Find the Source Model of a Copied Revit Cloud Model Using APS Data Management API

Have you ever copied a Revit cloud model in Forma (formerly ACC) and needed to trace back its original source programmatically? Now, we've got you covered!

Scenario

You have a Revit cloud model stored in Forma. Your team used the Copy feature on Forma Data Management to duplicate the published Revit Cloud Model from the working folder (e.g., ARCH/WIP) to another folder (e.g., Shared). Now you want to identify the original source model of that copy — all through the APS Data Management API.

Solution

The key is the GET projects/:project_id/versions/:version_id/relationships/refs endpoint. Call it with the copied model's version URN (URL-encoded), then look for a ref entry where `meta.extension.type` equals `"derived:autodesk.bim360:CopyFile"`.

curl --location 'https://developer.api.autodesk.com/data/v1/projects/{project_id}/versions/{encoded_version_id}/relationships/refs' \
--header 'Authorization: Bearer {token}' \
--header 'Content-Type: application/vnd.api+json'

Note: The `version_id` in the URL must be URL-encoded. For example, `urn:adsk.wipprod:fs.file:vf.xxx?version=1` becomes `urn%3Aadsk.wipprod%3Afs.file%3Avf.xxx%3Fversion%3D1`.

Here is an example response:

{
    "data": [
        {
            "type": "versions",
            "id": "urn:adsk.wipprod:fs.file:vf.iA3QsSBKRHGc5J3mJajVxw?version=3",
            "meta": {
                "refType": "derived",
                "fromId": "urn:adsk.wipprod:fs.file:vf.iA3QsSBKRHGc5J3mJajVxw?version=3", //!<<< Source model version URN
                "fromType": "versions",
                "toId": "urn:adsk.wipprod:fs.file:vf.OEmreSP4S9qtM5f4wUO0nw?version=1",   //!<<< Copied model version URN
                "toType": "versions",
                "direction": "to",
                "extension": {
                    "type": "derived:autodesk.bim360:CopyFile", //!<<< Filter by this type
                    "version": "1.0",
                    "schema": {
                        "href": "https://developer.api.autodesk.com/schema/v1/versions/derived:autodesk.bim360:CopyFile-1.0"
                    },
                    "data": {}
                }
            }
        }
    ]
}

Once you find the entry with `meta.extension.type = "derived:autodesk.bim360:CopyFile"`, the `meta.fromId` is the version URN of the original source model, and `meta.toId` is the version URN of the copied model.

Notes

Although the `extension.type` contains `bim360` in the namespace, this behavior applies to Forma (formerly ACC) — it is a historical naming from the API layer.
The `direction: "to"` field indicates the copy relationship flows `from` the source model (`fromId`) `to` the copied model (`toId`).
If the `data` array in the response is empty, there are two possible reasons:
- The version URN you passed in is incorrect.
- The model was not created via the Copy feature, so no such relationship exists.