diff -ruN a/config.def.h b/config.def.h
--- a/config.def.h	2026-05-20 13:18:06.149571116 +0200
+++ b/config.def.h	2026-05-20 13:19:12.046956614 +0200
@@ -1,23 +1,29 @@
 /* See LICENSE file for copyright and license details. */
 
-/* progress bar glyphs (ASCII default) */
+/* progress bar glyphs (ASCII default).
+ * Runtime config file ~/.config/ttym/config can override these via
+ * bar_fill / bar_empty keys.
+ */
 static const char *const BAR_FILL  = ">";
 static const char *const BAR_EMPTY = "-";
 
 /* persistent alert: keep ringing the bell until any key is pressed.
  * Foreground-only; backgrounded runs always fall through.
- * Override per-run with --no-persist.
+ * Override per-run with --no-persist, or via the alert_persist key
+ * in the runtime config file (~/.config/ttym/config).
  */
 static const int ALERT_PERSIST = 1;
 
 /* reverse-video flash during the alert loop.
- * Override per-run with --flash on|off.
+ * Override per-run with --flash on|off, or via the flash key in the
+ * runtime config file (~/.config/ttym/config).
  */
 static const int FLASH = 1;
 
 /* desktop notification on countdown completion.
  * Tokens are split on whitespace; placeholders {title} and {msg} are expanded.
  * Set NULL or "" to disable.
+ * The runtime config file can override these via title / notify_cmd keys.
  */
 static const char *const TITLE      = "Timer";
 static const char *const NOTIFY_CMD = "notify-send -u critical {title} {msg}";
@@ -25,6 +31,7 @@
 /* sound on countdown completion. If SOUND_CMD is "" the binary autodetects
  * a player (paplay/aplay/mpv/ffplay) and plays a default freedesktop sound.
  * SOUND_CMD is split on whitespace; same token rules as NOTIFY_CMD.
+ * The runtime config file can override this via the sound_cmd key.
  */
 static const char *const SOUND_CMD  = "";
 
@@ -35,5 +42,6 @@
 
 /* default bar style: "" autodetects (unicode if locale is UTF-8, else ascii).
  * Available: unicode | ascii | hash | dots | line | block | arrow | minimal.
+ * The runtime config file can override this via the bar_style key.
  */
 static const char *const BAR_STYLE = "";
diff -ruN a/ttym.c b/ttym.c
--- a/ttym.c	2026-05-20 13:18:06.149571116 +0200
+++ b/ttym.c	2026-05-20 13:19:12.046956614 +0200
@@ -30,10 +30,12 @@
 	int alert_persist;    /* alert loop until keypress; --no-persist disables */
 	int flash;            /* reverse-video flash during alert loop */
 	char comment[512];    /* -c TEXT: logged with each entry */
+	char bar_fill[16];    /* override (utf-8 ok); from runtime config */
+	char bar_empty[16];   /* override */
 	char bar_style[32];   /* --bar STYLE */
-	const char *title;
-	const char *notify_cmd;
-	const char *sound_cmd;
+	char title[256];      /* override; from runtime config */
+	char notify_cmd[512]; /* override; from runtime config */
+	char sound_cmd[512];  /* override; from runtime config */
 	char msg[1024];
 } Config;
 
@@ -409,7 +411,7 @@
 static void
 notify_and_sound(const Config *c)
 {
-	if (c->notify_cmd && c->notify_cmd[0] && command_exists("notify-send")) {
+	if (c->notify_cmd[0] && command_exists("notify-send")) {
 		char **a;
 		if (build_argv(c->notify_cmd, c, &a) > 0) {
 			spawn_bg(a);
@@ -417,7 +419,7 @@
 		}
 	}
 	if (!c->quiet) {
-		if (c->sound_cmd && c->sound_cmd[0]) {
+		if (c->sound_cmd[0]) {
 			char **a;
 			if (build_argv(c->sound_cmd, c, &a) > 0) {
 				spawn_bg(a);
@@ -832,6 +834,112 @@
 	}
 }
 
+/* ===== runtime config file (~/.config/ttym/config) =====
+ * key = value lines; '#' comments. Unknown keys ignored.
+ */
+
+static void
+trim(char *s)
+{
+	char *p = s;
+	while (*p && isspace((unsigned char)*p)) p++;
+	if (p != s) memmove(s, p, strlen(p) + 1);
+	size_t n = strlen(s);
+	while (n > 0 && isspace((unsigned char)s[n-1])) s[--n] = '\0';
+}
+
+static void
+ensure_default_config_file(const char *path)
+{
+	if (access(path, F_OK) == 0) return;
+	char dir[512];
+	snprintf(dir, sizeof(dir), "%s", path);
+	char *slash = strrchr(dir, '/');
+	if (slash) { *slash = '\0'; mkdir_p(dir, 0700); }
+	FILE *f = fopen(path, "w");
+	if (!f) return;
+	fputs(
+"# ttym configuration file\n"
+"#\n"
+"# Location : ~/.config/ttym/config   (/etc/ttym.conf is read first, if present)\n"
+"# Syntax   : key = value   -- one entry per line; '#' begins a comment.\n"
+"#            A commented-out or absent key keeps its built-in default.\n"
+"#            Command-line flags override anything set in this file.\n"
+"#\n"
+"# Every key below is recognised by this build. Uncomment and edit to taste.\n"
+"# ---------------------------------------------------------------------------\n"
+"\n"
+"# Progress-bar glyphs. Set BOTH or NEITHER -- mismatched display widths\n"
+"# break bar alignment. Multi-byte UTF-8 is fine. These override bar_style.\n"
+"# bar_fill  = >\n"
+"# bar_empty = -\n"
+"\n"
+"# Named progress-bar style. One of:\n"
+"#   unicode  ascii  hash  dots  line  block  arrow  minimal\n"
+"# Leave unset to auto-detect (unicode on a UTF-8 locale, otherwise ascii).\n"
+"# bar_style = unicode\n"
+"\n"
+"# Reverse-video flash during the completion alert.   on | off\n"
+"# flash = on\n"
+"\n"
+"# Persistent alert: keep ringing the bell until a key is pressed\n"
+"# (foreground runs only).                            on | off\n"
+"# alert_persist = on\n"
+"\n"
+"# Desktop-notification title.\n"
+"# title = Timer\n"
+"\n"
+"# Desktop-notification command run when a countdown finishes. Tokens are\n"
+"# split on whitespace; {title}/{msg} placeholders expand. Empty disables.\n"
+"# notify_cmd = notify-send -u critical {title} {msg}\n"
+"\n"
+"# Sound played when a countdown finishes. Leave unset to auto-detect a\n"
+"# player (paplay/aplay/mpv/ffplay) and play a default system sound.\n"
+"# Tokens are split on whitespace; {title}/{msg} placeholders expand.\n"
+"# sound_cmd = paplay /usr/share/sounds/freedesktop/stereo/complete.oga\n",
+	f);
+	fclose(f);
+	chmod(path, 0600);
+}
+
+static void
+load_config_file(Config *c, const char *path)
+{
+	FILE *f = fopen(path, "r");
+	if (!f) return;
+	char line[1024];
+	while (fgets(line, sizeof(line), f)) {
+		char *hash = strchr(line, '#');
+		if (hash) *hash = '\0';
+		char *eq = strchr(line, '=');
+		if (!eq) continue;
+		*eq = '\0';
+		char *k = line, *v = eq + 1;
+		trim(k); trim(v);
+		if (!*k) continue;
+		if      (!strcmp(k, "bar_fill"))      snprintf(c->bar_fill,  sizeof(c->bar_fill),  "%s", v);
+		else if (!strcmp(k, "bar_empty"))     snprintf(c->bar_empty, sizeof(c->bar_empty), "%s", v);
+		else if (!strcmp(k, "bar_style"))     snprintf(c->bar_style, sizeof(c->bar_style), "%s", v);
+		else if (!strcmp(k, "flash"))         c->flash         = parse_bool_str(v);
+		else if (!strcmp(k, "alert_persist")) c->alert_persist = parse_bool_str(v);
+		else if (!strcmp(k, "title"))         snprintf(c->title,      sizeof(c->title),      "%s", v);
+		else if (!strcmp(k, "notify_cmd"))    snprintf(c->notify_cmd, sizeof(c->notify_cmd), "%s", v);
+		else if (!strcmp(k, "sound_cmd"))     snprintf(c->sound_cmd,  sizeof(c->sound_cmd),  "%s", v);
+	}
+	fclose(f);
+}
+
+static void
+load_config(Config *c)
+{
+	load_config_file(c, "/etc/ttym.conf");
+	char path[512];
+	if (build_config_path(path, sizeof(path), "config") == 0) {
+		ensure_default_config_file(path);
+		load_config_file(c, path);
+	}
+}
+
 /* ===== bar styles ===== */
 
 typedef struct { const char *name, *fill, *empty; } BarStyle;
@@ -908,7 +1016,8 @@
 "  -h              help\n"
 "\n"
 "controls:  [space] pause/resume   [q | Ctrl+C] quit\n"
-"hooks:     ~/.config/ttym/hooks/{on_start,on_done,on_quit}  (executable)\n");
+"hooks:     ~/.config/ttym/hooks/{on_start,on_done,on_quit}  (executable)\n"
+"config:    ~/.config/ttym/config  (auto-generated on first run)\n");
 }
 
 /* ===== run loop ===== */
@@ -924,6 +1033,10 @@
 	const char *fill_glyph, *empty_glyph;
 	int minimal = 0;
 	resolve_bar(cfg, &fill_glyph, &empty_glyph, &minimal);
+	/* explicit per-glyph overrides from the runtime config file
+	 * (bar_fill / bar_empty) win over the named --bar style. */
+	if (cfg->bar_fill[0])  fill_glyph  = cfg->bar_fill;
+	if (cfg->bar_empty[0]) empty_glyph = cfg->bar_empty;
 
 	ttyfd = open("/dev/tty", O_RDONLY);
 	if (ttyfd >= 0 && isatty(ttyfd)) {
@@ -1075,10 +1188,11 @@
 	Config cfg = {0};
 	cfg.alert_persist = ALERT_PERSIST;
 	cfg.flash         = FLASH;
-	cfg.title      = TITLE;
-	cfg.notify_cmd = NOTIFY_CMD;
-	cfg.sound_cmd  = SOUND_CMD;
+	snprintf(cfg.title,      sizeof(cfg.title),      "%s", TITLE      ? TITLE      : "");
+	snprintf(cfg.notify_cmd, sizeof(cfg.notify_cmd), "%s", NOTIFY_CMD ? NOTIFY_CMD : "");
+	snprintf(cfg.sound_cmd,  sizeof(cfg.sound_cmd),  "%s", SOUND_CMD  ? SOUND_CMD  : "");
 	snprintf(cfg.msg, sizeof(cfg.msg), "%s", "Time is up");
+	load_config(&cfg);
 
 	/* Pre-strip long-form flags before getopt. Stop at "--". */
 	int new_argc = 0;