checking-what-a-change-affects

checking-what-a-change-affects is a skill for Claude Code from FlyFission/nuclear-grade-context-engineering. It costs 72 tokens per session (1,110 once invoked), scanned A, original, MIT.

A change-impact review skill for finding documents, tests, skills, commands, templates, prompts, releases, saved versions, and runtime behavior that may become outdated after a controlled change.

In plain words
What is it for?
Use it to list affected areas, assign each an update, defer, leave-alone, or block decision, and record what should trigger another review.
Why use it?
It prevents related work from quietly relying on stale information or contracts after one item is modified.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the nuclear-grade plugin — 29 skills, 28 commands, 5 agents shipped together

Good fit Use it to list affected areas, assign each an update, defer, leave-alone, or block decision, and record what should trigger another review.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/flyfission/nuclear-grade-context-engineering/checking-what-a-change-affects
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.

Any agent
npx skills add FlyFission/nuclear-grade-context-engineering --skill checking-what-a-change-affects
Clone the repo
git clone --depth 1 https://github.com/FlyFission/nuclear-grade-context-engineering

Made for: Claude Code.

Or install nuclear-grade, the plugin that ships this one along with the rest of its 29 skills, 28 commands, 5 agents.

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 checking-what-a-change-affects

README.md
[![agentmods](https://agentmods.dev/badge/skills/flyfission/nuclear-grade-context-engineering/checking-what-a-change-affects.svg)](https://agentmods.dev/skills/flyfission/nuclear-grade-context-engineering/checking-what-a-change-affects)
Your own site
<a href="https://agentmods.dev/skills/flyfission/nuclear-grade-context-engineering/checking-what-a-change-affects"><img src="https://agentmods.dev/badge/skills/flyfission/nuclear-grade-context-engineering/checking-what-a-change-affects.svg" alt="Measured on agentmods" height="20"></a>
Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,110 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00072 $0.01110
Opus 5 $0.00036 $0.00555
Sonnet 5 $0.00014 $0.00222
Haiku 4.5 $0.00007 $0.00111

Measured 7d ago against content hash 72c699ed1f89, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

checking-what-a-change-affects 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 7d 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.

skills/checking-what-a-change-affects/SKILL.md · 92 lines

How it starts

The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Checking What a Change Affects

Overview

An impact screen asks a simple question. When a controlled item changes, what else does that change leave out of date? You look downstream for ripple effects before they surprise you.

Decision contract

  • Claim checked: every artifact a controlled change could leave stale -- docs, tests, checkers, skills, commands, templates, prompts, releases, saved versions, and runtime blast radius (schema/state migration, API consumers, backward-compatibility, rollback-of-state) -- has one named action with evidence, and no stale surface is quietly accepted.
  • Artifact observed: the controlled-item list, risk.md, basis.md, plan.md, the diff, and change-impact.md -> change-impact.md with per-item actions, re-check triggers, and required follow-ups.
  • Decision affected: block -- per affected item, update / leave alone / defer / block; blockers carry into ship.md.
  • Failure class: missed-ripple (a stale doc, test, checker, or runtime contract quietly accepted).
  • Next action: assign each stale surface an action with an owner and trigger; escalate when it touches outside trust, security, or the release.

When to Use

  • A change affects more than one kind of artifact.
  • A change touches a running system, a schema, stored data, or an API other code depends on (brownfield or migration work).
  • Public claims, where ideas came from, checkers, tests, templates, skills, commands, dependencies, prompts, or the release may need updates.
  • A saved version or a re-check trigger may change.
  • A near miss, a weak control, or a lesson from real operation (OPEX) hints at hidden ripple effects.

When Not to Use

  • The change is clearly Quick. It affects one local item and needs one proof step.
  • A current change-impact.md already covers the exact scope.

Inputs

  • The controlled-item list.
  • risk.md, basis.md, plan.md, and the diff.
  • docs/02-operating-system/change-impact.md.

Process

  1. Name the kinds of artifacts the change might affect. When the change touches a running system or stored data, screen the runtime blast radius too — schema and state migration, API consumers that depend on the contract, backward-compatibility, and rollback-of-state — not just repo artifacts. See docs/02-operating-system/change-impact.md.
  2. For each kind, pick one action: update it, leave it alone, defer it, or block on it.
  3. Name the stale links, evidence, examples, claims, handoffs, or controls.
  4. Link evidence for each choice.
  5. Record the triggers to re-check.
  6. Carry any blockers or accepted gaps into ship.md.

Read the full file on GitHub · 92 lines

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. 7d ago First seen · 92 lines · 72 tokens per session scan A 72c699ed1f89

Subscribe to this mod's changes

checking-what-a-change-affects is a skill published in the GitHub repository FlyFission/nuclear-grade-context-engineering (33 stars, last pushed yesterday), licensed MIT. It adds 72 tokens to every session and 1,110 once invoked, about $0.0004 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 2026-08-30.