> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prefect.io/llms.txt
> Use this file to discover all available pages before exploring further.
# csrf_token
# `prefect.server.models.csrf_token`
## Functions
### `create_or_update_csrf_token`
```python theme={null}
create_or_update_csrf_token(db: PrefectDBInterface, session: AsyncSession, client: str) -> core.CsrfToken
```
Create or update a CSRF token for a client. If the client already has a
token, it will be updated.
**Args:**
* `session`: The database session
* `client`: The client identifier
**Returns:**
* core.CsrfToken: The CSRF token
### `read_token_for_client`
```python theme={null}
read_token_for_client(db: PrefectDBInterface, session: AsyncSession, client: str) -> Optional[core.CsrfToken]
```
Read a CSRF token for a client.
**Args:**
* `session`: The database session
* `client`: The client identifier
**Returns:**
* Optional\[core.CsrfToken]: The CSRF token, if it exists and is not
expired.
### `delete_expired_tokens`
```python theme={null}
delete_expired_tokens(db: PrefectDBInterface, session: AsyncSession) -> int
```
Delete expired CSRF tokens.
**Args:**
* `session`: The database session
**Returns:**
* The number of tokens deleted