Module fastmcp_extensions.prompts

MCP prompt utilities.

This module provides utilities for working with MCP prompts, including a generic get_prompt_text helper for agents that cannot otherwise access prompt assets.

Functions

async def get_prompt_text(app: FastMCP, prompt_name: str, arguments: dict[str, Any] | None = None) ‑> str

Expand source code

async def get_prompt_text(
    app: FastMCP,
    prompt_name: str,
    arguments: dict[str, Any] | None = None,
) -> str:
    """Get the text content of a prompt by name.

    This is a helper function for agents that cannot otherwise access prompt
    assets directly. It retrieves the prompt and returns its text content.

    Args:
        app: The FastMCP app instance
        prompt_name: Name of the prompt to retrieve
        arguments: Optional arguments to pass to the prompt

    Returns:
        The text content of the prompt

    Raises:
        ValueError: If the prompt is not found or has no content
    """
    async with Client(app) as client:
        result = await client.get_prompt(prompt_name, arguments or {})

        if not result.messages:
            raise ValueError(f"Prompt '{prompt_name}' returned no messages")

        text_parts = []
        for message in result.messages:
            if hasattr(message, "content"):
                content = message.content
                if isinstance(content, str):
                    text_parts.append(content)
                elif hasattr(content, "text"):
                    text_parts.append(content.text)

        if not text_parts:
            raise ValueError(f"Prompt '{prompt_name}' returned no text content")

        return "\n\n".join(text_parts)

Get the text content of a prompt by name.

This is a helper function for agents that cannot otherwise access prompt assets directly. It retrieves the prompt and returns its text content.

Args

app

The FastMCP app instance

prompt_name

Name of the prompt to retrieve

arguments

Optional arguments to pass to the prompt

Returns

The text content of the prompt

Raises

ValueError

If the prompt is not found or has no content

async def list_prompts(app: FastMCP) ‑> list[dict[str, Any]]

Expand source code

async def list_prompts(app: FastMCP) -> list[dict[str, Any]]:
    """List all available prompts.

    Args:
        app: The FastMCP app instance

    Returns:
        List of prompt information dictionaries
    """
    async with Client(app) as client:
        prompts = await client.list_prompts()

        return [
            {
                "name": p.name,
                "description": p.description,
                "arguments": [
                    {
                        "name": arg.name,
                        "description": arg.description,
                        "required": arg.required,
                    }
                    for arg in (p.arguments or [])
                ],
            }
            for p in prompts
        ]

List all available prompts.

Args

app

The FastMCP app instance

Returns

List of prompt information dictionaries