> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-lginte-1765488813-6406a61.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Learn

> Tutorials, conceptual guides, and resources to help you get started.

In the **Learn** section of the documentation, you'll find a collection of tutorials, conceptual overviews, and additional resources to help you build powerful applications with LangChain and LangGraph.

## Use Cases

Below are tutorials for common use cases, organized by framework.

### LangChain

[LangChain](/oss/python/langchain/overview) [agent](/oss/python/langchain/agents) implementations make it easy to get started for most use cases.

<Card title="Semantic Search" icon="magnifying-glass" href="/oss/python/langchain/knowledge-base" horizontal>
  Build a semantic search engine over a PDF with LangChain components.
</Card>

<Card title="RAG Agent" icon="user-magnifying-glass" href="/oss/python/langchain/rag" horizontal>
  Create a Retrieval Augmented Generation (RAG) agent.
</Card>

<Card title="SQL Agent" icon="database" href="/oss/python/langchain/sql-agent" horizontal>
  Build a SQL agent to interact with databases with human-in-the-loop review.
</Card>

<Card title="Supervisor Agent" icon="sitemap" href="/oss/python/langchain/supervisor" horizontal>
  Build a personal assistant that delegates to sub-agents.
</Card>

<Card title="Voice Agent" icon="microphone" href="/oss/python/langchain/voice-agent" horizontal>
  Build an agent you can speak and listen to.
</Card>

### LangGraph

LangChain's [agent](/oss/python/langchain/agents) implementations use [LangGraph](/oss/python/langgraph/overview) primitives.
If deeper customization is required, agents can be implemented directly in LangGraph.

<Card title="Custom RAG Agent" icon="user-magnifying-glass" href="/oss/python/langgraph/agentic-rag" horizontal>
  Build a RAG agent using LangGraph primitives for fine-grained control.
</Card>

<Card title="Custom SQL Agent" icon="database" href="/oss/python/langgraph/sql-agent" horizontal>
  Implement a SQL agent directly in LangGraph for maximum flexibility.
</Card>

## Conceptual Overviews

These guides explain the core concepts and APIs underlying LangChain and LangGraph.

<Card title="Memory" icon="brain" href="/oss/python/concepts/memory" horizontal>
  Understand persistence of interactions within and across threads.
</Card>

<Card title="Context engineering" icon="book-open" href="/oss/python/concepts/context" horizontal>
  Learn methods for providing AI applications the right information and tools to accomplish a task.
</Card>

<Card title="Graph API" icon="chart-network" href="/oss/python/langgraph/graph-api" horizontal>
  Explore LangGraph’s declarative graph-building API.
</Card>

<Card title="Functional API" icon="code" href="/oss/python/langgraph/functional-api" horizontal>
  Build agents as a single function.
</Card>

## Additional Resources

<Card title="LangChain Academy" icon="graduation-cap" href="https://academy.langchain.com/" horizontal>
  Courses and exercises to level up your LangChain skills.
</Card>

<Card title="Case Studies" icon="screen-users" href="/oss/python/langgraph/case-studies" horizontal>
  See how teams are using LangChain and LangGraph in production.
</Card>

***

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