Borrowing it
Nothing to install: this file belongs to j5ik2o/event-store-adapter-js. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/j5ik2o/event-store-adapter-js/main/.agents/skills/error-classification/SKILL.mdgit clone --depth 1 https://github.com/j5ik2o/event-store-adapter-jsWrote 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/j5ik2o/event-store-adapter-js/error-classification)<a href="https://agentmods.dev/skills/j5ik2o/event-store-adapter-js/error-classification"><img src="https://agentmods.dev/badge/skills/j5ik2o/event-store-adapter-js/error-classification/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/j5ik2o/event-store-adapter-js/error-classification"><img src="https://agentmods.dev/badge/skills/j5ik2o/event-store-adapter-js/error-classification.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00241 | $0.02104 |
| Opus 5.5 | $0.00096 | $0.00842 |
| Sonnet 5.5 | $0.00048 | $0.00421 |
| Haiku 4.5 | $0.00024 | $0.00210 |
Grade A, and why
error-classification 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 1mo 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.
This is a copy
100% identical to error-classification — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Error, Defect, Fault, Failure 分類ガイド
ソフトウェアの非正常状態を正確に分類し、適切な対処戦略を導く。
なぜ分類が重要か
Error, Defect, Fault, Failure は混同されやすいが、それぞれ異なる概念であり、対処戦略も異なる。用語を曖昧に使うと、設計判断を誤る原因となる。
規格別定義の比較
| 種別 | Error（エラー） | Defect（欠陥） | Fault（障害） | Failure（故障） |
|---|---|---|---|---|
| JIS X 0014:1999 | 値または状態の不一致（人的過誤を含まない） | - | 機能単位の能力の縮退・喪失を引き起こす異常な状態 | 要求された機能を遂行する機能単位の能力がなくなること |
| JIS Z 8115:2000 | 値または条件の不一致（人的過誤を含む） | - | 機能を遂行不可能なアイテムの状態 | アイテムが要求機能達成能力を失うこと |
| JSTQB | 間違った結果を生み出す人間の行為 | 機能が実現できない原因となる不備（Bug含む） | 欠陥(Defect)と同義 | 期待した機能から逸脱すること |
| Bertrand Meyer | 開発中になされた誤った決定 | 意図した振る舞いからシステムが逸れる原因となる特性 | 実行中に意図した振る舞いから逸れるイベント | - |
| JIS Q 9000:2006 | - | 意図された用途に関連する要求事項を満たしていないこと | - | - |
実用的な解釈
Error（エラー）
入力値と期待値の相違状態。
- バリデーションエラー（入力値が期待する範囲外）
- ファイルが存在しないなどリカバリ可能な想定内の事象
- 呼び出し元が対処可能
例: ユーザー入力のメールアドレス形式不正、存在しないリソースへのアクセス
対処: Either/Result型で表現し、呼び出し元に判断を委ねる
Defect（欠陥）
要求事項を満たしていない状態。バグを含む。本来発生してはいけないもの。
- 契約（Design by Contract）の不履行
- 呼び出し元が事前条件を満たしていない
- アサーション（表明）で対応すべき
例: null不可の引数にnullが渡された、不正な状態遷移の試行
対処: アサーション（require/assert）で即座に検出・停止
Fault（障害）
機能遂行不可の異常状態。リカバリ不能。
- 呼び出し先のバグまたは責任不明
- システムの異常状態
- Akka/ErlangではError KernelとLet it crashパターンで耐性を持てる
例: DBコネクション枯渇、メモリ不足、外部サービスの完全停止
対処: 障害の隔離（Error Kernel）、監視と再起動（Let it crash）
Failure（故障）
機能達成能力を失った状態。
- Faultが解消されない結果としてシステムが機能を提供できなくなる
- ユーザーから見た最終的な症状
例: サービス全体のダウン、レスポンス不能
対処: 冗長化、フェイルオーバー、サーキットブレーカー
因果関係
Error（エラー）
→ 想定内。呼び出し元で対処可能
Defect（欠陥）
→ 本来あってはならない。アサーションで検出
→ 修正されなければ Fault を引き起こす
Fault（障害）
→ 異常状態。リカバリ困難
→ 継続すると Failure に至る
Failure（故障）
→ 機能喪失。ユーザーに影響
設計への適用
分類に基づく対処戦略
| 分類 | 対処戦略 | 実装パターン |
|---|---|---|
| Error | 呼び出し元で対処 | Either/Result型、バリデーション |
| Defect | 即座に検出・停止 | アサーション（require/assert）、事前条件チェック |
| Fault | 隔離と回復 | Error Kernel、Let it crash、サーキットブレーカー |
| Failure | 予防と冗長化 | フェイルオーバー、冗長構成、監視・アラート |
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.
- 1mo ago First seen · 160 lines · 241 tokens per session scan A eaafb4e4db4a
error-classification is a skill published in the GitHub repository j5ik2o/event-store-adapter-js (25 stars, last pushed today), licensed Apache-2.0. It adds 241 tokens to every session and 2,104 once invoked, about $0.0010 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to error-classification, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
cratis-chronicle-cli-operations
Inspect and operate a running Chronicle server with the cratis CLI - contexts and connection resolution, machine-readable output, failed partitions, observers, event sequences, read models, projections and jobs, and the authorization discipline for replay, retry, quarantine clearing and other mutations. Use when the…
cratis-lens-browser-extension
Use the Cratis Lens browser extension against a running Cratis Arc application — building and side-loading it, what the Arc app must already serve for Lens to work, switching the active user and tenant, and executing a command or query from the popup. Use when setting Lens up, when Lens does not detect an Arc app, or…
cratis-arc-observable-query-http
Inspect a Cratis Arc observable query from a terminal with curl or another plain HTTP client — snapshot GET, waiting for the first result, Server-Sent Events streaming, and long polling, plus the exact query-string keys, status codes, and payload shape. Use when debugging or exploring an observable query without…
cratis-cli-terminal-workbench
Navigate the cratis CLI's terminal Workbench - the full-screen TUI launched with cratis chronicle workbench. Use when exploring a running Chronicle store interactively rather than answering one question with a single command, when locating an observer, failure, event type, projection or read model by name, or when…
cratis-engineering-regression-cluster
Stop fixing instances when one surface keeps breaking - name the failure class, add the gate that owns it, prove the gate fails, then fix the instance. Use when a third bug, regression, revert or review finding lands on the same screen, endpoint, command, workflow or module, when the same kind of fix keeps being…
cratis-screenplay-toolchain
How to run and check Cratis Screenplay .play models: locating the model, choosing the standalone screenplay tool or the cratis CLI, the exact command behind each verdict V1 to V5 and what a pass looks like, the executable and renderable subsets, reading PLAY, STAGE and CLI-RENDER diagnostics, traps, and a compiled…