Fix #155: Incorrect temperature parameter for OpenAI gpt-4o-search-preview and gpt-4o-mini-search-preview models

Now OpenAI search models work!

Author: crmne

lib/ruby_llm/providers/openai/capabilities.rb

@@ -215,10 +215,13 @@ def special_prefix_format(prefix)
           end
         end
 
-        def normalize_temperature(temperature, model_id)
+        def self.normalize_temperature(temperature, model_id)
           if model_id.match?(/^o\d/)
             RubyLLM.logger.debug "Model #{model_id} requires temperature=1.0, ignoring provided value"
             1.0
+          elsif model_id.match?(/-search/)
+            RubyLLM.logger.debug "Model #{model_id} does not accept temperature parameter, removing"
+            nil
           else
             temperature
           end

lib/ruby_llm/providers/openai/chat.rb

@@ -12,18 +12,22 @@ def completion_url
         module_function
 
         def render_payload(messages, tools:, temperature:, model:, stream: false)
-          {
+          payload = {
             model: model,
             messages: format_messages(messages),
-            temperature: temperature,
             stream: stream
-          }.tap do |payload|
-            if tools.any?
-              payload[:tools] = tools.map { |_, tool| tool_for(tool) }
-              payload[:tool_choice] = 'auto'
-            end
-            payload[:stream_options] = { include_usage: true } if stream
+          }
+
+          # Only include temperature if it's not nil (some models don't accept it)
+          payload[:temperature] = temperature unless temperature.nil?
+
+          if tools.any?
+            payload[:tools] = tools.map { |_, tool| tool_for(tool) }
+            payload[:tool_choice] = 'auto'
           end
+
+          payload[:stream_options] = { include_usage: true } if stream
+          payload
         end
 
         def parse_completion_response(response)

spec/ruby_llm/providers/openai/capabilities_spec.rb

@@ -13,10 +13,19 @@
       end
     end
 
-    it 'preserves temperature for non-O1 models' do
-      non_o1_models = ['gpt-4', 'gpt-4o', 'claude-3-opus']
+    it 'returns nil for search preview models' do
+      search_models = %w[gpt-4o-search-preview gpt-4o-mini-search-preview]
 
-      non_o1_models.each do |model|
+      search_models.each do |model|
+        result = described_class.normalize_temperature(0.7, model)
+        expect(result).to be_nil
+      end
+    end
+
+    it 'preserves temperature for standard models' do
+      standard_models = ['gpt-4', 'gpt-4o', 'gpt-4o-mini', 'claude-3-opus']
+
+      standard_models.each do |model|
         result = described_class.normalize_temperature(0.7, model)
         expect(result).to eq(0.7)
       end