Task Errors

These errors surface from the task-augmented tool invocation system (per the MCP 2025-11-25 task-support protocol). All inherit from PublicMcpError (safe to surface to clients) except TaskStoreNotInitializedError.

Reference

Class	Inherits	JSON-RPC Code	When
`TaskNotFoundError`	`PublicMcpError`	`-32602`	`tasks/get`, `tasks/cancel`, or `tasks/result` referenced an unknown task ID
`TaskAlreadyTerminalError`	`PublicMcpError`	`-32602`	`tasks/cancel` invoked on a task already in `succeeded`/`failed`/`cancelled`
`TaskAugmentationNotSupportedError`	`PublicMcpError`	`-32601`	Client invoked `tools/call` with task augmentation on a tool that opts out
`TaskAugmentationRequiredError`	`PublicMcpError`	`-32601`	Tool declared `taskSupport: 'required'` but client did not request a task
`TaskStoreNotInitializedError`	`InternalMcpError`	—	Internal: task store provider not registered when task subsystem is required

Usage

import { TaskNotFoundError, TaskAlreadyTerminalError } from '@frontmcp/sdk';

if (!task) {
  throw new TaskNotFoundError(taskId);
}

if (isTerminal(task.status)) {
  throw new TaskAlreadyTerminalError(task.status);
}

Tasks — opt a tool into task augmentation
Errors Overview

Decorators

API

Errors

Reference

Usage

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Reference

Usage

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