---
title: settings
sidebarTitle: settings
---
# `fastmcp.settings`
## Classes
### `ExtendedEnvSettingsSource`
A special EnvSettingsSource that allows for multiple env var prefixes to be used.
Raises a deprecation warning if the old `FASTMCP_SERVER_` prefix is used.
**Methods:**
#### `get_field_value`
```python
get_field_value(self, field: FieldInfo, field_name: str) -> tuple[Any, str, bool]
```
### `ExtendedSettingsConfigDict`
### `ExperimentalSettings`
### `Settings`
FastMCP settings.
**Methods:**
#### `get_setting`
```python
get_setting(self, attr: str) -> Any
```
Get a setting. If the setting contains one or more `__`, it will be
treated as a nested setting.
#### `set_setting`
```python
set_setting(self, attr: str, value: Any) -> None
```
Set a setting. If the setting contains one or more `__`, it will be
treated as a nested setting.
#### `settings_customise_sources`
```python
settings_customise_sources(cls, settings_cls: type[BaseSettings], init_settings: PydanticBaseSettingsSource, env_settings: PydanticBaseSettingsSource, dotenv_settings: PydanticBaseSettingsSource, file_secret_settings: PydanticBaseSettingsSource) -> tuple[PydanticBaseSettingsSource, ...]
```
#### `settings`
```python
settings(self) -> Self
```
This property is for backwards compatibility with FastMCP < 2.8.0,
which accessed fastmcp.settings.settings
#### `normalize_log_level`
```python
normalize_log_level(cls, v)
```
#### `server_auth_class`
```python
server_auth_class(self) -> AuthProvider | None
```