feat(memory): LangChain 'Facts' Support. Refactor Facts (#123)

* move facts to sessions

* facts in memory. update langcahin

* deps

examples/langchain-langserve/pyproject.toml

@@ -13,6 +13,10 @@ python = "^3.11"
 uvicorn = "^0.23.2"
 langserve = {extras = ["server"], version = ">=0.0.30"}
 pydantic = ">2, <3"
+python-dotenv = "^1.0.1"
+zep-python = {path = "../.."}
+bs4 = "^0.0.2"
+langchain-openai = "^0.0.8"
 
 
 [tool.poetry.group.dev.dependencies]

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "zep-python"
-version = "2.0.0-rc.1"
+version = "2.0.0-rc.2"
 description = "Zep: Fast, scalable building blocks for LLM apps. This is the Python client for the Zep service."
 authors = ["Daniel Chalef <[email protected]>"]
 readme = "README.md"
@@ -9,8 +9,6 @@ readme = "README.md"
 python = ">=3.9.0,<4"
 httpx = "^0.26.0"
 pydantic = ">=2.0.0"
-packaging = "^23.1"
-black = "24.2.0"
 
 [tool.poetry.group.test.dependencies]
 pytest = "^7.3.1"
@@ -21,6 +19,7 @@ mypy = "^1.2.0"
 pytest-mock = "^3.10.0"
 
 [tool.poetry.group.dev.dependencies]
+packaging = "^23.1"
 black = "^24.2.0"
 ruff = ">=0.0.291"
 mypy = "^1.2.0"
@@ -32,7 +31,7 @@ pdoc3 = "^0.10.0"
 langchain = "^0.1.3"
 openai = "^1.9.0"
 langchain-openai = "^0.0.3"
-langchain-cli = {extras = ["serve"], version = "^0.0.21"}
+langchain-cli = { extras = ["serve"], version = "^0.0.21" }
 bs4 = "^0.0.2"
 
 [build-system]

tests/memory_test.py

@@ -46,12 +46,6 @@
     ]
 )
 
-mock_messages_with_facts = mock_messages.copy()
-mock_messages_with_facts["facts"] = [
-    "fact1",
-    "fact2",
-]
-
 
 def filter_unset_fields(d: Dict) -> Dict:
     filtered = {}
@@ -71,18 +65,16 @@ def filter_unset_fields(d: Dict) -> Dict:
     return filtered
 
 
-def validate_memory(memory: Memory, with_facts: bool = False):
-    mock_values = mock_messages_with_facts if with_facts else mock_messages
-
-    assert len(memory.messages) == len(mock_values["messages"])
+def validate_memory(memory: Memory):
+    assert len(memory.messages) == len(mock_messages["messages"])
 
     for i in range(len(memory.messages)):
-        assert memory.messages[i].uuid == mock_values["messages"][i]["uuid"]
-        assert memory.messages[i].role == mock_values["messages"][i]["role"]
-        assert memory.messages[i].content == mock_values["messages"][i]["content"]
-        assert memory.messages[i].metadata == mock_values["messages"][i]["metadata"]
+        assert memory.messages[i].uuid == mock_messages["messages"][i]["uuid"]
+        assert memory.messages[i].role == mock_messages["messages"][i]["role"]
+        assert memory.messages[i].content == mock_messages["messages"][i]["content"]
+        assert memory.messages[i].metadata == mock_messages["messages"][i]["metadata"]
 
-    assert filter_unset_fields(memory.model_dump()) == mock_values
+    assert filter_unset_fields(memory.model_dump()) == mock_messages
 
 
 @pytest.mark.asyncio
@@ -130,17 +122,6 @@ async def test_aget_memory_missing_values(httpx_mock: HTTPXMock):
     assert len(memory.messages) == 2
 
 
-@pytest.mark.asyncio
-async def test_aget_memory_with_facts(httpx_mock: HTTPXMock):
-    session_id = str(uuid4())
-
-    async with ZepClient(**mock_auth) as client:
-        httpx_mock.add_response(status_code=200, json=mock_messages_with_facts)
-        memory = await client.memory.aget_memory(session_id)
-
-        validate_memory(memory, with_facts=True)
-
-
 def test_get_memory(httpx_mock: HTTPXMock):
     session_id = str(uuid4())
 
@@ -752,6 +733,7 @@ def test_search_memory_invalid_search_type(httpx_mock: HTTPXMock):
     "session_id": "abc123",
     "metadata": {},
     "user_id": "user123",
+    "facts": ["fact1", "fact2"],
 }
 
 

zep_python/langchain/history.py

@@ -39,7 +39,8 @@ class ZepChatMessageHistory(BaseChatMessageHistory):
     api_key : str
         The Zep API key. Not required if using Zep Open Source.
     memory_type : str
-        The type of memory to use. Can be "message_window" or "perpetual".
+        The type of memory to use. Can be "perpetual", "summary_retrieval",
+        or "message_window". Defaults to "perpetual".
     """
 
     def __init__(
@@ -56,7 +57,7 @@ def __init__(
             self._client = zep_client
 
         self.session_id = session_id
-        self.memory_type = memory_type or "message_window"
+        self.memory_type = memory_type or "perpetual"
 
     @property
     def messages(self) -> List[BaseMessage]:  # type: ignore
@@ -67,7 +68,10 @@ def messages(self) -> List[BaseMessage]:  # type: ignore
             return []
 
         messages: List[BaseMessage] = []
-        # Extract summary, if present, and messages
+        # Extract facts and summary, if present, and messages
+        if zep_memory.facts:
+            messages.append(SystemMessage(content="\n".join(zep_memory.facts)))
+
         if zep_memory.summary:
             if len(zep_memory.summary.content) > 0:
                 messages.append(SystemMessage(content=zep_memory.summary.content))

zep_python/memory/models.py

@@ -16,6 +16,7 @@ class SearchScope(str, Enum):
 class MemoryType(str, Enum):
     message_window = "message_window"
     perpetual = "perpetual"
+    summary_retriever = "summary_retriever"
 
 
 class Session(BaseModel):
@@ -41,6 +42,8 @@ class Session(BaseModel):
         The unique identifier of the session.
     metadata : Dict[str, Any]
         The metadata associated with the session.
+    facts : Optional[List[str]]
+        A list of facts derived from the session.
     """
 
     uuid: Optional[str] = None
@@ -51,6 +54,7 @@ class Session(BaseModel):
     session_id: str
     user_id: Optional[str] = None
     metadata: Optional[Dict[str, Any]] = None
+    facts: Optional[List[str]] = Field(default=None)
 
 
 class Summary(BaseModel):
@@ -106,14 +110,15 @@ class Memory(BaseModel):
         A dictionary containing metadata associated with the memory.
     summary : Optional[Summary]
         A Summary object.
-    facts : Optional[List[str]]
-        A list of facts derived from the memory.
     uuid : Optional[str]
         A unique identifier for the memory.
     created_at : Optional[str]
         The timestamp when the memory was created.
     token_count : Optional[int]
         The token count of the memory.
+    facts : Optional[List[str]]
+        Most recent list of facts derived from the session. Included only with
+        perpetual memory type.
 
     Methods
     -------
@@ -127,10 +132,10 @@ class Memory(BaseModel):
     )
     metadata: Optional[Dict[str, Any]] = Field(default=None)
     summary: Optional[Summary] = Field(default=None)
-    facts: Optional[List[str]] = Field(default=None)
     uuid: Optional[str] = Field(default=None)
     created_at: Optional[str] = Field(default=None)
     token_count: Optional[int] = Field(default=None)
+    facts: Optional[List[str]] = Field(default=None)
 
     def to_dict(self) -> Dict[str, Any]:
         return self.model_dump(exclude_unset=True, exclude_none=True)