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LangChain

LangChain provides open-source frameworks for building LLM applications and agents, with LangGraph for controlled workflows and LangSmith for tracing, evaluation, deployment, and monitoring.

Try LangChain

langchain.com·Free + paid plans·Checked 2026-08-28

LangChain screenshotLangGraph Studio: The first agent IDEHow to implement generative user interfaces with LangGraphUX for Agents, Part 1: ChatUX for Agents, Part 3: Spreadsheet, Generative, and Collaborative UI/UX
LangChainlangchain.com
LangChain screenshot
LangChainlangchain.com

What is LangChain?

LangChain is a Python and TypeScript framework for applications that use chat models, embeddings, retrievers, tools, prompts, and chains. Its ecosystem includes LangGraph for stateful agent workflows with branching and human approval steps, and LangSmith for tracing, evaluation, debugging, deployment, and monitoring. Developers can connect models and data sources through a broad integration ecosystem.

What are the pros and cons of LangChain?

Strengths

Covers common LLM application building blocks, including models, embeddings, retrievers, tools, prompts, and chains
LangGraph supports explicit state, branching, and human-in-the-loop steps for more controlled agents
LangSmith combines tracing, evaluation, debugging, deployment, and production monitoring
Supports agents built with any model provider
The open-source framework ecosystem has a broad set of integrations

Trade-offs

The abstractions that speed up initial prototyping can become difficult to manage as applications move into production
Teams building stateful, production-grade workflows may need to use LangGraph rather than LangChain's simpler agent patterns
LangSmith usage beyond included trace allowances is billed pay-as-you-go
Some LangSmith infrastructure features and advanced hosting options are limited to paid or custom plans

What are LangChain’s key features?

Build LLM applications with chat models, embeddings, retrievers, tools, prompts, and chains
Create stateful, multi-step agent workflows with LangGraph
Trace agent runs and inspect execution steps in LangSmith
Run offline and online evaluations for LLM applications
Deploy agents on infrastructure for long-running tasks and persistent state
Run agent-generated code in isolated sandboxes
Control model calls, spending, and sensitive-data handling with LLM Gateway

What are the best use cases for LangChain?

Prototype LLM applications using reusable model, retrieval, tool, and prompt abstractions
Build production agents with explicit state, branching, and human-in-the-loop actions
Trace and debug agent runs before and after deployment
Evaluate agent behavior, monitor regressions, and measure cost, latency, errors, and tool use
Deploy agents that require persistent state or isolated code execution

What is the pricing for LangChain?

PlanPriceDetails
Developer$0 / seat per monthFor solo users, with up to 5k base traces per month, one seat, and community support.
Plus$39 / seat per monthFor teams, with up to 10k base traces per month, unlimited seats, and access to Deployment, Engine, and more.
EnterpriseCustom pricingAdds self-hosted and hybrid deployment options, custom SSO, ABAC and RBAC, support SLA, and custom seats and workspaces.

Trace usage beyond the included allowances is pay-as-you-go. LangChain Compute Units cost $1.50 / LCU and LangChain Storage Units cost $1.00 / LSU. Discounted rates and credits are available for some VC-backed startups.

Checked 2026-08-28 · source

Who is LangChain best for?

developersA fit for developers who want reusable abstractions for models, retrieval, tools, prompts, and agent applications.
small teamThe Plus plan suits teams building and deploying agents that need shared seats, tracing, evaluation, and deployment features.
enterpriseEnterprise teams can use custom hosting, access controls, support SLAs, and deployment options through LangSmith.
Not for
  • Teams that want a thin abstraction layer may prefer direct model and tool integrations instead of LangChain's framework abstractions.
  • Teams seeking only a simple chatbot or model API may not need the additional orchestration, evaluation, and observability components.
  • Buyers who need fixed, all-inclusive pricing should account for LangSmith's usage-based charges.

What are the best LangChain alternatives?

Where can I try LangChain?

Open langchain.com