# Preview the data source to be added

Preview the number of deduplicated files and tables before selecting a source by database or volume. Confirm the quantity before adding the source.

```text
POST https://moi.matrixorigin.cn/newmoi/semantic-models/{model_id}/source-selections/preview
```

## Preparation before calling

First confirm the identification of the database, volume, and its tables and files to be selected in the Catalog. 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.
- `$MODEL_ID`: Knowledge base ID for source selection to be previewed.
- `$DATABASE_ID`: Catalog database ID to preview.
- `$TABLE_ID`: Table ID in the database to be explicitly selected.

This API previews Catalog data only.

## Request example

```bash
curl -X POST "https://moi.matrixorigin.cn/newmoi/semantic-models/$MODEL_ID/source-selections/preview" \
  -H "X-API-Key: $AI_STUDIO_API_KEY" \
  -H "X-Workspace-ID: $WORKSPACE_ID" \
  -H 'Content-Type: application/json' \
  -d '{
    "source_selections": [
      {
        "kind": "database_tables",
        "database_id": '"$DATABASE_ID"',
        "all_selected": false,
        "selected_table_ids": ['"$TABLE_ID"']
      }
    ]
  }'
```

## Path parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `model_id` | integer | Yes | The knowledge base ID to preview the source selection. |

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `source_selections` | object[] | Yes | Source selection to preview. |
| `source_selections[].kind` | string | Yes | `database_tables` or `volume_files`. |
| `source_selections[].database_id` | integer | Conditionally required | Catalog Database ID of `database_tables`. |
| `source_selections[].volume_id` | integer | Conditionally required | Catalog Volume ID of `volume_files`. |
| `source_selections[].all_selected` | boolean | Yes | `true` selects all objects in the current range; `false` must provide the corresponding explicit selection ID. |
| `source_selections[].selected_table_ids` | array | Conditionally required | Catalog table IDs explicitly selected when `all_selected` is `false`. |
| `source_selections[].selected_file_ids` | array | Conditionally required | Catalog file IDs explicitly selected when `all_selected` is `false`. |
| `source_selections[].excluded_table_ids` | array | No | Catalog table IDs to exclude when selecting all. |
| `source_selections[].excluded_file_ids` | array | No | Catalog file IDs to exclude when selecting all. |
| `source_selections[].filters` | object | No | Further filter by table name, file name, or extension. |

In field paths, `[]` means each item in an array. For example, `source_selections[].kind` is the `kind` field of each item in `source_selections`.

### Selection scope

| Scope | `kind` | Scope identifier | Explicit selection field |
| --- | --- | --- | --- |
| Database | `database_tables` | `database_id` | `selected_table_ids` |
| Volume | `volume_files` | `volume_id` | `selected_file_ids` |

Do not use another `kind` or data sources outside Catalog.

## Successful response

Returns `200` on success. `data` returns the source quantity after deduplication; confirm the quantity before adding the source.

```json
{
  "code": "OK",
  "msg": "OK",
  "data": {
    "file_count": 2,
    "table_count": 1,
    "total_count": 3
  }
}
```

The response fields are as follows.

| Field | Type | Description |
| --- | --- | --- |
| `code` | string | `OK` on success. |
| `msg` | string | `OK` on success. |
| `data.file_count` | integer | The number of file sources that will be added after deduplication. |
| `data.table_count` | integer | The number of table sources that will be added after deduplication. |
| `data.total_count` | integer | Total number of file and table sources. |

## Error response

```json
{
  "code": "ErrParamInvalid",
  "msg": "invalid source selection",
  "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`
  - `source_selections` is missing, or the selection type and ID are invalid.
  - Correct your selections and try again.
* - `401`
  - `ErrUnauthorized`
  - The API Key is invalid or has expired.
  - Check API Key.
* - `403`
  - `ErrForbidden`
  - The caller does not have permission to update the knowledge base or read the selected source.
  - Check workspace and object authorization.
* - `404`
  - `ErrNotFound`
  - The knowledge base does not exist or is not visible.
  - Reconfirm `model_id`.
* - `500`
  - `ErrServer`
  - Service failed to preview source selection.
  - Keep the desensitized response information and try again.
```

## Follow-up operations

After confirming the quantity [Add data source](add-data-sources.md).