Add /conversations endpoint for conversation history management

- Add GET /v1/conversations/{conversation_id} to retrieve conversation history
- Add DELETE /v1/conversations/{conversation_id} to delete conversations
- Use llama-stack client.agents.session.retrieve and .delete methods
- Map conversation ID to agent ID for LlamaStack operations
- Add ConversationResponse and ConversationDeleteResponse models
- Include conversations router in main app routing
- Maintain consistent error handling and authentication patterns

Author: eranco74

src/app/endpoints/conversations.py

@@ -0,0 +1,263 @@
+"""Handler for REST API calls to manage conversation history."""
+
+import logging
+from typing import Any
+
+from llama_stack_client import APIConnectionError, NotFoundError
+
+from fastapi import APIRouter, HTTPException, status, Depends
+
+from client import LlamaStackClientHolder
+from configuration import configuration
+from models.responses import ConversationResponse, ConversationDeleteResponse
+from auth import get_auth_dependency
+from utils.endpoints import check_configuration_loaded
+from utils.suid import check_suid
+
+logger = logging.getLogger("app.endpoints.handlers")
+router = APIRouter(tags=["conversations"])
+auth_dependency = get_auth_dependency()
+
+conversation_id_to_agent_id: dict[str, str] = {}
+
+conversation_responses: dict[int | str, dict[str, Any]] = {
+    200: {
+        "conversation_id": "123e4567-e89b-12d3-a456-426614174000",
+        "session_data": {
+            "session_id": "123e4567-e89b-12d3-a456-426614174000",
+            "turns": [],
+            "started_at": "2024-01-01T00:00:00Z",
+        },
+    },
+    404: {
+        "detail": {
+            "response": "Conversation not found",
+            "cause": "The specified conversation ID does not exist.",
+        }
+    },
+    503: {
+        "detail": {
+            "response": "Unable to connect to Llama Stack",
+            "cause": "Connection error.",
+        }
+    },
+}
+
+conversation_delete_responses: dict[int | str, dict[str, Any]] = {
+    200: {
+        "conversation_id": "123e4567-e89b-12d3-a456-426614174000",
+        "success": True,
+        "message": "Conversation deleted successfully",
+    },
+    404: {
+        "detail": {
+            "response": "Conversation not found",
+            "cause": "The specified conversation ID does not exist.",
+        }
+    },
+    503: {
+        "detail": {
+            "response": "Unable to connect to Llama Stack",
+            "cause": "Connection error.",
+        }
+    },
+}
+
+
+def simplify_session_data(session_data: Any) -> list[dict[str, Any]]:
+    """Simplify session data to include only essential conversation information.
+
+    Args:
+        session_data: The full session data from llama-stack
+
+    Returns:
+        Simplified session data with only input_messages and output_message per turn
+    """
+    session_dict = session_data.model_dump()
+    # Create simplified structure
+    chat_history = []
+
+    # Extract only essential data from each turn
+    for turn in session_dict.get("turns", []):
+        # Clean up input messages
+        cleaned_messages = []
+        for msg in turn.get("input_messages", []):
+            cleaned_msg = {
+                "content": msg.get("content"),
+                "type": msg.get("role"),  # Rename role to type
+            }
+            cleaned_messages.append(cleaned_msg)
+
+        # Clean up output message
+        output_msg = turn.get("output_message", {})
+        cleaned_messages.append(
+            {
+                "content": output_msg.get("content"),
+                "type": output_msg.get("role"),  # Rename role to type
+            }
+        )
+
+        simplified_turn = {
+            "messages": cleaned_messages,
+            "started_at": turn.get("started_at"),
+            "completed_at": turn.get("completed_at"),
+        }
+        chat_history.append(simplified_turn)
+
+    return chat_history
+
+
+@router.get("/conversations/{conversation_id}", responses=conversation_responses)
+def get_conversation_endpoint_handler(
+    conversation_id: str,
+    _auth: Any = Depends(auth_dependency),
+) -> ConversationResponse:
+    """Handle request to retrieve a conversation by ID."""
+    check_configuration_loaded(configuration)
+
+    # Validate conversation ID format
+    if not check_suid(conversation_id):
+        logger.error("Invalid conversation ID format: %s", conversation_id)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail={
+                "response": "Invalid conversation ID format",
+                "cause": f"Conversation ID {conversation_id} is not a valid UUID",
+            },
+        )
+
+    agent_id = conversation_id_to_agent_id.get(conversation_id)
+    if not agent_id:
+        logger.error("Agent ID not found for conversation %s", conversation_id)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "conversation ID not found",
+                "cause": f"conversation ID {conversation_id} not found!",
+            },
+        )
+
+    logger.info("Retrieving conversation %s", conversation_id)
+
+    try:
+        client = LlamaStackClientHolder().get_client()
+
+        session_data = client.agents.session.retrieve(
+            agent_id=agent_id, session_id=conversation_id
+        )
+
+        logger.info("Successfully retrieved conversation %s", conversation_id)
+
+        # Simplify the session data to include only essential conversation information
+        chat_history = simplify_session_data(session_data)
+
+        return ConversationResponse(
+            conversation_id=conversation_id,
+            chat_history=chat_history,
+        )
+
+    except APIConnectionError as e:
+        logger.error("Unable to connect to Llama Stack: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail={
+                "response": "Unable to connect to Llama Stack",
+                "cause": str(e),
+            },
+        ) from e
+    except NotFoundError as e:
+        logger.error("Conversation not found: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "Conversation not found",
+                "cause": f"Conversation {conversation_id} could not be retrieved: {str(e)}",
+            },
+        ) from e
+    except Exception as e:
+        # Handle case where session doesn't exist or other errors
+        logger.error("Error retrieving conversation %s: %s", conversation_id, e)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "Conversation not found",
+                "cause": f"Conversation {conversation_id} could not be retrieved: {str(e)}",
+            },
+        ) from e
+
+
+@router.delete(
+    "/conversations/{conversation_id}", responses=conversation_delete_responses
+)
+def delete_conversation_endpoint_handler(
+    conversation_id: str,
+    _auth: Any = Depends(auth_dependency),
+) -> ConversationDeleteResponse:
+    """Handle request to delete a conversation by ID."""
+    check_configuration_loaded(configuration)
+
+    # Validate conversation ID format
+    if not check_suid(conversation_id):
+        logger.error("Invalid conversation ID format: %s", conversation_id)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail={
+                "response": "Invalid conversation ID format",
+                "cause": f"Conversation ID {conversation_id} is not a valid UUID",
+            },
+        )
+    agent_id = conversation_id_to_agent_id.get(conversation_id)
+    if not agent_id:
+        logger.error("Agent ID not found for conversation %s", conversation_id)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "conversation ID not found",
+                "cause": f"conversation ID {conversation_id} not found!",
+            },
+        )
+    logger.info("Deleting conversation %s", conversation_id)
+
+    try:
+        # Get Llama Stack client
+        client = LlamaStackClientHolder().get_client()
+        # Delete session using the conversation_id as session_id
+        # In this implementation, conversation_id and session_id are the same
+        client.agents.session.delete(agent_id=agent_id, session_id=conversation_id)
+
+        logger.info("Successfully deleted conversation %s", conversation_id)
+
+        return ConversationDeleteResponse(
+            conversation_id=conversation_id,
+            success=True,
+            response="Conversation deleted successfully",
+        )
+
+    except APIConnectionError as e:
+        logger.error("Unable to connect to Llama Stack: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail={
+                "response": "Unable to connect to Llama Stack",
+                "cause": str(e),
+            },
+        ) from e
+    except NotFoundError as e:
+        logger.error("Conversation not found: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "Conversation not found",
+                "cause": f"Conversation {conversation_id} could not be deleted: {str(e)}",
+            },
+        ) from e
+    except Exception as e:
+        # Handle case where session doesn't exist or other errors
+        logger.error("Error deleting conversation %s: %s", conversation_id, e)
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail={
+                "response": "Conversation not found",
+                "cause": f"Conversation {conversation_id} could not be deleted: {str(e)}",
+            },
+        ) from e

src/app/endpoints/query.py

@@ -23,6 +23,7 @@
 
 from client import LlamaStackClientHolder
 from configuration import configuration
+from app.endpoints.conversations import conversation_id_to_agent_id
 from models.responses import QueryResponse, UnauthorizedResponse, ForbiddenResponse
 from models.requests import QueryRequest, Attachment
 import constants
@@ -97,6 +98,8 @@ def get_agent(
     )
     conversation_id = agent.create_session(get_suid())
     _agent_cache[conversation_id] = agent
+    conversation_id_to_agent_id[conversation_id] = agent.agent_id
+
     return agent, conversation_id
 
 

src/app/endpoints/streaming_query.py

@@ -26,6 +26,7 @@
 from utils.suid import get_suid
 from utils.types import GraniteToolParser
 
+from app.endpoints.conversations import conversation_id_to_agent_id
 from app.endpoints.query import (
     get_rag_toolgroups,
     is_transcripts_enabled,
@@ -67,6 +68,7 @@ async def get_agent(
     )
     conversation_id = await agent.create_session(get_suid())
     _agent_cache[conversation_id] = agent
+    conversation_id_to_agent_id[conversation_id] = agent.agent_id
     return agent, conversation_id
 
 

src/app/routers.py

@@ -12,6 +12,7 @@
     feedback,
     streaming_query,
     authorized,
+    conversations,
 )
 
 
@@ -28,6 +29,7 @@ def include_routers(app: FastAPI) -> None:
     app.include_router(streaming_query.router, prefix="/v1")
     app.include_router(config.router, prefix="/v1")
     app.include_router(feedback.router, prefix="/v1")
+    app.include_router(conversations.router, prefix="/v1")
 
     # road-core does not version these endpoints
     app.include_router(health.router)