import { ErrorCode, McpError } from '@modelcontextprotocol/sdk/types.js';
import { AuthenticationError, FreshRSSError, NotFoundError } from '../api/index.js';
function formatSnippet(snippet?: string): string {
if (snippet === undefined || snippet.trim() === '') return '';
return `\nResponse snippet: ${snippet}`;
}
export function mapErrorToMcp(toolName: string, error: unknown): McpError {
if (error instanceof McpError) return error;
if (error instanceof AuthenticationError) {
return new McpError(
ErrorCode.InvalidParams,
'FreshRSS authentication failed. Verify FRESHRSS_URL, FRESHRSS_USERNAME, and FRESHRSS_API_PASSWORD, and ensure the API is enabled.'
);
}
if (error instanceof NotFoundError) {
return new McpError(ErrorCode.InvalidParams, error.message);
}
if (error instanceof FreshRSSError) {
const status = error.statusCode;
if (status === 429) {
return new McpError(
ErrorCode.InternalError,
`FreshRSS rate limited the request for ${toolName}. Please retry shortly.`
);
}
if (status !== undefined && status >= 500) {
return new McpError(
ErrorCode.InternalError,
`FreshRSS server error (${status.toString()}) while running ${toolName}. Please retry later.`
);
}
return new McpError(
ErrorCode.InternalError,
`${error.message}${formatSnippet(error.responseSnippet)}`
);
}
if (error instanceof Error) {
if (error.name === 'AbortError') {
return new McpError(
ErrorCode.RequestTimeout,
`FreshRSS request timed out while running ${toolName}. Try again.`
);
}
if (error.name === 'ZodError') {
return new McpError(
ErrorCode.InvalidParams,
`Invalid arguments for ${toolName}: ${error.message}`
);
}
return new McpError(ErrorCode.InternalError, `Error in ${toolName}: ${error.message}`);
}
return new McpError(ErrorCode.InternalError, `Unexpected error in ${toolName}: ${String(error)}`);
}
export function wrapTool<TResult>(
toolName: string,
fn: () => Promise<TResult>
): () => Promise<TResult>;
export function wrapTool<TArgs, TResult>(
toolName: string,
fn: (args: TArgs) => Promise<TResult>
): (args: TArgs) => Promise<TResult>;
export function wrapTool(
toolName: string,
fn: (...args: unknown[]) => Promise<unknown>
): (...args: unknown[]) => Promise<unknown> {
return async (...args: unknown[]): Promise<unknown> => {
try {
return await fn(...args);
} catch (err) {
throw mapErrorToMcp(toolName, err);
}
};
}
