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fastmcp.server.tasks.config

TaskConfig for MCP SEP-1686 background task execution modes. This module defines the configuration for how tools, resources, and prompts handle task-augmented execution as specified in SEP-1686.

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Classes

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TaskMeta

Metadata for task-augmented execution requests. When passed to call_tool/read_resource/get_prompt, signals that the operation should be submitted as a background task. Attributes:
  • ttl: Client-requested TTL in milliseconds. If None, uses server default.
  • fn_key: Docket routing key. Auto-derived from component name if None.

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TaskConfig

Configuration for MCP background task execution (SEP-1686). Controls how a component handles task-augmented requests:
  • “forbidden”: Component does not support task execution. Clients must not request task augmentation; server returns -32601 if they do.
  • “optional”: Component supports both synchronous and task execution. Client may request task augmentation or call normally.
  • “required”: Component requires task execution. Clients must request task augmentation; server returns -32601 if they don’t.
Methods:

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from_bool 

from_bool(cls, value: bool) -> TaskConfig
Convert boolean task flag to TaskConfig. Args:
  • value: True for “optional” mode, False for “forbidden” mode.
Returns:
  • TaskConfig with appropriate mode.

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supports_tasks 

supports_tasks(self) -> bool
Check if this component supports task execution. Returns:
  • True if mode is “optional” or “required”, False if “forbidden”.

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validate_function 

validate_function(self, fn: Callable[..., Any], name: str) -> None
Validate that function is compatible with this task config. Task execution requires:
  1. fastmcp[tasks] to be installed (pydocket)
  2. Async functions
Raises ImportError if mode is “optional” or “required” but pydocket is not installed. Raises ValueError if function is synchronous. Args:
  • fn: The function to validate (handles callable classes and staticmethods).
  • name: Name for error messages.
Raises:
  • ImportError: If task execution is enabled but pydocket not installed.
  • ValueError: If task execution is enabled but function is sync.