fix-visual-stability/environment/skills/react-best-practices/rules/server-serialization.md

metadata

title: Minimize Serialization at RSC Boundaries
impact: HIGH
impactDescription: reduces data transfer size
tags: server, rsc, serialization, props

Minimize Serialization at RSC Boundaries

The React Server/Client boundary serializes all object properties into strings and embeds them in the HTML response and subsequent RSC requests. This serialized data directly impacts page weight and load time, so size matters a lot. Only pass fields that the client actually uses.

Incorrect (serializes all 50 fields):

async function Page() {
  const user = await fetchUser()  // 50 fields
  return <Profile user={user} />
}

'use client'
function Profile({ user }: { user: User }) {
  return <div>{user.name}</div>  // uses 1 field
}

Correct (serializes only 1 field):

async function Page() {
  const user = await fetchUser()
  return <Profile name={user.name} />
}

'use client'
function Profile({ name }: { name: string }) {
  return <div>{name}</div>
}