Resilient Error Handling & Fault Tolerance

What it does

Resilient Error Handling & Fault Tolerance is a Cursor skill: a SKILL.md playbook that AgenticKit installs at .cursor/skills/error-handling. Cursor's agent loads it when the task matches the skill description, instead of stuffing the same rules into every chat.

Comprehensive error handling strategy across frontend and backend, with typed error classes, graceful fallback states, and structured error logs.

Try-catch boundaries, custom error classes, graceful degradation, and logs. The file is domain knowledge, not a slash macro. You do not type it. The agent reads it when the job is error handling.

Why it exists

Default Cursor has no memory of how your team ships code, schema, and tests. Founders paste the same conventions into chat, then watch the model drift on the next turn. This skill exists so those conventions live on disk and load only when relevant.

It ships in the Engineering Kit. It is wired to Root Cause Debugger (debugger), Site Reliability Engineer (sre-engineer), and Senior Backend Architect (backend-architect). It is wired to the /fix: Automated Bug & Exception Debugger and /audit: Codebase Quality & Security Auditor commands. That graph is the point: the skill is the standard, the agent is the role, the command is the trigger.

When to use it

• Use Resilient Error Handling & Fault Tolerance when the work is specifically about try-catch boundaries, custom error classes, graceful degradation, and logs.
• Load it before a long session that will touch this surface more than once. A one-line edit does not need the full playbook.
• Use it on production SaaS work (multi-tenant apps, paid features, anything that will be reviewed) rather than a throwaway prototype.

When not to use it

• Do not treat the skill as a replacement for a slash command. Skills teach. Commands run a pipeline.
• Do not paste the whole SKILL.md into chat. If Cursor is not loading it, fix the description or invoke the matching command.
• Do not use it as a generic 'write better code' rule. Scope is this domain only.

Example workflow

1. Install the Engineering Kit so .cursor/skills/error-handling lands in the repo.
2. Open a new Cursor agent chat pointed at the files this skill governs.
3. Ask the Root Cause Debugger (debugger) to read the skill, or run /fix: Automated Bug & Exception Debugger.
4. Review the first artifact against the practices below. If it violates one, stop and correct the file. Do not prompt 'just finish it'.
5. Commit the skill-guided files with the rest of the slice so the next session inherits the same standard.

Example usage

Example prompt: "Read .cursor/skills/error-handling and apply it to this change. Do not invent extra conventions."

Or trigger the pipeline: /fix: Automated Bug & Exception Debugger. That command is written to load this skill.

Check the output against: Define custom Error subclasses with HTTP status codes and machine-readable error codes

Example output

• The skill itself does not write a single output file. It changes what the agent is allowed to produce in code, schema, and tests.
• When you run /fix: Automated Bug & Exception Debugger, expect repo files plus notes under docs/, not a chat-only answer.

Best practices

• Define custom Error subclasses with HTTP status codes and machine-readable error codes
• Wrap asynchronous operations in try-catch blocks with explicit fallback responses
• Catch uncaught UI render errors with React ErrorBoundary components
• Log errors with contextual metadata (user ID, request ID, timestamp) in structured JSON

Common mistakes

• Ignoring "Define custom Error subclasses with HTTP status codes and machine-readable error codes" and hoping a later prompt will clean it up.
• Copying the skill into .cursor/rules as always-on. That burns context and fights Cursor's load-on-match design.
• Running two overlapping skills that contradict each other in the same turn.
• Letting the agent skip tests or types because 'the skill is about architecture'.