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/api/api.py

@@ -116,10 +116,47 @@ MemoryBankConfig = Annotated[
 ]
 
 
-@json_schema_type
+class MemoryQueryGenerator(Enum):
+    default = "default"
+    llm = "llm"
+    custom = "custom"
+
+
+class DefaultMemoryQueryGeneratorConfig(BaseModel):
+    type: Literal[MemoryQueryGenerator.default.value] = (
+        MemoryQueryGenerator.default.value
+    )
+    sep: str = " "
+
+
+class LLMMemoryQueryGeneratorConfig(BaseModel):
+    type: Literal[MemoryQueryGenerator.llm.value] = MemoryQueryGenerator.llm.value
+    model: str
+    template: str
+
+
+class CustomMemoryQueryGeneratorConfig(BaseModel):
+    type: Literal[MemoryQueryGenerator.custom.value] = MemoryQueryGenerator.custom.value
+
+
+MemoryQueryGeneratorConfig = Annotated[
+    Union[
+        DefaultMemoryQueryGeneratorConfig,
+        LLMMemoryQueryGeneratorConfig,
+        CustomMemoryQueryGeneratorConfig,
+    ],
+    Field(discriminator="type"),
+]
+
+
 class MemoryToolDefinition(ToolDefinitionCommon):
     type: Literal[AgenticSystemTool.memory.value] = AgenticSystemTool.memory.value
     memory_bank_configs: List[MemoryBankConfig] = Field(default_factory=list)
+    # This config defines how a query is generated using the messages
+    # for memory bank retrieval.
+    query_generator_config: MemoryQueryGeneratorConfig = Field(
+        default=DefaultMemoryQueryGeneratorConfig()
+    )
     max_tokens_in_context: int = 4096
     max_chunks: int = 10
 

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,

llama_toolchain/agentic_system/meta_reference/rag/context_retriever.py

@@ -0,0 +1,76 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import List
+
+from jinja2 import Template
+from llama_models.llama3.api import *  # noqa: F403
+
+
+from llama_toolchain.agentic_system.api import (
+    DefaultMemoryQueryGeneratorConfig,
+    LLMMemoryQueryGeneratorConfig,
+    MemoryQueryGenerator,
+    MemoryQueryGeneratorConfig,
+)
+from termcolor import cprint  # noqa: F401
+from llama_toolchain.inference.api import *  # noqa: F403
+
+
+async def generate_rag_query(
+    config: MemoryQueryGeneratorConfig,
+    messages: List[Message],
+    **kwargs,
+):
+    """
+    Generates a query that will be used for
+    retrieving relevant information from the memory bank.
+    """
+    if config.type == MemoryQueryGenerator.default.value:
+        query = await default_rag_query_generator(config, messages, **kwargs)
+    elif config.type == MemoryQueryGenerator.llm.value:
+        query = await llm_rag_query_generator(config, messages, **kwargs)
+    else:
+        raise NotImplementedError(f"Unsupported memory query generator {config.type}")
+    # cprint(f"Generated query >>>: {query}", color="green")
+    return query
+
+
+async def default_rag_query_generator(
+    config: DefaultMemoryQueryGeneratorConfig,
+    messages: List[Message],
+    **kwargs,
+):
+    return config.sep.join(interleaved_text_media_as_str(m.content) for m in messages)
+
+
+async def llm_rag_query_generator(
+    config: LLMMemoryQueryGeneratorConfig,
+    messages: List[Message],
+    **kwargs,
+):
+    assert "inference_api" in kwargs, "LLMRAGQueryGenerator needs inference_api"
+    inference_api = kwargs["inference_api"]
+
+    m_dict = {"messages": [m.model_dump() for m in messages]}
+
+    template = Template(config.template)
+    content = template.render(m_dict)
+
+    model = config.model
+    message = UserMessage(content=content)
+    response = inference_api.chat_completion(
+        ChatCompletionRequest(
+            model=model,
+            messages=[message],
+            stream=False,
+        )
+    )
+
+    async for chunk in response:
+        query = chunk.completion_message.content
+
+    return query