Get form fields

GET http://{host}:{port}/qoppapdf/v1/documents/mydir/mydoc.pdf/fields

Export form fields

GET http://{host}:{port}/qoppapdf/v1/documents/mydir/mydoc.pdf/fields/content?exportEmptyFields=true
Accept: application/xfdf

Import form fields

POST http://{host}:{port}/qoppapdf/v1/documents/mydir/otherdoc.pdf/fields
Content-Type: application/xfdf
(xfdf file in message body)

Flatten form fields

POST http://{host}:{port}/qoppapdf/v1/documents/mydir/mydoc.pdf
(sample JSON in message body)
{
  "FlattenFieldsAction": {
    "paintButtons": true,
    "paintOnlyImageButtons": true,
    "paintNonPrintableFields": true,
    "savePath": "flatFields/mydoc.pdf"
  }
}