diff -ruN a/ttym.c b/ttym.c
--- a/ttym.c	2026-05-20 12:02:00.123998202 +0200
+++ b/ttym.c	2026-05-20 12:24:33.731972801 +0200
@@ -12,6 +12,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
 #include <termios.h>
 #include <time.h>
 #include <unistd.h>
@@ -23,6 +25,7 @@
 typedef struct {
 	int quiet;            /* -q: suppress completion bell */
 	int silent;           /* -s: no bell, no extras */
+	char comment[512];    /* passed as 3rd arg to hooks */
 } Config;
 
 static struct termios oldtios;
@@ -226,6 +229,43 @@
 	fflush(stdout);
 }
 
+/* ===== hooks ===== */
+
+static int
+build_hook_path(char *buf, size_t bufsz, const char *name)
+{
+	const char *home = getenv("HOME");
+	const char *xdg  = getenv("XDG_CONFIG_HOME");
+	if (xdg && *xdg)        snprintf(buf, bufsz, "%s/ttym/hooks/%s", xdg, name);
+	else if (home && *home) snprintf(buf, bufsz, "%s/.config/ttym/hooks/%s", home, name);
+	else return -1;
+	return 0;
+}
+
+static void
+run_hook(const char *name, const char *mode, long duration_s, const char *comment)
+{
+	char path[512];
+	if (build_hook_path(path, sizeof(path), name) < 0) return;
+	if (access(path, X_OK) != 0) return;
+	char dur[32];
+	snprintf(dur, sizeof(dur), "%ld", duration_s);
+	pid_t pid = fork();
+	if (pid == 0) {
+		int devnull = open("/dev/null", O_RDWR);
+		if (devnull >= 0) {
+			dup2(devnull, 0); dup2(devnull, 1); dup2(devnull, 2);
+			if (devnull > 2) close(devnull);
+		}
+		char *argv[] = { path, (char *)mode, dur,
+		                 (char *)(comment ? comment : ""), NULL };
+		execvp(argv[0], argv);
+		_exit(127);
+	} else if (pid > 0) {
+		waitpid(pid, NULL, 0);
+	}
+}
+
 /* ===== usage =====
  * Patches MUST update this in lockstep with new flags so -h always
  * reflects the build.
@@ -241,12 +281,14 @@
 "\n"
 "DURATION:  25m | 90s | 2h | 1h30m | 01:30:00 | 25:00\n"
 "FLAGS:\n"
+"  -c TEXT         comment, passed as 3rd arg to hooks\n"
 "  -q              no sound\n"
 "  -s              silent\n"
 "  --              end of options\n"
 "  -h              help\n"
 "\n"
-"controls:  [space] pause/resume   [q | Ctrl+C] quit\n");
+"controls:  [space] pause/resume   [q | Ctrl+C] quit\n"
+"hooks:     ~/.config/ttym/hooks/{on_start,on_done,on_quit}  (executable)\n");
 }
 
 /* ===== run loop ===== */
@@ -280,6 +322,9 @@
 	if (out_tty)
 		fputs("\033[?25l\033[?7l", stdout);
 
+	run_hook("on_start", stopwatch ? "stopwatch" : "countdown",
+	         stopwatch ? 0 : total, cfg->comment);
+
 	long start_ms    = now_ms();
 	long pause_accum = 0;
 	long pause_start = 0;
@@ -356,6 +401,7 @@
 			printf("\r\033[32mSTOP %s%*s\033[0m\n", el, 30, "");
 		else
 			printf("STOP %s\n", el);
+		run_hook("on_quit", "stopwatch", elapsed_s, cfg->comment);
 	} else if (user_quit) {
 		char el[24];
 		fmt_clock(elapsed_s, el, sizeof(el));
@@ -363,6 +409,7 @@
 			printf("\r\033[33mQUIT at %s%*s\033[0m\n", el, 30, "");
 		else
 			printf("QUIT at %s\n", el);
+		run_hook("on_quit", "countdown", elapsed_s, cfg->comment);
 	} else {
 		char tb[24];
 		fmt_clock(total, tb, sizeof(tb));
@@ -370,6 +417,7 @@
 			printf("\r\033[32mDONE %s 100%%%*s\033[0m\n", tb, 20, "");
 		else
 			printf("DONE %s 100%%\n", tb);
+		run_hook("on_done", "countdown", total, cfg->comment);
 		if (!cfg->silent && !cfg->quiet && out_tty) {
 			fputc('\a', stdout);
 			fflush(stdout);
@@ -404,10 +452,11 @@
 	new_argv[new_argc] = NULL;
 
 	int opt;
-	while ((opt = getopt(new_argc, new_argv, "qsh")) != -1) {
+	while ((opt = getopt(new_argc, new_argv, "qsc:h")) != -1) {
 		switch (opt) {
 		case 'q': cfg.quiet  = 1; break;
 		case 's': cfg.silent = 1; break;
+		case 'c': snprintf(cfg.comment, sizeof(cfg.comment), "%s", optarg); break;
 		case 'h': usage(stdout); free(new_argv); return 0;
 		default:  usage(stderr); free(new_argv); return 1;
 		}