How Stripe Built Enterprise Agent Kai in One Week Using Deep Agents

Leveraging LangChain's open-source Deep Agents framework, Stripe built Kai—a company-wide knowledge AI platform—with a single engineer completing the initial version in just one week. The system maintains long-context coherence through an S3-based virtual file system and dynamic summarization middleware, while securely executing data analysis code within isolated sandboxes. Integrated with more than 500 internal MCP tools and over 1,000 business skills, Kai relies on dynamic loading to manage context and currently reaches 83% of Stripe's weekly active employees.