Error: Anonymous inline object "header" needs top-level schema type for GraphQL

This is a common error when deploying GraphQL with Sanity schemas that contain inline/anonymous objects. GraphQL requires all nested objects to be defined as named, top-level schema types rather than defined inline within a field.

In your case, you have a header field defined as an inline object within your Config type. To fix this, you need to "lift" that anonymous object into its own named schema type.

Here's how to resolve it:

1. Extract the inline object into a named type

Instead of defining the object inline like this:

// ❌ This causes the GraphQL error
{
  name: 'config',
  type: 'document',
  fields: [
    {
      name: 'header',
      type: 'object', // anonymous inline object
      fields: [
        { name: 'title', type: 'string' },
        { name: 'logo', type: 'image' }
        // ... other fields
      ]
    }
  ]
}

Create a separate, named schema type:

// ✅ Create a top-level schema type
export const header = {
  name: 'header',
  type: 'object',
  fields: [
    { name: 'title', type: 'string' },
    { name: 'logo', type: 'image' }
    // ... other fields
  ]
}

// Then reference it in your config
export const config = {
  name: 'config',
  type: 'document',
  fields: [
    {
      name: 'header',
      type: 'header' // reference the named type
    }
  ]
}

2. Add the new type to your schema

Make sure to include your new header type in your schema array when you initialize the Studio:

import { header } from './schemas/header'
import { config } from './schemas/config'

export default {
  // ... other config
  schema: {
    types: [header, config, /* other types */]
  }
}

The Sanity documentation on this specific issue provides more details, and there's also a helpful community answer about creating top-level schemas for GraphQL.

After making these changes, redeploy your GraphQL API and the error should be resolved. This pattern of creating named object types is also better for reusability if you ever need to use the same structure elsewhere in your schema.