TanStack Start gets RSC

TanStack Start has shipped experimental React Server Components (RSC) support with a fundamentally different philosophy from Next.js. Rather than making the server own the component tree by default, TanStack Start treats RSC as plain React Flight streams that clients fetch, cache, and render like any other async resource via TanStack Query. Key differences include client-owned trees, explicit server functions via createServerFn (avoiding recent RSC CVEs), a new Composite Components primitive, and fully opt-in adoption. On tanstack.com, migrating to RSC cut ~153KB gzipped from the client bundle and reduced Total Blocking Time from 1,200ms to 260ms on content-heavy pages. The newsletter also covers Bun v1.3.12 with native headless browser automation, a North Korean supply chain attack on the Better-Auth library, and various other frontend links.