diff --git a/blog b/blog
index 9918182..759f669 100755
--- a/blog
+++ b/blog
@@ -254,3 +254,31 @@ multi MAIN(
         }
     }
 }
+
+#| Add or remove a tag to a post
+multi MAIN(
+    "post",
+    "tag",
+    #| The id of the post to display information for
+    Int $id,
+    #| The tag to add/remove
+    Str $tag,
+    #| remove the tag instead of adding it
+    Bool :$remove,
+    #| The path of the database directory
+    IO::Path(Str) :$db-dir = $default-db-dir,
+) {
+    my $db = read-db $db-dir;
+    my $post = $db.posts{$id.Int};
+    if $remove {
+        die "Post did not have requested tag"
+            unless $tag ~~ any($post.tags);
+        my $index = $post.tags.first: $tag;
+        $post.tags.=grep(* ne $tag);
+    } else {
+        die "Post already had requested tag"
+            if $tag ~~ any($post.tags);
+        $post.tags.push: $tag;
+    }
+    $db.write: $db-dir;
+}
diff --git a/lib/DB/Post.rakumod b/lib/DB/Post.rakumod
index 246753e..c1e98c7 100644
--- a/lib/DB/Post.rakumod
+++ b/lib/DB/Post.rakumod
@@ -37,7 +37,7 @@ DateTime:D @.edited-at
 #| An optional list of extra slugs to use for this post
 has Str:D @.slugs is json = [];
 #| An optional list of tags for this post
-has Str:D @.tags is json = [];
+has Str:D @.tags is rw is json = [];
 #| Should the post be hidden from the main list
 has Bool:D $.hidden is json is rw = False;