post https://api.shift.io/v3/assets//metadata
Adds metadata to a specific asset
This call adds metadata in the form of a key/value pair to a specific asset. Start by entering the 32-character asset id as a path parameter. Then, include a key and value as body parameters. A 204 code is returned when the key/value pair is successfully added.
This request allows you to add more metadata to a file that already has metadata, without touching the existing metadata. If you enter a key that already exists, then the new value you enter will replace the original value.