LangChain, one of the earliest breakout startups of the generative AI era, announced a $125 million Series B funding round on Monday at a $1.25 billion valuation. The startup, which created an eponymous open-source framework for connecting AI apps to real-time data, hopes its tools can become the default building blocks that companies use to unleash a multitude of AI agents—while its investors believe the company has the potential to become as successful as other foundational digital infrastruct...