What is LangChain?
LangChain is a company and open source ecosystem for building AI agents. Its open source frameworks (langchain, langgraph and deepagents) let developers build agents with any model provider, from quick template-based setups to low-level control over agent behavior. Its commercial product, LangSmith, covers the rest of the agent development lifecycle: tracing and debugging agent runs step by step, evaluating agent quality on datasets, deploying long-running agents with persistent state, and monitoring production issues with alerts and dashboards.
In practice, teams use LangSmith to trace every model call and tool use, turn expert reviews into evals, and run agents in isolated sandboxes for agent-generated code. Additional products include Engine, which detects production issues and suggests fixes, Fleet for building no-code agents for a whole company, and LLM Gateway for controlling model calls, spend and sensitive data. The page states that deployment can be SaaS, BYOC or self-hosted.
Key features
- Open source agent frameworks: langchain, langgraph, deepagents
- Step-by-step tracing and debugging of agent runs
- Online and offline evaluations with datasets and annotation queues
- Deployment of long-running agents with persistent state and 30+ endpoints
- Sandboxes for running agent-generated code
- LLM Gateway for model call control, spend limits and sensitive data detection
Who is it for
- AI engineers and developers
- Engineering teams building production agents
- Enterprises needing self-hosted or BYOC deployment
- Startups building LLM applications
How to get started with LangChain
- Install the langchain library in your Python or JavaScript environment
- Choose a language model provider and set your API key
- Build a simple agent using langgraph or deepagents
- Create a LangSmith account and connect it to your agent code
- You build AI agent applications with a developer team
- You need tracing, testing, and monitoring of agents in production
- You want to work with any language model provider
- You need a ready-made no-code interface, because the platform is accessed via web and API and has no Polish interface
- You need a free plan for a larger team, because the free plan covers only 1 user
Pros and cons
- Open source frameworks with a large community (350M+ monthly downloads per the page)
- Covers the full agent lifecycle from build to monitor and govern
- Supports self-hosted and hybrid deployment
- Usage-based pricing (LSU metering) makes costs harder to predict
- Advanced hosting, security and support require custom enterprise pricing
LangChain pricing
| Plan | Price | Includes |
|---|---|---|
| Developer | 0 USD / month | per seat; 1 seat, up to 5k base traces/mo, then pay-as-you-go; community support |
| Plus | 39 USD / month | per seat; up to 10k base traces/mo, then pay-as-you-go; access to Deployment and Engine; unlimited seats |
Prices copied from LangChain pricing, checked October 12, 2026. Currency as shown by the vendor; taxes may apply.
Is LangChain free?
Yes, there is a free plan. Developer plan: free, 1 seat, up to 5k base traces per month, then pay-as-you-go, community support. Open source frameworks are free to use.
LangChain alternatives
| Tool | Price from | Free plan | Category |
|---|---|---|---|
 Gemini Enterprise Agent Platform | 0,75 USD | ? | Website & app builders |
 Mastra | 250 USD/mo | yes | Website & app builders |
 Pipedream | 99 USD/mo | yes | Website & app builders |
 Langflow | not listed | yes | Website & app builders |
 Dify | 590 USD/yr | yes | Website & app builders |
 JetBrains Air | 100 EUR/yr | ? | Website & app builders |
All alternatives to LangChain →
FAQ
What is LangChain used for?
Open agent engineering platform for building, testing, deploying and monitoring AI agents, aimed at engineering teams.
Is LangChain free?
Yes, there is a free plan. Developer plan: free, 1 seat, up to 5k base traces per month, then pay-as-you-go, community support. Open source frameworks are free to use.
How much does LangChain cost?
The cheapest paid plan is 39 USD/mo (vendor pricing, October 12, 2026).
What are the best LangChain alternatives?
Closest alternatives: Gemini Enterprise Agent Platform, Mastra, Pipedream, Langflow, Dify.
Data checked October 12, 2026 on the vendor website (langchain.com).