diff --git a/.github/workflows/rspec.yml b/.github/workflows/rspec.yml
index 8272487..6dceb8d 100644
--- a/.github/workflows/rspec.yml
+++ b/.github/workflows/rspec.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        ruby: [ '2.5', '2.6', '3.0', '3.1' ]
+        ruby: [ '2.5', '2.6', '3.0', head ]
     steps:
       - uses: actions/checkout@v2
       - uses: ruby/setup-ruby@v1
diff --git a/lib/warframe/models/vallis_cycle.rb b/lib/warframe/models/vallis_cycle.rb
new file mode 100644
index 0000000..df03a0d
--- /dev/null
+++ b/lib/warframe/models/vallis_cycle.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require_relative './base'
+require_relative './attributes/id'
+require_relative './attributes/active'
+require_relative './attributes/expiry'
+
+module Warframe
+  module Models
+    # Model for VallisCycle data.
+    # {https://api.warframestat.us/pc/vallisCycle /:platform/vallisCycle}
+    class VallisCycle < Warframe::Models::Base
+      include Warframe::Models::Attributes::ID
+      include Warframe::Models::Attributes::Expiry
+      include Warframe::Models::Attributes::Activation
+
+      # @!attribute time_left
+      # @return [String] time left until next cycle.
+      attr_reader :time_left
+
+      # @!attribute is_warm?
+      # @return [Boolean] whether or not it currently is warm.
+      attr_reader :is_warm
+      alias is_warm? is_warm
+
+      # @!attribute state
+      # @return [String] the current world state (Cold or Warm)
+      attr_reader :state
+
+      # @!attribute short_string
+      # @return [String] the time remaining until state change. Ex: `5m to Warm`.
+      attr_reader :short_string
+    end
+  end
+end
diff --git a/lib/warframe/rest/api.rb b/lib/warframe/rest/api.rb
index 9a5acdb..2c4891e 100644
--- a/lib/warframe/rest/api.rb
+++ b/lib/warframe/rest/api.rb
@@ -11,9 +11,10 @@
 require_relative 'api/sortie'
 require_relative 'api/steel_path'
 require_relative 'api/syndicate_missions'
+require_relative 'api/vallis_cycle'
 
 module Warframe
-  # A REST-ful API service, provided by https://api.warframestat.us.
+  # A REST-ful API service, provided by https://api.warframestat.us
   module REST
     # The API Router for getting live data.
     #
@@ -32,6 +33,7 @@ module API
       include Warframe::REST::API::Sortie
       include Warframe::REST::API::SteelPath
       include Warframe::REST::API::SyndicateMissions
+      include Warframe::REST::API::VallisCycle
     end
   end
 end
diff --git a/lib/warframe/rest/api/vallis_cycle.rb b/lib/warframe/rest/api/vallis_cycle.rb
new file mode 100644
index 0000000..5a4b380
--- /dev/null
+++ b/lib/warframe/rest/api/vallis_cycle.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'warframe/models/vallis_cycle'
+require_relative '../utils'
+
+module Warframe
+  module REST
+    module API
+      # API endpoint for getting information on current VallisCycle data.
+      #
+      # {https://api.warframestat.us/pc/vallisCycle Example Response}
+      module VallisCycle
+        include Warframe::REST::Utils
+
+        # Gets the current vallisCycle Data.
+        # @return [Warframe::Models::VallisCycle]
+        def vallis_cycle
+          get('/vallisCycle', Warframe::Models::VallisCycle)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/fixtures/vallis_cycle.json b/spec/fixtures/vallis_cycle.json
new file mode 100644
index 0000000..1124773
--- /dev/null
+++ b/spec/fixtures/vallis_cycle.json
@@ -0,0 +1,9 @@
+{
+  "id": "vallisCycle1641060420000",
+  "expiry": "2022-01-01T18:27:08.000Z",
+  "isWarm": false,
+  "state": "cold",
+  "activation": "2022-01-01T18:07:00.000Z",
+  "timeLeft": "5m 32s",
+  "shortString": "5m to Warm"
+}
diff --git a/spec/models/vallis_cycle_spec.rb b/spec/models/vallis_cycle_spec.rb
new file mode 100644
index 0000000..ca65bcf
--- /dev/null
+++ b/spec/models/vallis_cycle_spec.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+RSpec.describe Warframe::Models::VallisCycle do
+  let(:json) { load_json_file 'vallis_cycle' }
+
+  it 'can be instantiated from JSON' do
+    expect { Warframe::Models::VallisCycle.new(json) }.to_not raise_error
+  end
+
+  let(:cycle) { Warframe::Models::VallisCycle.new(json) }
+
+  it 'can read VallisCycle data' do
+    expect(cycle.state).to eq 'cold'
+    expect(cycle.is_warm?).to eq false
+  end
+end
diff --git a/spec/rest/rest_spec.rb b/spec/rest/rest_spec.rb
index ac0157d..161fced 100644
--- a/spec/rest/rest_spec.rb
+++ b/spec/rest/rest_spec.rb
@@ -48,6 +48,18 @@ def nightwave
   end
 end
 
+def vallis_cycle
+  context '#vallis_cycle' do
+    it 'does not raise error on call' do
+      expect { client.vallis_cycle }.to_not raise_error
+    end
+
+    it 'properly loads data into model' do
+      expect(client.vallis_cycle).to be_a Warframe::Models::VallisCycle
+    end
+  end
+end
+
 RSpec.describe Warframe::REST::API do
   let(:client) { Warframe::REST::Client.new }
 
@@ -55,4 +67,5 @@ def nightwave
   cetus
   cambion
   nightwave
+  vallis_cycle
 end