Query generators for RAG query (#54)

* Query generators for rag query

* use agent.inference_api instead of passing host/port again

* drop classes for functions

---------

Co-authored-by: Hardik Shah <hjshah@fb.com>

llama_toolchain/agentic_system/meta_reference/agent_instance.py

@@ -31,6 +31,7 @@ from llama_toolchain.tools.builtin import (
     SingleMessageBuiltinTool,
 )
 
+from .rag.context_retriever import generate_rag_query
 from .safety import SafetyException, ShieldRunnerMixin
 
 
@@ -664,7 +665,9 @@ class ChatAgent(ShieldRunnerMixin):
             # (i.e., no prior turns uploaded an Attachment)
             return None, []
 
-        query = " ".join(m.content for m in messages)
+        query = await generate_rag_query(
+            memory.query_generator_config, messages, inference_api=self.inference_api
+        )
         tasks = [
             self.memory_api.query_documents(
                 bank_id=bank_id,