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Merge pull request #949 from jlowin/fix-doc-render

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fix a couple parsing issues
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nate nowack 2025-06-25 11:28:12 -05:00 • committed by GitHub
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189
docs/python-sdk/fastmcp-server-server.mdx
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@ -10,7 +10,7 @@ FastMCP - A more ergonomic interface for MCP servers.
## Functions
### `add_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1865"><Icon icon="github" size="14" /></a></sup>
### `add_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1879"><Icon icon="github" size="14" /></a></sup>
```python
add_resource_prefix(uri: str, prefix: str, prefix_format: Literal['protocol', 'path'] | None = None) -> str
@ -28,18 +28,27 @@ Add a prefix to a resource URI.
**Examples:**
>>> add_resource_prefix("resource://path/to/resource", "prefix")
"resource://prefix/path/to/resource" # with new style
>>> add_resource_prefix("resource://path/to/resource", "prefix")
"prefix+resource://path/to/resource" # with legacy style
>>> add_resource_prefix("resource:///absolute/path", "prefix")
"resource://prefix//absolute/path" # with new style
With new style:
```python
add_resource_prefix("resource://path/to/resource", "prefix")
"resource://prefix/path/to/resource"
```
With legacy style:
```python
add_resource_prefix("resource://path/to/resource", "prefix")
"prefix+resource://path/to/resource"
```
With absolute path:
```python
add_resource_prefix("resource:///absolute/path", "prefix")
"resource://prefix//absolute/path"
```
**Raises:**
- `ValueError`: If the URI doesn't match the expected protocol\://path format
### `remove_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1916"><Icon icon="github" size="14" /></a></sup>
### `remove_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1939"><Icon icon="github" size="14" /></a></sup>
```python
remove_resource_prefix(uri: str, prefix: str, prefix_format: Literal['protocol', 'path'] | None = None) -> str
@ -58,18 +67,27 @@ Returns:
**Examples:**
>>> remove_resource_prefix("resource://prefix/path/to/resource", "prefix")
"resource://path/to/resource" # with new style
>>> remove_resource_prefix("prefix+resource://path/to/resource", "prefix")
"resource://path/to/resource" # with legacy style
>>> remove_resource_prefix("resource://prefix//absolute/path", "prefix")
"resource:///absolute/path" # with new style
With new style:
```python
remove_resource_prefix("resource://prefix/path/to/resource", "prefix")
"resource://path/to/resource"
```
With legacy style:
```python
remove_resource_prefix("prefix+resource://path/to/resource", "prefix")
"resource://path/to/resource"
```
With absolute path:
```python
remove_resource_prefix("resource://prefix//absolute/path", "prefix")
"resource:///absolute/path"
```
**Raises:**
- `ValueError`: If the URI doesn't match the expected protocol\://path format
### `has_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1974"><Icon icon="github" size="14" /></a></sup>
### `has_resource_prefix` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L2006"><Icon icon="github" size="14" /></a></sup>
```python
has_resource_prefix(uri: str, prefix: str, prefix_format: Literal['protocol', 'path'] | None = None) -> bool
@ -87,12 +105,21 @@ Check if a resource URI has a specific prefix.
**Examples:**
>>> has_resource_prefix("resource://prefix/path/to/resource", "prefix")
True # with new style
>>> has_resource_prefix("prefix+resource://path/to/resource", "prefix")
True # with legacy style
>>> has_resource_prefix("resource://other/path/to/resource", "prefix")
With new style:
```python
has_resource_prefix("resource://prefix/path/to/resource", "prefix")
True
```
With legacy style:
```python
has_resource_prefix("prefix+resource://path/to/resource", "prefix")
True
```
With other path:
```python
has_resource_prefix("resource://other/path/to/resource", "prefix")
False
```
**Raises:**
- `ValueError`: If the URI doesn't match the expected protocol\://path format
@ -140,7 +167,7 @@ Run the FastMCP server. Note this is a synchronous function.
add_middleware(self, middleware: Middleware) -> None
```
#### `custom_route` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L383"><Icon icon="github" size="14" /></a></sup>
#### `custom_route` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L384"><Icon icon="github" size="14" /></a></sup>
```python
custom_route(self, path: str, methods: list[str], name: str | None = None, include_in_schema: bool = True)
@ -161,7 +188,7 @@ Starlette's reverse URL lookup feature)
- `include_in_schema`: Whether to include in OpenAPI schema, defaults to True
#### `add_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L738"><Icon icon="github" size="14" /></a></sup>
#### `add_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L742"><Icon icon="github" size="14" /></a></sup>
```python
add_tool(self, tool: Tool) -> None
@ -176,7 +203,7 @@ with the Context type annotation. See the @tool decorator for examples.
- `tool`: The Tool instance to register
#### `remove_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L750"><Icon icon="github" size="14" /></a></sup>
#### `remove_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L754"><Icon icon="github" size="14" /></a></sup>
```python
remove_tool(self, name: str) -> None
@ -191,19 +218,19 @@ Remove a tool from the server.
- `NotFoundError`: If the tool is not found
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L763"><Icon icon="github" size="14" /></a></sup>
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L767"><Icon icon="github" size="14" /></a></sup>
```python
tool(self, name_or_fn: AnyFunction) -> FunctionTool
```
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L776"><Icon icon="github" size="14" /></a></sup>
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L780"><Icon icon="github" size="14" /></a></sup>
```python
tool(self, name_or_fn: str | None = None) -> Callable[[AnyFunction], FunctionTool]
```
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L788"><Icon icon="github" size="14" /></a></sup>
#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L792"><Icon icon="github" size="14" /></a></sup>
```python
tool(self, name_or_fn: str | AnyFunction | None = None) -> Callable[[AnyFunction], FunctionTool] | FunctionTool
@ -227,12 +254,37 @@ This decorator supports multiple calling patterns:
- `name`: Optional name for the tool (keyword-only, alternative to name_or_fn)
- `description`: Optional description of what the tool does
- `tags`: Optional set of tags for categorizing the tool
- `annotations`: Optional annotations about the tool's behavior (e.g. {"is_async"\: True})
- `annotations`: Optional annotations about the tool's behavior
- `exclude_args`: Optional list of argument names to exclude from the tool schema
- `enabled`: Optional boolean to enable or disable the tool
**Examples:**
#### `add_resource` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L904"><Icon icon="github" size="14" /></a></sup>
Register a tool with a custom name:
```python
@server.tool
def my_tool(x: int) -> str:
return str(x)
# Register a tool with a custom name
@server.tool
def my_tool(x: int) -> str:
return str(x)
@server.tool("custom_name")
def my_tool(x: int) -> str:
return str(x)
@server.tool(name="custom_name")
def my_tool(x: int) -> str:
return str(x)
# Direct function call
server.tool(my_function, name="custom_name")
```
#### `add_resource` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L912"><Icon icon="github" size="14" /></a></sup>
```python
add_resource(self, resource: Resource) -> None
@ -244,7 +296,7 @@ Add a resource to the server.
- `resource`: A Resource instance to add
#### `add_template` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L914"><Icon icon="github" size="14" /></a></sup>
#### `add_template` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L922"><Icon icon="github" size="14" /></a></sup>
```python
add_template(self, template: ResourceTemplate) -> None
@ -256,7 +308,7 @@ Add a resource template to the server.
- `template`: A ResourceTemplate instance to add
#### `add_resource_fn` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L922"><Icon icon="github" size="14" /></a></sup>
#### `add_resource_fn` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L930"><Icon icon="github" size="14" /></a></sup>
```python
add_resource_fn(self, fn: AnyFunction, uri: str, name: str | None = None, description: str | None = None, mime_type: str | None = None, tags: set[str] | None = None) -> None
@ -276,7 +328,7 @@ has parameters, it will be registered as a template resource.
- `tags`: Optional set of tags for categorizing the resource
#### `resource` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L961"><Icon icon="github" size="14" /></a></sup>
#### `resource` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L969"><Icon icon="github" size="14" /></a></sup>
```python
resource(self, uri: str) -> Callable[[AnyFunction], Resource | ResourceTemplate]
@ -305,8 +357,36 @@ has parameters, it will be registered as a template resource.
- `tags`: Optional set of tags for categorizing the resource
- `enabled`: Optional boolean to enable or disable the resource
**Examples:**
#### `add_prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1081"><Icon icon="github" size="14" /></a></sup>
Register a resource with a custom name:
```python
@server.resource("resource://my-resource")
def get_data() -> str:
return "Hello, world!"
@server.resource("resource://my-resource")
async get_data() -> str:
data = await fetch_data()
return f"Hello, world! {data}"
@server.resource("resource://{city}/weather")
def get_weather(city: str) -> str:
return f"Weather for {city}"
@server.resource("resource://{city}/weather")
def get_weather_with_context(city: str, ctx: Context) -> str:
ctx.info(f"Fetching weather for {city}")
return f"Weather for {city}"
@server.resource("resource://{city}/weather")
async def get_weather(city: str) -> str:
data = await fetch_weather(city)
return f"Weather for {city}: {data}"
```
#### `add_prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1092"><Icon icon="github" size="14" /></a></sup>
```python
add_prompt(self, prompt: Prompt) -> None
@ -318,19 +398,19 @@ Add a prompt to the server.
- `prompt`: A Prompt instance to add
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1091"><Icon icon="github" size="14" /></a></sup>
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1102"><Icon icon="github" size="14" /></a></sup>
```python
prompt(self, name_or_fn: AnyFunction) -> FunctionPrompt
```
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1102"><Icon icon="github" size="14" /></a></sup>
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1113"><Icon icon="github" size="14" /></a></sup>
```python
prompt(self, name_or_fn: str | None = None) -> Callable[[AnyFunction], FunctionPrompt]
```
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1112"><Icon icon="github" size="14" /></a></sup>
#### `prompt` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1123"><Icon icon="github" size="14" /></a></sup>
```python
prompt(self, name_or_fn: str | AnyFunction | None = None) -> Callable[[AnyFunction], FunctionPrompt] | FunctionPrompt
@ -356,9 +436,11 @@ Decorator to register a prompt.
tags: Optional set of tags for categorizing the prompt
enabled: Optional boolean to enable or disable the prompt
Example:
Examples:
```python
@server.prompt
def analyze_table(table_name: str) -> list\[Message]:
def analyze_table(table_name: str) -> list[Message]:
schema = read_table_schema(table_name)
return [
{
@ -369,7 +451,7 @@ Decorator to register a prompt.
]
@server.prompt()
def analyze_with_context(table_name: str, ctx: Context) -> list\[Message]:
def analyze_with_context(table_name: str, ctx: Context) -> list[Message]:
ctx.info(f"Analyzing table {table_name}")
schema = read_table_schema(table_name)
return [
@ -381,7 +463,7 @@ Decorator to register a prompt.
]
@server.prompt("custom_name")
def analyze_file(path: str) -> list\[Message]:
def analyze_file(path: str) -> list[Message]:
content = await read_file(path)
return [
{
@ -397,14 +479,15 @@ Decorator to register a prompt.
]
@server.prompt(name="custom_name")
def another_prompt(data: str) -> list\[Message]:
def another_prompt(data: str) -> list[Message]:
return [{"role": "user", "content": data}]
# Direct function call
server.prompt(my_function, name="custom_name")
```
#### `sse_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1330"><Icon icon="github" size="14" /></a></sup>
#### `sse_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1344"><Icon icon="github" size="14" /></a></sup>
```python
sse_app(self, path: str | None = None, message_path: str | None = None, middleware: list[ASGIMiddleware] | None = None) -> StarletteWithLifespan
@ -418,7 +501,7 @@ Create a Starlette app for the SSE server.
- `middleware`: A list of middleware to apply to the app
#### `streamable_http_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1361"><Icon icon="github" size="14" /></a></sup>
#### `streamable_http_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1375"><Icon icon="github" size="14" /></a></sup>
```python
streamable_http_app(self, path: str | None = None, middleware: list[ASGIMiddleware] | None = None) -> StarletteWithLifespan
@ -431,7 +514,7 @@ Create a Starlette app for the StreamableHTTP server.
- `middleware`: A list of middleware to apply to the app
#### `http_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1382"><Icon icon="github" size="14" /></a></sup>
#### `http_app` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1396"><Icon icon="github" size="14" /></a></sup>
```python
http_app(self, path: str | None = None, middleware: list[ASGIMiddleware] | None = None, json_response: bool | None = None, stateless_http: bool | None = None, transport: Literal['http', 'streamable-http', 'sse'] = 'http') -> StarletteWithLifespan
@ -448,7 +531,7 @@ Create a Starlette app using the specified HTTP transport.
- A Starlette application configured with the specified transport
#### `mount` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1456"><Icon icon="github" size="14" /></a></sup>
#### `mount` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1470"><Icon icon="github" size="14" /></a></sup>
```python
mount(self, server: FastMCP[LifespanResultT], prefix: str | None = None, as_proxy: bool | None = None) -> None
@ -502,7 +585,7 @@ automatically determined based on whether the server has a custom lifespan
- `prompt_separator`: Deprecated. Separator character for prompt names.
#### `from_openapi` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1706"><Icon icon="github" size="14" /></a></sup>
#### `from_openapi` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1720"><Icon icon="github" size="14" /></a></sup>
```python
from_openapi(cls, openapi_spec: dict[str, Any], client: httpx.AsyncClient, route_maps: list[RouteMap] | None = None, route_map_fn: OpenAPIRouteMapFn | None = None, mcp_component_fn: OpenAPIComponentFn | None = None, mcp_names: dict[str, str] | None = None, tags: set[str] | None = None, **settings: Any) -> FastMCPOpenAPI
@ -511,7 +594,7 @@ from_openapi(cls, openapi_spec: dict[str, Any], client: httpx.AsyncClient, route
Create a FastMCP server from an OpenAPI specification.
#### `from_fastapi` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1734"><Icon icon="github" size="14" /></a></sup>
#### `from_fastapi` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1748"><Icon icon="github" size="14" /></a></sup>
```python
from_fastapi(cls, app: Any, name: str | None = None, route_maps: list[RouteMap] | None = None, route_map_fn: OpenAPIRouteMapFn | None = None, mcp_component_fn: OpenAPIComponentFn | None = None, mcp_names: dict[str, str] | None = None, httpx_client_kwargs: dict[str, Any] | None = None, tags: set[str] | None = None, **settings: Any) -> FastMCPOpenAPI
@ -520,7 +603,7 @@ from_fastapi(cls, app: Any, name: str | None = None, route_maps: list[RouteMap]
Create a FastMCP server from a FastAPI application.
#### `as_proxy` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1776"><Icon icon="github" size="14" /></a></sup>
#### `as_proxy` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1790"><Icon icon="github" size="14" /></a></sup>
```python
as_proxy(cls, backend: Client[ClientTransportT] | ClientTransport | FastMCP[Any] | AnyUrl | Path | MCPConfig | dict[str, Any] | str, **settings: Any) -> FastMCPProxy
@ -528,13 +611,13 @@ as_proxy(cls, backend: Client[ClientTransportT] | ClientTransport | FastMCP[Any]
Create a FastMCP proxy server for the given backend.
The ``backend`` argument can be either an existing :class:`~fastmcp.client.Client`
instance or any value accepted as the ``transport`` argument of
:class:`~fastmcp.client.Client`. This mirrors the convenience of the
``Client`` constructor.
The `backend` argument can be either an existing `fastmcp.client.Client`
instance or any value accepted as the `transport` argument of
`fastmcp.client.Client`. This mirrors the convenience of the
`fastmcp.client.Client` constructor.
#### `from_client` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1806"><Icon icon="github" size="14" /></a></sup>
#### `from_client` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1820"><Icon icon="github" size="14" /></a></sup>
```python
from_client(cls, client: Client[ClientTransportT], **settings: Any) -> FastMCPProxy
@ -543,4 +626,4 @@ from_client(cls, client: Client[ClientTransportT], **settings: Any) -> FastMCPPr
Create a FastMCP proxy server from a FastMCP client.
### `MountedServer` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1859"><Icon icon="github" size="14" /></a></sup>
### `MountedServer` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/server.py#L1873"><Icon icon="github" size="14" /></a></sup>

87
docs/python-sdk/fastmcp-tools-tool_transform.mdx
View file

@ -18,38 +18,58 @@ descriptions, add default values, or hide them from clients while passing consta
**Examples:**
# Rename argument 'old_name' to 'new_name'
Rename argument 'old_name' to 'new_name'
```python
ArgTransform(name="new_name")
```
# Change description only
Change description only
```python
ArgTransform(description="Updated description")
```
# Add a default value (makes argument optional)
Add a default value (makes argument optional)
```python
ArgTransform(default=42)
```
# Add a default factory (makes argument optional)
Add a default factory (makes argument optional)
```python
ArgTransform(default_factory=lambda: time.time())
```
# Change the type
Change the type
```python
ArgTransform(type=str)
```
# Hide the argument entirely from clients
Hide the argument entirely from clients
```python
ArgTransform(hide=True)
```
# Hide argument but pass a constant value to parent
Hide argument but pass a constant value to parent
```python
ArgTransform(hide=True, default="constant_value")
```
# Hide argument but pass a factory-generated value to parent
Hide argument but pass a factory-generated value to parent
```python
ArgTransform(hide=True, default_factory=lambda: uuid.uuid4().hex)
```
# Make an optional parameter required (removes any default)
Make an optional parameter required (removes any default)
```python
ArgTransform(required=True)
```
# Combine multiple transformations
Combine multiple transformations
```python
ArgTransform(name="new_name", description="New desc", default=None, type=int)
```
### `TransformedTool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/tools/tool_transform.py#L179"><Icon icon="github" size="14" /></a></sup>
### `TransformedTool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/tools/tool_transform.py#L199"><Icon icon="github" size="14" /></a></sup>
A tool that is transformed from another tool.
@ -65,7 +85,7 @@ with transformed arguments.
**Methods:**
#### `from_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/tools/tool_transform.py#L260"><Icon icon="github" size="14" /></a></sup>
#### `from_tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/tools/tool_transform.py#L280"><Icon icon="github" size="14" /></a></sup>
```python
from_tool(cls, tool: Tool, name: str | None = None, description: str | None = None, tags: set[str] | None = None, transform_fn: Callable[..., Any] | None = None, transform_args: dict[str, ArgTransform] | None = None, annotations: ToolAnnotations | None = None, serializer: Callable[[Any], str] | None = None, enabled: bool | None = None) -> TransformedTool
@ -81,9 +101,9 @@ argument names.
- `name`: New name for the tool. Defaults to parent tool's name.
- `transform_args`: Optional transformations for parent tool arguments.
Only specified arguments are transformed, others pass through unchanged\:
- str\: Simple rename
- ArgTransform\: Complex transformation (rename/description/default/drop)
- None\: Drop the argument
- Simple rename (str)
- Complex transformation (rename/description/default/drop) (ArgTransform)
- Drop the argument (None)
- `description`: New description. Defaults to parent's description.
- `tags`: New tags. Defaults to parent's tags.
- `annotations`: New annotations. Defaults to parent's annotations.
@ -92,17 +112,28 @@ Only specified arguments are transformed, others pass through unchanged\:
**Returns:**
- TransformedTool with the specified transformations.
Examples:
- # Transform specific arguments only
- Tool.from_tool(parent, transform_args={"old": "new"}) # Others unchanged
- # Custom function with partial transforms
- async def custom(x: int, y: int) -> str:
result = await forward(x=x, y=y)
return f"Custom: {result}"
- Tool.from_tool(parent, transform_fn=custom, transform_args={"a": "x", "b": "y"})
- # Using **kwargs (gets all args, transformed and untransformed)
- async def flexible(**kwargs) -> str:
result = await forward(**kwargs)
return f"Got: {kwargs}"
- Tool.from_tool(parent, transform_fn=flexible, transform_args={"a": "x"})
**Examples:**
# Transform specific arguments only
```python
Tool.from_tool(parent, transform_args={"old": "new"}) # Others unchanged
```
# Custom function with partial transforms
```python
async def custom(x: int, y: int) -> str:
result = await forward(x=x, y=y)
return f"Custom: {result}"
Tool.from_tool(parent, transform_fn=custom, transform_args={"a": "x", "b": "y"})
```
# Using **kwargs (gets all args, transformed and untransformed)
```python
async def flexible(**kwargs) -> str:
result = await forward(**kwargs)
return f"Got: {kwargs}"
Tool.from_tool(parent, transform_fn=flexible, transform_args={"a": "x"})
```

103
src/fastmcp/server/server.py
View file

@ -363,6 +363,7 @@ class FastMCP(Generic[LifespanResultT]):
return await self._resource_manager.get_resource_templates()
async def get_resource_template(self, key: str) -> ResourceTemplate:
"""Get a registered resource template by key."""
templates = await self.get_resource_templates()
if key not in templates:
raise NotFoundError(f"Unknown resource template: {key}")
@ -403,9 +404,12 @@ class FastMCP(Generic[LifespanResultT]):
include_in_schema: Whether to include in OpenAPI schema, defaults to True
Example:
Register a custom HTTP route for a health check endpoint:
```python
@server.custom_route("/health", methods=["GET"])
async def health_check(request: Request) -> Response:
return JSONResponse({"status": "ok"})
```
"""
def decorator(
@ -814,15 +818,18 @@ class FastMCP(Generic[LifespanResultT]):
name: Optional name for the tool (keyword-only, alternative to name_or_fn)
description: Optional description of what the tool does
tags: Optional set of tags for categorizing the tool
annotations: Optional annotations about the tool's behavior (e.g. {"is_async": True})
annotations: Optional annotations about the tool's behavior
exclude_args: Optional list of argument names to exclude from the tool schema
enabled: Optional boolean to enable or disable the tool
Example:
Examples:
Register a tool with a custom name:
```python
@server.tool
def my_tool(x: int) -> str:
return str(x)
# Register a tool with a custom name
@server.tool
def my_tool(x: int) -> str:
return str(x)
@ -837,6 +844,7 @@ class FastMCP(Generic[LifespanResultT]):
# Direct function call
server.tool(my_function, name="custom_name")
```
"""
if isinstance(annotations, dict):
annotations = ToolAnnotations(**annotations)
@ -991,7 +999,9 @@ class FastMCP(Generic[LifespanResultT]):
tags: Optional set of tags for categorizing the resource
enabled: Optional boolean to enable or disable the resource
Example:
Examples:
Register a resource with a custom name:
```python
@server.resource("resource://my-resource")
def get_data() -> str:
return "Hello, world!"
@ -1014,6 +1024,7 @@ class FastMCP(Generic[LifespanResultT]):
async def get_weather(city: str) -> str:
data = await fetch_weather(city)
return f"Weather for {city}: {data}"
```
"""
# Check if user passed function directly instead of calling decorator
if inspect.isroutine(uri):
@ -1138,7 +1149,9 @@ class FastMCP(Generic[LifespanResultT]):
tags: Optional set of tags for categorizing the prompt
enabled: Optional boolean to enable or disable the prompt
Example:
Examples:
```python
@server.prompt
def analyze_table(table_name: str) -> list[Message]:
schema = read_table_schema(table_name)
@ -1182,6 +1195,7 @@ class FastMCP(Generic[LifespanResultT]):
# Direct function call
server.prompt(my_function, name="custom_name")
```
"""
if isinstance(name_or_fn, classmethod):
@ -1787,10 +1801,10 @@ class FastMCP(Generic[LifespanResultT]):
) -> FastMCPProxy:
"""Create a FastMCP proxy server for the given backend.
The ``backend`` argument can be either an existing :class:`~fastmcp.client.Client`
instance or any value accepted as the ``transport`` argument of
:class:`~fastmcp.client.Client`. This mirrors the convenience of the
``Client`` constructor.
The `backend` argument can be either an existing `fastmcp.client.Client`
instance or any value accepted as the `transport` argument of
`fastmcp.client.Client`. This mirrors the convenience of the
`fastmcp.client.Client` constructor.
"""
from fastmcp.client.client import Client
from fastmcp.server.proxy import FastMCPProxy
@ -1827,14 +1841,14 @@ class FastMCP(Generic[LifespanResultT]):
Given a component, determine if it should be enabled. Returns True if it should be enabled; False if it should not.
Rules:
• If the component's enabled property is False, always return False.
• If both include_tags and exclude_tags are None, return True.
• If exclude_tags is provided, check each exclude tag:
- If the component's enabled property is False, always return False.
- If both include_tags and exclude_tags are None, return True.
- If exclude_tags is provided, check each exclude tag:
- If the exclude tag is a string, it must be present in the input tags to exclude.
• If include_tags is provided, check each include tag:
- If include_tags is provided, check each include tag:
- If the include tag is a string, it must be present in the input tags to include.
• If include_tags is provided and none of the include tags match, return False.
• If include_tags is not provided, return True.
- If include_tags is provided and none of the include tags match, return False.
- If include_tags is not provided, return True.
"""
if not component.enabled:
return False
@ -1875,12 +1889,21 @@ def add_resource_prefix(
The resource URI with the prefix added
Examples:
>>> add_resource_prefix("resource://path/to/resource", "prefix")
"resource://prefix/path/to/resource" # with new style
>>> add_resource_prefix("resource://path/to/resource", "prefix")
"prefix+resource://path/to/resource" # with legacy style
>>> add_resource_prefix("resource:///absolute/path", "prefix")
"resource://prefix//absolute/path" # with new style
With new style:
```python
add_resource_prefix("resource://path/to/resource", "prefix")
"resource://prefix/path/to/resource"
```
With legacy style:
```python
add_resource_prefix("resource://path/to/resource", "prefix")
"prefix+resource://path/to/resource"
```
With absolute path:
```python
add_resource_prefix("resource:///absolute/path", "prefix")
"resource://prefix//absolute/path"
```
Raises:
ValueError: If the URI doesn't match the expected protocol://path format
@ -1926,12 +1949,21 @@ def remove_resource_prefix(
The resource URI with the prefix removed
Examples:
>>> remove_resource_prefix("resource://prefix/path/to/resource", "prefix")
"resource://path/to/resource" # with new style
>>> remove_resource_prefix("prefix+resource://path/to/resource", "prefix")
"resource://path/to/resource" # with legacy style
>>> remove_resource_prefix("resource://prefix//absolute/path", "prefix")
"resource:///absolute/path" # with new style
With new style:
```python
remove_resource_prefix("resource://prefix/path/to/resource", "prefix")
"resource://path/to/resource"
```
With legacy style:
```python
remove_resource_prefix("prefix+resource://path/to/resource", "prefix")
"resource://path/to/resource"
```
With absolute path:
```python
remove_resource_prefix("resource://prefix//absolute/path", "prefix")
"resource:///absolute/path"
```
Raises:
ValueError: If the URI doesn't match the expected protocol://path format
@ -1984,12 +2016,21 @@ def has_resource_prefix(
True if the URI has the specified prefix, False otherwise
Examples:
>>> has_resource_prefix("resource://prefix/path/to/resource", "prefix")
True # with new style
>>> has_resource_prefix("prefix+resource://path/to/resource", "prefix")
True # with legacy style
>>> has_resource_prefix("resource://other/path/to/resource", "prefix")
With new style:
```python
has_resource_prefix("resource://prefix/path/to/resource", "prefix")
True
```
With legacy style:
```python
has_resource_prefix("prefix+resource://path/to/resource", "prefix")
True
```
With other path:
```python
has_resource_prefix("resource://other/path/to/resource", "prefix")
False
```
Raises:
ValueError: If the URI doesn't match the expected protocol://path format

58
src/fastmcp/tools/tool_transform.py
View file

@ -100,35 +100,55 @@ class ArgTransform:
examples: Examples for the argument. Use ... for no change.
Examples:
# Rename argument 'old_name' to 'new_name'
Rename argument 'old_name' to 'new_name'
```python
ArgTransform(name="new_name")
```
# Change description only
Change description only
```python
ArgTransform(description="Updated description")
```
# Add a default value (makes argument optional)
Add a default value (makes argument optional)
```python
ArgTransform(default=42)
```
# Add a default factory (makes argument optional)
Add a default factory (makes argument optional)
```python
ArgTransform(default_factory=lambda: time.time())
```
# Change the type
Change the type
```python
ArgTransform(type=str)
```
# Hide the argument entirely from clients
Hide the argument entirely from clients
```python
ArgTransform(hide=True)
```
# Hide argument but pass a constant value to parent
Hide argument but pass a constant value to parent
```python
ArgTransform(hide=True, default="constant_value")
```
# Hide argument but pass a factory-generated value to parent
Hide argument but pass a factory-generated value to parent
```python
ArgTransform(hide=True, default_factory=lambda: uuid.uuid4().hex)
```
# Make an optional parameter required (removes any default)
Make an optional parameter required (removes any default)
```python
ArgTransform(required=True)
```
# Combine multiple transformations
Combine multiple transformations
```python
ArgTransform(name="new_name", description="New desc", default=None, type=int)
```
"""
name: str | EllipsisType = NotSet
@ -279,9 +299,9 @@ class TransformedTool(Tool):
name: New name for the tool. Defaults to parent tool's name.
transform_args: Optional transformations for parent tool arguments.
Only specified arguments are transformed, others pass through unchanged:
- str: Simple rename
- ArgTransform: Complex transformation (rename/description/default/drop)
- None: Drop the argument
- Simple rename (str)
- Complex transformation (rename/description/default/drop) (ArgTransform)
- Drop the argument (None)
description: New description. Defaults to parent's description.
tags: New tags. Defaults to parent's tags.
annotations: New annotations. Defaults to parent's annotations.
@ -290,23 +310,29 @@ class TransformedTool(Tool):
Returns:
TransformedTool with the specified transformations.
Examples:
Examples:
# Transform specific arguments only
```python
Tool.from_tool(parent, transform_args={"old": "new"}) # Others unchanged
```
# Custom function with partial transforms
```python
async def custom(x: int, y: int) -> str:
result = await forward(x=x, y=y)
return f"Custom: {result}"
Tool.from_tool(parent, transform_fn=custom, transform_args={"a": "x", "b": "y"})
```
# Using **kwargs (gets all args, transformed and untransformed)
```python
async def flexible(**kwargs) -> str:
result = await forward(**kwargs)
return f"Got: {kwargs}"
Tool.from_tool(parent, transform_fn=flexible, transform_args={"a": "x"})
```
"""
transform_args = transform_args or {}
@ -423,8 +449,8 @@ class TransformedTool(Tool):
Returns:
A tuple containing:
- dict: The new JSON schema for the transformed tool
- Callable: Async function that validates and forwards calls to the parent tool
- The new JSON schema for the transformed tool as a dictionary
- Async function that validates and forwards calls to the parent tool
"""
# Build transformed schema and mapping