Add S()/System() helper

README.md

@@ -23,14 +23,24 @@ Or you can use this convenience RubyGem with some nice helpers to get you starte
 
 include Groq::Helpers
 @client.chat([
-    U("Hi"),
-    A("Hello back. Ask me anything. I'll reply with 'cat'"),
-    U("Favourite food?")
+  User("Hi"),
+  Assistant("Hello back. Ask me anything. I'll reply with 'cat'"),
+  User("Favourite food?")
 ])
 # => {"role"=>"assistant", "content"=>"Um... CAT"}
 # => {"role"=>"assistant", "content"=>"Not a cat! It's a pizza!"}
 # => {"role"=>"assistant", "content"=>"Pizza"}
 # => {"role"=>"assistant", "content"=>"Cat"}
+
+@client.chat([
+  System("I am an obedient AI"),
+  U("Hi"),
+  A("Hello back. Ask me anything. I'll reply with 'cat'"),
+  U("Favourite food?")
+])
+# => {"role"=>"assistant", "content"=>"Cat"}
+# => {"role"=>"assistant", "content"=>"cat"}
+# => {"role"=>"assistant", "content"=>"Cat"}
 ```
 
 ## Installation
@@ -98,18 +108,16 @@ The remaining examples below will use `@client` variable to allow you to copy+pa
 
 ### Message helpers
 
-We also have some handy `U`, `A`, and `F` methods to produce the `{role:, content:}` hashes:
+We also have some handy `U`, `A`, `S`, and `F` methods to produce the `{role:, content:}` hashes:
 
 ```ruby
 include Groq::Helpers
 @client.chat([
-    U("Hi"),
-    A("Hello back. Ask me anything. I'll reply with 'cat'"),
-    U("Favourite food?")
+  S("I am an obedient AI"),
+  U("Hi"),
+  A("Hello back. Ask me anything. I'll reply with 'cat'"),
+  U("Favourite food?")
 ])
-# => {"role"=>"assistant", "content"=>"Um... CAT"}
-# => {"role"=>"assistant", "content"=>"Not a cat! It's a pizza!"}
-# => {"role"=>"assistant", "content"=>"Pizza"}
 # => {"role"=>"assistant", "content"=>"Cat"}
 ```
 
@@ -124,6 +132,7 @@ There are also aliases for each helper function:
 
 * `U(content)` is also `User(content)`
 * `A(content)` is also `Assistant(content)`
+* `S(content)` is also `System(content)`
 * `T(content, ...)` is also `Tool`, `ToolReply`, `Function`, `F`
 
 ### Specifying an LLM model

lib/groq/client.rb

@@ -19,6 +19,7 @@ def initialize(config = {}, &faraday_middleware)
     @faraday_middleware = faraday_middleware
   end
 
+  # TODO: support stream: true; or &stream block
   def chat(messages, model_id: nil, tools: nil)
     unless messages.is_a?(Array) || messages.is_a?(String)
       raise ArgumentError, "require messages to be an Array or String"

lib/groq/helpers.rb

@@ -13,6 +13,11 @@ def A(content)
     end
     alias_method :Assistant, :A
 
+    def S(content)
+      {role: "system", content: content}
+    end
+    alias_method :System, :S
+
     def T(content, tool_call_id:, name:)
       {role: "function", tool_call_id: tool_call_id, name: name, content: content}
     end

test/groq/test_client.rb

@@ -56,6 +56,7 @@ def test_chat_messages_with_U_A_helpers
       client = Groq::Client.new
       # and with U/A helper methods
       response = client.chat([
+        S("I am an obedient AI."),
         U("What's the next day after Wednesday?"),
         A("The next day after Wednesday is Thursday."),
         U("What's the next day after that?")