engineering-rigor

engineering-rigor is a skill for Claude Code, Codex from lootlog/monorepo. It costs 54 tokens per session (325 once invoked), scanned A, original, MIT.

Guidance for making and checking engineering changes that cross module, package, or system boundaries. It covers architecture, shared state, public interfaces, migrations, retries, and changes affecting several workspaces.

In plain words
What is it for?
Use it for architectural changes, API or contract changes, migrations, shared state, retry behavior, public interfaces, and multi-workspace work.
Why use it?
A locally correct change can still break callers or related systems. This approach keeps the change complete and verifies the real result across its boundaries.

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/lootlog/monorepo/engineering-rigor
Any agent
npx skills add lootlog/monorepo --skill engineering-rigor
Clone the repo
git clone --depth 1 https://github.com/lootlog/monorepo

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 engineering-rigor

README.md
[![agentmods](https://agentmods.dev/badge/skills/lootlog/monorepo/engineering-rigor.svg)](https://agentmods.dev/skills/lootlog/monorepo/engineering-rigor)
Your own site
<a href="https://agentmods.dev/skills/lootlog/monorepo/engineering-rigor"><img src="https://agentmods.dev/badge/skills/lootlog/monorepo/engineering-rigor.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 325 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00054 $0.00325
Opus 5 $0.00027 $0.00162
Sonnet 5 $0.00011 $0.00065
Haiku 4.5 $0.00005 $0.00032

Measured today against content hash 6b0d88b0b019, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

engineering-rigor 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 today.

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.

.agents/skills/engineering-rigor/SKILL.md · 34 lines

What it actually says

Engineering rigor

Make the smallest complete change that reaches the intended architecture.

Shape

  • Model the domain in data structures instead of scattered conditions.
  • Concentrate parsing, validation, and framework adaptation at system boundaries.
  • Prefer deep modules with small interfaces and low reader load.
  • Remove dead code and redundant layers before adding abstractions.
  • Redesign from the requirement as a first-class constraint instead of bolting on exceptions.

Change

  • Migrate every caller and delete the legacy internal API in the same change.
  • For internal APIs, migrate callers instead of adding compatibility layers unless the user requests them. Preserve deployed and persisted contracts required by AGENTS.md, including coordinated rollout where needed.
  • Delete re-export-only wrappers and import from the owning module.
  • Separate concurrent writers before adding locks. When shared state is necessary, make operations idempotent across retries and partial failures.
  • Break wide work into verifiable units. Keep every intermediate commit or phase coherent.

Prove

  • Reproduce defects before fixing them when practical.
  • Verify the real artifact, not only a proxy such as compilation.
  • Inspect the diff and generated output.
  • Run targeted tests, typecheck, lint, and broader checks in proportion to risk.

Use blast-radius when the main risk lies outside the edited symbols.

Files

What ships with it

1 file 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. today Changed · -1 lines 6b0d88b0b019
  2. 5d ago First seen · 35 lines · 54 tokens per session scan A 61c9e346db19

Subscribe to this mod's changes

engineering-rigor is a skill published in the GitHub repository lootlog/monorepo (10 stars, last pushed today), licensed MIT. It adds 54 tokens to every session and 325 once invoked, about $0.0003 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 2026-08-31.

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