Environment Promotion API: Cannot create packages or change status via API

Hi everyone,

We're trying to automate our Workfront Environment Promotion workflow via API but encountering several blocking issues. We're on Workfront Ultimate using API v15.0.

Issues Found:

1. Cannot create packages via API

POST /environment-promotion/api/v1/packages

Result: HTTP 500 - Package created but status is ASSEMBLING_FAILED

Tested with CTGY, PARAM, TMPL, GROUP objects. Same objects work fine via UI.

2. Cannot change status to TESTING or ACTIVE via API

PATCH /environment-promotion/api/v1/packages/{id}

Body: { "status": "TESTING" } or { "status": "ACTIVE" }

Result: HTTP 200 - But package becomes UNASSEMBLED instead

The PATCH returns success but triggers a re-assembly that empties the package.

What works

- GET /packages - List/get packages

- POST /packages/{id}/prepare-installation - Prepare install

- POST /packages/{id}/install - Execute install

Current workaround

We must use the UI for package creation and status changes. Only installation works via API.

Questions

1. Is there a working way to create packages via API?

2. Is there a correct endpoint/format to change status without triggering re-assembly?

3. Is this a known limitation or a bug?

Any help would be appreciated. We want to implement a CI/CD pipeline but these limitations block full automation.

Thanks!