diff --git a/lib/context.rb b/lib/context.rb
index a2028c6..964065d 100644
--- a/lib/context.rb
+++ b/lib/context.rb
@@ -21,6 +21,7 @@ def self.create(clock, config, data_future, data_provider,
   def initialize(clock, config, data_future, data_provider,
                  event_handler, event_logger, variable_parser, audience_matcher)
     @index = []
+    @context_custom_fields = {}
     @achievements = []
     @assignment_cache = {}
     @assignments = {}
@@ -203,6 +204,52 @@ def variable_value(key, default_value)
     default_value
   end
 
+  def custom_field_keys
+    check_ready?(true)
+    keys = []
+
+    @data.experiments.each do |experiment|
+      custom_field_values = experiment.custom_field_values
+      if custom_field_values != nil
+        custom_field_values.each do |custom_field|
+          keys.append(custom_field.name)
+        end
+      end
+    end
+
+    return keys.sort.uniq
+  end
+
+  def custom_field_value(experimentName, key)
+    check_ready?(true)
+
+    experiment_custom_fields = @context_custom_fields[experimentName]
+
+    if experiment_custom_fields != nil
+      field = experiment_custom_fields[key]
+      if field != nil
+        return field.value
+      end
+    end
+
+    return nil
+  end
+
+  def custom_field_type(experimentName, key)
+    check_ready?(true)
+
+    experiment_custom_fields = @context_custom_fields[experimentName]
+
+    if experiment_custom_fields != nil
+      field = experiment_custom_fields[key]
+      if field != nil
+        return field.type
+      end
+    end
+
+    return nil
+  end
+
   def peek_variable_value(key, default_value)
     check_ready?(true)
 
@@ -451,8 +498,11 @@ def assign_data(data)
       @data = data
       @index = {}
       @index_variables = {}
+
       if data && !data.experiments.nil? && !data.experiments.empty?
         data.experiments.each do |experiment|
+          @experimentCustomFieldValues = {}
+
           experiment_variables = ExperimentVariables.new
           experiment_variables.data = experiment
           experiment_variables.variables ||= []
@@ -467,7 +517,36 @@ def assign_data(data)
             end
           end
 
+          if !experiment.custom_field_values.nil?
+            experiment.custom_field_values.each do |custom_field_value|
+              value = ContextCustomFieldValues.new
+              value.type = custom_field_value.type
+
+              if !custom_field_value.value.nil?
+                custom_value = custom_field_value.value
+
+                if custom_field_value.type.start_with?("json")
+                  value.value = @variable_parser.parse(self, experiment.name, custom_field_value.name, custom_value)
+
+                elsif custom_field_value.type.start_with?("boolean")
+                  value.value = custom_value.to_bool
+
+                elsif custom_field_value.type.start_with?("number")
+                  value.value = custom_value.to_i
+
+                else
+                  value.value = custom_field_value.value
+                end
+
+                @experimentCustomFieldValues[custom_field_value.name] = value
+
+              end
+
+            end
+          end
+
           @index[experiment.name] = experiment_variables
+          @context_custom_fields[experiment.name] = @experimentCustomFieldValues
         end
       end
     end
@@ -544,5 +623,9 @@ class ExperimentVariables
   attr_accessor :data, :variables
 end
 
+class ContextCustomFieldValues
+  attr_accessor :type, :value
+end
+
 class IllegalStateException < StandardError
 end
diff --git a/lib/json/experiment.rb b/lib/json/experiment.rb
index 35d43d5..42e70e3 100644
--- a/lib/json/experiment.rb
+++ b/lib/json/experiment.rb
@@ -3,11 +3,12 @@
 require_relative "../string"
 require_relative "experiment_application"
 require_relative "experiment_variant"
+require_relative "custom_field_value"
 
 class Experiment
   attr_accessor :id, :name, :unit_type, :iteration, :seed_hi, :seed_lo, :split,
                 :traffic_seed_hi, :traffic_seed_lo, :traffic_split, :full_on_variant,
-                :applications, :variants, :audience_strict, :audience
+                :applications, :variants, :audience_strict, :audience, :custom_field_values
 
   def initialize(args = {})
     args.each do |name, value|
@@ -15,6 +16,10 @@ def initialize(args = {})
         @applications = assign_to_klass(ExperimentApplication, value)
       elsif name == :variants
         @variants = assign_to_klass(ExperimentVariant, value)
+      elsif name == :customFieldValues
+        if value != nil
+          @custom_field_values = assign_to_klass(CustomFieldValue, value)
+        end
       else
         self.instance_variable_set("@#{name.to_s.underscore}", value)
       end
@@ -42,7 +47,7 @@ def ==(o)
       @unit_type == that.unit_type && @split == that.split &&
       @traffic_split == that.traffic_split && @applications == that.applications &&
       @variants == that.variants && @audience_strict == that.audience_strict &&
-      @audience == that.audience
+      @audience == that.audience && @custom_field_values == that.custom_field_values
   end
 
   def hash_code
@@ -57,7 +62,8 @@ def hash_code
       traffic_seed_lo: @traffic_seed_lo,
       full_on_variant: @full_on_variant,
       audience_strict: @audience_strict,
-      audience: @audience
+      audience: @audience,
+      custom_field_values: @custom_field_values
     }
   end
 
@@ -78,6 +84,7 @@ def to_s
       ", variants=#{@variants.join}" +
       ", audienceStrict=#{@audience_strict}" +
       ", audience='#{@audience}'" +
+      ", custom_field_values='#{@custom_field_values}'" +
       "}"
   end
 end
diff --git a/spec/context_spec.rb b/spec/context_spec.rb
index 8542af6..7fa2bcb 100644
--- a/spec/context_spec.rb
+++ b/spec/context_spec.rb
@@ -698,6 +698,44 @@ def faraday_response(content)
     expect(variable_experiments).to eq(context.variable_keys)
   end
 
+  it "getCustomFieldKeys" do
+    context = create_context(data_future_ready)
+
+    expect(["country", "languages", "overrides"]).to eq(context.custom_field_keys)
+  end
+
+  it "getCustomFieldValues" do
+    context = create_context(data_future_ready)
+
+    expect(context.custom_field_value("not_found", "not_found")).to be_nil
+    expect(context.custom_field_value("exp_test_ab", key: "not_found")).to be_nil
+    expect(context.custom_field_value("exp_test_ab", "country")).to eq("US,PT,ES,DE,FR")
+    expect(context.custom_field_type("exp_test_ab", "country")).to eq("string")
+
+    data = {"123":  1, "456": 0}
+    expect(context.custom_field_value("exp_test_ab", "overrides")).to eq(data)
+    expect(context.custom_field_type("exp_test_ab", "overrides")).to eq("json")
+
+    expect(context.custom_field_value("exp_test_ab", "languages")).to be_nil
+    expect(context.custom_field_type("exp_test_ab", "languages")).to be_nil
+
+    expect(context.custom_field_value("exp_test_abc", "overrides")).to be_nil
+    expect(context.custom_field_type("exp_test_abc", "overrides")).to be_nil
+
+    expect(context.custom_field_value("exp_test_abc", "languages")).to eq("en-US,en-GB,pt-PT,pt-BR,es-ES,es-MX")
+    expect(context.custom_field_type("exp_test_abc", "languages")).to eq("string")
+
+    expect(context.custom_field_value("exp_test_no_custom_fields", "country")).to be_nil
+    expect(context.custom_field_type("exp_test_no_custom_fields", "country")).to be_nil
+
+    expect(context.custom_field_type("exp_test_no_custom_fields", "overrides")).to be_nil
+    expect(context.custom_field_value("exp_test_no_custom_fields", "overrides")).to be_nil
+
+    expect(context.custom_field_type("exp_test_no_custom_fields", "languages")).to be_nil
+    expect(context.custom_field_value("exp_test_no_custom_fields", "languages")).to be_nil
+
+  end
+
   it "peek_treatmentReturnsOverrideVariant" do
     context = create_ready_context
 
diff --git a/spec/default_context_data_deserializer_spec.rb b/spec/default_context_data_deserializer_spec.rb
index 775d6f2..de605b9 100644
--- a/spec/default_context_data_deserializer_spec.rb
+++ b/spec/default_context_data_deserializer_spec.rb
@@ -32,6 +32,10 @@
       ExperimentVariant.new("A", nil),
       ExperimentVariant.new("B", "{\"banner.border\":1,\"banner.size\":\"large\"}")
     ]
+    experiment0.custom_field_values = [
+      CustomFieldValue.new("country", "US,PT,ES,DE,FR", "string"),
+      CustomFieldValue.new("overrides", "{\"123\":1,\"456\":0}", "json"),
+    ]
     experiment0.audience_strict = false
     experiment0.audience = nil
 
@@ -53,6 +57,10 @@
       ExperimentVariant.new("B", "{\"button.color\":\"blue\"}"),
       ExperimentVariant.new("C", "{\"button.color\":\"red\"}")
     ]
+    experiment1.custom_field_values = [
+      CustomFieldValue.new("country", "US,PT,ES,DE,FR", "string"),
+      CustomFieldValue.new("languages", "en-US,en-GB,pt-PT,pt-BR,es-ES,es-MX", "string"),
+    ]
     experiment1.audience_strict = false
     experiment1.audience = ""
 
diff --git a/spec/fixtures/resources/context.json b/spec/fixtures/resources/context.json
index 6d5c4fa..036ed53 100644
--- a/spec/fixtures/resources/context.json
+++ b/spec/fixtures/resources/context.json
@@ -33,7 +33,19 @@
 					"config":"{\"banner.border\":1,\"banner.size\":\"large\"}"
 				}
 			],
-			"audience": null
+			"audience": null,
+			"customFieldValues": [
+				{
+					"name": "country",
+					"value": "US,PT,ES,DE,FR",
+					"type": "string"
+				},
+				{
+					"name": "overrides",
+					"value": "{\"123\":1,\"456\":0}",
+					"type": "json"
+				}
+			]
 		},
 		{
 			"id":2,
@@ -73,7 +85,19 @@
 					"config":"{\"button.color\":\"red\"}"
 				}
 			],
-			"audience": ""
+			"audience": "",
+			"customFieldValues": [
+				{
+					"name": "country",
+					"value": "US,PT,ES,DE,FR",
+					"type": "string"
+				},
+				{
+					"name": "languages",
+					"value": "en-US,en-GB,pt-PT,pt-BR,es-ES,es-MX",
+					"type": "string"
+				}
+			]
 		},
 		{
 			"id":3,
@@ -113,7 +137,8 @@
 					"config":"{\"card.width\":\"75%\"}"
 				}
 			],
-			"audience": "{}"
+			"audience": "{}",
+			"customFieldValues": null
 		},
 		{
 			"id":4,