# Set Tag

Launch stage: GA

`POST /api/2.0/mlflow/runs/set-tag`

Sets a tag on a run. Tags are run metadata that can be updated during a run and after
 a run completes.

API scopes: mlflow

## Request body

- `run_id` (string, optional)
  ID of the run under which to log the tag. Must be provided.
- `run_uuid` (string, optional)
  [Deprecated, use `run_id` instead] ID of the run under which to log the tag. This field will
   be removed in a future MLflow version.
- `key` (string, optional)
  Name of the tag. Keys up to 250 bytes in size are supported.
- `value` (string, optional)
  String value of the tag being logged. Values up to 64KB in size are supported.

## Response

```json
{}
```