error-handler

error-handler is a skill for Claude Code, Codex from EliasOulkadi/shokunin. It costs 125 tokens per session (3,768 once invoked), scanned A, original, MIT.

An assistant for handling application errors and monitoring services with logs, metrics, and traces. OpenTelemetry is a standard toolkit for recording these signals so a request can be followed across services.

In plain words
What is it for?
Use it to add OpenTelemetry instrumentation, classify errors, implement retries with jitter, timeouts, circuit breakers, and bulkheads, and define service-level objectives and error-budget alerts.
Why use it?
It helps explain what went wrong, where a failure occurred, and how serious it is. It also provides patterns for retrying temporary failures and deciding when production problems need an alert.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/eliasoulkadi/shokunin/error-handler
Any agent
npx skills add EliasOulkadi/shokunin --skill error-handler
Clone the repo
git clone --depth 1 https://github.com/EliasOulkadi/shokunin

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for error-handler

README.md
[![agentmods](https://agentmods.dev/badge/skills/eliasoulkadi/shokunin/error-handler.svg)](https://agentmods.dev/skills/eliasoulkadi/shokunin/error-handler)
Your own site
<a href="https://agentmods.dev/skills/eliasoulkadi/shokunin/error-handler"><img src="https://agentmods.dev/badge/skills/eliasoulkadi/shokunin/error-handler.svg" alt="Measured on agentmods" height="20"></a>
Per session 125 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,768 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00125 $0.03768
Opus 5 $0.00063 $0.01884
Sonnet 5 $0.00025 $0.00754
Haiku 4.5 $0.00013 $0.00377

Measured 5d ago against content hash 36d7f7a59251, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

error-handler scanned grade A with 1 finding 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (assets/error-middleware.template.ts, scripts/setup-opentelemetry.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

| OpenTelemetry SDK not exporting traces | Exporter endpoint unreachable or `OTEL_EXPORTER_OTLP_ENDPOINT` not set | Verify endpoint with `curl $OTEL_EXPORTER_OTLP_ENDPOINT/v1/traces`. Set env var before SDK initializatio
.pack/skills/error-handler/SKILL.md · 378 lines

How it starts

The opening of the file, as written. The whole thing — 378 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Error Handler

Observability that makes debugging fast and production predictable. Based on Google SRE (Site Reliability Engineering), OpenTelemetry semantic conventions, and production patterns from Sentry, Honeycomb, and Datadog.

Sub-Commands

Command Description
setup Set up OpenTelemetry SDK + instrumentation for a service
classify Classify errors by HTTP status, severity, and alert priority
recover Implement recovery patterns: retry with jitter, circuit breaker, timeout
slo Define error budget, SLO, and burn rate alerts
audit Audit existing error handling against best practices

The 3 Signals (OpenTelemetry)

Signal Purpose Example
Traces Follow a request across services User request ? API Gateway ? Auth ? DB
Metrics Aggregate measurements over time Request count, error rate, latency p50/p95/p99
Logs Discrete events with context "User login failed: invalid credentials for user_abc123"

All three signals share trace_id + span_id for correlation.

Workflow

Step 1: Classify errors

Category HTTP Severity Log level SLO impact Alert?
Validation (user error) 400 Low info No No
Authentication 401 Medium warn No Only if spike detected
Authorization 403 Medium warn No Only if spike detected
Not Found 404 Low debug No No
Conflict 409 Medium info No No
Rate Limit 429 Low warn No No
Internal 500 High error Yes Yes
Downstream failure 502/503 High error Yes Yes
Timeout 504 High error Yes Yes

Step 2: Set up OpenTelemetry (exact configuration)

import { NodeSDK } from '@opentelemetry/sdk-node'
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http'
import { Resource } from '@opentelemetry/resources'
import { ATTR_SERVICE_NAME } from '@opentelemetry/semantic-conventions'

const sdk = new NodeSDK({
  resource: new Resource({
    [ATTR_SERVICE_NAME]: 'api-service',
    'deployment.environment': process.env.NODE_ENV,
  }),
  traceExporter: new OTLPTraceExporter({
    url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
  }),
  instrumentations: [
    new HttpInstrumentation(),
    new ExpressInstrumentation(),
    new PgInstrumentation(),
    new RedisInstrumentation(),
  ],
})

sdk.start()

process.on('SIGTERM', async () => {
  await sdk.shutdown()
})

Read the full file on GitHub · 378 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

  1. 5d ago First seen · 378 lines · 125 tokens per session scan A 36d7f7a59251

Subscribe to this mod's changes

error-handler is a skill published in the GitHub repository EliasOulkadi/shokunin (113 stars, last pushed 1mo ago), licensed MIT. It adds 125 tokens to every session and 3,768 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

memory-protocol

Universal protocol for total-agent-memory MCP server. Activate at session start, before any non-trivial task, after every significant action, on errors, and at session end. Relevant whenever the user mentions: memory, recall, past context, decisions history, conventions, lessons learned, "продолжаем", "сохранись"…

vbcherepanov/total-agent-memory · 120 tokens

memory

Activate this skill when starting a new session, beginning a new task, saving knowledge, recalling past decisions, or after completing significant work. Also activate on errors to log them for pattern analysis. Relevant when the user asks about memory, past context, lessons learned, decisions history, project…

vbcherepanov/total-agent-memory · 65 tokens

design-explore

Explore 2-4 design options with pros/cons/criteria matrix before writing code. Use for L3-L4 tasks (refactors, architecture, new subsystems). Pairs with savedecision MCP tool.

vbcherepanov/total-agent-memory · 48 tokens

mnema

Use the Mnema MCP server to give the AI long-term, searchable memory. Use it whenever the user shares durable facts, preferences, decisions, or context worth recalling in future sessions. Mnema stores memories in a vector database and recalls them with semantic + hybrid search, with decay scoring and summarization so…

mienetic/mnema · 130 tokens

dejavu-rules

Manage dejavu rules manually. Use when user says "add a rule", "remember this", "edit rule", "remove rule", "이거 기억해", "룰 추가해", or wants to manage CLAUDE.md rules through conversation.

cmg8431/claude-dejavu · 56 tokens

dejavu

Review and manage learned antipattern rules. Use when Claude should review its past mistakes, apply learned rules to CLAUDE.md, or check rule effectiveness. Triggers on "/dejavu", "review rules", "what did you learn".

cmg8431/claude-dejavu · 51 tokens