How to resolve/dereference a reference field in Sanity?

When you see a reference object with _ref and _type fields, you're looking at an unresolved reference. To get the actual document data, you need to dereference it using the -> operator in your GROQ query.

Here's how to resolve your reference:

*[_type == "yourDocumentType"] {
  ...,
  origin->
}

The -> operator tells GROQ to fetch the complete document that the reference points to. So instead of getting:

{
  "origin": {
    "_ref": "1ec9e722-3636-490d-9094-e102a4fca275",
    "_type": "reference"
  }
}

You'll get the actual document:

{
  "origin": {
    "_id": "1ec9e722-3636-490d-9094-e102a4fca275",
    "_type": "someType",
    "name": "Actual Data",
    // ... other fields from the referenced document
  }
}

Selecting specific fields

If you only need certain fields from the referenced document, you can use a projection:

*[_type == "yourDocumentType"] {
  ...,
  origin->{
    name,
    someField
  }
}

For arrays of references

If your field contains multiple references in an array:

*[_type == "yourDocumentType"] {
  ...,
  origins[]->
}

The Reference Access Operator documentation has more details on how the -> operator works internally—it essentially executes a subquery to fetch the matching document by _id.