diff --git a/scripts/_common.sh b/scripts/_common.sh
new file mode 100644
index 0000000..1526a14
--- /dev/null
+++ b/scripts/_common.sh
@@ -0,0 +1,45 @@
+#
+# Common variables
+#
+
+# Shaarli version
+VERSION="0.8.3"
+
+# Download shaarli (dependencies included)
+# Full Shaarli sources tarball URL
+SHAARLI_SOURCE_URL=https://github.com/shaarli/Shaarli/releases/download/v${VERSION}/shaarli-v${VERSION}-full.tar.gz
+
+# Full Shaarli sources tarball checksum
+SHAARLI_SOURCE_SHA256="dbf0fd3fbe679ebd642ddef5f5a90244e07beda28d1aedd35ef04f9c7d74068f"
+
+#
+# Common helpers
+#
+
+# Source app helpers
+. /usr/share/yunohost/helpers
+
+# Download and extract Shaarli sources to the given directory
+# usage: extract_shaarli DESTDIR [AS_USER]
+extract_shaarli() {
+    local AS_USER=${6:-$USER}
+
+    # Retrieve and extract Shaarli tarball
+    sh_tarball="/tmp/shaarli.tar.gz"
+    rm -f "$sh_tarball"
+    wget -q -O "$sh_tarball" "$SHAARLI_SOURCE_URL" \
+        || ynh_die "Unable to download Shaarli tarball"
+    echo "$SHAARLI_SOURCE_SHA256 $sh_tarball" | sha256sum -c >/dev/null \
+        || ynh_die "Invalid checksum of downloaded tarball"
+    sudo tar xf "$sh_tarball" -C "$final_path" --strip-components 1 \
+        || ynh_die "Unable to extract Shaarli tarball"
+    rm -f "$sh_tarball"
+
+    wget -q -O "$sh_tarball" "$SHAARLI_SOURCE_URL" \
+        || ynh_die "Unable to download Shaarli tarball"
+    echo "$SHAARLI_SOURCE_SHA256 $sh_tarball" | sha256sum -c >/dev/null \
+        || ynh_die "Invalid checksum of downloaded tarball"
+    sudo tar xf "$sh_tarball" -C "$final_path" --strip-components 1 \
+        || ynh_die "Unable to extract Shaarli tarball"
+    sudo chown -R www-data: $final_path
+}