diff --git a/lib/rubyai/client.rb b/lib/rubyai/client.rb
index d17a1cd..4f4c0da 100644
--- a/lib/rubyai/client.rb
+++ b/lib/rubyai/client.rb
@@ -3,7 +3,11 @@ class Client
     attr_accessor :configuration
 
     def initialize(config = {})
-      @configuration = RubyAI.config(config)
+      if RubyAI.instance_variable_defined?(:@config)
+        RubyAI.config.set_instance_variables(config)
+        return @configuration = RubyAI.config
+      end
+      @configuration = RubyAI.config(config) 
     end
 
     def call
diff --git a/lib/rubyai/configuration.rb b/lib/rubyai/configuration.rb
index bcf6ce4..b500124 100644
--- a/lib/rubyai/configuration.rb
+++ b/lib/rubyai/configuration.rb
@@ -11,40 +11,52 @@ class Configuration
                   :provider
 
     def initialize(config = nil)
-      @openai ||= Providers::OpenAI.new
-      @anthropic ||= Providers::Anthropic.new
-      @gemini ||= Providers::Gemini.new
-      @bedrock_anthropic ||= Providers::BedrockAnthropic.new
+      set_instances_of_providers
       return if config.nil? || config.empty?
+      
+      set_instance_variables(config)
+    end
+    
+    def self.config(config = {})
+      @config ||= RubyAI.config(config)
+    end
+
+    def self.configure
+      yield(config)
+    end
 
-      provider_key = if config.fetch(:model,
-                                     nil).nil?
-                       "openai"
-                     else
-                       Provider.models.find do |_provider, models|
-                         models.include?(config[:model])
-                       end.first
-                     end
+    def set_instance_variables(config)
+      @provider = find_provider(config)
 
-      raise ArgumentError, "Unknown model: #{config[:model]}" unless provider_key
+      raise ArgumentError, "Unknown model: #{config[:model]}" unless @provider
 
       @model = config.fetch(:model, Provider.models["openai"]["gpt-3.5-turbo"])
-      provider = send(provider_key)
-      provider.api = config[:api_key]
-      @api_key = provider.api
-      provider.messages = config[:messages]
+      provider = send(@provider)
+      provider.api = config.fetch(:api_key) if provider.api.nil?
+      provider.messages = config.fetch(:messages, nil)
       @messages = provider.messages
-      @provider = provider_key
+      @api_key = provider.api
       provider.temperature = config.fetch(:temperature, 0.7)
       @temperature = provider.temperature
     end
 
-    def self.config
-      @config ||= RubyAI.config({})
+    private 
+
+    def set_instances_of_providers
+      @openai ||= Providers::OpenAI.new
+      @anthropic ||= Providers::Anthropic.new
+      @gemini ||= Providers::Gemini.new
+      @bedrock_anthropic ||= Providers::BedrockAnthropic.new
     end
 
-    def self.configure
-      yield(config)
+    def find_provider(config)
+      if config.fetch(:model, nil).nil?
+        "openai"
+      else
+        Provider.models.find do |_provider, models|
+          models.include?(config[:model])
+        end.first
+      end
     end
   end
 end
diff --git a/lib/rubyai/providers/anthropic.rb b/lib/rubyai/providers/anthropic.rb
index 945cc25..8a7ff0a 100644
--- a/lib/rubyai/providers/anthropic.rb
+++ b/lib/rubyai/providers/anthropic.rb
@@ -1,7 +1,7 @@
 module RubyAI
   module Providers
     class Anthropic < Base
-      attr_accessor :api, :messages, :temperature, :max_tokens
+      attr_accessor :max_tokens
 
       def initialize(api: nil, messages: nil, temperature: 0.7, model: "claude-2")
         @api = api
@@ -21,6 +21,10 @@ def models
         }.freeze
       end
 
+      def default_model
+        models['claude-1.3-sonnet']
+      end
+
       def build_http_body(messages = nil, model = nil, temperature = nil)
         {
           "model" => RubyAI::Provider.models["anthropic"][model || @model],
diff --git a/lib/rubyai/providers/base.rb b/lib/rubyai/providers/base.rb
index 4e5b9ab..5431567 100644
--- a/lib/rubyai/providers/base.rb
+++ b/lib/rubyai/providers/base.rb
@@ -1,6 +1,8 @@
 module RubyAI
   module Providers
     class Base
+      attr_accessor :api, :messages, :model, :temperature
+
       def configure
         yield self
       end
diff --git a/lib/rubyai/providers/bedrock_anthropic.rb b/lib/rubyai/providers/bedrock_anthropic.rb
index fe4491c..9be18a8 100644
--- a/lib/rubyai/providers/bedrock_anthropic.rb
+++ b/lib/rubyai/providers/bedrock_anthropic.rb
@@ -4,10 +4,7 @@
 module RubyAI
   module Providers
     class BedrockAnthropic < Base
-      attr_accessor :messages,
-                    :temperature,
-                    :max_tokens,
-                    :model,
+      attr_accessor :max_tokens,
                     :region,
                     :aws_access_key_id,
                     :aws_secret_access_key,
@@ -55,6 +52,10 @@ def models
         }.freeze
       end
 
+      def default_model
+        "claude-instant"
+      end
+
       def build_http_body(messages = nil, _model = nil, temperature = nil)
         {
           "anthropic_version" => "bedrock-2023-05-31",
diff --git a/lib/rubyai/providers/gemini.rb b/lib/rubyai/providers/gemini.rb
index de955d2..5a99474 100644
--- a/lib/rubyai/providers/gemini.rb
+++ b/lib/rubyai/providers/gemini.rb
@@ -1,7 +1,7 @@
 module RubyAI
   module Providers
     class Gemini < Base
-      attr_accessor :api, :messages, :temperature, :max_tokens, :model
+      attr_accessor :max_tokens
 
       def initialize(api: nil, messages: nil, temperature: 0.7, max_tokens: 1000)
         @api = api
@@ -18,6 +18,10 @@ def models
         }
       end
 
+      def default_model
+        models["gemini-1.5-flash"]
+      end
+
       def build_http_body(messages = nil, _model, temperature, max_tokens: 1000)
         {
           contents: [
diff --git a/lib/rubyai/providers/openai.rb b/lib/rubyai/providers/openai.rb
index 0d3675f..289590f 100644
--- a/lib/rubyai/providers/openai.rb
+++ b/lib/rubyai/providers/openai.rb
@@ -1,8 +1,6 @@
 module RubyAI
   module Providers
     class OpenAI < Base
-      attr_accessor :api, :messages, :temperature, :model
-
       def initialize(api: nil, messages: nil, temperature: 0.7)
         @api = api
         @messages = messages
@@ -22,6 +20,10 @@ def models
         }
       end
 
+      def default_model
+        models["gpt-3.5-turbo"]
+      end
+
       def build_http_body(messages = nil, model = "gpt-3.5-turbo", temperature = nil)
         {
           model: RubyAI::Provider.models["openai"][model],