diff --git a/examples/demo/highlight.js b/examples/demo/highlight.js
new file mode 100644
index 0000000..7651e3a
--- /dev/null
+++ b/examples/demo/highlight.js
@@ -0,0 +1,36 @@
+const hl = Ant.highlight;
+const render = hl.render;
+
+console.log(render('<red>Red text</red> and back to normal'));
+console.log(render('<green>Green</green>, <blue>Blue</blue>, <yellow>Yellow</yellow>'));
+
+console.log(render('<bright_red>Bright Red</bright_red> vs <red>Normal Red</red>'));
+
+console.log(render('<bg_red>Red background</bg_red> with text'));
+console.log(render('<bg_blue><white>Blue bg with white text</white></bg_blue>'));
+
+console.log(render('<bold>Bold text</bold> and <dim>dim text</dim>'));
+console.log(render('<ul>Underlined</ul> text'));
+console.log(render('<i>Italic</i> or <italic>italic</italic>, <strike>strikethrough</strike>, <invert>inverted</invert>'));
+
+console.log(render('<bold_red>Bold red</bold_red> or <bold+blue>bold blue</bold+blue>'));
+console.log(render('<dim_cyan>Dim cyan</dim_cyan> and <i+bright_green>italic green</i+bright_green>'));
+
+console.log(render('<#ff8800>Orange hex color</#ff8800>'));
+console.log(render('<#0f0>Bright green shorthand</#0f0>'));
+console.log(render('<bg_#ff00ff>Magenta background</bg_#ff00ff>'));
+
+console.log(render('<bold>Number: 42, String: hello</bold>'));
+console.log(render('<green>Hex: 0xff, Float: 3.14</green>'));
+
+console.log(render('<red>red <reset/>back to normal immediately'));
+
+console.log(render('Literal <<: less than, >>: greater than'));
+console.log(render('Literal %%: percent sign'));
+
+const code = `\nconst x = 42;
+function greet(name) {
+  console.log(\`Hello, \${name}!\`);
+}`;
+
+console.log(hl(code));
diff --git a/examples/demo/kat.js b/examples/demo/kat.js
new file mode 100755
index 0000000..ed4b17c
--- /dev/null
+++ b/examples/demo/kat.js
@@ -0,0 +1,21 @@
+#!/usr/bin/env ant
+
+import fs from 'node:fs';
+import path from 'node:path';
+
+function exit(error) {
+  console.log(error);
+  process.exit(1);
+}
+
+const file = process.argv[2];
+if (!file) exit('usage: kat <file>');
+
+try {
+  const content = fs.readFileSync(file, 'utf8');
+  if (/\.(c|m)?(j|t)s$/.test(path.extname(file))) {
+    console.log(Ant.highlight(content));
+  } else console.log(content);
+} catch (err) {
+  exit(err.message);
+}
diff --git a/src/highlight/iter.c b/src/highlight/iter.c
index 0950d9a..404e4bb 100644
--- a/src/highlight/iter.c
+++ b/src/highlight/iter.c
@@ -356,6 +356,13 @@ bool hl_iter_next(hl_iter *it, hl_span *out) {
     return true;
   }
 
+  if (i == 0 && c == '#' && i + 1 < input_len && input[i + 1] == '!') {
+    while (i < input_len && input[i] != '\n') i++;
+    *out = (hl_span){ 0, i, HL_COMMENT };
+    it->pos = i;
+    return true;
+  }
+
   if (it->state.mode == HL_STATE_STRING_SINGLE || it->state.mode == HL_STATE_STRING_DOUBLE) {
     char quote = (it->state.mode == HL_STATE_STRING_SINGLE) ? '\'' : '"';
     size_t start = i;
diff --git a/src/modules/builtin.c b/src/modules/builtin.c
index 6f557af..66b4737 100644
--- a/src/modules/builtin.c
+++ b/src/modules/builtin.c
@@ -6,6 +6,7 @@
 #include <string.h>
 #include <time.h>
 #include <errno.h>
+#include <crprintf.h>
 
 #ifdef __APPLE__
 #include <mach/mach.h>
@@ -18,6 +19,7 @@
 #include "errors.h"
 #include "runtime.h"
 #include "internal.h"
+#include "highlight.h"
 #include "descriptors.h"
 
 #include "silver/engine.h"
@@ -358,6 +360,57 @@ static ant_value_t js_match(ant_t *js, ant_value_t *args, int nargs) {
   return js_mkundef();
 }
 
+static ant_value_t hl_get_tagged(ant_t *js, ant_value_t *args, int nargs) {
+  size_t input_len;
+  char *input = js_getstr(js, args[0], &input_len);
+
+  size_t out_size = input_len * 8 + 1;
+  char *out = malloc(out_size);
+  if (!out) return js_mkerr(js, "out of memory");
+
+  int len = ant_highlight(input, input_len, out, out_size);
+  ant_value_t result = js_mkstr(js, out, (size_t)len);
+  free(out);
+  
+  return result;
+}
+
+static ant_value_t hl_render_tagged(ant_t *js, ant_value_t tagged) {
+  size_t tagged_len;
+  char *tagged_str = js_getstr(js, tagged, &tagged_len);
+
+  size_t ansi_size = tagged_len * 2 + 1;
+  char *ansi = malloc(ansi_size);
+  if (!ansi) return js_mkerr(js, "out of memory");
+
+  int len = crsprintf_stateful(ansi, ansi_size, NULL, tagged_str);
+  ant_value_t result = js_mkstr(js, ansi, len < 0 ? 0 : (size_t)len);
+  free(ansi);
+  
+  return result;
+}
+
+static ant_value_t js_highlight(ant_t *js, ant_value_t *args, int nargs) {
+  if (nargs < 1) return js_mkerr(js, "Ant.highlight() requires 1 argument");
+  if (vtype(args[0]) != T_STR) return js_mkerr(js, "Ant.highlight() argument must be a string");
+
+  ant_value_t tagged = hl_get_tagged(js, args, nargs);
+  if (is_err(tagged)) return tagged;
+  return hl_render_tagged(js, tagged);
+}
+
+static ant_value_t js_highlight_render(ant_t *js, ant_value_t *args, int nargs) {
+  if (nargs < 1) return js_mkerr(js, "Ant.highlight.render() requires 1 argument");
+  if (vtype(args[0]) != T_STR) return js_mkerr(js, "Ant.highlight.render() argument must be a string");
+  return hl_render_tagged(js, args[0]);
+}
+
+static ant_value_t js_highlight_tags(ant_t *js, ant_value_t *args, int nargs) {
+  if (nargs < 1) return js_mkerr(js, "Ant.highlight.tags() requires 1 argument");
+  if (vtype(args[0]) != T_STR) return js_mkerr(js, "Ant.highlight.tags() argument must be a string");
+  return hl_get_tagged(js, args, nargs);
+}
+
 void init_builtin_module() {
   ant_t *js = rt->js;
   ant_value_t ant_obj = rt->ant_obj;
@@ -368,6 +421,14 @@ void init_builtin_module() {
   js_set(js, ant_obj, "sleep", js_mkfun(js_sleep));
   js_set(js, ant_obj, "msleep", js_mkfun(js_msleep));
   js_set(js, ant_obj, "usleep", js_mkfun(js_usleep));
+  
+  ant_value_t hl_obj = js_newobj(js);
+  ant_value_t hl_fn = js_obj_to_func(hl_obj);
+  
+  js_set_slot(hl_obj, SLOT_CFUNC, js_mkfun(js_highlight));
+  js_set(js, hl_fn, "render", js_mkfun(js_highlight_render));
+  js_set(js, hl_fn, "tags", js_mkfun(js_highlight_tags));
+  js_set(js, ant_obj, "highlight", hl_fn);
 
   ant_value_t raw_obj = js_newobj(js);
   js_set_getter_desc(js, js_as_obj(raw_obj), "stack", 5, js_mkfun(js_raw_stack), JS_DESC_C);
diff --git a/src/readline.c b/src/readline.c
index e2015e4..f071055 100644
--- a/src/readline.c
+++ b/src/readline.c
@@ -308,24 +308,20 @@ static void refresh_line(const char *line, int len, int pos, const char *prompt)
   repl_clear_to_end();
   if (crprintf_get_color() && len > 0) {
     if (len <= 2048) {
-      char tagged[8192];
-      char rendered[8192];
-
-      highlight_state state = hl_line_state;
-      ant_highlight_stateful(line, (size_t)len, tagged, sizeof(tagged), &state);
-
-      hl_prog = crprintf_recompile(hl_prog, tagged);
-      crprintf_state *rs = crprintf_state_new();
-      crsprintf_compiled(rendered, sizeof(rendered), rs, hl_prog);
-      crprintf_state_free(rs);
-
-      fputs(rendered, stdout);
-    } else {
-      fwrite(line, 1, (size_t)len, stdout);
-    }
-  } else if (len > 0) {
-    fwrite(line, 1, (size_t)len, stdout);
-  }
+    char tagged[8192];
+    char rendered[8192];
+    
+    highlight_state state = hl_line_state;
+    ant_highlight_stateful(line, (size_t)len, tagged, sizeof(tagged), &state);
+    
+    hl_prog = crprintf_recompile(hl_prog, tagged);
+    crprintf_state *rs = crprintf_state_new();
+    crsprintf_compiled(rendered, sizeof(rendered), rs, hl_prog);
+    crprintf_state_free(rs);
+    
+    fputs(rendered, stdout);
+    } else fwrite(line, 1, (size_t)len, stdout);
+  } else if (len > 0) fwrite(line, 1, (size_t)len, stdout);
   
 #ifndef _WIN32
   if ((x_end == 0) && (y_end > 0) && (len > 0) && (line[len - 1] != '\n')) {