fastmcp/docs/python-sdk/fastmcp-prompts-function_prompt.mdx
Jeremiah Lowin 9b248a15b3
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---
title: function_prompt
sidebarTitle: function_prompt
---
# `fastmcp.prompts.function_prompt`
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>
```python
prompt(name_or_fn: str | Callable[..., Any] | None = None) -> Any
```
Standalone decorator to mark a function as an MCP prompt.
Returns the original function with metadata attached. Register with a server
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>
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>
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>
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>
```python
from_function(cls, fn: Callable[..., Any]) -> FunctionPrompt
```
Create a Prompt from a function.
**Args:**
- `fn`: The function to wrap
- `metadata`: PromptMeta object with all configuration. If provided,
individual parameters must not be passed.
- `name, title, etc.`: Individual parameters for backwards compatibility.
Cannot be used together with metadata parameter.
The function can return:
- str: wrapped as single user Message
- list\[Message | str]: converted to list\[Message]
- 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>
```python
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>
```python
register_with_docket(self, docket: Docket) -> None
```
Register this prompt with docket for background execution.
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>
```python
add_to_docket(self, docket: Docket, arguments: dict[str, Any] | None, **kwargs: Any) -> Execution
```
Schedule this prompt for background execution via docket.
FunctionPrompt splats the arguments dict since .fn expects **kwargs.
**Args:**
- `docket`: The Docket instance
- `arguments`: Prompt arguments
- `fn_key`: Function lookup key in Docket registry (defaults to self.key)
- `task_key`: Redis storage key for the result
- `**kwargs`: Additional kwargs passed to docket.add()