The default starting point for developers building agents, with free libraries; LangSmith costs extra once you need production tracing.
Kenning's take
What it does
LangChain makes free open-source libraries for building AI agents (langchain, LangGraph and Deep Agents) that work with many model providers. Its paid LangSmith platform adds tracing, evaluation, deployment, sandboxes and a model gateway for running agents in production. There is also Fleet, a no-code way for staff to build agents in plain language.
- Open-source langchain, LangGraph and Deep Agents frameworks
- LangSmith tracing and observability
- Evaluations built from real traces
- Agent deployment with 30+ Agent Server endpoints
- Sandboxes for agent-generated code
- Fleet no-code agents
Who it suits. Developers and engineering teams building AI agents and LLM apps.
Key facts
- Category
- Developer tools
- Made by
- LangChain
- Based in
- United States
- Launched
- 2022
- How to get it
- open-source libraries free on GitHub; LangSmith free Developer plan, paid Plus and Enterprise plans
- Works on
- Python, JavaScript, Web, self-hosted
- In the UK
- Yes
- Free plan
- open-source frameworks; LangSmith Developer plan with 1 seat and up to 5k base traces a month
- API price
- pay as you go at $1.00 per LangChain Standard Unit (LSU) above plan allowances
Pricing
| Plan | Price | Billed |
|---|---|---|
| Developer | $0 | month |
| Plus | $39 | month, per seat |
| Enterprise | Custom pricing | custom |
FAQ
Is LangChain free?
The langchain, LangGraph and Deep Agents libraries are open source and free. LangSmith has a free Developer plan, and Plus costs $39 per seat a month plus usage.
What is LangSmith?
LangChain's paid platform for tracing, evaluating, deploying and monitoring AI agents.
When did LangChain start?
It began as Harrison Chase's side project in late 2022, and the company was formed in early 2023.
Facts from the maker's own pages and the sources listed. Checked 2026-10-11.
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