start-server-core

Server-side request handling for TanStack Start uses a three-phase processing pipeline that dispatches server functions, handles server routes, and falls back to application SSR across React, Solid, and Vue frameworks. This unified runtime centralizes routing logic without manual wiring.

AsyncLocalStorage context makes request-scoped utilities available anywhere in the call stack during processing, allowing access to request objects, headers, IP, and URL from any nested function without passing them manually as parameters.

Yes, you can manage encrypted cookie-based sessions with built-in utilities to use, update, and clear session data. The runtime provides encrypted cookie-based sessions to securely handle authentication and dehydrated state.

The best way to set response headers and status during server function processing is using the provided response utilities, which allow manipulating response headers, status codes, and cookies from anywhere during the active request lifecycle.

Yes, the TanStack Start server runtime supports validated query parsing to ensure incoming request data meets technical requirements, integrated directly into the server functions and server routes handling phases.

You need a unified server runtime for session management and SSR when building a server entry point that routes API calls, applies middleware, sets authentication cookies, and renders pages with dehydrated state without wiring these concerns manually.