> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stateset.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Register a subtype relationship

> **Required scope:** write

**Required scope:** `write`

### Request body

`RegisterSubtypeRequest`

<ParamField body="subtype" type="string" required>
  The subtype
</ParamField>

<ParamField body="supertype" type="string" required>
  The supertype
</ParamField>

### Response

No response body. Subtype relationship registered.

### Status codes

| Code  | Meaning                                            |
| ----- | -------------------------------------------------- |
| `201` | Subtype relationship registered                    |
| `400` | Invalid subtype definition                         |
| `401` | Unauthorized — missing or invalid credentials      |
| `403` | Forbidden — the key/token lacks the required scope |
| `429` | Rate limited — see Retry-After / X-RateLimit-Reset |

<RequestExample>
  ```bash cURL theme={null}
  curl --request POST \
    --url 'https://api.nsr.stateset.com/api/v1/types/subtypes' \
    --header 'X-API-Key: YOUR_API_KEY' \
    --header 'Content-Type: application/json' \
    --data '{
    "subtype": "philosopher",
    "supertype": "person"
  }'
  ```
</RequestExample>