diff --git a/src/build.sh b/src/build.sh
new file mode 100644
index 0000000..e5653c4
--- /dev/null
+++ b/src/build.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env nix-shell
+#! nix-shell -i bash --pure
+#! nix-shell -p bash curl gcc zlib libffi icu77
+VERSION="140.4.0esr"
+DOWNLOAD="https://ftp.mozilla.org/pub/firefox/releases/$VERSION/source/firefox-$VERSION.source.tar.xz/"
+BUILDPATH=$(realpath .)
+#unzip this or something
+curl -RO $DOWNLOAD
+tar -xzf "firefox-$VERSION.source.tar.xz src"
+
+cd "src/js/src"
+
+mkdir _build
+cd _build
+
+../configure --disable-jemalloc --with-system-zlib --with-system-icu --prefix=$BUILDPATH \
+    --with-intl-api --enable-optimize
+
+make 
+make install
\ No newline at end of file