| `id` | integer/string | yes | The ID or [URL-encoded path of the project](index.md#namespaced-path-encoding) owned by the authenticated user |
| `ref` | string | yes | Reference to commit |
| `ref` | string | yes | The branch or tag to run the pipeline on. |
| `variables` | array | no | An array containing the variables available in the pipeline, matching the structure `[{ 'key': 'UPLOAD_TO_S3', 'variable_type': 'file', 'value': 'true' }, {'key': 'TEST', 'value': 'test variable'}]`. If `variable_type` is excluded, it defaults to `env_var`. |
