CXone Admin API bulk skill update 400 error

need some help troubleshooting the cxone admin api for bulk updating agent skill proficiencies.

i am posting to /api/v2/admin/skills/bulk-update with a payload like:

{
 "updates": [
 {
 "agentId": "12345",
 "skillId": "67890",
 "proficiency": "expert"
 }
 ]
}

the response is a 400 bad request with message invalid proficiency value. the docs list expert as valid. is there a specific enum casing or hidden format requirement i am missing?

400 Bad Request: invalid proficiency value. The API expects integer proficiency levels, not string labels like “expert”.

Make sure you map “expert” to its corresponding numeric value, usually 5, before sending the payload.

{
 "updates": [
 {
 "agentId": "12345",
 "skillId": "67890",
 "proficiency": 5
 }
 ]
}

Check your endpoint path. /api/v2/admin/skills/bulk-update is invalid for agent assignments. Use /api/v2/users/{userId}/skills instead. The proficiency field expects a float or int, not a string. See https://developer.nice.com/docs/api/cxone/ucm/users#update-skills for the correct schema.