LangChain ranks #2 in AI/ML Infrastructure & LLM Tools AI search.

LangChain is a San Francisco-based AI infrastructure company offering an end-to-end agent engineering platform. Founded in 2022 by Harrison Chase and Ankush Gola, it began as an open-source Python framework for connecting large language models to external tools and data sources. Today the company ships three open-source frameworks—LangChain, LangGraph, and Deep Agents—alongside LangSmith, a commercial platform covering agent observability, evaluation, deployment, and a no-code Fleet agent builder. The project attracts over 100 million monthly open-source downloads and powers 6,000-plus active LangSmith customers including Klarna, LinkedIn, Workday, Cisco, The Home Depot, and Coinbase. LangChain reached unicorn status in October 2025 following a $125 million Series B led by IVP.

LangChain provides a full-lifecycle agent engineering platform combining open-source frameworks (LangChain for rapid agent prototyping, LangGraph for stateful graph-based agent orchestration, Deep Agents for long-running autonomous tasks) with LangSmith, a commercial SaaS product offering trace-level observability, automated and human-in-the-loop evaluation, managed agent deployment with memory and durable checkpointing, and Fleet—a natural-language no-code agent builder for business users. The platform supports Python, TypeScript, Go, and Java SDKs, native OpenTelemetry, MCP and A2A protocol integration, and over 100 integrations with LLM providers and vector databases.