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[Draft] Support functools.partial as tools, prompts, and resources #3269

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0ef51d9
Support functools.partial as tools, prompts, and resources
Feb 21, 2026
7ef84c0
chore: Update SDK documentation
marvin-context-protocol[bot] Feb 21, 2026
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16 changes: 8 additions & 8 deletions docs/python-sdk/fastmcp-prompts-function_prompt.mdx
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ Standalone @prompt decorator for FastMCP.

## Functions

### `prompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L398" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `prompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L407" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
prompt(name_or_fn: str | Callable[..., Any] | None = None) -> Any
Expand All @@ -25,27 +25,27 @@ using mcp.add_prompt().

## Classes

### `DecoratedPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L49" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `DecoratedPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L50" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Protocol for functions decorated with @prompt.


### `PromptMeta` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L58" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `PromptMeta` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L59" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Metadata attached to functions by the @prompt decorator.


### `FunctionPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L74" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `FunctionPrompt` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L75" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A prompt that is a function.


**Methods:**

#### `from_function` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L80" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `from_function` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L81" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_function(cls, fn: Callable[..., Any]) -> FunctionPrompt
Expand All @@ -66,7 +66,7 @@ The function can return:
- PromptResult: used directly


#### `render` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L281" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `render` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L290" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
render(self, arguments: dict[str, Any] | None = None) -> PromptResult
Expand All @@ -75,7 +75,7 @@ render(self, arguments: dict[str, Any] | None = None) -> PromptResult
Render the prompt with arguments.


#### `register_with_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L331" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `register_with_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L340" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
register_with_docket(self, docket: Docket) -> None
Expand All @@ -87,7 +87,7 @@ FunctionPrompt registers the underlying function, which has the user's
Depends parameters for docket to resolve.


#### `add_to_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L341" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `add_to_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/prompts/function_prompt.py#L350" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
add_to_docket(self, docket: Docket, arguments: dict[str, Any] | None, **kwargs: Any) -> Execution
Expand Down
14 changes: 7 additions & 7 deletions docs/python-sdk/fastmcp-resources-function_resource.mdx
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ Standalone @resource decorator for FastMCP.

## Functions

### `resource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L236" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `resource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L245" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
resource(uri: str) -> Callable[[F], F]
Expand All @@ -25,19 +25,19 @@ using mcp.add_resource().

## Classes

### `DecoratedResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L36" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `DecoratedResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L37" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Protocol for functions decorated with @resource.


### `ResourceMeta` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L45" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `ResourceMeta` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L46" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Metadata attached to functions by the @resource decorator.


### `FunctionResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L64" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
### `FunctionResource` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L65" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A resource that defers data loading by wrapping a function.
Expand All @@ -54,7 +54,7 @@ The function can return:

**Methods:**

#### `from_function` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L80" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `from_function` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L81" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_function(cls, fn: Callable[..., Any], uri: str | AnyUrl | None = None) -> FunctionResource
Expand All @@ -71,7 +71,7 @@ individual parameters must not be passed.
Cannot be used together with metadata parameter.


#### `read` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L204" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `read` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L213" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
read(self) -> str | bytes | ResourceResult
Expand All @@ -80,7 +80,7 @@ read(self) -> str | bytes | ResourceResult
Read the resource by calling the wrapped function.


#### `register_with_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L225" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
#### `register_with_docket` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/resources/function_resource.py#L234" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
register_with_docket(self, docket: Docket) -> None
Expand Down
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