No Context Chat Backend

backend/alembic/versions/5809c0787398_add_chat_sessions.py

@@ -0,0 +1,85 @@
+"""Add Chat Sessions
+
+Revision ID: 5809c0787398
+Revises: d929f0c1c6af
+Create Date: 2023-09-04 15:29:44.002164
+
+"""
+import fastapi_users_db_sqlalchemy
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "5809c0787398"
+down_revision = "d929f0c1c6af"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "chat_session",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column(
+            "user_id",
+            fastapi_users_db_sqlalchemy.generics.GUID(),
+            nullable=True,
+        ),
+        sa.Column("description", sa.Text(), nullable=False),
+        sa.Column("deleted", sa.Boolean(), nullable=False),
+        sa.Column(
+            "time_updated",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.Column(
+            "time_created",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.ForeignKeyConstraint(
+            ["user_id"],
+            ["user.id"],
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_table(
+        "chat_message",
+        sa.Column("chat_session_id", sa.Integer(), nullable=False),
+        sa.Column("message_number", sa.Integer(), nullable=False),
+        sa.Column("edit_number", sa.Integer(), nullable=False),
+        sa.Column("parent_edit_number", sa.Integer(), nullable=True),
+        sa.Column("latest", sa.Boolean(), nullable=False),
+        sa.Column("message", sa.Text(), nullable=False),
+        sa.Column(
+            "message_type",
+            sa.Enum(
+                "SYSTEM",
+                "USER",
+                "ASSISTANT",
+                "DANSWER",
+                name="messagetype",
+                native_enum=False,
+            ),
+            nullable=False,
+        ),
+        sa.Column(
+            "time_sent",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.ForeignKeyConstraint(
+            ["chat_session_id"],
+            ["chat_session.id"],
+        ),
+        sa.PrimaryKeyConstraint("chat_session_id", "message_number", "edit_number"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("chat_message")
+    op.drop_table("chat_session")

backend/alembic/versions/d929f0c1c6af_feedback_feature.py

@@ -24,13 +24,13 @@ def upgrade() -> None:
         sa.Column("query", sa.String(), nullable=False),
         sa.Column(
             "selected_search_flow",
-            sa.Enum("KEYWORD", "SEMANTIC", name="searchtype"),
+            sa.Enum("KEYWORD", "SEMANTIC", name="searchtype", native_enum=False),
             nullable=True,
         ),
         sa.Column("llm_answer", sa.String(), nullable=True),
         sa.Column(
             "feedback",
-            sa.Enum("LIKE", "DISLIKE", name="qafeedbacktype"),
+            sa.Enum("LIKE", "DISLIKE", name="qafeedbacktype", native_enum=False),
             nullable=True,
         ),
         sa.Column(
@@ -65,6 +65,7 @@ def upgrade() -> None:
                 "HIDE",
                 "UNHIDE",
                 name="searchfeedbacktype",
+                native_enum=False,
             ),
             nullable=True,
         ),

backend/danswer/chat/chat_llm.py

@@ -0,0 +1,27 @@
+from collections.abc import Iterator
+
+from langchain.schema.messages import AIMessage
+from langchain.schema.messages import BaseMessage
+from langchain.schema.messages import HumanMessage
+from langchain.schema.messages import SystemMessage
+
+from danswer.configs.constants import MessageType
+from danswer.db.models import ChatMessage
+from danswer.llm.build import get_default_llm
+
+
+def llm_chat_answer(previous_messages: list[ChatMessage]) -> Iterator[str]:
+    prompt: list[BaseMessage] = []
+    for msg in previous_messages:
+        content = msg.message
+        if msg.message_type == MessageType.SYSTEM:
+            prompt.append(SystemMessage(content=content))
+        if msg.message_type == MessageType.ASSISTANT:
+            prompt.append(AIMessage(content=content))
+        if (
+            msg.message_type == MessageType.USER
+            or msg.message_type == MessageType.DANSWER  # consider using FunctionMessage
+        ):
+            prompt.append(HumanMessage(content=content))
+
+    return get_default_llm().stream(prompt)

backend/danswer/configs/app_configs.py

@@ -144,6 +144,7 @@
 QA_TIMEOUT = int(os.environ.get("QA_TIMEOUT") or "10")  # 10 seconds
 # Include additional document/chunk metadata in prompt to GenerativeAI
 INCLUDE_METADATA = False
+HARD_DELETE_CHATS = os.environ.get("HARD_DELETE_CHATS", "True").lower() != "false"
 
 
 #####

backend/danswer/configs/constants.py

@@ -79,3 +79,11 @@ class SearchFeedbackType(str, Enum):
     REJECT = "reject"  # down-boost this document for all future queries
     HIDE = "hide"  # mark this document as untrusted, hide from LLM
     UNHIDE = "unhide"
+
+
+class MessageType(str, Enum):
+    # Using OpenAI standards, Langchain equivalent shown in comment
+    SYSTEM = "system"  # SystemMessage
+    USER = "user"  # HumanMessage
+    ASSISTANT = "assistant"  # AIMessage
+    DANSWER = "danswer"  # FunctionMessage