migrate examples to pydantic 2 (#745)

Migrate examples to pydantic 2

examples/agent/server.py

@@ -23,12 +23,12 @@
 from langchain.agents import AgentExecutor
 from langchain.agents.format_scratchpad import format_to_openai_functions
 from langchain.agents.output_parsers import OpenAIFunctionsAgentOutputParser
-from langchain.pydantic_v1 import BaseModel
 from langchain_community.vectorstores import FAISS
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
 from langchain_core.tools import tool
 from langchain_core.utils.function_calling import format_tool_to_openai_function
 from langchain_openai import ChatOpenAI, OpenAIEmbeddings
+from pydantic import BaseModel
 
 from langserve import add_routes
 

examples/agent_custom_streaming/server.py

@@ -57,9 +57,9 @@
 from langchain_core.tools import tool
 from langchain_core.utils.function_calling import format_tool_to_openai_tool
 from langchain_openai import ChatOpenAI
+from pydantic import BaseModel
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel
 
 prompt = ChatPromptTemplate.from_messages(
     [

examples/agent_with_history/server.py

@@ -36,9 +36,9 @@
 from langchain_core.tools import tool
 from langchain_core.utils.function_calling import format_tool_to_openai_tool
 from langchain_openai import ChatOpenAI
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 prompt = ChatPromptTemplate.from_messages(
     [

examples/auth/api_handler/server.py

@@ -44,10 +44,10 @@
 )
 from langchain_core.vectorstores import VectorStore
 from langchain_openai import OpenAIEmbeddings
+from pydantic import BaseModel, ConfigDict
 from typing_extensions import Annotated
 
 from langserve import APIHandler
-from langserve.pydantic_v1 import BaseModel
 
 
 class User(BaseModel):
@@ -150,10 +150,9 @@ class PerUserVectorstore(RunnableSerializable):
     user_id: Optional[str]
     vectorstore: VectorStore
 
-    class Config:
-        # Allow arbitrary types since VectorStore is an abstract interface
-        # and not a pydantic model
-        arbitrary_types_allowed = True
+    model_config = ConfigDict(
+        arbitrary_types_allowed=True,
+    )
 
     def _invoke(
         self, input: str, config: Optional[RunnableConfig] = None, **kwargs: Any

examples/auth/per_req_config_modifier/server.py

@@ -45,10 +45,10 @@
 )
 from langchain_core.vectorstores import VectorStore
 from langchain_openai import OpenAIEmbeddings
+from pydantic import BaseModel, ConfigDict
 from typing_extensions import Annotated
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel
 
 
 class User(BaseModel):
@@ -147,10 +147,9 @@ class PerUserVectorstore(RunnableSerializable):
     user_id: Optional[str]
     vectorstore: VectorStore
 
-    class Config:
-        # Allow arbitrary types since VectorStore is an abstract interface
-        # and not a pydantic model
-        arbitrary_types_allowed = True
+    model_config = ConfigDict(
+        arbitrary_types_allowed=True,
+    )
 
     def _invoke(
         self, input: str, config: Optional[RunnableConfig] = None, **kwargs: Any

examples/chat_playground/legacy_input/server.py

@@ -8,9 +8,9 @@
 from langchain_anthropic import ChatAnthropic
 from langchain_core.messages import AIMessage, HumanMessage, SystemMessage
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 app = FastAPI(
     title="LangChain Server",

examples/chat_playground/server.py

@@ -8,9 +8,9 @@
 from langchain_anthropic.chat_models import ChatAnthropic
 from langchain_core.messages import AIMessage, HumanMessage, SystemMessage
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 app = FastAPI(
     title="LangChain Server",

examples/chat_with_persistence/server.py

@@ -18,9 +18,9 @@
 from langchain_core.chat_history import BaseChatMessageHistory
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
 from langchain_core.runnables.history import RunnableWithMessageHistory
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 
 def _is_valid_identifier(value: str) -> bool:

examples/configurable_agent_executor/server.py

@@ -20,7 +20,6 @@
 from langchain.agents import AgentExecutor
 from langchain.agents.format_scratchpad import format_to_openai_functions
 from langchain.agents.output_parsers import OpenAIFunctionsAgentOutputParser
-from langchain.pydantic_v1 import BaseModel
 from langchain_community.vectorstores import FAISS
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
 from langchain_core.runnables import (
@@ -33,6 +32,7 @@
 from langchain_core.tools import tool
 from langchain_core.utils.function_calling import format_tool_to_openai_function
 from langchain_openai import ChatOpenAI, OpenAIEmbeddings
+from pydantic import BaseModel
 
 from langserve import add_routes
 

examples/configurable_retrieval/server.py

@@ -15,9 +15,9 @@
 )
 from langchain_core.vectorstores import VectorStore
 from langchain_openai import OpenAIEmbeddings
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 vectorstore1 = FAISS.from_texts(
     ["cats like fish", "dogs like sticks"], embedding=OpenAIEmbeddings()

examples/conversational_retrieval_chain/server.py

@@ -18,9 +18,9 @@
 from langchain_core.prompts import ChatPromptTemplate, PromptTemplate, format_document
 from langchain_core.runnables import RunnableMap, RunnablePassthrough
 from langchain_openai import ChatOpenAI, OpenAIEmbeddings
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 _TEMPLATE = """Given the following conversation and a follow up question, rephrase the 
 follow up question to be a standalone question, in its original language.

examples/file_processing/server.py

@@ -15,10 +15,10 @@
 import base64
 
 from fastapi import FastAPI
-from langchain.pydantic_v1 import Field
 from langchain_community.document_loaders.parsers.pdf import PDFMinerParser
 from langchain_core.document_loaders import Blob
 from langchain_core.runnables import RunnableLambda
+from pydantic import Field
 
 from langserve import CustomUserType, add_routes
 

examples/widgets/chat/message_list/server.py

@@ -10,9 +10,9 @@
 from langchain_core.messages import AIMessage, HumanMessage, SystemMessage
 from langchain_core.output_parsers import StrOutputParser
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
+from pydantic import BaseModel, Field
 
 from langserve import add_routes
-from langserve.pydantic_v1 import BaseModel, Field
 
 app = FastAPI(
     title="LangChain Server",

examples/widgets/chat/tuples/server.py

@@ -6,7 +6,6 @@
 
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
-from langchain.pydantic_v1 import BaseModel, Field
 from langchain_community.document_loaders.parsers.pdf import PDFMinerParser
 from langchain_core.document_loaders import Blob
 from langchain_core.messages import (
@@ -17,6 +16,7 @@
 )
 from langchain_core.runnables import RunnableLambda, RunnableParallel
 from langchain_openai import ChatOpenAI
+from pydantic import BaseModel, Field
 
 from langserve import CustomUserType
 from langserve.server import add_routes