--- a
+++ b/docs/jekyll-theme-cayman.gemspec
@@ -0,0 +1,20 @@
+Gem::Specification.new do |s|
+  s.name          = 'jekyll-theme-cayman'
+  s.version       = '0.1.1'
+  s.license       = 'CC0-1.0'
+  s.authors       = ['Jason Long', 'GitHub, Inc.']
+  s.email         = ['opensource+jekyll-theme-cayman@github.com']
+  s.homepage      = 'https://github.com/pages-themes/cayman'
+  s.summary       = 'Cayman is a Jekyll theme for GitHub Pages'
+
+  s.files         = `git ls-files -z`.split("\x0").select do |f|
+    f.match(%r{^((_includes|_layouts|_sass|assets)/|(LICENSE|README)((\.(txt|md|markdown)|$)))}i)
+  end
+
+  s.platform = Gem::Platform::RUBY
+  s.add_runtime_dependency 'jekyll', '~> 3.5'
+  s.add_runtime_dependency 'jekyll-seo-tag', '~> 2.0'
+  s.add_development_dependency 'html-proofer', '~> 3.0'
+  s.add_development_dependency 'rubocop', '~> 0.50'
+  s.add_development_dependency 'w3c_validators', '~> 1.3'
+end