diff --git a/.gitignore b/.gitignore
index 85226e9..0b0a77a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .cache/
 _site/
 .direnv/
+engine/envvars.sh
diff --git a/Makefile b/Makefile
index 019188d..43308b8 100644
--- a/Makefile
+++ b/Makefile
@@ -67,7 +67,7 @@ ALL += indexcache
 DST_INDEX_FILES ?= $(patsubst %.xml,%.index, $(DST_XML_FILES))
 MK_INDEX_ENTRY := ./engine/mk-index-entry.sh
 INDEX_CACHE_DIR ?= $(CACHE_DIR)/rss
-$(INDEX_CACHE_DIR)/%.index: $(INDEX_CACHE_DIR)/%.xml $(MK_INDEX_ENTRY)
+$(INDEX_CACHE_DIR)/%.index: $(INDEX_CACHE_DIR)/%.xml $(MK_INDEX_ENTRY) $(ENV_VARS)
 	@mkdir -p $(INDEX_CACHE_DIR)
 	$(MK_INDEX_ENTRY) "$<" "$@"
 
@@ -81,8 +81,14 @@ $(HTML_INDEX): $(DST_INDEX_FILES) $(MKINDEX) $(INDEX_TEMPLATE)
 index: $(HTML_INDEX)
 ALL += index
 
+ENV_VARS := ./engine/envvars.sh
+NIX_FILES := ./shell.nix  $(shell find nix -type f)
+$(ENV_VARS): $(NIX_FILES)
+	echo "export PATH=\"${PATH}\"" >> ./engine/envvars.sh
+ALL += ./engine/envvars.sh
+
 # RSS
-DST_RSS_FILES ?= $(patsubst %.xml,%.rss, $(DST_XML_FILES))
+DST_RSS_FILES ?= $(patsubst %.xml,%.rss, $(DST_XML_FILES)) $(ENV_VARS)
 MK_RSS_ENTRY := ./engine/mk-rss-entry.sh
 $(RSS_CACHE_DIR)/%.rss: $(RSS_CACHE_DIR)/%.xml $(MK_RSS_ENTRY)
 	@mkdir -p $(RSS_CACHE_DIR)
@@ -90,7 +96,7 @@ $(RSS_CACHE_DIR)/%.rss: $(RSS_CACHE_DIR)/%.xml $(MK_RSS_ENTRY)
 
 RSS := $(DST_DIR)/rss.xml
 MKRSS := engine/mkrss.sh
-$(RSS): $(DST_RSS_FILES) $(MKRSS)
+$(RSS): $(DST_RSS_FILES) $(MKRSS) $(ENV_VARS)
 	$(MKRSS)
 
 .PHONY: rss
@@ -115,7 +121,7 @@ gmi: $(DST_GMI_FILES)
 # GEMINI INDEX
 GMI_INDEX := $(DST_DIR)/index.gmi
 MK_GMI_INDEX := engine/mk-gemini-index.sh
-$(GMI_INDEX): $(DST_GMI_FILES) $(MK_GMI_INDEX)
+$(GMI_INDEX): $(DST_GMI_FILES) $(MK_GMI_INDEX) $(ENV_VARS)
 	@mkdir -p $(DST_DIR)
 	$(MK_GMI_INDEX)
 ALL += $(GMI_INDEX)
diff --git a/engine/mk-gemini-index.sh b/engine/mk-gemini-index.sh
index 9e33042..3a2d95d 100755
--- a/engine/mk-gemini-index.sh
+++ b/engine/mk-gemini-index.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env zsh
 
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 # Directory
 webdir="_site"
 postsdir="$webdir/posts"
diff --git a/engine/mk-index-entry.sh b/engine/mk-index-entry.sh
index 4080b0c..ff98a87 100755
--- a/engine/mk-index-entry.sh
+++ b/engine/mk-index-entry.sh
@@ -1,5 +1,6 @@
 #!/usr/bin/env zsh
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 xfic="$1"
 dst="$2"
 
@@ -10,9 +11,11 @@ indexdir=".cache/rss"
 dateaccessor='.yyydate'
 # title and keyword shouldn't be changed
 titleaccessor='title'
+keywordsaccessor='meta[name=keywords]::attr(content)'
 
 finddate(){ < $1 hxselect -c $dateaccessor | sed 's/\[//g;s/\]//g;s/ .*$//' }
 findtitle(){ < $1 hxselect -c $titleaccessor }
+findkeywords(){ < $1 hxselect -c $keywordsaccessor | sed 's/,/ /g' }
 
 autoload -U colors && colors
 
@@ -20,7 +23,6 @@ blogfile="$(echo "$xfic"|sed 's#.xml$#.html#;s#^'$indexdir'/#posts/#')"
 printf "%-30s" $blogfile
 d=$(finddate $xfic)
 echo -n " [$d]"
-rssdate=$(formatdate $d)
 title=$(findtitle $xfic)
 keywords=( $(findkeywords $xfic) )
 printf ": %-55s" "$title ($keywords)"
diff --git a/engine/mk-index.sh b/engine/mk-index.sh
index 88ab85e..0d3e525 100755
--- a/engine/mk-index.sh
+++ b/engine/mk-index.sh
@@ -2,6 +2,7 @@
 
 autoload -U colors && colors
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 # Directory
 webdir="_site"
 indexfile="$webdir/index.html"
diff --git a/engine/mk-rss-entry.sh b/engine/mk-rss-entry.sh
index 7bb8b31..b455642 100755
--- a/engine/mk-rss-entry.sh
+++ b/engine/mk-rss-entry.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env zsh
 
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 # Directory
 webdir="_site"
 postsdir="$webdir/posts"
diff --git a/engine/mkrss.sh b/engine/mkrss.sh
index 0a137fd..62507b9 100755
--- a/engine/mkrss.sh
+++ b/engine/mkrss.sh
@@ -1,6 +1,7 @@
-#!/usr/bin/env zsh
+#! /usr/bin/env zsh
 
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 # Directory
 webdir="_site"
 postsdir="$webdir/posts"
@@ -104,4 +105,4 @@ cp -f "$rssfile" "$legacyenrss"
 cp -f "$rssfile" "$legacyfrrss"
 
 rm -rf $tmpdir
-echo "* RSS [done]"
+echo "\* RSS [done]"
diff --git a/engine/update-file-size.sh b/engine/update-file-size.sh
index d12d4de..c5a0fe6 100755
--- a/engine/update-file-size.sh
+++ b/engine/update-file-size.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env zsh
 
 cd "$(git rev-parse --show-toplevel)" || exit 1
+source ./engine/envvars.sh
 webdir="_optim"
 
 sizeof() {
diff --git a/shell.nix b/shell.nix
index 66631e5..fd21969 100644
--- a/shell.nix
+++ b/shell.nix
@@ -13,7 +13,8 @@ pkgs.mkShell {
       [ cacert
         coreutils
         entr
-        html-xml-utils
+        pandoc
+        html-xml-utils # hxselect
         zsh
         perl
         perlPackages.URI