---
title: enabled
sidebarTitle: enabled
---
# `fastmcp.server.transforms.enabled`
Enabled transform for marking component enabled state.
Each Enabled instance marks components via internal metadata. Multiple
enabled transforms can be stacked - later transforms override earlier ones.
Final filtering happens at the Provider level.
## Functions
### `is_enabled`
```python
is_enabled(component: FastMCPComponent) -> bool
```
Check if component is enabled.
Returns True if:
- No enabled mark exists (default is enabled)
- Enabled mark is True
Returns False if enabled mark is False.
**Args:**
- `component`: Component to check.
**Returns:**
- True if component should be enabled/visible to clients.
### `get_visibility_rules`
```python
get_visibility_rules(context: Context) -> list[dict[str, Any]]
```
Load visibility rule dicts from session state.
### `save_visibility_rules`
```python
save_visibility_rules(context: Context, rules: list[dict[str, Any]]) -> None
```
Save visibility rule dicts to session state and send notifications.
**Args:**
- `context`: The context to save rules for.
- `rules`: The visibility rules to save.
- `components`: Optional hint about which component types are affected.
If None, sends notifications for all types (safe default).
If provided, only sends notifications for specified types.
### `create_enabled_transforms`
```python
create_enabled_transforms(rules: list[dict[str, Any]]) -> list[Enabled]
```
Convert rule dicts to Enabled transforms.
### `get_session_transforms`
```python
get_session_transforms(context: Context) -> list[Enabled]
```
Get session-specific Enabled transforms from state store.
### `enable_components`
```python
enable_components(context: Context) -> None
```
Enable components matching criteria for this session only.
Session rules override global transforms. Rules accumulate - each call
adds a new rule to the session. Later marks override earlier ones
(Enabled transform semantics).
Sends notifications to this session only: ToolListChangedNotification,
ResourceListChangedNotification, and PromptListChangedNotification.
**Args:**
- `context`: The context for this session.
- `names`: Component names or URIs to match.
- `keys`: Component keys to match (e.g., {"tool\:my_tool@v1"}).
- `version`: Component version spec to match.
- `tags`: Tags to match (component must have at least one).
- `components`: Component types to match (e.g., {"tool", "prompt"}).
- `match_all`: If True, matches all components regardless of other criteria.
### `disable_components`
```python
disable_components(context: Context) -> None
```
Disable components matching criteria for this session only.
Session rules override global transforms. Rules accumulate - each call
adds a new rule to the session. Later marks override earlier ones
(Enabled transform semantics).
Sends notifications to this session only: ToolListChangedNotification,
ResourceListChangedNotification, and PromptListChangedNotification.
**Args:**
- `context`: The context for this session.
- `names`: Component names or URIs to match.
- `keys`: Component keys to match (e.g., {"tool\:my_tool@v1"}).
- `version`: Component version spec to match.
- `tags`: Tags to match (component must have at least one).
- `components`: Component types to match (e.g., {"tool", "prompt"}).
- `match_all`: If True, matches all components regardless of other criteria.
### `reset_components`
```python
reset_components(context: Context) -> None
```
Clear all session visibility rules.
Use this to reset session visibility back to global defaults.
Sends notifications to this session only: ToolListChangedNotification,
ResourceListChangedNotification, and PromptListChangedNotification.
**Args:**
- `context`: The context for this session.
### `apply_session_transforms`
```python
apply_session_transforms(components: Sequence[ComponentT]) -> Sequence[ComponentT]
```
Apply session-specific visibility transforms to components.
This helper applies session-level enable/disable rules by marking
components with their enabled state. Session transforms override
global transforms due to mark-based semantics (later marks win).
**Args:**
- `components`: The components to apply session transforms to.
**Returns:**
- The components with session transforms applied.
## Classes
### `Enabled`
Sets enabled state on matching components.
Does NOT filter inline - just marks components with enabled state.
Later transforms in the chain can override earlier marks.
Final filtering happens at the Provider level after all transforms run.
**Methods:**
#### `list_tools`
```python
list_tools(self, call_next: ListToolsNext) -> Sequence[Tool]
```
Mark tools by enabled state.
#### `get_tool`
```python
get_tool(self, name: str, call_next: GetToolNext) -> Tool | None
```
Mark tool if found.
#### `list_resources`
```python
list_resources(self, call_next: ListResourcesNext) -> Sequence[Resource]
```
Mark resources by enabled state.
#### `get_resource`
```python
get_resource(self, uri: str, call_next: GetResourceNext) -> Resource | None
```
Mark resource if found.
#### `list_resource_templates`
```python
list_resource_templates(self, call_next: ListResourceTemplatesNext) -> Sequence[ResourceTemplate]
```
Mark resource templates by enabled state.
#### `get_resource_template`
```python
get_resource_template(self, uri: str, call_next: GetResourceTemplateNext) -> ResourceTemplate | None
```
Mark resource template if found.
#### `list_prompts`
```python
list_prompts(self, call_next: ListPromptsNext) -> Sequence[Prompt]
```
Mark prompts by enabled state.
#### `get_prompt`
```python
get_prompt(self, name: str, call_next: GetPromptNext) -> Prompt | None
```
Mark prompt if found.