# Source: https://gofastmcp.com/python-sdk/fastmcp-server-transforms-visibility.md

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

# visibility

# `fastmcp.server.transforms.visibility`

Visibility transform for marking component visibility state.

Each Visibility instance marks components via internal metadata. Multiple
visibility transforms can be stacked - later transforms override earlier ones.
Final filtering happens at the Provider level.

## Functions

### `is_enabled` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L271" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
is_enabled(component: FastMCPComponent) -> bool
```

Check if component is enabled.

Returns True if:

* No visibility mark exists (default is enabled)
* Visibility mark is True

Returns False if visibility mark is False.

**Args:**

* `component`: Component to check.

**Returns:**

* True if component should be enabled/visible to clients.

### `get_visibility_rules` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L300" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_visibility_rules(context: Context) -> list[dict[str, Any]]
```

Load visibility rule dicts from session state.

### `save_visibility_rules` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L305" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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_visibility_transforms` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L332" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
create_visibility_transforms(rules: list[dict[str, Any]]) -> list[Visibility]
```

Convert rule dicts to Visibility transforms.

### `get_session_transforms` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L360" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_session_transforms(context: Context) -> list[Visibility]
```

Get session-specific Visibility transforms from state store.

### `enable_components` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L372" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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
(Visibility 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` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L426" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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
(Visibility 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_visibility` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L480" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
reset_visibility(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` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L497" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 visibility 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

### `Visibility` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L39" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

Sets visibility state on matching components.

Does NOT filter inline - just marks components with visibility state.
Later transforms in the chain can override earlier marks.
Final filtering happens at the Provider level after all transforms run.

**Methods:**

#### `list_tools` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L196" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
list_tools(self, tools: Sequence[Tool]) -> Sequence[Tool]
```

Mark tools by visibility state.

#### `get_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L200" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_tool(self, name: str, call_next: GetToolNext) -> Tool | None
```

Mark tool if found.

#### `list_resources` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L213" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
list_resources(self, resources: Sequence[Resource]) -> Sequence[Resource]
```

Mark resources by visibility state.

#### `get_resource` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L217" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_resource(self, uri: str, call_next: GetResourceNext) -> Resource | None
```

Mark resource if found.

#### `list_resource_templates` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L234" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
list_resource_templates(self, templates: Sequence[ResourceTemplate]) -> Sequence[ResourceTemplate]
```

Mark resource templates by visibility state.

#### `get_resource_template` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L240" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_resource_template(self, uri: str, call_next: GetResourceTemplateNext) -> ResourceTemplate | None
```

Mark resource template if found.

#### `list_prompts` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L257" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
list_prompts(self, prompts: Sequence[Prompt]) -> Sequence[Prompt]
```

Mark prompts by visibility state.

#### `get_prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/transforms/visibility.py#L261" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
get_prompt(self, name: str, call_next: GetPromptNext) -> Prompt | None
```

Mark prompt if found.