Hi HandsomeGiraffe70
There is a way, this is the API. You can use it this way :
retrieve the task the model belongs to retrieve the model you want (from a lit of input and output models) create the metadata inject them to the model
Here is an example :

` from clearml import Task
from clearml.backend_api import Session
from clearml.backend_api.services import models
from clearml.backend_api.services.v2_13.models import MetadataItem

task = Task.get_task(project_name=project_name, task_name=task_name)
model = task.models['output'][0]

my_metadata = [MetadataItem(
key='this is my unique key 0000',
type='any_type',
value='My brand new Metadata')
]

session = Session()

res = session.send(models.AddOrUpdateMetadataRequest(
model=model.id,
metadata=my_metadata
))

print(res.response_data) `