Sitecore Headless: Patch Serialization Depth to Fix Broken JSON

Fixing Deep JSON References in Sitecore Layout Service

While working with headless Sitecore applications, you might notice that some deeply nested components or referenced items show up in the Layout Service JSON response as "Sitecore.Data.Items.Item" or just as string references.

This usually happens when the rendering tree or field references go beyond the default serialization depth limit. The Layout Service stops serializing full item data after a certain level and instead outputs a string representation.

Good news: Sitecore allows you to configure how deep the Layout Service should go using the serializationMaxDepth setting.

When Do You Need This?

If your components include:

• Multiple multilist or dropdown fields
• References to content that itself has references (e.g. images, metadata)
• Recursive data structures like mega menus, category trees, etc.

... then you may encounter partial or string-based output in your JSON.

Solution: Patch the Max Depth Setting

You can increase the depth by patching the configuration like this:

<?xml version="1.0"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <layoutService>
      <serializationMaxDepth patch:instead="serializationMaxDepth">5</serializationMaxDepth>
    </layoutService>
  </sitecore>
</configuration>

This tells Sitecore to serialize rendering output and referenced items up to 5 levels deep.

How Deep Should You Go?

Use Case	Recommended Depth
Simple components with few references	2–3
Components with list or dropdown fields	4–5
Recursive or structured content (menus, etc.)	6+

Conclusion

If your Layout Service JSON is cutting off data or showing object references as strings, don’t panic. In most cases, it’s just a matter of adjusting serializationMaxDepth to match your data model. This small change can clean up your JSON output and reduce confusion for frontend developers working with Sitecore Headless.