When starting to develop with AI, you will come across frameworks like LangChain and LangGraph that have emerged to simplify building applications that with large language models (LLMs).

While both frameworks aim to streamline the process of creating AI-powered workflows, they serve distinct purposes and cater to different kinds of use cases. I am going to explore the the differences between LangChain and LangGraph in this article.
 

What is LangChain?

 
LangChain is a versatile framework designed to help developers create chains of operations or workflows that leverage LLMs. Its primary purpose in enabling applications to connect language models with various tools like APIs, databases, and memory modules.
LangChain is particularly well-suited for:

• Chaining multiple tasks together in a linear or branching fashion.
• Handling user queries with context retention using memory.
• Integrating with external APIs and tools (e.g., calculators, search engines).
• Querying structured and unstructured data sources.

Key Features of LangChain:

1. Memory Management:

• LangChain provides memory modules to store conversational context or intermediate results for subsequent use in a chain.

2. Tool Integration:

• Built-in support for external tools and APIs to enhance LLM capabilities.

3. Prompt Engineering:

• Simplifies prompt templates and chaining operations for efficient querying.

4. Agent Framework:

• Supports dynamic decision-making by enabling LLMs to select the right tool or path based on a user query.

Best Use Cases for LangChain:

1. Conversational AI:

• Building chatbots or virtual assistants that require context retention.

2. Data-Driven Queries:

• Fetching information from APIs or databases and summarising results.

3. Tool-Driven Tasks:

• Combining LLMs with external tools to perform specific functions like calculations, searches, or file generation.   ## What is LangGraph?   LangGraph takes a different approach by focusing on stateful workflows represented as directed graphs. Unlike LangChain, which builds sequential or branching chains of operations, LangGraph allows for the creation of complex, conditional workflows with multiple interconnected nodes. Each node in the graph represents a specific operation, and transitions between nodes are determined by conditions or external triggers.   ## Key Features of LangGraph:

1. State Management:

• LangGraph tracks the state throughout the workflow, making it easy to manage complex operations where intermediate results or conditions affect subsequent actions.

2. Conditional Branching:

• Workflows can include conditional logic, allowing for dynamic decision-making within a graph.

3. Interconnected Workflows:

• LangGraph is ideal for creating systems where tasks are interdependent or involve looping structures.

4. Tool and API Integration:

• Like LangChain, LangGraph supports tool integration but focuses on maintaining state throughout the workflow.

Best Use Cases for LangGraph:

1. Complex Workflow Automation:

• Automating multi-step processes that require conditional logic and decision-making (e.g., data pipelines, task management).

2. LLM-Driven State Management:

• Applications where intermediate states need to be tracked and updated dynamically during the workflow.

3. Dynamic Systems:

• Creating workflows that involve real-time updates, such as monitoring systems or event-driven architectures.

LangChain and LangGraph are powerful frameworks, each excelling in different scenarios. While LangChain simplifies the process of chaining tasks with LLMs and external tools, LangGraph offers a more sophisticated approach for building dynamic, stateful workflows.