diff --git a/books b/books
index 8c68f03..19e3e3e 100755
--- a/books
+++ b/books
@@ -496,6 +496,8 @@ download () {
 				dl_src_direct "$db" "$md5" "$filename"
 			fi
 		fi
+
+		log_info "downloaded: $filename"
 	done
 }
 
diff --git a/books_functions b/books_functions
index 80ace78..4bdfb2b 100644
--- a/books_functions
+++ b/books_functions
@@ -88,6 +88,30 @@ trap_clean () {
         exit
 }
 
+_log () {
+	msg="$*"
+	logdir="${XDG_STATE_HOME:-$HOME/.state}/books"
+	logfile=$(basename "$0").log
+	mkdir -p "$logdir"
+	echo "$(date -Iseconds): $msg" >> "$logdir/$logfile"
+}
+
+log_err () {
+	_log "E: $*"
+}
+
+log_warn () {
+	_log "W: $*"
+}
+
+log_info () {
+	_log "I: $*"
+}
+
+log_debug () {
+	_log "D: $*"
+}
+
 # DATABASE
 dbx () {
         db="$1"