Async And Errors

What this skill does

This skill provides a comprehensive approach to managing asynchronous operations and error handling in JavaScript environments using async/await patterns. It covers best practices for handling errors in parallel async calls, creating and using custom error types, and implementing utilities like asyncErrorWrapper to catch errors in asynchronous functions consistently. The skill also addresses error propagation across application layers and highlights common pitfalls such as unhandled promise rejections and fire-and-forget async calls.

Who it's for

This skill is designed for backend developers working on API services where robust error handling ensures stability and clear failure responses. It also benefits growth leads and agency strategists coordinating teams to build scalable systems with reliable error reporting and monitoring. Performance marketers implementing data pipelines or integrations that rely on asynchronous calls will find guidance here to prevent silent failures and maintain accurate tracking.

Key workflows

Practitioners begin by structuring asynchronous calls, deciding between Promise.all for parallel execution with shared error handling or Promise.allSettled to capture and report individual failures. Next, they define custom error classes to standardize API responses and improve clarity in error boundaries. Then, they wrap async route handlers or functions with an asyncErrorWrapper utility to centralize error catching and forwarding to middleware. Finally, error propagation is managed by capturing exceptions at each layer—repository, service, controller—to maintain context and support monitoring tools like Sentry.

Common questions

How do I handle errors from multiple parallel async calls? Use Promise.allSettled to capture each result separately and log individual errors without failing the entire batch. Can I create specific error responses? Yes, by defining custom error classes with codes and HTTP status codes to identify issues like validation or not found errors. What’s the safest way to avoid unhandled promise rejections? Always await async calls or attach catch handlers; using asyncErrorWrapper ensures thrown errors are caught and processed.

How to use in Metaflow

Attach this skill to any Metaflow agent task that involves asynchronous API calls or operations requiring precise error handling. Expect clear error propagation and reporting, reducing silent failures in your workflows. This skill integrates with monitoring setups to capture exceptions and supports implementing consistent error responses across your data pipeline. For detailed usage and examples, see the related internal resources on async patterns and error monitoring.

For broader context, see our roundup of claude skills for marketing, and read common Claude Code content mistakes for related setup guidance.