diff --git a/README.md b/README.md
index 95c515f..1614ab7 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,20 @@ Eureka also parses a [twtxt](https://twtxt.readthedocs.io/en/latest/) file at `S
 6. Edit your `inc/meta.nav.htm` again to reference your new page.
 7. Run `./build.sh` again! You will be warned of any orphaned files.
 
+## build options
+
+Currently these build options are supported, and they must be supplied __in this order__ if used together:
+- `-r`: Regenerate all thumbnails
+- `-d`: Delete the latest twtxt entry; if used together with `-t`, the new entry replaces the old one
+- `-t`: Add the next arg (quoted string) as a twtxt entry
+
+Combined argument format like `./build.sh -rdt "twt stuff"` is not supported. Use this format instead:
+```
+./build.sh -r -d -t "twt stuff"
+```
+
+## debugging
+
 If you run into issues with your markup crashing `eureka`, edit the `build.sh` file to uncomment the linux debug build line and comment the fast build; this will show you a stack trace of where you are running into buffer overflows, and give you a hint of where your markup is messed up. To see the individual file that has the error, also uncomment the line in `fpinject()` that prints the file names.
 
 # markup
diff --git a/build.sh b/build.sh
index 3a62ab4..77f1144 100755
--- a/build.sh
+++ b/build.sh
@@ -41,14 +41,32 @@ cc main.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o main
 # echo "$(du -b ./main | cut -f1) bytes written"
 
 # Run
+if [ "$1" = "-r" ]; then
+  regen="true"
+  shift
+fi
+if [ "$1" = "-d" ]; then
+  shift
+  tmptwtxt=$(mktemp)
+  tail -n +2 ../www/twtxt.txt > ${tmptwtxt}
+  cp ${tmptwtxt} ../www/twtxt.txt
+  rm ${tmptwtxt}
+  echo "Deleted latest twtxt"
+fi
 if [ "$1" = "-t" ]; then
   shift && ./tw.sh $@
+  echo "Twtxt added"
 fi
 ./main
 exitstatus=$?
 if [ "${exitstatus}" = "0" ]; then
-  echo "Generating thumbnails in the background"
-  (./thumbnailer.sh build > /dev/null 2>&1) &
+  if [ "${regen}" = "true" ]; then
+    echo "Clearing thumbnails and regenerating in the background"
+    (./thumbnailer.sh clean > /dev/null 2>&1; ./thumbnailer.sh build > /dev/null 2>&1) &
+  else
+    echo "Generating thumbnails in the background"
+    (./thumbnailer.sh build > /dev/null 2>&1) &
+  fi
 fi
 
 # Cleanup