// Custom error classes for MCP server
export class MCPError extends Error {
constructor(
message: string,
public code: string = 'INTERNAL_ERROR',
public statusCode: number = 500
) {
super(message);
this.name = 'MCPError';
}
}
export class AuthenticationError extends MCPError {
constructor(message: string = 'Authentication failed') {
super(message, 'AUTHENTICATION_ERROR', 401);
this.name = 'AuthenticationError';
}
}
export class PermissionError extends MCPError {
constructor(message: string = 'Permission denied') {
super(message, 'PERMISSION_ERROR', 403);
this.name = 'PermissionError';
}
}
export class NotFoundError extends MCPError {
constructor(resource: string) {
super(`${resource} not found`, 'NOT_FOUND', 404);
this.name = 'NotFoundError';
}
}
export class ValidationError extends MCPError {
constructor(message: string) {
super(message, 'VALIDATION_ERROR', 400);
this.name = 'ValidationError';
}
}
export class RateLimitError extends MCPError {
constructor(message: string = 'Rate limit exceeded') {
super(message, 'RATE_LIMIT_ERROR', 429);
this.name = 'RateLimitError';
}
}
/**
* Format error for MCP response
*/
export function formatError(error: unknown): { code: string; message: string } {
if (error instanceof MCPError) {
return {
code: error.code,
message: error.message,
};
}
if (error instanceof Error) {
return {
code: 'INTERNAL_ERROR',
message: error.message,
};
}
return {
code: 'INTERNAL_ERROR',
message: 'An unexpected error occurred',
};
}
/**
* Log error with context
* Uses stderr to avoid corrupting JSON-RPC messages on stdout
*/
export function logError(error: unknown, context?: Record<string, any>): void {
// Import logger dynamically to avoid circular dependencies
import('./logger.js').then(({ logger }) => {
logger.error('MCP Server Error', error, context);
}).catch(() => {
// Fallback if logger import fails
process.stderr.write(JSON.stringify({
level: 'ERROR',
error: error instanceof Error ? error.message : String(error),
stack: error instanceof Error ? error.stack : undefined,
...context,
}) + '\n');
});
}
