Nuxt 4.6 adds useSession: server sessions in a sealed cookie, no database

Nuxt 4.6, released October 5, 2026, ships useSession, a server helper that keeps session data entirely inside an encrypted, signed cookie — no session store, database row or Redis. The key comes from runtimeConfig.appSecret via the NUXT_APP_SECRET environment variable.

• useSession seals session data into a cookie via h3's iron format, no DB or Redis
• The secret is set through runtimeConfig.appSecret and NUXT_APP_SECRET
• Any edit to the cookie fails to unseal, so the request is treated as sessionless
• 4.6.0 shipped October 5, 2026; patches 4.6.1 and 4.6.2 don't touch sessions