TanStack Start Project Structure

Standard TanStack Start project structure I use for my projects, can be copied into a CLAUDE.md/AGENTS.md file for agents to follow.

Project Structure

• src/lib contains the project's library code, grouped by domain via this naming convention (e.g. for a todos domain):
  • todos.server.ts — server-only code, usually paired with todos.server.test.ts to unit test it.
  • todos.functions.ts — a thin wrapper exposing server functions, importing from todos.server.ts.
    • Exported server functions should be named with the Fn suffix, e.g. getTodosFn, createTodoFn, etc.
      • This makes it clearer what is a server function and what isn't
  • todos.schemas.ts — Zod schemas for the domain.
  • todo.types.ts — TypeScript types for the domain, usually used if Zod schemas are not required.
  • todos.ts — isomorphic code that can run on either the client or server (e.g. date helpers), usually paired with todos.test.ts to unit test it.