LangChain Catalyst - LLM Orchestration Essentials

Wed, 14 Jan 2026 00:00:00 +0000

LangChain Catalyst - LLM Orchestration Essentials

LangChain v0.2.x (Jan 2026 release cycle), Python 3.10+

Core Syntax

Instantiate a ChatModel and get a basic completion. Ensure OPENAI_API_KEY is set in your environment.

from langchain_openai import ChatOpenAI # Modern practice: specific integration imports
from langchain_core.messages import HumanMessage # Standard message types
# Initialize a chat model. Default model is typically gpt-3.5-turbo.
llm = ChatOpenAI(temperature=0.7) # Adjust creativity (0.0-1.0)
# Invoke the model with a simple message.
response = llm.invoke([
HumanMessage(content="What is the capital of France?") # Input as a list of messages
])
print(response.content) # Access the generated text content

Essential Patterns

Combine prompts and models using LangChain Expression Language (LCEL) for robust, composable chains.

ChatModel on AI VOID

LangChain Catalyst - LLM Orchestration Essentials

LangChain Catalyst - LLM Orchestration Essentials

Core Syntax

Essential Patterns