The UID field is a unique identifier that can be used specifically to create SEO-friendly website URLs.
This field requires the content writer to enter a lowercase, space-free unique id such as: using-the-uid-field. Whatever the writer chooses can be used to create a human-friendly url such as www.example.com/using-the-uid-field.
Each document in a custom type that contains a UID field must have a unique value for this field. The value of this field has to be unique per custom type & locale. This ensures that all your urls will be unique for a given Custom Type.
You can assign the UID field a Field name, and Field placeholder text that will display in the entry editor.
A custom type can only ever have one instance of this field. If defined in the Custom Type, the UID becomes a mandatory field for the content writers.
You can use all past UIDs to query a given content document. This prevents breaking URLs that rely on older UIDs.
Here is a description of how to build the UID field with the JSON editor.
A Custom Type can only define one field of type UID, and its API ID must be "uid":
"label": "Unique ID",
"placeholder": "Enter a meaningful unique identifier..."
"type": (string, required) Value must equal "UID"
"config": (object, optional) Options listed below
"label": (string) Sets the label that shows up for the field in the entry editor
"placeholder": (string) Sets a user-friendly placeholder into the field
"useAsTitle": (boolean) If set to true, this field will be used for the document name on the document listing page
Old UID Values
A UID field will save all previous UID values
We save all the previous UID values of a given document so that your old links won’t be broken on your site when you change a UID value.
Because the UID value must be unique, this means that an old UID value can not be reused on a different document. If you try to use an old UID name on a different document you will receive the following error.
This value is already used by another <custom-type-name> document