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 agentmods add commands/christopherlouet/claude-base/dev-error-handlinggit clone --depth 1 https://github.com/christopherlouet/claude-baseWrote 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/commands/christopherlouet/claude-base/dev-error-handling)<a href="https://agentmods.dev/commands/christopherlouet/claude-base/dev-error-handling"><img src="https://agentmods.dev/badge/commands/christopherlouet/claude-base/dev-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 | $0.00000 | $0.00332 |
| Opus 5 | $0.00000 | $0.00166 |
| Sonnet 5 | $0.00000 | $0.00066 |
| Haiku 4.5 | $0.00000 | $0.00033 |
Grade A, and why
dev-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 2d 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
DEV-ERROR-HANDLING Agent
Implements a robust and consistent error handling strategy.
Request context
$ARGUMENTS
Goal
Set up professional error handling that improves reliability, makes debugging easier and provides a better user experience.
Workflow
- Classify errors (Validation, Business, Auth, NotFound, External, Infrastructure)
- Structure a custom error hierarchy with code, statusCode, context and timestamp
- Implement handling patterns (global middleware, async handler, Result pattern)
- Propagate across layers (Repository wraps, Service throw/re-throw, Controller passes through, Middleware formats)
- Log in a structured way with context (no console.log)
- Recover with retry (exponential backoff), circuit breaker and graceful fallback
Expected output
- Custom error classes (AppError base + specialized)
- Global handling middleware
- Retry/circuit breaker utilities
- Structured logging configuration
- Error case tests
Related agents
| Agent | When to use |
|---|---|
/dev:dev-debug |
Diagnose errors |
/dev:dev-tdd |
Test error cases |
/ops:ops-monitoring |
Alerts on errors |
/dev:dev-api |
Document API errors |
/qa:qa-review |
Review error handling |
IMPORTANT: Every error must be either handled or propagated. Never swallowed.
YOU MUST use typed errors with context.
YOU MUST log errors with structured context.
NEVER use empty catch or console.log for errors.
Think hard about the recovery strategy for each type of error.
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.
- 2d ago First seen · 51 lines · 0 tokens per session scan A 92d904df4a21
dev-error-handling is a command published in the GitHub repository christopherlouet/claude-base (5 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 332 tokens. 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.
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Identify and safely remove dead code with test verification.
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Auto-detect and fix LSP errors, linting issues, and type errors.
loop
Iteratively fix issues until all resolved or max iterations reached.
contract-version-bump
Classify and apply a version bump to a machine-readable contract (JSON Schema, API spec, config schema) — version literals, consumer compatibility, changelog entry, downstream drift.
debug
Run a 4-phase systematic debugging investigation before proposing any fix. Iron Law — NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST. Produces a .orchestrator/debug/ artifact the fixer agent must reference.
health-check
Run diagnostics on Claude Code toolkit configuration and status.