VERCEL_HEADERS.md

Vercel Cache Prevention Headers

To prevent auth session caching issues in preview deployments, add these headers to your Vercel configuration.

vercel.json

{
  "headers": [
    {
      "source": "/",
      "headers": [
        {
          "key": "Cache-Control",
          "value": "no-cache, no-store, must-revalidate"
        }
      ]
    },
    {
      "source": "/(dashboard|profile|calendar|search|new-entry)(.*)",
      "headers": [
        {
          "key": "Cache-Control", 
          "value": "no-cache, no-store, must-revalidate"
        }
      ]
    }
  ]
}

Alternative: _headers file

Create public/_headers file:

/*
  Cache-Control: no-cache, no-store, must-revalidate

/dashboard/*
  Cache-Control: no-cache, no-store, must-revalidate
  
/profile/*
  Cache-Control: no-cache, no-store, must-revalidate
  
/calendar/*
  Cache-Control: no-cache, no-store, must-revalidate
  
/search/*
  Cache-Control: no-cache, no-store, must-revalidate
  
/new-entry/*
  Cache-Control: no-cache, no-store, must-revalidate

Purpose

These headers prevent Vercel from caching:

• Auth-sensitive pages in preview deployments
• Static assets that might contain stale session data
• API responses that depend on authentication state

Combined with environment-specific storage keys in supabase.ts, this ensures clean auth state between deployments.