diff --git a/bin/console b/bin/console
index e43cf3d..1095622 100755
--- a/bin/console
+++ b/bin/console
@@ -12,6 +12,8 @@ RubyLLM.configure do |config|
   config.anthropic_api_key = ENV.fetch('ANTHROPIC_API_KEY', nil)
   config.gemini_api_key = ENV.fetch('GEMINI_API_KEY', nil)
   config.deepseek_api_key = ENV.fetch('DEEPSEEK_API_KEY', nil)
+
+  config.openai_base_url_override = ENV.fetch('OPENAI_BASE_URL', nil)
 end
 
 IRB.start(__FILE__)
diff --git a/lib/ruby_llm/configuration.rb b/lib/ruby_llm/configuration.rb
index 72a878a..c9075de 100644
--- a/lib/ruby_llm/configuration.rb
+++ b/lib/ruby_llm/configuration.rb
@@ -18,7 +18,9 @@ class Configuration
                   :default_embedding_model,
                   :default_image_model,
                   :request_timeout,
-                  :max_retries
+                  :max_retries,
+                  :openai_base_url_override,
+                  :additional_headers
 
     def initialize
       @request_timeout = 120
diff --git a/lib/ruby_llm/provider.rb b/lib/ruby_llm/provider.rb
index 6e2ad48..c1463e6 100644
--- a/lib/ruby_llm/provider.rb
+++ b/lib/ruby_llm/provider.rb
@@ -60,7 +60,9 @@ def stream_response(payload, &block)
       end
 
       def post(url, payload)
+        additional_headers = RubyLLM.config.additional_headers
         connection.post url, payload do |req|
+          req.headers.merge! additional_headers unless additional_headers.nil?
           req.headers.merge! headers
           yield req if block_given?
         end
diff --git a/lib/ruby_llm/providers/openai.rb b/lib/ruby_llm/providers/openai.rb
index f78062e..83d8883 100644
--- a/lib/ruby_llm/providers/openai.rb
+++ b/lib/ruby_llm/providers/openai.rb
@@ -29,7 +29,8 @@ def self.extended(base)
       module_function
 
       def api_base
-        'https://api.openai.com/v1'
+        return 'https://api.openai.com/v1' unless RubyLLM.config.openai_base_url_override
+        return RubyLLM.config.openai_base_url_override
       end
 
       def headers