# Switch the current segment version

Switch an existing segment version to the source current version.

```text
PATCH https://moi.matrixorigin.cn/newmoi/semantic-models/{model_id}/sources/{source_row_id}/segment-versions/{version_id}/current
```

## Preparation before calling

First [query the document details](get-document.md), obtain the current segment version ID and index version as the baseline, and confirm the segment version ID to be switched to. Prepare a personal access token and target workspace ID that has access to the target workspace.

The example below uses:

- `$AI_STUDIO_API_KEY`: The actual personal access token, passed through the `X-API-Key` Header.
- `$WORKSPACE_ID`: Target workspace ID, passed through `X-Workspace-ID` Header.
- `$MODEL_ID`: Knowledge Base ID.
- `$SOURCE_ROW_ID`: Source record ID.
- `$VERSION_ID`: The segment version ID to switch to.

## Request example

```bash
curl -X PATCH "https://moi.matrixorigin.cn/newmoi/semantic-models/$MODEL_ID/sources/$SOURCE_ROW_ID/segment-versions/$VERSION_ID/current" \
  -H "X-API-Key: $AI_STUDIO_API_KEY" \
  -H "X-Workspace-ID: $WORKSPACE_ID" \
  -H 'Content-Type: application/json' \
  -d '{
    "base_segment_version_id": "<SEGMENT_VERSION_ID>",
    "base_index_version": <INDEX_VERSION>
  }'
```

## Path parameters

| Parameters | Type | Description |
| --- | --- | --- |
| `model_id` | integer | Knowledge base ID. |
| `source_row_id` | string | Source record ID. |
| `version_id` | string | The segment version ID to switch to. |

## Request body

The current version baseline of the commit source. `version_id` points to the version to switch to and should not override the baseline field.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `base_segment_version_id` | string | Yes | The current segment version ID read before the call. |
| `base_index_version` | integer | Yes | The current index version read before the call. |

## Successful response

Returns `200` and the updated source document snapshot on success.

```json
{
  "code": "OK",
  "msg": "OK",
  "data": {
    "document": {
      "source": {
        "row_id": "src_01",
        "model_id": 401
      },
      "segment_status": {
        "available": true,
        "total": 2
      },
      "current_segment_version_id": "ver_01",
      "current_index_version": 1,
      "segment_versions": [
        {
          "version_id": "ver_01",
          "current": true,
          "index_version": 1
        },
        {
          "version_id": "ver_02",
          "current": false,
          "index_version": 2
        }
      ],
      "segments": [
        {
          "segment_id": "seg_01",
          "enabled": true
        }
      ]
    }
  }
}
```

The response fields are as follows.

| Field | Type | Description |
| --- | --- | --- |
| `code` | string | `OK` on success. |
| `msg` | string | `OK` on success. |
| `data.document` | object | Snapshot of the source document after switching. |
| `data.document.current_segment_version_id` | string | ID of the current segment version that has been switched to. |
| `data.document.current_index_version` | integer | Current index version. |
| `data.document.segment_versions` | object[] | All segmented versions. |
| `data.document.segment_versions[].version_id` | string | Segment version ID. |
| `data.document.segment_versions[].current` | boolean | Whether it is the current version. |
| `data.document.segments` | object[] | New segment in current version. |

In field paths, `[]` means each item in an array. For example, `data.document.segment_versions[].version_id` is the `version_id` field of each item in `data.document.segment_versions`.

## Error response

```json
{
  "code": "ErrNotFound",
  "msg": "resource not found",
  "data": null
}
```

### Common HTTP errors

```{list-table}
:header-rows: 1
:widths: 12 22 32 34

* - HTTP status code
  - error code
  - Common causes
  - Recommended actions
* - `400`
  - `ErrParamInvalid`
  - Invalid path ID or staging version baseline.
  - Use current baseline after rereading document.
* - `401`
  - `ErrUnauthorized`
  - The API Key is invalid or has expired.
  - Check API Key.
* - `403`
  - `ErrForbidden`
  - The caller does not have permission to update the source.
  - Check workspace and object authorization.
* - `404`
  - `ErrNotFound`
  - The repository, source, or staging version does not exist or is not visible to the current caller.
  - Reconfirm the path ID.
* - `409`
  - `ErrConflict`
  - The current segment version has changed.
  - Retry after reading the latest document.
* - `500`
  - `ErrServer`
  - The service failed to switch the current version.
  - Keep the desensitized response information and try again.
```

## Follow-up operations

[Query document details](get-document.md) Confirm that the current segment version has been switched.