Explain Chat History Structure (#913)

backend/danswer/server/query_and_chat/models.py

@@ -66,17 +66,33 @@ class DocumentSearchRequest(BaseModel):
     skip_rerank: bool = False
 
 
+"""
+Currently the different branches are generated by changing the search query
+
+                 [Empty Root Message]  This allows the first message to be branched as well
+              /           |           \
+[First Message] [First Message Edit 1] [First Message Edit 2]
+       |                  |
+[Second Message]  [Second Message of Edit 1 Branch]
+"""
+
+
 class CreateChatMessageRequest(BaseModel):
+    """Before creating messages, be sure to create a chat_session and get an id"""
+
     chat_session_id: int
+    # This is the primary-key (unique identifier) for the previous message of the tree
     parent_message_id: int | None
+    # New message contents
     message: str
     # If no prompt provided, provide canned retrieval answer, no actually LLM flow
+    # Use prompt_id 0 to use the system default prompt which is Answer-Question
     prompt_id: int | None
     # If search_doc_ids provided, then retrieval options are unused
     search_doc_ids: list[int] | None
     retrieval_options: RetrievalDetails | None
     # allows the caller to specify the exact search query they want to use
-    # will disable query re-wording if specified
+    # will disable Query Rewording if specified
     query_override: str | None = None
 
     @root_validator
@@ -87,7 +103,7 @@ class CreateChatMessageRequest(BaseModel):
 
         if search_doc_ids is None and retrieval_options is None:
             raise ValueError(
-                "Either search_doc_ids or retrieval_options must be provided, but not both None."
+                "Either search_doc_ids or retrieval_options must be provided, but not both or neither."
             )
 
         return values