assess-impact

assess-impact is a skill for Claude Code, Codex from panbanda/omen. It costs 35 tokens per session (749 once invoked), scanned A, original, Apache-2.0.

A workflow for checking which parts of a codebase may be affected before changing shared code. It uses Omen, a command-line code analysis tool, to trace dependencies, related files, and ownership.

In plain words
What is it for?
Use it before changing core components, shared code, or breaking APIs to inspect symbol usage, file dependencies, temporal coupling, and ownership.
Why use it?
It helps reveal indirect callers and files that may need changes, reducing unexpected breakage during refactoring or API changes.

Skill for Claude CodeCodex

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

Part of the omen-development plugin — 13 skills shipped together

Good fit Use it before changing core components, shared code, or breaking APIs to inspect symbol usage, file dependencies, temporal coupling, and ownership.

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

Made for: Claude Code, Codex.

Or install omen-development, the plugin that ships this one along with the rest of its 13 skills.

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 assess-impact

README.md
[![agentmods](https://agentmods.dev/badge/skills/panbanda/omen/assess-impact.svg)](https://agentmods.dev/skills/panbanda/omen/assess-impact)
Your own site
<a href="https://agentmods.dev/skills/panbanda/omen/assess-impact"><img src="https://agentmods.dev/badge/skills/panbanda/omen/assess-impact.svg" alt="Measured on agentmods" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 749 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00035 $0.00749
Opus 5 $0.00017 $0.00375
Sonnet 5 $0.00007 $0.00150
Haiku 4.5 $0.00003 $0.00075

Measured 8d ago against content hash 2080e8e9bf2a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

assess-impact 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 8d 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.

plugins/development/skills/assess-impact/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Assess Impact

Understand the potential blast radius of changes before making them by analyzing dependencies, coupling patterns, and ownership.

Prerequisites

Omen CLI must be installed and available in PATH.

Workflow

Step 1: Check Symbol Blast Radius

Use the impact command to get transitive callers and callees in one call:

omen -f json impact <symbol-name> --depth 2

This returns affected files, caller/callee BFS levels, and the total count — much faster than building the picture manually.

To inspect a specific symbol first:

omen -f json symbol <symbol-name>

Step 2: Map File-Level Dependencies

Run the dependency graph analysis for file-level coupling:

omen -f json graph --compact

Identify:

  • Direct dependents (files that import the target)
  • Transitive dependents (files that import the dependents)

Step 3: Check Temporal Coupling

Run the temporal coupling analysis:

omen -f json temporal

Files with high temporal coupling to the target often need to change together even without explicit imports.

Step 3: Identify Stakeholders

Run the ownership analysis:

omen -f json ownership

Identify:

  • Primary owner of the target file
  • Owners of dependent files
  • Subject matter experts to consult

Impact Categories

Classify impact by type:

Category Description Action
Direct Explicit imports/calls Will break if signature changes
Implicit Temporal coupling May break due to shared assumptions
Behavioral Same owner/team Likely understands the change
Unknown No coupling, different owner Needs extra review

Output Format

Present impact analysis as:

# Change Impact: `target/file.go:FunctionName`

## Direct Dependencies (will break)
- `consumer/a.go` - calls FunctionName directly
- `consumer/b.go` - uses returned type
- `test/target_test.go` - tests the function

## Implicit Dependencies (may break)
- `related/cache.go` - 0.85 temporal coupling
  - Always changes with target
  - Likely shares state or assumptions
- `related/config.go` - 0.72 temporal coupling
  - Often changes together
  - May depend on same configuration

## Stakeholders to Notify
- [email protected] - Primary owner of target (85% of commits)
- [email protected] - Owns consumer/a.go
- [email protected] - Owns related/cache.go

## Risk Assessment
- **Blast Radius**: 5 files directly, 12 files transitively
- **Coupling Risk**: 2 files with implicit dependencies
- **Team Impact**: 3 developers should be notified

## Recommended Approach
1. Coordinate with alice (primary owner)
2. Update tests in target_test.go first
3. Check related/cache.go for shared assumptions
4. Notify bob and charlie before merging

Read the full file on GitHub · 123 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. 8d ago First seen · 123 lines · 35 tokens per session scan A 2080e8e9bf2a

Subscribe to this mod's changes

assess-impact is a skill published in the GitHub repository panbanda/omen (19 stars, last pushed today), licensed Apache-2.0. It adds 35 tokens to every session and 749 once invoked, about $0.0002 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.

Related

Other skills, from other repositories

chrome-devtools-cli

Use this skill to write shell scripts or run shell commands to automate tasks in the browser or otherwise use Chrome DevTools via CLI.

ChromeDevTools/chrome-devtools-mcp · 31 tokens

a11y-debugging

Uses Chrome DevTools MCP for accessibility (a11y) debugging and auditing based on web.dev guidelines. Use when testing semantic HTML, ARIA labels, focus states, keyboard navigation, tap targets, and color contrast.

ChromeDevTools/chrome-devtools-mcp · 50 tokens

chrome-devtools

Uses Chrome DevTools via MCP for efficient debugging, troubleshooting and browser automation. Use when debugging web pages, automating browser interactions, analyzing performance, or inspecting network requests. This skill does not apply to --slim mode (MCP configuration).

ChromeDevTools/chrome-devtools-mcp · 55 tokens

n8n-error-handling

Wire n8n error handling so failures are loud, structured, and recoverable. Use when building any webhook/API workflow, a scheduled or unattended workflow, or any path where a silent failure would drop user-visible work — and whenever the user mentions error handling, onError, continueErrorOutput, error…

czlonkowski/n8n-mcp · 128 tokens

n8n-validation-expert

Interpret validation errors and guide fixing them. Use when encountering validation errors, validation warnings, false positives, operator structure issues, or need help understanding validation results. Also use when asking about validation profiles, error types, the validation loop process, or auto-fix capabilities.…

czlonkowski/n8n-mcp · 91 tokens

agentcore-investigation

Investigate Bedrock AgentCore runtime sessions via CloudWatch Logs Insights — resolve session/trace IDs, query OTEL spans, filter noise, build timelines. Use when debugging AgentCore agent sessions, tracing tool calls, or analyzing latency.

awslabs/mcp · 52 tokens