diff --git a/.github/category_list.rb b/.github/osia_category_list.rb
similarity index 55%
rename from .github/category_list.rb
rename to .github/osia_category_list.rb
index 1364299c..65ac6b6f 100644
--- a/.github/category_list.rb
+++ b/.github/osia_category_list.rb
@@ -1,8 +1,6 @@
-require 'json'
-
-c = File.read 'contents.json'
-j = JSON.parse c
+require_relative 'osia_helper'
 
+j = get_json
 c = j['categories']
 
 c.sort_by { |h| h['title']}
diff --git a/.github/convert.rb b/.github/osia_convert.rb
similarity index 98%
rename from .github/convert.rb
rename to .github/osia_convert.rb
index 40ed3a55..04563a78 100644
--- a/.github/convert.rb
+++ b/.github/osia_convert.rb
@@ -1,45 +1,11 @@
+require_relative 'osia_helper'
 require 'date'
-require 'json'
 
 README = 'README.md'
 
 ARCHIVE = 'ARCHIVE.md'
 ARCHIVE_TAG = 'archive'
 
-def output_stars(number)
-  case number
-  when 100...200
-    '🔥'
-  when 200...500
-    '🔥🔥'
-  when 500...1000
-    '🔥🔥🔥'
-  when 1000...2000
-    '🔥🔥🔥🔥'
-  when 2000...100000
-    '🔥🔥🔥🔥🔥'
-  else
-    ''
-  end
-end
-
-def output_flag(lang)
-  case lang
-  when 'jpn'
-    '🇯🇵'
-  when 'ltz'
-    '🇱🇺'
-  when 'por'
-    '🇧🇷'
-  when 'spa'
-    '🇪🇸'
-  when 'zho'
-    '🇨🇳'
-  else
-    ''
-  end
-end
-
 def apps_archived(apps)
   a = apps.select {|a| a['tags'] != nil }.select {|b| b['tags'].include?ARCHIVE_TAG}
   a.sort_by { |k, v| k['title'] }
@@ -103,6 +69,40 @@ def output_apps(apps)
   o
 end
 
+def output_flag(lang)
+  case lang
+  when 'jpn'
+    '🇯🇵'
+  when 'ltz'
+    '🇱🇺'
+  when 'por'
+    '🇧🇷'
+  when 'spa'
+    '🇪🇸'
+  when 'zho'
+    '🇨🇳'
+  else
+    ''
+  end
+end
+
+def output_stars(number)
+  case number
+  when 100...200
+    '🔥'
+  when 200...500
+    '🔥🔥'
+  when 500...1000
+    '🔥🔥🔥'
+  when 1000...2000
+    '🔥🔥🔥🔥'
+  when 2000...100000
+    '🔥🔥🔥🔥🔥'
+  else
+    ''
+  end
+end
+
 def write_readme(j)
   t    = j['title']
   desc = j['description']
@@ -178,8 +178,7 @@ def write_archive(j)
   puts "wrote #{file} ✨"
 end
 
-c = File.read 'contents.json'
-j = JSON.parse c
+j = get_json
 
 write_readme(j)
 write_archive(j)
diff --git a/.github/osia_helper.rb b/.github/osia_helper.rb
new file mode 100644
index 00000000..f9e0933d
--- /dev/null
+++ b/.github/osia_helper.rb
@@ -0,0 +1,7 @@
+require 'json'
+
+FILE = 'contents.json'
+
+def get_json
+  JSON.parse(File.read FILE)
+end
diff --git a/.github/update_stars.rb b/.github/osia_update_stars.rb
similarity index 89%
rename from .github/update_stars.rb
rename to .github/osia_update_stars.rb
index f227ddd7..c9f7081e 100644
--- a/.github/update_stars.rb
+++ b/.github/osia_update_stars.rb
@@ -1,15 +1,11 @@
-require 'json'
+require_relative 'osia_helper'
 
 require 'octokit'
 require 'netrc'
 
-FILE = 'contents.json'
-
-c = File.read FILE
-j = JSON.parse c
-
 client = Octokit::Client.new(:netrc => true)
 
+j = get_json
 apps = j['projects']
 updated = []
 
diff --git a/.github/osia_validate_categories.rb b/.github/osia_validate_categories.rb
new file mode 100644
index 00000000..6c023ab4
--- /dev/null
+++ b/.github/osia_validate_categories.rb
@@ -0,0 +1,34 @@
+require_relative 'osia_helper'
+
+j = get_json
+c = j['categories']
+a = j['projects']
+
+def failed(cat, app)
+  puts "‼️  #{cat} is not a valid category for #{app}"
+  exit 1
+end
+
+def verify(cat, allowed, app)
+  failed(cat, app) unless allowed.include? cat
+end
+
+allowed_categories = c.sort_by { |h| h['title']}.map { |x| x['id']}
+
+a.each do |a|
+  cat = a['category']
+
+  if cat.nil?
+    # failed(cat, a)
+    puts "missing category for #{a}"
+    exit 1
+  end
+
+  if cat.class == String
+    verify(cat, allowed_categories, a)
+  elsif cat.class == Array
+    cat.each { |c| verify(c, allowed_categories, a) }
+  end
+end
+
+puts 'categories validated ✅'
diff --git a/circle.yml b/circle.yml
index e3dbc925..92f2c97d 100644
--- a/circle.yml
+++ b/circle.yml
@@ -8,6 +8,7 @@ test:
   override:
     - awesome_bot contents.json --white-list developer.apple
     - json validate --schema-file=.github/schema.json --document-file=contents.json
+    - ruby .github/osia_validate_categories.rb
 general:
   artifacts:
     - "ab-results.json"
@@ -15,5 +16,5 @@ deployment:
   master:
     branch: master
     commands:
-      - ruby .github/convert.rb
+      - ruby .github/osia_convert.rb
       - ./.github/deploy.sh