> ## Documentation Index > Fetch the complete documentation index at: https://gofastmcp.com/llms.txt > Use this file to discover all available pages before exploring further. # 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} default_proxy_log_handler(message: LogMessage) -> None ``` Forward log notification from remote server to proxy's connected clients. ### `default_proxy_progress_handler` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` A Tool that represents and executes a tool on a remote server. **Methods:** #### `model_copy` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} model_copy(self, **kwargs: Any) -> ProxyTool ``` Override to preserve \_backend\_name when name changes. #### `from_mcp_tool` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} run(self, arguments: dict[str, Any], context: Context | None = None) -> ToolResult ``` Executes the tool by making a call through the client. #### `get_span_attributes` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get_span_attributes(self) -> dict[str, Any] ``` ### `ProxyResource` A Resource that represents and reads a resource from a remote server. **Methods:** #### `model_copy` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} model_copy(self, **kwargs: Any) -> ProxyResource ``` Override to preserve \_backend\_uri when uri changes. #### `from_mcp_resource` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} read(self) -> ResourceResult ``` Read the resource content from the remote server. #### `get_span_attributes` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get_span_attributes(self) -> dict[str, Any] ``` ### `ProxyTemplate` A ResourceTemplate that represents and creates resources from a remote server template. **Methods:** #### `model_copy` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} model_copy(self, **kwargs: Any) -> ProxyTemplate ``` Override to preserve \_backend\_uri\_template when uri\_template changes. #### `from_mcp_template` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get_span_attributes(self) -> dict[str, Any] ``` ### `ProxyPrompt` A Prompt that represents and renders a prompt from a remote server. **Methods:** #### `model_copy` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} model_copy(self, **kwargs: Any) -> ProxyPrompt ``` Override to preserve \_backend\_name when name changes. #### `from_mcp_prompt` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} render(self, arguments: dict[str, Any]) -> PromptResult ``` Render the prompt by making a call through the client. #### `get_span_attributes` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get_span_attributes(self) -> dict[str, Any] ``` ### `ProxyProvider` 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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` 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` 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` 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` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} clear(self) ``` Clear all cached clients and force disconnect them. #### `new_stateful` ```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} 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.