Hello everyone, I’m encountering an issue when trying to update device template variables via the vManage REST API. The API consistently returns an HTTP 400 Bad Request, even though the workflow follows Cisco’s documented process and mirrors the web UI “Change Device Values” operation. Our goal is to automate template variable updates that are currently performed manually in the UI. Workflow Attempted Step 1 – Authentication POST /j_security_check and GET /dataservice/client/token → ✅  Step 2 – Retrieve Device Info GET /dataservice/device → ✅ Step 3 – Get Template Info GET /dataservice/template/device/config/attached/{templateId} → ✅  Step 4 – Get Current Variables POST /dataservice/template/device/config/input → ✅ retrieved full variable list Step 5 – Update Variables ( Failing ) POST /dataservice/template/device/config/attachfeature → ❌ HTTP 400 Bad Request What I’ve Tried Verified isEdited = true Confirmed variable names match template fields Ensured values are string type Compared structure with working iTest automation payloads Rechecked JSON against API documentation Questions Is the payload for /attachfeature missing any required fields or structure? How can I get detailed error information for 400 responses? Is this the right endpoint, or should a detach/attach sequence be used? Does the web UI trigger additional backend calls that need to be replicated? ... View more