ai-framework
(2)
Sam Bhagwat
Sam Bhagwat is the founder and CEO of Mastra, an open-source TypeScript framework for building AI agents that pulls in millions of monthly downloads. He earlier co-founded Gatsby, the React-based web framework used by hundreds of thousands of developers and later acquired by Netlify. A Stanford economics grad and longtime open-source builder, he wrote 'Modular: The Web's New Architecture' and 'Principles of Building AI Agents,' the latter dubbed by one YC founder 'the most popular book in San Francisco.' Mastra went through Y Combinator's Winter 2025 batch and raised a $22M Series A led by Spark Capital.
LlamaIndex
LlamaIndex is a San Francisco company building the data framework and cloud platform that lets enterprises turn messy unstructured documents into knowledge agents powered by large language models. Its open-source library is one of the most-used scaffolds for retrieval-augmented generation, and its hosted product, LlamaCloud, packages parsing, extraction, and indexing for production teams.