anvien-impact-analysis

anvien-impact-analysis is a skill for Claude Code, Codex from tamnguyendinh/Anvien. It costs 49 tokens per session (745 once invoked), scanned A, a copy of gitnexus-impact-analysis, MIT.

A code-change analysis skill that maps which parts of a codebase depend on a function, file, or other target. It also checks affected execution flows and current changes.

In plain words
What is it for?
Use it to check whether a change is safe, find callers and importers, estimate the affected area, and review current changes before committing.
Why use it?
It helps reveal the likely consequences of an edit before the change is made or committed. This reduces the chance of missing direct or indirect users of the code.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to check whether a change is safe, find callers and importers, estimate the affected area, and review current changes before committing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/tamnguyendinh/anvien/anvien-impact-analysis
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 tamnguyendinh/Anvien --skill anvien-impact-analysis
Clone the repo
git clone --depth 1 https://github.com/tamnguyendinh/Anvien

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 anvien-impact-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/tamnguyendinh/anvien/anvien-impact-analysis/github.svg)](https://agentmods.dev/skills/tamnguyendinh/anvien/anvien-impact-analysis)
Your own site
<a href="https://agentmods.dev/skills/tamnguyendinh/anvien/anvien-impact-analysis"><img src="https://agentmods.dev/badge/skills/tamnguyendinh/anvien/anvien-impact-analysis/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for anvien-impact-analysis

Your own site · 80×15
<a href="https://agentmods.dev/skills/tamnguyendinh/anvien/anvien-impact-analysis"><img src="https://agentmods.dev/badge/skills/tamnguyendinh/anvien/anvien-impact-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 745 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 86% copy Near-identical to another mod 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 $0.00049 $0.00745
Opus 5 $0.00024 $0.00373
Sonnet 5 $0.00010 $0.00149
Haiku 4.5 $0.00005 $0.00075

Measured 12d ago against content hash d4cae0ac3d91, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

anvien-impact-analysis 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 12d 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.

Origin

This is a copy

86% identical to gitnexus-impact-analysis — 10 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

anvien-claude-plugin/skills/anvien-impact-analysis/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Impact Analysis with Anvien

When to Use

  • "Is it safe to change this function?"
  • "What will break if I modify X?"
  • "Show me the blast radius"
  • "Who uses this code?"
  • Before making non-trivial code changes
  • Before committing — to understand what your changes affect

Workflow

1. impact({target: "X", direction: "upstream"})  → What depends on this
2. READ anvien://repo/{name}/processes                   → Check affected execution flows
3. detect_changes()                               → Map current git changes to affected flows
4. Assess risk and report to user

If "Index is stale" → run anvien analyze in terminal.

Checklist

- [ ] impact({target, direction: "upstream"}) to find dependents
- [ ] Review d=1 items first (these WILL BREAK)
- [ ] Check high-confidence (>0.8) dependencies
- [ ] READ processes to check affected execution flows
- [ ] detect_changes() for pre-commit check
- [ ] Assess risk level and report to user

Understanding Output

Depth Risk Level Meaning
d=1 WILL BREAK Direct callers/importers
d=2 LIKELY AFFECTED Indirect dependencies
d=3 MAY NEED TESTING Transitive effects

Risk Assessment

Affected Risk
<5 symbols, few processes LOW
5-15 symbols, 2-5 processes MEDIUM
>15 symbols or many processes HIGH
Critical path (auth, payments) CRITICAL

Tools

impact — the primary tool for symbol blast radius:

impact({
  target: "validateUser",
  direction: "upstream",
  minConfidence: 0.8,
  maxDepth: 3
})

→ d=1 (WILL BREAK):
  - loginHandler (src/auth/login.ts:42) [CALLS, 100%]
  - apiMiddleware (src/api/middleware.ts:15) [CALLS, 100%]

→ d=2 (LIKELY AFFECTED):
  - authRouter (src/routes/auth.ts:22) [CALLS, 95%]

detect_changes — git-diff based impact analysis:

Read the full file on GitHub · 98 lines

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. 12d ago First seen · 98 lines · 49 tokens per session scan A d4cae0ac3d91

Subscribe to this mod's changes

anvien-impact-analysis is a skill published in the GitHub repository tamnguyendinh/Anvien (9 stars, last pushed today), licensed MIT. It adds 49 tokens to every session and 745 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to gitnexus-impact-analysis, differing in 10 lines, and is treated as a copy.

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