diff --git a/antora-ui/build.sh b/antora-ui/build.sh
index 44a7c18..850029e 100755
--- a/antora-ui/build.sh
+++ b/antora-ui/build.sh
@@ -7,11 +7,15 @@ if [ -z "$npm_version" ]; then
   echo "npm is not installed"
   exit 1
 fi
+
 gulp_version=$(gulp --version 2>/dev/null)
 if [ -z "$gulp_version" ]; then
   echo "gulp is not installed"
   exit 1
 fi
 
-npm install
+if [ ! -d "node_modules" ] || [ "$(find package.json -prune -printf '%T@\n' | cut -d . -f 1)" -gt "$(find node_modules -prune -printf '%T@\n' | cut -d . -f 1)" ]; then
+  npm install
+fi
+
 gulp bundle
diff --git a/antora-ui/src/partials/footer-content.hbs b/antora-ui/src/partials/footer-content.hbs
index cdeeb47..2724c41 100644
--- a/antora-ui/src/partials/footer-content.hbs
+++ b/antora-ui/src/partials/footer-content.hbs
@@ -1,4 +1,11 @@
 <footer class="footer">
   <p>This page was built using the Antora default UI.</p>
   <p>The source code for this UI is licensed under the terms of the MPL-2.0 license.</p>
+  <p><a href="https://github.com/cppalliance/site-docs">https://github.com/cppalliance/site-docs</a></p>
+  {{#if page.attributes.boost-branch}}
+    <p>boost-branch: {{ page.attributes.boost-branch }}</p>
+  {{/if}}
+  {{#if page.attributes.commit-id}}
+    <p>commit-id: {{ page.attributes.commit-id }}</p>
+  {{/if}}
 </footer>
diff --git a/build.sh b/build.sh
index deb3bf2..f07ef64 100755
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,13 @@
 #!/bin/sh
 
-./sitedoc.sh develop
+if command -v git >/dev/null && git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+  branch=$(git rev-parse --abbrev-ref HEAD)
+else
+  branch="develop"
+fi
+
+if [ "$branch" != "master" ] && [ "$branch" != "develop" ]; then
+  branch="develop"
+fi
+
+./sitedoc.sh "$branch"
diff --git a/libdoc.sh b/libdoc.sh
index a09b274..31b05d9 100755
--- a/libdoc.sh
+++ b/libdoc.sh
@@ -55,18 +55,27 @@ if ! [ -e "$script_dir/antora-ui/build/ui-bundle.zip" ]; then
   cd "$cwd" || exit
 fi
 
+if command -v git >/dev/null && git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+  commit_id=$(git rev-parse HEAD)
+  commit_id=$(expr substr "$commit_id" $(expr length "$commit_id" - 7) 8)
+else
+  commit_id=""
+fi
+
 # Run antora command
 while test $# -gt 0; do
   if [ "$1" = "develop" ] || [ "$1" = "master" ]; then
     $ANTORA_CMD --fetch \
       --attribute page-boost-branch=$1 \
       --attribute page-boost-ui-branch=$1 \
+      --attribute page-commit-id="$commit_id" \
       libs.playbook.yml
 
   elif [ "$1" = "release" ]; then
     $ANTORA_CMD --fetch \
       --attribute page-boost-branch=master \
       --attribute page-boost-ui-branch=master \
+      --attribute page-commit-id="$commit_id" \
       --attribute page-boost-is-release=true \
       libs.playbook.yml
 
@@ -77,6 +86,7 @@ while test $# -gt 0; do
       $ANTORA_CMD --fetch \
       --attribute page-boost-branch=$1 \
       --attribute page-boost-ui-branch=master \
+      --attribute page-commit-id="$commit_id" \
         "$f"
     else
       echo "Playbook \"$f\" does not exist"
diff --git a/libs.playbook.yml b/libs.playbook.yml
index 473be68..67ecb05 100644
--- a/libs.playbook.yml
+++ b/libs.playbook.yml
@@ -30,6 +30,7 @@ asciidoc:
     page-boost-branch: develop
     page-boost-ui-branch: develop
     page-boost-is-release: ''
+    page-commit-id: ''
 
 site:
   url: https://antora.cppalliance.org/${page-boost-branch}/lib/doc
diff --git a/site.playbook.yml b/site.playbook.yml
index 7c8ccd8..114e40d 100644
--- a/site.playbook.yml
+++ b/site.playbook.yml
@@ -20,6 +20,7 @@
 asciidoc:
   attributes:
     page-boost-branch: develop
+    page-commit-id: ''
 
 site:
   url: https://antora.cppalliance.org
diff --git a/sitedoc.sh b/sitedoc.sh
index 8c5eb69..0a4ad32 100755
--- a/sitedoc.sh
+++ b/sitedoc.sh
@@ -42,23 +42,27 @@ fi
 
 cwd=$(pwd)
 script_dir=$(dirname "$(readlink -f "$0")")
-if ! [ -e "$script_dir/antora-ui/build/ui-bundle.zip" ]; then
+if ! [ -e "$script_dir/antora-ui/build/ui-bundle.zip" ] || \
+   find "$script_dir/antora-ui" -newer "$script_dir/antora-ui/build/ui-bundle.zip" -print -quit | grep -q .
+then
   cd "$script_dir/antora-ui" || exit
   ./build.sh
   cd "$cwd" || exit
 fi
 
-while test $# -gt 0; do
-  if [ "$1" = "develop" ]; then
-    $ANTORA_CMD --fetch \
-      --attribute page-boost-branch=$1 \
-      site.playbook.yml
-  elif [ "$1" = "master" ]; then
-    $ANTORA_CMD --fetch \
-      --attribute page-boost-branch=$1 \
-      site.playbook.yml
-  else
-    echo "invalid argument: '$1'"
-  fi
-  shift
-done
+if command -v git >/dev/null && git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+  commit_id=$(git rev-parse HEAD)
+  commit_id=$(expr substr "$commit_id" $(expr length "$commit_id" - 7) 8)
+else
+  commit_id=""
+fi
+
+if [ "$1" != "develop" ] && [ "$1" != "master" ]; then
+  echo "invalid argument: '$1'"
+  exit 1
+fi
+
+$ANTORA_CMD --fetch \
+  --attribute page-boost-branch="$1" \
+  --attribute page-commit-id="$commit_id" \
+  site.playbook.yml