diff --git a/lib/splitclient-rb/engine/api/splits.rb b/lib/splitclient-rb/engine/api/splits.rb
index 10d4544c..4d01a1bb 100644
--- a/lib/splitclient-rb/engine/api/splits.rb
+++ b/lib/splitclient-rb/engine/api/splits.rb
@@ -10,15 +10,19 @@ def initialize(api_key, config, telemetry_runtime_producer)
         @telemetry_runtime_producer = telemetry_runtime_producer
       end
 
-      def since(since, fetch_options = { cache_control_headers: false, till: nil })
+      def since(since, fetch_options = { cache_control_headers: false, till: nil, sets: nil })
         start = Time.now
-        
+
         params = { since: since }
         params[:till] = fetch_options[:till] unless fetch_options[:till].nil?
+        params[:sets] = fetch_options[:sets].join(",") unless fetch_options[:sets].nil?
         response = get_api("#{@config.base_uri}/splitChanges", @api_key, params, fetch_options[:cache_control_headers])
+        if response.status == 414
+          @config.logger.error("Error fetching feature flags; the amount of flag sets provided are too big, causing uri length error.")
+          raise ApiException.new response.body, 414
+        end
         if response.success?
           result = splits_with_segment_names(response.body)
-
           unless result[:splits].empty?
             @config.split_logger.log_if_debug("#{result[:splits].length} feature flags retrieved. since=#{since}")
           end
diff --git a/lib/splitclient-rb/exceptions.rb b/lib/splitclient-rb/exceptions.rb
index 493045a1..f8b9c62d 100644
--- a/lib/splitclient-rb/exceptions.rb
+++ b/lib/splitclient-rb/exceptions.rb
@@ -12,4 +12,15 @@ def initialize(event)
       @event = event
     end
   end
+
+  class ApiException < SplitIoError
+    def initialize(msg, exception_code)
+      @@exception_code = exception_code
+      super(msg)
+    end
+    def exception_code
+      @@exception_code
+    end
+  end
+
 end
diff --git a/spec/engine/api/splits_spec.rb b/spec/engine/api/splits_spec.rb
index 73264a96..9ae5ca6f 100644
--- a/spec/engine/api/splits_spec.rb
+++ b/spec/engine/api/splits_spec.rb
@@ -27,6 +27,72 @@
     end
   end
 
+  context '#sets' do
+    it 'returns the splits - with sets param' do
+      stub_request(:get, 'https://sdk.split.io/api/splitChanges?since=-1&sets=set_1')
+        .with(headers: {
+                'Accept' => '*/*',
+                'Accept-Encoding' => 'gzip',
+                'Authorization' => 'Bearer',
+                'Connection' => 'keep-alive',
+                'Keep-Alive' => '30',
+                'Splitsdkversion' => "#{config.language}-#{config.version}"
+              })
+        .to_return(status: 200, body: splits)
+
+      fetch_options = { cache_control_headers: false, till: nil, sets: ['set_1'] }
+      returned_splits = splits_api.since(-1, fetch_options)
+      expect(returned_splits[:segment_names]).to eq(Set.new(%w[demo employees]))
+
+      expect(log.string).to include '2 feature flags retrieved. since=-1'
+      expect(log.string).to include returned_splits.to_s
+    end
+
+    it 'returns the splits - with 2 sets param' do
+      stub_request(:get, 'https://sdk.split.io/api/splitChanges?since=-1&sets=set_1,set_2')
+        .with(headers: {
+                'Accept' => '*/*',
+                'Accept-Encoding' => 'gzip',
+                'Authorization' => 'Bearer',
+                'Connection' => 'keep-alive',
+                'Keep-Alive' => '30',
+                'Splitsdkversion' => "#{config.language}-#{config.version}"
+              })
+        .to_return(status: 200, body: splits)
+
+      fetch_options = { cache_control_headers: false, till: nil, sets: ['set_1','set_2'] }
+      returned_splits = splits_api.since(-1, fetch_options)
+      expect(returned_splits[:segment_names]).to eq(Set.new(%w[demo employees]))
+
+      expect(log.string).to include '2 feature flags retrieved. since=-1'
+      expect(log.string).to include returned_splits.to_s
+    end
+
+    it 'raise api exception when status 409' do
+      stub_request(:get, 'https://sdk.split.io/api/splitChanges?since=-1&sets=set_1,set_2')
+        .with(headers: {
+                'Accept' => '*/*',
+                'Accept-Encoding' => 'gzip',
+                'Authorization' => 'Bearer',
+                'Connection' => 'keep-alive',
+                'Keep-Alive' => '30',
+                'Splitsdkversion' => "#{config.language}-#{config.version}"
+              })
+        .to_return(status: 409, body: splits)
+
+      fetch_options = { cache_control_headers: false, till: nil, sets: ['set_1','set_2'] }
+      captured = 0
+      begin
+        returned_splits = splits_api.since(-1, fetch_options)
+      rescue SplitIoClient::ApiException => e
+        captured = e.exception_code
+      end
+      expect(captured).to eq(409)
+    end
+
+
+  end
+
   context '#since' do
     it 'returns the splits - checking headers when cache_control_headers is false' do
       stub_request(:get, 'https://sdk.split.io/api/splitChanges?since=-1')
@@ -59,7 +125,7 @@
               })
         .to_return(status: 200, body: splits)
 
-      fetch_options = { cache_control_headers: false, till: 123_123 }
+      fetch_options = { cache_control_headers: false, till: 123_123, sets: nil }
       returned_splits = splits_api.since(-1, fetch_options)
       expect(returned_splits[:segment_names]).to eq(Set.new(%w[demo employees]))
 
@@ -80,7 +146,7 @@
               })
         .to_return(status: 200, body: splits)
 
-      fetch_options = { cache_control_headers: true, till: nil }
+      fetch_options = { cache_control_headers: true, till: nil, sets: nil }
       returned_splits = splits_api.since(-1, fetch_options)
       expect(returned_splits[:segment_names]).to eq(Set.new(%w[demo employees]))
 
diff --git a/spec/test_data/splits/splits.json b/spec/test_data/splits/splits.json
index a57dfe77..7bd101db 100644
--- a/spec/test_data/splits/splits.json
+++ b/spec/test_data/splits/splits.json
@@ -99,7 +99,8 @@
                   }
                ]
             }
-         ]
+         ],
+         "sets":["set_1"]
       },
       {
          "trafficTypeName":"user",
@@ -256,7 +257,8 @@
                   }
                ]
             }
-         ]
+         ],
+         "sets":["set_1","set_2"]
       }
    ],
    "since":-1,