Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add niels-emmer/myace --skill fullstack-error-handlinggit clone --depth 1 https://github.com/niels-emmer/myaceWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/niels-emmer/myace/fullstack-error-handling)<a href="https://agentmods.dev/skills/niels-emmer/myace/fullstack-error-handling"><img src="https://agentmods.dev/badge/skills/niels-emmer/myace/fullstack-error-handling.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00024 | $0.00285 |
| Opus 5 | $0.00012 | $0.00143 |
| Sonnet 5 | $0.00005 | $0.00057 |
| Haiku 4.5 | $0.00002 | $0.00028 |
Grade A, and why
Full-Stack Error Handling scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Purpose
Ensure every backend error reaches the frontend UI correctly, with no unhandled error states.
When to use it
Designing or reviewing any feature that involves frontend-backend communication.
Checklist
- Backend error envelope: standardize on
{ "error": { "code": "...", "message": "...", "details": [...] } }. - Frontend fetch wrapper: parse the error envelope and throw typed errors, not generic exceptions.
- Component-level handling: map
error.codeto specific UI treatment — validation errors show field messages, not-found redirects, server errors show retry option. - No unhandled states: every data-fetching component has loading, empty, error, and success states.
- Consistency: same error shape across all endpoints; same error handling pattern across all components.
Expected output
A consistent error propagation chain where every backend failure mode has a corresponding frontend UI treatment.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 28 lines · 24 tokens per session scan A d14bcf55f0fe
Full-Stack Error Handling is a skill published in the GitHub repository niels-emmer/myace (1 stars, last pushed yesterday), licensed MIT. It adds 24 tokens to every session and 285 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
airflow-plugins
Builds Airflow 3.1+ plugins that embed FastAPI apps, custom UI pages, React components, middleware, macros, and operator links directly into the Airflow UI. Use when building anything custom inside Airflow 3.1+ that involves Python and a browser-facing interface - creating an Airflow plugin, adding a custom UI page or…
nextjs-patterns
Next.js best practices, server components, app router patterns, caching strategies, and full-stack architecture.
yida-canvas-data-binding
A method for connecting a YidaCodeCanvas page to real data from Yida forms, connectors, or same-site APIs. YidaCodeCanvas is the component used to run custom React pages inside Yida.
html-draft
Use when user wants a standalone HTML diagram in flat engineering blueprint style — architecture diagrams, system flows, technical spec sheets, component maps. Generates one HTML file using Tailwind v4 (browser CDN) for layout and D3 v7 (CDN) for SVG diagrams. User-invoked only — do NOT auto-trigger. Triggers on…
tg-bot-ops
A guide for operating and troubleshooting Telegram bots and systems that connect Telegram to an AI agent. It covers how messages arrive, get processed, and produce replies.
openyida
A skill for creating and changing applications on 宜搭 (Yida), a Chinese low-code platform for building business apps with less hand-written code. It first checks the available tools, login status, project folder, and target application before making changes.