fastmcp/docs/python-sdk/fastmcp-server-providers-proxy.mdx

---
title: proxy
sidebarTitle: proxy
---

# `fastmcp.server.providers.proxy`


ProxyProvider for proxying to remote MCP servers.

This module provides the `ProxyProvider` class that proxies components from
a remote MCP server via a client factory. It also provides proxy component
classes that forward execution to remote servers.


## Functions

### `default_proxy_roots_handler` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L842" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
default_proxy_roots_handler(context: RequestContext[ClientSession, LifespanContextT]) -> RootsList
```


Forward list roots request from remote server to proxy's connected clients.


### `default_proxy_sampling_handler` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L850" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
default_proxy_sampling_handler(messages: list[mcp.types.SamplingMessage], params: mcp.types.CreateMessageRequestParams, context: RequestContext[ClientSession, LifespanContextT]) -> mcp.types.CreateMessageResult
```


Forward sampling request from remote server to proxy's connected clients.


### `default_proxy_elicitation_handler` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L873" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
default_proxy_elicitation_handler(message: str, response_type: type, params: mcp.types.ElicitRequestParams, context: RequestContext[ClientSession, LifespanContextT]) -> ElicitResult
```


Forward elicitation request from remote server to proxy's connected clients.


### `default_proxy_log_handler` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L895" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
default_proxy_log_handler(message: LogMessage) -> None
```


Forward log notification from remote server to proxy's connected clients.


### `default_proxy_progress_handler` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L903" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
default_proxy_progress_handler(progress: float, total: float | None, message: str | None) -> None
```


Forward progress notification from remote server to proxy's connected clients.


## Classes

### `ProxyTool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L69" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Tool that represents and executes a tool on a remote server.


**Methods:**

#### `model_copy` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L86" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
model_copy(self, **kwargs: Any) -> ProxyTool
```

Override to preserve _backend_name when name changes.


#### `from_mcp_tool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L96" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_mcp_tool(cls, client_factory: ClientFactoryT, mcp_tool: mcp.types.Tool) -> ProxyTool
```

Factory method to create a ProxyTool from a raw MCP tool schema.


#### `run` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L113" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
run(self, arguments: dict[str, Any], context: Context | None = None) -> ToolResult
```

Executes the tool by making a call through the client.


#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L168" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_span_attributes(self) -> dict[str, Any]
```

### `ProxyResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L175" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Resource that represents and reads a resource from a remote server.


**Methods:**

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

```python
model_copy(self, **kwargs: Any) -> ProxyResource
```

Override to preserve _backend_uri when uri changes.


#### `from_mcp_resource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L210" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_mcp_resource(cls, client_factory: ClientFactoryT, mcp_resource: mcp.types.Resource) -> ProxyResource
```

Factory method to create a ProxyResource from a raw MCP resource schema.


#### `read` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L230" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
read(self) -> ResourceResult
```

Read the resource content from the remote server.


#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L275" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_span_attributes(self) -> dict[str, Any]
```

### `ProxyTemplate` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L282" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A ResourceTemplate that represents and creates resources from a remote server template.


**Methods:**

#### `model_copy` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L299" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
model_copy(self, **kwargs: Any) -> ProxyTemplate
```

Override to preserve _backend_uri_template when uri_template changes.


#### `from_mcp_template` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L309" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_mcp_template(cls, client_factory: ClientFactoryT, mcp_template: mcp.types.ResourceTemplate) -> ProxyTemplate
```

Factory method to create a ProxyTemplate from a raw MCP template schema.


#### `create_resource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L328" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
create_resource(self, uri: str, params: dict[str, Any], context: Context | None = None) -> ProxyResource
```

Create a resource from the template by calling the remote server.


#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L390" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_span_attributes(self) -> dict[str, Any]
```

### `ProxyPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L397" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Prompt that represents and renders a prompt from a remote server.


**Methods:**

#### `model_copy` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L414" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
model_copy(self, **kwargs: Any) -> ProxyPrompt
```

Override to preserve _backend_name when name changes.


#### `from_mcp_prompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L424" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_mcp_prompt(cls, client_factory: ClientFactoryT, mcp_prompt: mcp.types.Prompt) -> ProxyPrompt
```

Factory method to create a ProxyPrompt from a raw MCP prompt schema.


#### `render` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L448" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
render(self, arguments: dict[str, Any]) -> PromptResult
```

Render the prompt by making a call through the client.


#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L470" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_span_attributes(self) -> dict[str, Any]
```

### `ProxyProvider` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L498" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Provider that proxies to a remote MCP server via a client factory.

This provider fetches components from a remote server and returns Proxy*
component instances that forward execution to the remote server.

All components returned by this provider have task_config.mode="forbidden"
because tasks cannot be executed through a proxy.

Component lists (tools, resources, templates, prompts) are cached so that
individual lookups (e.g. during ``call_tool``) can resolve from the cache
instead of opening a new backend connection.  The cache stores the
backend's raw component metadata and is shared across all sessions;
per-session visibility and auth filtering are applied after cache lookup
by the server layer.  The cache is refreshed whenever a ``list_*`` call
is made, and entries expire after ``cache_ttl`` seconds (default 300).
Set ``cache_ttl=0`` to disable caching.  Disabling is recommended for
backends whose component lists change dynamically.


**Methods:**

#### `get_tasks` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L714" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_tasks(self) -> Sequence[FastMCPComponent]
```

Return empty list since proxy components don't support tasks.

Override the base implementation to avoid calling list_tools() during
server lifespan initialization, which would open the client before any
context is set. All Proxy* components have task_config.mode="forbidden".


### `FastMCPProxy` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L795" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A FastMCP server that acts as a proxy to a remote MCP-compliant server.

This is a convenience wrapper that creates a FastMCP server with a
ProxyProvider. For more control, use FastMCP with add_provider(ProxyProvider(...)).


### `ProxyClient` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L967" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A proxy client that forwards advanced interactions between a remote MCP server and the proxy's connected clients.

Supports forwarding roots, sampling, elicitation, logging, and progress.


### `StatefulProxyClient` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L1000" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A proxy client that provides a stateful client factory for the proxy server.

The stateful proxy client bound its copy to the server session.
And it will be disconnected when the session is exited.

This is useful to proxy a stateful mcp server such as the Playwright MCP server.
Note that it is essential to ensure that the proxy server itself is also stateful.

Because session reuse means the receive-loop task inherits a stale
``request_ctx`` ContextVar snapshot, the default proxy handlers are
replaced with versions that restore the ContextVar before forwarding.
``ProxyTool.run`` stashes the current ``RequestContext`` in
``_proxy_rc_ref`` before each backend call, and the handlers consult
it to detect (and correct) staleness.


**Methods:**

#### `clear` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L1051" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
clear(self)
```

Clear all cached clients and force disconnect them.


#### `new_stateful` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/proxy.py#L1057" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
new_stateful(self) -> Client[ClientTransportT]
```

Create a new stateful proxy client instance with the same configuration.

Use this method as the client factory for stateful proxy server.