Snowflake Cortex gives you instant access to industry-leading large language models (LLMs) trained by researchers at companies like Mistral, Reka, Meta, and Google, including Snowflake Arctic, an open enterprise-grade model developed by Snowflake. This example goes over how to use LangChain to interact with Snowflake Cortex.

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Installation and setup

We start by installing the snowflake-snowpark-python library, using the command below. Then we configure the credentials for connecting to Snowflake, as environment variables or pass them directly. 
%pip install -qU snowflake-snowpark-python

import getpass
import os

# First step is to set up the environment variables, to connect to Snowflake,
# you can also pass these snowflake credentials while instantiating the model

if os.environ.get("SNOWFLAKE_ACCOUNT") is None:
    os.environ["SNOWFLAKE_ACCOUNT"] = getpass.getpass("Account: ")

if os.environ.get("SNOWFLAKE_USERNAME") is None:
    os.environ["SNOWFLAKE_USERNAME"] = getpass.getpass("Username: ")

if os.environ.get("SNOWFLAKE_PASSWORD") is None:
    os.environ["SNOWFLAKE_PASSWORD"] = getpass.getpass("Password: ")

if os.environ.get("SNOWFLAKE_DATABASE") is None:
    os.environ["SNOWFLAKE_DATABASE"] = getpass.getpass("Database: ")

if os.environ.get("SNOWFLAKE_SCHEMA") is None:
    os.environ["SNOWFLAKE_SCHEMA"] = getpass.getpass("Schema: ")

if os.environ.get("SNOWFLAKE_WAREHOUSE") is None:
    os.environ["SNOWFLAKE_WAREHOUSE"] = getpass.getpass("Warehouse: ")

if os.environ.get("SNOWFLAKE_ROLE") is None:
    os.environ["SNOWFLAKE_ROLE"] = getpass.getpass("Role: ")

from langchain_community.chat_models import ChatSnowflakeCortex
from langchain_core.messages import HumanMessage, SystemMessage

# By default, we'll be using the cortex provided model: `mistral-large`, with function: `complete`
chat = ChatSnowflakeCortex()
The above cell assumes that your Snowflake credentials are set in your environment variables. If you would rather manually specify them, use the following code: 
chat = ChatSnowflakeCortex(
    # Change the default cortex model and function
    model="mistral-large",
    cortex_function="complete",

    # Change the default generation parameters
    temperature=0,
    max_tokens=10,
    top_p=0.95,

    # Specify your Snowflake Credentials
    account="YOUR_SNOWFLAKE_ACCOUNT",
    username="YOUR_SNOWFLAKE_USERNAME",
    password="YOUR_SNOWFLAKE_PASSWORD",
    database="YOUR_SNOWFLAKE_DATABASE",
    schema="YOUR_SNOWFLAKE_SCHEMA",
    role="YOUR_SNOWFLAKE_ROLE",
    warehouse="YOUR_SNOWFLAKE_WAREHOUSE"
)

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Calling the chat model

We can now call the chat model using the invoke or stream methods. messages = [ SystemMessage(content=“You are a friendly assistant.”), HumanMessage(content=“What are large language models?”), ] chat.invoke(messages)

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Stream

# Sample input prompt
messages = [
    SystemMessage(content="You are a friendly assistant."),
    HumanMessage(content="What are large language models?"),
]

# Invoke the stream method and print each chunk as it arrives
print("Stream Method Response:")
for chunk in chat._stream(messages):
    print(chunk.message.content)