impact

A focused report showing what may be affected when you change a function, class, symbol, or file. It finds callers and groups the effects as direct, indirect, or test-only.

In plain words
What is it for?
Use it before changing an exported symbol, a named function such as requireAuth, or every exported symbol in a file. It saves the analysis in a state file and can refresh an existing result.
Why use it?
It reduces the need to search through the codebase and reason about every possible consequence by hand before making a change.

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/bostonorange/claude-code-framework/impact
Any agent
npx skills add BostonOrange/claude-code-framework --skill impact
Clone the repo
git clone --depth 1 https://github.com/BostonOrange/claude-code-framework

Made for: Claude Code, Codex.

Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,190 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 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 $0.00068 $0.01190
Opus 5 $0.00034 $0.00595
Sonnet 5 $0.00014 $0.00238
Haiku 4.5 $0.00007 $0.00119

Measured yesterday against content hash 958c27f34ab6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

impact scanned grade B 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 yesterday.

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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

description: On-demand precise impact analysis for a symbol or file before changing it. Spawns impact-analyzer to grep callers, classify the cascade (direct/indirect/test-only), and produce a confidence-scored report. Di
skills/impact/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Impact — On-Demand Cascade Analysis

Before making a confident-but-wrong change to a function, class, or file, run /impact to see what would break.

/impact answers questions like "if I change the return type of requireAuth, what breaks?" — without you having to grep callers, read each one, and reason about cascades by hand. Output is a structured report at .claude/state/impact-<hash>.md plus a short summary.

This complements .claude/state/architecture.md:

  • architecture.md is the broad map (module boundaries, dependency direction, top-10 hotspots) refreshed by /improve each session
  • /impact <symbol> is the focused drill-down for a specific change you're about to make

Usage

/impact <file>                          analyze every exported symbol in the file
/impact <file>:<symbol>                 analyze just that symbol
/impact <symbol>                        bare symbol; spawns analyzer to find definition first
/impact --refresh <target>              ignore cache; re-run analysis

Examples:

/impact lib/auth/middleware.ts
/impact lib/auth/middleware.ts:requireAuth
/impact requireAuth
/impact AccountTriggerHandler.cls:beforeInsert    # Apex

Process

Phase 1: Spawn impact-analyzer

Run impact analysis on <target>. Locate the definition, find direct callers,
classify references (direct/type/test), trace second-order public callers
(depth=2 max), score confidence, write the report to .claude/state/impact-<hash>.md.
End with the surface summary.

The agent is read-only by tool restriction (Read, Glob, Grep, Bash — no Edit/Write). Its only filesystem write is the report file.

Phase 2: Surface to user

Read the agent's summary output. Show:

  • Total references + breakdown (direct / type / test)
  • Confidence level + top caveat
  • Top 3 most-impacted files
  • Recommendation one-liner
  • Path to the full report

Phase 3: Hand-off

If the user is iterating on a change:

  • "Confidence is high — proceed; the test suite at <paths> should catch regressions"
  • "Confidence is medium — review the second-order callers in .claude/state/impact-<hash>.md before merging"
  • "Confidence is low — string-keyed lookups detected; grep can't see them all. Consider running tests in addition"

Read the full file on GitHub · 103 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. yesterday First seen · 103 lines · 68 tokens per session scan B 958c27f34ab6

Subscribe to this mod's changes

impact is a skill published in the GitHub repository BostonOrange/claude-code-framework (2 stars, last pushed 1mo ago), licensed MIT. It adds 68 tokens to every session and 1,190 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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