1. Habit
  2. Skills
  3. Understand Diff skill
egonex-ai · 4K installs

Understand Diff skill
Runs by itself, pull request opened.

Every PR gets an impact map.

Install the Understand Diff skill and make it a habit: follow https://gethabit.dev/skills/egonex-ai/understand-diff.md

  1. 1Copy
  2. 2Paste into Claude Code, Codex or Cursor
  3. 3It runs by itself

4K installs88K starsMIT licenceSource on GitHub ↗

Understand Diff

by egonex-ai · 4K installs

The skill

Understand diff analyzes git diffs and pull requests against a codebase knowledge graph to show changed components, affected neighbours, touched layers and a risk rating.

Only when you ask.

The habit

Every PR gets an impact map.

↻ Runs by itselfpull request opened

How the habit works.
You don't have to.

Three questionsWhen does it start? How does it check its work? What does it remember?

01

It starts by itself

pull request opened. Runs in GitHub Actions or Claude Code routine.

  • ↻ pull request opened
  • pull_request opened or synchronize

02

It checks its work

graph found, overlay written. If a check fails, it tells you.

  • ✓knowledge-graph.json exists in the data directory
  • ✓changed file list is not empty
  • ✓diff-overlay.json is written with changedNodeIds and affectedNodeIds
  • ✓stale graph warning shown when the project diff lists files

03

It remembers

diff overlay file. The next run reads it first: the last overlay's base branch and affected node ids.

.ua/diff-overlay.json

One run, step by step.
Then it stops.

Stop ruleStops after one pull request per run.

  1. 01

    Find the graph

    Resolve .ua or the older .understand-anything and stop with a hint to run /understand if no graph exists.

  2. 02

    List changes

    Get changed files with git diff --name-only or against the base branch.

  3. 03

    Check freshness

    Compare the graph commit with HEAD and the project diff and warn if the graph is stale.

  4. 04

    Map nodes

    Grep the graph for each changed filePath and note the node ids.

  5. 05

    Follow edges

    Find upstream and downstream nodes one hop away and the layers they sit in.

  6. 06

    Rate the risk

    Use complexity, cross-layer edges and blast radius to say what to review closely.

  7. 07

    Write the overlay

    Save diff-overlay.json so the dashboard can show the change.

What it may do.
Nothing more.

Safe by defaultIt writes only in its own folder and asks you before anything goes out.

Is it for you?
Use it when it fits.

Quick checkRead both lists. If the left one sounds like you, the Understand Diff skill helps.

Use it when

  • ✓ reviewing a pull request
  • ✓ checking the blast radius of a change
  • ✓ seeing which layers a branch touches

Skip it when

  • – no knowledge graph exists yet
  • – a one-line change

Questions

Understand Diff skill, answered.

Do I need the graph first?

Yes. Run /understand once to build it; this loop only reads it.

Can I see the result visually?

Yes. Run /understand-anything:understand-dashboard to view the overlay.

How do I install the Understand Diff skill?

Copy the prompt at the top into your agent. It installs the skill from egonex-ai/understand-anything and sets up the habit. Or run npx skills add egonex-ai/understand-anything --skill understand-diff.

Is the Understand Diff skill free?

Yes. It is published under MIT. Habit is free too.

Understand Diff. Now as a habit.

Install the Understand Diff skill and make it a habit: follow https://gethabit.dev/skills/egonex-ai/understand-diff.md

  • Free
  • No account
  • Undo in one line

All egonex-ai skills →More code skills →

Works in

  • Claude Code
  • Codex
  • Cursor
  • ChatGPT
  • Claude app

Made by egonex-ai, published under MIT. Habit links to the original and never changes it. Is this your skill?

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