# FAQ

Common questions and their answers!

## Do I need to use LangChain to use LangGraph? What’s the difference?

No. LangGraph is an orchestration framework for complex agentic systems and is more low-level and controllable than LangChain agents. LangChain provides a standard interface to interact with models and other components, useful for straight-forward chains and retrieval flows.

## How is LangGraph different from other agent frameworks?

Other agentic frameworks can work for simple, generic tasks but fall short for complex tasks. LangGraph provides a more expressive framework to handle your unique tasks without restricting you to a single black-box cognitive architecture.

## Does LangGraph impact the performance of my app?

LangGraph will not add any overhead to your code and is specifically designed with streaming workflows in mind.

## Is LangGraph open source? Is it free?

Yes. LangGraph is an MIT-licensed open-source library and is free to use.

## How are LangGraph and LangGraph Platform different?

LangGraph is a stateful, orchestration framework that brings added control to agent workflows. LangGraph Platform is a service for deploying and scaling LangGraph applications, with an opinionated API for building agent UXs, plus an integrated developer studio.

| Features            | LangGraph (open source)                                   | LangGraph Platform                                                                                     |
| ------------------- | --------------------------------------------------------- | ------------------------------------------------------------------------------------------------------ |
| Description         | Stateful orchestration framework for agentic applications | Scalable infrastructure for deploying LangGraph applications                                           |
| SDKs                | Python and JavaScript                                     | Python and JavaScript                                                                                  |
| HTTP APIs           | None                                                      | Yes - useful for retrieving & updating state or long-term memory, or creating a configurable assistant |
| Streaming           | Basic                                                     | Dedicated mode for token-by-token messages                                                             |
| Checkpointer        | Community contributed                                     | Supported out-of-the-box                                                                               |
| Persistence Layer   | Self-managed                                              | Managed Postgres with efficient storage                                                                |
| Deployment          | Self-managed                                              | • Cloud SaaS <br> • Free self-hosted <br> • Enterprise (paid self-hosted)                              |
| Scalability         | Self-managed                                              | Auto-scaling of task queues and servers                                                                |
| Fault-tolerance     | Self-managed                                              | Automated retries                                                                                      |
| Concurrency Control | Simple threading                                          | Supports double-texting                                                                                |
| Scheduling          | None                                                      | Cron scheduling                                                                                        |
| Monitoring          | None                                                      | Integrated with LangSmith for observability                                                            |
| IDE integration     | LangGraph Studio                                          | LangGraph Studio                                                                                       |

## Is LangGraph Platform open source?

No. LangGraph Platform is proprietary software.

There is a free, self-hosted version of LangGraph Platform with access to basic features. The Cloud SaaS deployment option and the Self-Hosted deployment options are paid services. [Contact our sales team](https://www.langchain.com/contact-sales) to learn more.

For more information, see our [LangGraph Platform pricing page](https://www.langchain.com/pricing-langgraph-platform).

## Does LangGraph work with LLMs that don't support tool calling?

Yes! You can use LangGraph with any LLMs. The main reason we use LLMs that support tool calling is that this is often the most convenient way to have the LLM make its decision about what to do. If your LLM does not support tool calling, you can still use it - you just need to write a bit of logic to convert the raw LLM string response to a decision about what to do.

## Does LangGraph work with OSS LLMs?

Yes! LangGraph is totally ambivalent to what LLMs are used under the hood. The main reason we use closed LLMs in most of the tutorials is that they seamlessly support tool calling, while OSS LLMs often don't. But tool calling is not necessary (see [this section](#does-langgraph-work-with-llms-that-dont-support-tool-calling)) so you can totally use LangGraph with OSS LLMs.

## Can I use LangGraph Studio without logging in to LangSmith

Yes! You can use the [development version of LangGraph Server](../tutorials/langgraph-platform/local-server.md) to run the backend locally.
This will connect to the studio frontend hosted as part of LangSmith.
If you set an environment variable of `LANGSMITH_TRACING=false`, then no traces will be sent to LangSmith.

## What does "nodes executed" mean for LangGraph Platform usage?

**Nodes Executed** is the aggregate number of nodes in a LangGraph application that are called and completed successfully during an invocation of the application. If a node in the graph is not called during execution or ends in an error state, these nodes will not be counted. If a node is called and completes successfully multiple times, each occurrence will be counted.


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concepts/mcp.md
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