Worked on enhancing the reliability and clarity of the Stateless mode in the modelcontextprotocol/typescript-sdk repository, focusing on server-side development with TypeScript. Addressed a bug in the StreamableHTTPServerTransport by correcting the sessionIdGenerator behavior and updating both the interface and documentation to reflect that sessionIdGenerator is undefined in stateless mode. This technical approach improved API predictability for downstream clients and reduced the risk of misconfiguration. The work involved careful updates to TypeScript interfaces and comprehensive documentation improvements, ensuring that developers have clear guidance and reducing potential runtime errors when integrating or onboarding with the SDK in stateless scenarios.