How do I install the Diff Engine skill?

Run npx skillmds@latest add hoangsonww/diff-engine in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Diff Engine safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Diff Engine?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Diff Engine free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Diff Engine?

hoangsonww (@hoangsonww) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Diff Engine

Name: Diff Engine
Author: hoangsonww

Change comparison rules, severity, identity matching, or change correlation. Use when diffs look wrong, a capability needs a new ComparisonRule, or clustering/timeline is involved.

hoangsonww 2d657d4 1.1 KB Updated Sep 17, 2026

Coding & Dev Tools

Install

Press C to copy

$ npx skillmds@latest add hoangsonww/diff-engine

Installs into ~/.claude/skills (or .claude/skills inside a project). Restart Claude Code to pick it up.

Download SKILL.md

＋ Add to collection

README badge

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Trust & safety

Audits pending

Not yet audited · commit 2d657d4

Works with: Claude Code Claude.ai OpenAI Codex +

File contents

Diff engine

The engine is generic. Capabilities declare ComparisonRule and ChangeSeverity on property descriptors. Do not add if capability == .docker branches.

ValueComparator is the only place two readings are judged "the same".
Identity matching is EntityIdentity (normalized value + kind + optional scope). Path identities use EntityIdentity.path.
diff(A, A) is empty. Reverse diffs swap added/removed counts. Property tests in Packages/DiffuseDiff/Tests and Tests/Invariants guard this.
Severity can escalate on a major version jump; do not special-case tools by name.
Correlation (ChangeCorrelator) groups by time window, not by inference.

Read Documentation/DiffEngine.md and Documentation/adr/0003-schema-driven-diff.md.

After changes: swift test --filter DiffuseDiffTests and swift test --filter DiffuseInvariantTests.

hoangsonww/diffuse-native-apps/tree/main/.agents/skills/diff-engine commit 2d657d498d

Frequently asked questions

npx skillmds@latest add hoangsonww/diff-engine