> For the complete documentation index, see [llms.txt](https://dev.guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.guardian.hedera.com/developer-tools-and-resources/api-reference/system-schemas-apis/creates-new-system-schema.md).

# Creates New System Schema

**`POST /schemas/system/{username}`**

Creates a new system schema. Only users with the Standard Registry role are allowed to make this request.

**Authentication:** Bearer token required (`Authorization: Bearer <token>`)

**Permission:** `Permissions.SCHEMAS_SYSTEM_SCHEMA_CREATE`

***

## Request

### Path Parameters

| Parameter  | Type   | Required | Description                  |
| ---------- | ------ | -------- | ---------------------------- |
| `username` | string | Yes      | Username of the schema owner |

### Request Body

```json
{
  "name": "Example System Schema",
  "description": "A system schema for standard registry data",
  "entity": "STANDARD_REGISTRY",
  "document": {
    "$id": "#Example",
    "$schema": "http://json-schema.org/draft-07/schema",
    "type": "object",
    "properties": {}
  }
}
```

| Field         | Type   | Required | Description                                                                                    |
| ------------- | ------ | -------- | ---------------------------------------------------------------------------------------------- |
| `name`        | string | Yes      | Schema name                                                                                    |
| `description` | string | No       | Schema description                                                                             |
| `entity`      | string | Yes      | Entity type: `STANDARD_REGISTRY`, `USER`, `POLICY`, `MINT_TOKEN`, `WIPE_TOKEN`, `MINT_NFTOKEN` |
| `document`    | object | Yes      | JSON Schema definition                                                                         |

***

## Response

### Success Response

**Status:** `201 Created`

```json
{
  "id": "63e3e5e8a01b3c001234abcd",
  "name": "Example System Schema",
  "entity": "STANDARD_REGISTRY",
  "status": "DRAFT",
  "system": true,
  "active": false,
  "owner": "example_user"
}
```

### Error Responses

| Status                      | Description               |
| --------------------------- | ------------------------- |
| `401 Unauthorized`          | Missing or invalid token  |
| `403 Forbidden`             | Insufficient permissions  |
| `422 Unprocessable Entity`  | Invalid schema data       |
| `500 Internal Server Error` | Unexpected server failure |