fastmcp/docs/python-sdk/fastmcp-server-providers-fastmcp_provider.mdx
Jeremiah Lowin 3a9717e6be
Publish docs for v3.2.0 (#3713)
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Fix auto-close MRE script posting comment without closing (#3386)
Fix WorkOS token scope verification bypass 🤖 Generated with Codex (#3407)
Fix initialize McpError fallthrough 🤖 Generated with Codex (#3413)
Fix transform arg collisions with passthrough params (#3431)
Fix get_* returning None when latest version is disabled (#3439)
Fix get_* returning None when latest version is disabled (#3421)
Fix server lifespan overlap teardown (#3415)
Fix $ref output schema object detection regression (#3420)
resolved annotations (#3429)
Fix async partial callables rejected by iscoroutinefunction (#3438)
Fix async partial callables rejected by iscoroutinefunction (#3423)
fix: add version to components (#3458)
fix: use intent-based flag for OIDC scope patch in load_access_token (#3465)
Fixes #3461
fix: normalize Google scope shorthands and surface valid_scopes (#3477)
fix: resolve ty 0.0.23 type-checking errors and bump pin (#3481)
fix: shield lifespan teardown from cancellation (#3480)
fix: forward custom_route endpoints from mounted servers (#3462)
fix updates _get_additional_http_routes() to traverse providers,
Fixes #3457
fix: remove hardcoded version from CLI help text (#3456)
fix: monty 0.0.8 compatibility, drop external_functions from constructor (#3468)
fix: task test teardown hanging 5s per test (#3499)
Closes #3498
fix: validate workspace path is a directory before cursor install (#3440)
Fixes #3426
fix: handle re.error from malformed URI templates in build_regex (#3501)
fix: reject empty/OIDC-only required_scopes in AzureProvider (#3503)
fix: restrict $ref resolution to local refs only (SSRF/LFI) (#3502)
fix warnings and timeouts (#3504)
close upgrade check issue when build passes (#3505)
Closes #3484
fix: URL-encode path params to prevent SSRF/path traversal (GHSA-vv7q-7jx5-f767) (#3507)
fix: prevent path traversal in skill download (#3493)
fix: prefer IdP-granted scopes over client-requested scopes in OAuthProxy (#3492)
fix: remove unrelated transform and http.py changes from PR scope
fix: remove forced follow_redirects from httpx_client_factory calls (#3496)
fix: stop passing follow_redirects to httpx_client_factory
fix: restore follow_redirects=True for custom httpx client factories
Closes #3509
fix: CSRF double-submit cookie check in consent flow (#3519)
fix: validate server names in install commands (#3522)
fix: use raw strings for regex in pytest.raises match (#3523)
fix: reject refresh tokens used as Bearer access tokens (#3524)
fix: route ResourcesAsTools/PromptsAsTools through server middleware (#3495)
fix: resolve Pyright "Module is not callable" on @tool, @resource, @prompt decorators (#3540)
fix: filter warnings by message in KEY_PREFIX test (#3549)
fix: suppress output schema for ToolResult subclass annotations (#3548)
fix: increase sleep duration in proxy cache tests (#3567)
fix: store absolute token expiry to prevent stale expires_in on reload (#3572)
fix: preserve tool properties named 'title' during schema compression (#3582)
Fix loopback redirect URI port matching per RFC 8252 §7.3 (#3589)
Fix app tool routing: visibility check and middleware propagation (#3591)
Fix query parameter serialization to respect OpenAPI explode/style settings (#3595)
Fix dev apps form: union types, textarea support, JSON parsing (#3597)
fix(google): replace deprecated /oauth2/v1/tokeninfo with /oauth2/v3/userinfo (#3603)
fix: resolve EntraOBOToken dependency injection through MultiAuth (#3609)
fix(docs): correct misleading stateless_http header (#3622)
fix: filesystem provider import machinery (#3626)
Closes #3625 (issues 2, 3, 6)
fix: recover StdioTransport after subprocess exits (#3630)
fix(server): preserve mounted tool task metadata (#3632)
fix: scope deprecation warning filter to FastMCPDeprecationWarning (#3649)
fix imports, add PrefabAppConfig (#3650)
fix: resolve CurrentFastMCP/ctx.fastmcp to child server in mounted background tasks (#3651)
Fix blocking docs issues: chart imports, Select API, Rx consistency (#3652)
closed by default (#3657)
Fix prompt caching middleware missing wrap/unwrap round-trip (#3666)
fix: serialize object query params per OpenAPI style/explode rules (#3662)
Fixes #2857
fix: HTTP request headers not accessible in background task workers (#3631)
fix: restore HTTP headers in worker execution path for background tasks (#3681)
fix: strip discriminator after dereferencing schemas (#3682)
fix: remove stale ty:ignore directives for ty 0.0.26 (#3684)
Fix docs gaps in app provider pages (#3690)
fix: dev apps log panel UX improvements (#3698)
fix dev server empty string args (#3700)
2026-03-30 16:48:30 -04:00

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---
title: fastmcp_provider
sidebarTitle: fastmcp_provider
---
# `fastmcp.server.providers.fastmcp_provider`
FastMCPProvider for wrapping FastMCP servers as providers.
This module provides the `FastMCPProvider` class that wraps a FastMCP server
and exposes its components through the Provider interface.
It also provides FastMCPProvider* component classes that delegate execution to
the wrapped server's middleware, ensuring middleware runs when components are
executed.
## Classes
### `FastMCPProviderTool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L72" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
Tool that delegates execution to a wrapped server's middleware.
When `run()` is called, this tool invokes the wrapped server's
`_call_tool_middleware()` method, ensuring the server's middleware
chain is executed.
**Methods:**
#### `wrap` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L94" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
wrap(cls, server: Any, tool: Tool) -> FastMCPProviderTool
```
Wrap a Tool to delegate execution to the server's middleware.
#### `run` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L151" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
run(self, arguments: dict[str, Any]) -> ToolResult
```
Delegate to child server's call_tool() without task_meta.
This is called when the tool is used within a TransformedTool
forwarding function or other contexts where task_meta is not available.
#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L170" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_span_attributes(self) -> dict[str, Any]
```
### `FastMCPProviderResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L177" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
Resource that delegates reading to a wrapped server's read_resource().
When `read()` is called, this resource invokes the wrapped server's
`read_resource()` method, ensuring the server's middleware chain is executed.
**Methods:**
#### `wrap` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L198" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
wrap(cls, server: Any, resource: Resource) -> FastMCPProviderResource
```
Wrap a Resource to delegate reading to the server's middleware.
#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L241" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_span_attributes(self) -> dict[str, Any]
```
### `FastMCPProviderPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L248" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
Prompt that delegates rendering to a wrapped server's render_prompt().
When `render()` is called, this prompt invokes the wrapped server's
`render_prompt()` method, ensuring the server's middleware chain is executed.
**Methods:**
#### `wrap` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L269" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
wrap(cls, server: Any, prompt: Prompt) -> FastMCPProviderPrompt
```
Wrap a Prompt to delegate rendering to the server's middleware.
#### `render` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L320" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
render(self, arguments: dict[str, Any] | None = None) -> PromptResult
```
Delegate to child server's render_prompt() without task_meta.
This is called when the prompt is used within a transformed context
or other contexts where task_meta is not available.
#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L339" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_span_attributes(self) -> dict[str, Any]
```
### `FastMCPProviderResourceTemplate` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L346" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
Resource template that creates FastMCPProviderResources.
When `create_resource()` is called, this template creates a
FastMCPProviderResource that will invoke the wrapped server's middleware
when read.
**Methods:**
#### `wrap` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L368" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
wrap(cls, server: Any, template: ResourceTemplate) -> FastMCPProviderResourceTemplate
```
Wrap a ResourceTemplate to create FastMCPProviderResources.
#### `create_resource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L389" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
create_resource(self, uri: str, params: dict[str, Any]) -> Resource
```
Create a FastMCPProviderResource for the given URI.
The `uri` is the external/transformed URI (e.g., with namespace prefix).
We use `_original_uri_template` with `params` to construct the internal
URI that the nested server understands.
#### `read` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L439" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
read(self, arguments: dict[str, Any]) -> str | bytes | ResourceResult
```
Read the resource content for background task execution.
Reads the resource via the wrapped server and returns the ResourceResult.
This method is called by Docket during background task execution.
#### `register_with_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L460" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
register_with_docket(self, docket: Docket) -> None
```
No-op: the child's actual template is registered via get_tasks().
#### `add_to_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L463" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
add_to_docket(self, docket: Docket, params: dict[str, Any], **kwargs: Any) -> Execution
```
Schedule this template for background execution via docket.
The child's FunctionResourceTemplate.fn is registered (via get_tasks),
and it expects splatted **kwargs, so we splat params here.
#### `get_span_attributes` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L482" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_span_attributes(self) -> dict[str, Any]
```
### `FastMCPProvider` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L494" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
Provider that wraps a FastMCP server.
This provider enables mounting one FastMCP server onto another, exposing
the mounted server's tools, resources, and prompts through the parent
server.
Components returned by this provider are wrapped in FastMCPProvider*
classes that delegate execution to the wrapped server's middleware chain.
This ensures middleware runs when components are executed.
**Methods:**
#### `get_app_tool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L569" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_app_tool(self, app_name: str, tool_name: str) -> Tool | None
```
Delegate to nested server's get_app_tool, wrapping for middleware.
#### `get_tasks` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L671" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
get_tasks(self) -> Sequence[FastMCPComponent]
```
Return task-eligible components from the mounted server.
Returns the child's ACTUAL components (not wrapped) so their actual
functions get registered with Docket. Gets components with child
server's transforms applied, then applies this provider's transforms
for correct registration keys.
#### `lifespan` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/fastmcp_provider.py#L712" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
```python
lifespan(self) -> AsyncIterator[None]
```
Start the mounted server's user lifespan.
This starts only the wrapped server's user-defined lifespan, NOT its
full _lifespan_manager() (which includes Docket). The parent server's
Docket handles all background tasks.