# Create knowledge base

Create an empty knowledge base. Data sources and semantic entries can be added individually after creation.

```text
POST https://moi.matrixorigin.cn/newmoi/semantic-models
```

## Preparation before calling

Prepare a personal access token and target workspace ID that has access to the target workspace and permission to create a knowledge base.

The example below uses:

- `$AI_STUDIO_API_KEY`: The actual personal access token, passed through the `X-API-Key` Header.
- `$WORKSPACE_ID`: The ID of the workspace to create the knowledge base, passed through the `X-Workspace-ID` Header.

## Request example

```bash
curl -X POST "https://moi.matrixorigin.cn/newmoi/semantic-models" \
  -H "X-API-Key: $AI_STUDIO_API_KEY" \
  -H "X-Workspace-ID: $WORKSPACE_ID" \
  -H 'Content-Type: application/json' \
  -d '{
    "name": "<KNOWLEDGE_BASE_NAME>",
    "description": "<DESCRIPTION>",
    "tables": []
  }'
```

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | string | Yes | The name of the knowledge base. |
| `description` | string | No | Coverage and usage instructions. |
| `tables` | JSON | No | Compatible legacy table source definition. For new access sources, please use the add data source interface. |
| `files` | JSON | No | Compatible legacy file source definition. For new access sources, please use the add data source interface. |

## Successful response

Returns `201` on success. Save `data.id` and use it as `model_id` in subsequent interfaces.

```json
{
  "code": "OK",
  "msg": "OK",
  "data": {
    "id": 401,
    "name": "product_docs",
    "description": "产品文档",
    "tables": [],
    "source_counts": {
      "files": 0,
      "tables": 0,
      "total": 0
    },
    "created_at": 1735632000,
    "updated_at": 1735632000
  }
}
```

The response fields are as follows.

| Field | Type | Description |
| --- | --- | --- |
| `code` | string | `OK` on success. |
| `msg` | string | `OK` on success. |
| `data.id` | integer | New knowledge base ID. |
| `data.name` | string | Name of the created knowledge base. |
| `data.description` | string | The saved description; may be omitted if not set. |
| `data.tables` | JSON | Compatible legacy table source definition. |
| `data.files` | JSON | Compatible legacy file source definition. |
| `data.source_counts` | object | Source count in creation snapshot; empty knowledge base entry is `0`. |
| `data.created_at` | integer | Unix timestamp. |
| `data.updated_at` | integer | Unix timestamp. |

## Error response

```json
{
  "code": "ErrParamInvalid",
  "msg": "name is required",
  "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`
  - The request body is not valid JSON, or `name` is missing.
  - Provide non-empty name and check JSON.
* - `401`
  - `ErrUnauthorized`
  - The API Key is invalid or has expired.
  - Check API Key.
* - `403`
  - `ErrForbidden`
  - The caller does not have permission to create a knowledge base.
  - Check workspace authorization.
* - `409`
  - `ErrConflict`
  - The service rejects duplicate or conflicting knowledge base definitions.
  - Modify the conflicting object or use an existing knowledge base.
* - `500`
  - `ErrServer`
  - The service failed to create the knowledge base.
  - Keep the desensitized response information and try again.
```

## Follow-up operations

Use `data.id` [Add data source](add-data-sources.md) or [Upload local files](upload-local-file.md).