Different desk structure for `sanity start` vs `sanity build`

No worries about asking again! This is definitely a common roadblock. Let me clarify what's happening with environment variables in Sanity Studio.

The good news is that SANITY_STUDIO_ prefixed variables do work in Sanity Studio, but you need to set them up correctly using environment-specific .env files.

The Solution

Create two separate .env files in your Studio folder:

.env.development (loaded during sanity start):

SANITY_STUDIO_IS_PRODUCTION=false

.env.production (loaded during sanity build):

SANITY_STUDIO_IS_PRODUCTION=true

Then in your desk structure file, access them using process.env:

// In your desk structure file
export const structure = (S) => {
  const isProduction = process.env.SANITY_STUDIO_IS_PRODUCTION === 'true'
  
  if (isProduction) {
    // Production desk structure
    return S.list()
      .title('Content')
      .items([
        // your production items
      ])
  }
  
  // Development desk structure
  return S.list()
    .title('Content (Dev)')
    .items([
      // your dev items with extra tools, debug panels, etc.
    ])
}

Why This Works

According to the Sanity documentation on environment variables, Sanity Studio automatically loads the appropriate .env file based on the SANITY_ACTIVE_ENV variable, which defaults to:

• 'development' when running sanity start
• 'production' when running sanity build

The key requirements are:

1. Prefix with SANITY_STUDIO_ - This is mandatory for variables to be passed to the frontend
2. Use process.env - Access variables via process.env.SANITY_STUDIO_YOUR_VAR (not import.meta.env)
3. Create separate .env files - Use .env.development and .env.production for different environments

Important Notes

• These environment variables are exposed in your built application - they're not secret. Don't put sensitive tokens here.
• Remember to add .env* to your .gitignore if you add any sensitive values
• The values are embedded at build time, so if you change them, you need to rebuild

This approach gives you clean separation between your development and production desk structures without any hacky workarounds!