LangChain, an AI infrastructure startup providing tools to build and monitor LLM-powered applications, is raising a new round of funding at an approximate $1 billion valuation led by IVP, according to three sources with knowledge of the deal.

LangChain began its life in late 2022 as an open-source project founded by Harrison Chase, who was then an engineer at machine learning startup Robust Intelligence. After generating significant developer interest, Chase transformed the project into a startup, securing a $10 million seed round from Benchmark in April 2023, That round was followed a week later by a $25 million Series A led by Sequoia, reportedly valuing LangChain at $200 million.

The startup was an early darling of the AI era. When LangChain first emerged, LLMs lacked access to real-time information and the ability to perform actions such as searching the web, calling APIs, and interacting with databases. The startup’s open-source code  solved those problems with a framework for building apps on top of LLMs models. It became a hugely popular project on GitHub (111K stars, over 18,000 forks).

The LLM ecosystem has since expanded significantly, with new startups including LlamaIndex, Haystack, and AutoGPT now offering comparable features. Furthermore, leading LLM providers including OpenAI, Anthropic, and Google have evolved their APIs to directly offer capabilities that were once key differentiators for LangChain’s core technology.

So the company has added other products, including LangSmith, a separate, closed-source product for observability, evaluation, and monitoring of LLM applications, specifically agents. This product has soared in popularity, multiple people tell us.

Since its introduction last year, LangSmith has led the company to reach annual recurring revenue (ARR) between $12 million and $16 million, four sources told Read. The company didn’t respond to a request for comment. Developers can start working with LangSmith for free and upgrade to $39 per month for small team collaboration features, according to the company’s website.  LangChain also offers custom plans for large organizations.

Companies who use LangSmith include Klarna, Rippling, and Replit.

While LangSmith currently leads the burgeoning LLM operations space, it does have competitors like smaller, open-source Langfuse and Helicone. IVP declined to comment on this report.