I answered my own question with a little more digging in the Sling docs. I'm new to Sling so I'm still finding my way about.
According to the Sling documentation here: https://sling.apache.org/documentation/bundles/manipulating-content-the-slingpostservlet-servlets-post.html#typehint I have to add the following additional form field to the POST operation: publisher@typeHint=Reference Doing so resulted in the node being committed without error, and the reference-valued property way populated correctly. jgl ________________________________ From: John Logan <john.lo...@texture.com> Sent: Wednesday, September 21, 2016 10:40:14 AM To: users@sling.apache.org Subject: Setting the UUID for a reference property via SlingPostServlet? Hi, I'm trying to create a node that has a reference as part of its data type via the SlingPostServlet, and am seeing the following error when Sling tries to commit the change: Caused by: org.apache.jackrabbit.oak.api.CommitFailedException: OakConstraint0055: /build/john-dc-07/title/gag[[nimcb:Title]]: Required property type violation in publisher = 4902ecef-4415-4918-98c4-38e44ef680e6 The UUID is the jcr:uuid of an existing node. Is it possible to supply reference-valued properties via the SlingPostServlet, and if so, how does one do that? Thanks! John