Designing Backend Error Messages

Q: What is a Claude Code skill and how does the Designing Backend Error Messages skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Designing Backend Error Messages is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Security · Sub-category: security-misc · Last updated: 2026-05-21

type:audit type:review

Designs backend API error contracts with a REST-default approach using RFC 9457 Problem Details, stable machine-readable codes, retry semantics, validation error payloads, observability, and security-safe messaging. Reviews existing error handling against a binary rubric and proposes concrete fixes. Produces optional artifacts such as errors.yaml entries, Problem Details examples, OpenAPI fragments, and runbook templates. Use when creating or revising backend error responses, auditing API error quality, mapping status/code behavior, or documenting error handling for REST, gRPC, GraphQL, and async services.

Security AStatic scan found no risk patternsHow grading works ›

About this skill (catalog notes)

Designing Backend Error Messages includes worked examples; pricing or quota commentary; at least one code block. The SKILL.md runs to about 740 words, in the catalog's typical mid-range.

Original author: msewell
Indexed lastmod: 2026-05-21
Catalog position: Security · security-misc
Indexed related skills: 10

How Designing Backend Error Messages fits the catalog

Designing Backend Error Messages sits in the Security category under the security-misc sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

From the source SKILL.md

Author backend error-message contracts with a REST-first workflow. Switch transport guidance only when the task explicitly targets gRPC, GraphQL, or async/event systems.

What this skill does

Designing Backend Error Messages is a community-contributed Claude Code skill in the security-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/designing-backend-error-messages/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when creating or revising backend error responses, auditing API error quality, mapping status/code behavior, or documenting error handling for REST, gRPC, GraphQL, and async services.

Who uses this skill

The Designing Backend Error Messages Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 115,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/designing-backend-error-messages
curl -L https://claudskills.com/skills/designing-backend-error-messages/SKILL.md \
  -o ~/.claude/skills/designing-backend-error-messages/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/designing-backend-error-messages/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/designing-backend-error-messages/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\designing-backend-error-messages\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Designing Backend Error Messages Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/designing-backend-error-messages/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Designing Backend Error Messages skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Designing Backend Error Messages skill?

Use Designing Backend Error Messages when your Claude Code task falls under the Security category — specifically in the security misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Designing Backend Error Messages" or describe the task and let Claude pick). Browse related skills at /category/security/.

What is a Claude Code skill and how does the Designing Backend Error Messages skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Designing Backend Error Messages is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/msewell/agent-stuff/blob/HEAD/skills/designing-backend-error-messages/SKILL.md
Author: msewell

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

msewell. (2026). Designing Backend Error Messages [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/designing-backend-error-messages/

BibTeX

@misc{designing-backend-error-messages-2026,
  author    = {msewell},
  title     = {Designing Backend Error Messages [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/designing-backend-error-messages/}
}

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Badge

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Security scan

Grade A · scanned 2026-06-13 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/designing-backend-error-messages/#security)

More Security skills

Browse all Security skills in the ClaudSkills registry, or explore these other picks from the same category:

Browse all Security skills → Top 100 skills

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