Sanity Singletons

A "singleton" is a document with a fixed id that can be created exactly once. Common examples: site settings, navigation, footer content. Studio supports singletons as a first-class primitive via the document.singletons configuration registry plus a small set of Structure Tool helpers.

When to use this skill

• A developer asks how to create a "settings document" or "singleton".
• A studio configuration needs a document.singletons registry entry.
• Structure Tool needs to render a singleton as a list item or document pane.
• You're migrating an existing userland singleton implementation to the first-class API.
• You're migrating from a third-party singleton plugin such as sanity-plugin-singleton-management (or its predecessor sanity-plugin-singleton-tools).

Registering a singleton

Singletons are registered in configuration, not on the schema type. A singleton definition binds a definition id to a document id and a schema type:

import {defineConfig, defineSingleton} from 'sanity'