diff --git a/lib/optimizely/config/datafile_project_config.rb b/lib/optimizely/config/datafile_project_config.rb
index 25357133..9be9ba5d 100644
--- a/lib/optimizely/config/datafile_project_config.rb
+++ b/lib/optimizely/config/datafile_project_config.rb
@@ -27,7 +27,7 @@ class DatafileProjectConfig < ProjectConfig
     attr_reader :datafile, :account_id, :attributes, :audiences, :typed_audiences, :events,
                 :experiments, :feature_flags, :groups, :project_id, :bot_filtering, :revision,
                 :sdk_key, :environment_key, :rollouts, :version, :send_flag_decisions,
-                :attribute_key_map, :audience_id_map, :event_key_map, :experiment_feature_map,
+                :attribute_key_map, :attribute_id_to_key_map, :audience_id_map, :event_key_map, :experiment_feature_map,
                 :experiment_id_map, :experiment_key_map, :feature_flag_key_map, :feature_variable_key_map,
                 :group_id_map, :rollout_id_map, :rollout_experiment_id_map, :variation_id_map,
                 :variation_id_to_variable_usage_map, :variation_key_map, :variation_id_map_by_experiment_id,
@@ -82,6 +82,10 @@ def initialize(datafile, logger, error_handler)
 
       # Utility maps for quick lookup
       @attribute_key_map = generate_key_map(@attributes, 'key')
+      @attribute_id_to_key_map = {}
+      @attributes.each do |attribute|
+        @attribute_id_to_key_map[attribute['id']] = attribute['key']
+      end
       @event_key_map = generate_key_map(@events, 'key')
       @group_id_map = generate_key_map(@groups, 'id')
       @group_id_map.each do |key, group|
@@ -440,6 +444,40 @@ def get_attribute_id(attribute_key)
       nil
     end
 
+    def get_attribute_by_key(attribute_key)
+      # Get attribute for the provided attribute key.
+      #
+      # Args:
+      #   Attribute key for which attribute is to be fetched.
+      #
+      # Returns:
+      #   Attribute corresponding to the provided attribute key.
+      attribute = @attribute_key_map[attribute_key]
+      return attribute if @attribute_key_map.key?(attribute_key)
+
+      invalid_attribute_error = InvalidAttributeError.new(attribute_key)
+      @logger.log Logger::ERROR, invalid_attribute_error.message
+      @error_handler.handle_error invalid_attribute_error
+      nil
+    end
+
+    def get_attribute_key_by_id(attribute_id)
+      # Get attribute key for the provided attribute ID.
+      #
+      # Args:
+      #   Attribute ID for which attribute is to be fetched.
+      #
+      # Returns:
+      #   Attribute key corresponding to the provided attribute ID.
+      attribute = @attribute_id_to_key_map[attribute_id]
+      return attribute if @attribute_id_to_key_map.key?(attribute_id)
+
+      invalid_attribute_error = InvalidAttributeError.new(attribute_id)
+      @logger.log Logger::ERROR, invalid_attribute_error.message
+      @error_handler.handle_error invalid_attribute_error
+      nil
+    end
+
     def variation_id_exists?(experiment_id, variation_id)
       # Determines if a given experiment ID / variation ID pair exists in the datafile
       #
diff --git a/lib/optimizely/helpers/constants.rb b/lib/optimizely/helpers/constants.rb
index 02b815ae..eba265b3 100644
--- a/lib/optimizely/helpers/constants.rb
+++ b/lib/optimizely/helpers/constants.rb
@@ -201,6 +201,9 @@ module Constants
                 },
                 'forcedVariations' => {
                   'type' => 'object'
+                },
+                'cmab' => {
+                  'type' => 'object'
                 }
               },
               'required' => %w[
@@ -303,6 +306,20 @@ module Constants
               },
               'required' => %w[key]
             }
+          },
+          'cmab' => {
+            'type' => 'object',
+            'items' => {
+              'type' => 'object',
+              'properties' => {
+                'attributeIds' => {
+                  'type' => 'array'
+                },
+                'trafficAllocation' => {
+                  'type' => 'integer'
+                }
+              }
+            }
           }
         },
         'required' => %w[
diff --git a/lib/optimizely/project_config.rb b/lib/optimizely/project_config.rb
index b0d43aa3..43e86441 100644
--- a/lib/optimizely/project_config.rb
+++ b/lib/optimizely/project_config.rb
@@ -86,6 +86,10 @@ def get_whitelisted_variations(experiment_id); end
 
     def get_attribute_id(attribute_key); end
 
+    def get_attribute_by_key(attribute_key); end
+
+    def get_attribute_key_by_id(attribute_id); end
+
     def variation_id_exists?(experiment_id, variation_id); end
 
     def get_feature_flag_from_key(feature_flag_key); end
diff --git a/spec/config/datafile_project_config_spec.rb b/spec/config/datafile_project_config_spec.rb
index e30d07e1..362141d6 100644
--- a/spec/config/datafile_project_config_spec.rb
+++ b/spec/config/datafile_project_config_spec.rb
@@ -1078,6 +1078,67 @@
     end
   end
 
+  describe '#test_cmab_field_population' do
+    it 'Should return CMAB details' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0]['cmab'] = {'attributeIds' => %w[808797688 808797689], 'trafficAllocation' => 4000}
+      config_dict['experiments'][0]['trafficAllocation'] = []
+
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+
+      experiment = project_config.get_experiment_from_key('test_experiment')
+      expect(experiment['cmab']).to eq({'attributeIds' => %w[808797688 808797689], 'trafficAllocation' => 4000})
+
+      experiment2 = project_config.get_experiment_from_key('test_experiment_with_audience')
+      expect(experiment2['cmab']).to eq(nil)
+    end
+    it 'should return nil if cmab field is missing' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0].delete('cmab')
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+      experiment = project_config.get_experiment_from_key('test_experiment')
+      expect(experiment['cmab']).to eq(nil)
+    end
+
+    it 'should handle empty cmab object' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0]['cmab'] = {}
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+      experiment = project_config.get_experiment_from_key('test_experiment')
+      expect(experiment['cmab']).to eq({})
+    end
+
+    it 'should handle cmab with only attributeIds' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0]['cmab'] = {'attributeIds' => %w[808797688]}
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+      experiment = project_config.get_experiment_from_key('test_experiment')
+      expect(experiment['cmab']).to eq({'attributeIds' => %w[808797688]})
+    end
+
+    it 'should handle cmab with only trafficAllocation' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0]['cmab'] = {'trafficAllocation' => 1234}
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+      experiment = project_config.get_experiment_from_key('test_experiment')
+      expect(experiment['cmab']).to eq({'trafficAllocation' => 1234})
+    end
+
+    it 'should not affect other experiments when cmab is set' do
+      config_dict = Marshal.load(Marshal.dump(OptimizelySpec::VALID_CONFIG_BODY))
+      config_dict['experiments'][0]['cmab'] = {'attributeIds' => %w[808797688 808797689], 'trafficAllocation' => 4000}
+      config_json = JSON.dump(config_dict)
+      project_config = Optimizely::DatafileProjectConfig.new(config_json, logger, error_handler)
+      experiment2 = project_config.get_experiment_from_key('test_experiment_with_audience')
+      expect(experiment2['cmab']).to eq(nil)
+    end
+  end
+
   describe '#feature_experiment' do
     let(:config) { Optimizely::DatafileProjectConfig.new(config_body_JSON, logger, error_handler) }