected;
 }
 
+/*
+ * Interactive index whitelist prompt.
+ * Shown after transport selection when no --allow-index flag was given.
+ * Returns a malloc'd spec string (caller must free), or NULL for "all".
+ */
+static char *prompt_index_whitelist(void) {
+    char input[256];
+
+    for (;;) {
+        tui_render_content_screen(NULL, "Index whitelist — restrict which nostr_index values this session can access");
+        printf("Enter allowed indices, or press Enter for 'all' (no restriction):\n\n");
+        printf("  Examples:\n");
+        printf("    all          (default — allow all indices)\n");
+        printf("    0            (only index 0)\n");
+        printf("    0,1,3        (specific indices)\n");
+        printf("    0-3          (range 0 through 3)\n");
+        printf("    0,2-3,7      (mixed list and ranges)\n");
+        printf("\n  Enter = all\n");
+        printf("> ");
+        fflush(stdout);
+
+        if (read_line_stdin(input, sizeof(input)) != 0) {
+            return NULL;
+        }
+
+        /* Trim trailing whitespace */
+        {
+            size_t len = strlen(input);
+            while (len > 0 && (input[len-1] == '\n' || input[len-1] == '\r' ||
+                               input[len-1] == ' ' || input[len-1] == '\t')) {
+                input[--len] = '\0';
+            }
+        }
+
+        if (input[0] == '\0') {
+            /* Enter pressed — default to "all" */
+            return NULL;
+        }
+
+        /* Validate by parsing into a temp whitelist */
+        {
+            server_ctx_t tmp;
+            memset(&tmp, 0, sizeof(tmp));
+            if (server_set_index_whitelist(&tmp, input) != 0) {
+                printf("Invalid spec: '%s'. Try again or press Enter for 'all'.\n", input);
+                continue;
+            }
+        }
+
+        return strdup(input);
+    }
+}
+
 int main(int argc, char *argv[]) {
     mnemonic_state_t mnemonic;
     role_table_t role_table;
@@ -1969,6 +2022,14 @@ int main(int argc, char *argv[]) {
             return 1;
         }
 
+        /* Index whitelist prompt (only if --allow-index wasn't given on CLI) */
+        if (allow_index_spec == NULL) {
+            char *wl_spec = prompt_index_whitelist();
+            if (wl_spec != NULL) {
+                allow_index_spec = wl_spec;  /* will be freed at program exit */
+            }
+        }
+
         /* Persistent listeners — configure from menu selection */
         multi_listen = 1;