Tool & Prompt Errors

Overview

Tool and prompt errors are thrown when a tool or prompt cannot be found or when execution fails. Not-found errors are public and safe to expose to clients, while execution errors are internal and hide implementation details.

Error Reference

ToolNotFoundError

Thrown when a requested tool is not registered in the server.

Property	Type	Value
`code`	`string`	`TOOL_NOT_FOUND`
`statusCode`	`number`	`404`
`isPublic`	`boolean`	`true`

new ToolNotFoundError(toolName: string)

Example:

import { ToolNotFoundError } from '@frontmcp/sdk';

const tool = registry.get(name);
if (!tool) {
  throw new ToolNotFoundError(name);
}

ToolExecutionError

Thrown when a tool’s execute() method throws an unexpected error. This is an internal error — the original error details are hidden from clients.

Property	Type	Value
`code`	`string`	`TOOL_EXECUTION_ERROR`
`statusCode`	`number`	`500`
`isPublic`	`boolean`	`false`
`originalError`	`Error \| undefined`	The underlying cause

new ToolExecutionError(toolName: string, originalError?: Error)

Example:

import { ToolExecutionError } from '@frontmcp/sdk';

try {
  await tool.execute(input);
} catch (error) {
  throw new ToolExecutionError('my_tool', error);
}

ToolExecutionError extends InternalMcpError. Clients receive a generic message with an errorId for support correlation, not the original stack trace. A public error thrown from execute(), such as InvalidInputError, is not wrapped: the client gets its own message and code.

PromptNotFoundError

Thrown when a requested prompt is not registered in the server.

Property	Type	Value
`code`	`string`	`PROMPT_NOT_FOUND`
`statusCode`	`number`	`404`
`isPublic`	`boolean`	`true`

new PromptNotFoundError(promptName: string)

Example:

import { PromptNotFoundError } from '@frontmcp/sdk';

throw new PromptNotFoundError('summarize');
// "Prompt not found: summarize"

PromptExecutionError

Thrown when a prompt’s execute() method throws an unexpected error. This is an internal error. A public error, such as MissingPromptArgumentError or one passed to this.fail(), is not wrapped.

Property	Type	Value
`code`	`string`	`PROMPT_EXECUTION_FAILED`
`statusCode`	`number`	`500`
`isPublic`	`boolean`	`false`
`promptName`	`string`	The prompt that failed
`originalError`	`Error \| undefined`	The underlying cause

new PromptExecutionError(promptName: string, cause?: Error)

Example:

import { PromptExecutionError } from '@frontmcp/sdk';

try {
  await prompt.execute(args);
} catch (error) {
  throw new PromptExecutionError('summarize', error);
}

Decorators

API

Errors

Tool & Prompt Errors

Overview

Error Reference

ToolNotFoundError

ToolExecutionError

PromptNotFoundError

PromptExecutionError

​Overview

​Error Reference

​ToolNotFoundError

​ToolExecutionError

​PromptNotFoundError

​PromptExecutionError

Overview

Error Reference

ToolNotFoundError

ToolExecutionError

PromptNotFoundError

PromptExecutionError