Files
antigravity-skills-reference/skills/differential-review/SKILL.md
Al-Garadi ef285b5c97 fix: sync upstream main with Windows validation and skill guidance cleanup (#457)
* fix: stabilize validation and tests on Windows

* test: add Windows smoke coverage for skill activation

* refactor: make setup_web script CommonJS

* fix: repair aegisops-ai frontmatter

* docs: add when-to-use guidance to core skills

* docs: add when-to-use guidance to Apify skills

* docs: add when-to-use guidance to Google and Expo skills

* docs: add when-to-use guidance to Makepad skills

* docs: add when-to-use guidance to git workflow skills

* docs: add when-to-use guidance to fp-ts skills

* docs: add when-to-use guidance to Three.js skills

* docs: add when-to-use guidance to n8n skills

* docs: add when-to-use guidance to health analysis skills

* docs: add when-to-use guidance to writing and review skills

* meta: sync generated catalog metadata

* docs: add when-to-use guidance to Robius skills

* docs: add when-to-use guidance to review and workflow skills

* docs: add when-to-use guidance to science and data skills

* docs: add when-to-use guidance to tooling and automation skills

* docs: add when-to-use guidance to remaining skills

* fix: gate bundle helper execution in Windows activation

* chore: drop generated artifacts from contributor PR

* docs(maintenance): Record PR 457 sweep

Document the open issue triage, PR supersedence decision, local verification, and source-only cleanup that prepared PR #457 for re-running CI.

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Co-authored-by: sickn33 <sickn33@users.noreply.github.com>
2026-04-05 21:04:39 +02:00

6.4 KiB

name, description, risk, source
name description risk source
differential-review Security-focused code review for PRs, commits, and diffs. unknown community

Differential Security Review

Security-focused code review for PRs, commits, and diffs.

When to Use

  • You need a security-focused review of a PR, commit range, or diff rather than a general code review.
  • The changes touch auth, crypto, external calls, value transfer, permissions, or other high-risk logic.
  • You need findings backed by code evidence, attack scenarios, and an explicit report artifact.

Core Principles

  1. Risk-First: Focus on auth, crypto, value transfer, external calls
  2. Evidence-Based: Every finding backed by git history, line numbers, attack scenarios
  3. Adaptive: Scale to codebase size (SMALL/MEDIUM/LARGE)
  4. Honest: Explicitly state coverage limits and confidence level
  5. Output-Driven: Always generate comprehensive markdown report file

Rationalizations (Do Not Skip)

Rationalization Why It's Wrong Required Action
"Small PR, quick review" Heartbleed was 2 lines Classify by RISK, not size
"I know this codebase" Familiarity breeds blind spots Build explicit baseline context
"Git history takes too long" History reveals regressions Never skip Phase 1
"Blast radius is obvious" You'll miss transitive callers Calculate quantitatively
"No tests = not my problem" Missing tests = elevated risk rating Flag in report, elevate severity
"Just a refactor, no security impact" Refactors break invariants Analyze as HIGH until proven LOW
"I'll explain verbally" No artifact = findings lost Always write report

Quick Reference

Codebase Size Strategy

Codebase Size Strategy Approach
SMALL (<20 files) DEEP Read all deps, full git blame
MEDIUM (20-200) FOCUSED 1-hop deps, priority files
LARGE (200+) SURGICAL Critical paths only

Risk Level Triggers

Risk Level Triggers
HIGH Auth, crypto, external calls, value transfer, validation removal
MEDIUM Business logic, state changes, new public APIs
LOW Comments, tests, UI, logging

Workflow Overview

Pre-Analysis → Phase 0: Triage → Phase 1: Code Analysis → Phase 2: Test Coverage
    ↓              ↓                    ↓                        ↓
Phase 3: Blast Radius → Phase 4: Deep Context → Phase 5: Adversarial → Phase 6: Report

Decision Tree

Starting a review?

├─ Need detailed phase-by-phase methodology?
│  └─ Read: methodology.md
│     (Pre-Analysis + Phases 0-4: triage, code analysis, test coverage, blast radius)
│
├─ Analyzing HIGH RISK change?
│  └─ Read: adversarial.md
│     (Phase 5: Attacker modeling, exploit scenarios, exploitability rating)
│
├─ Writing the final report?
│  └─ Read: reporting.md
│     (Phase 6: Report structure, templates, formatting guidelines)
│
├─ Looking for specific vulnerability patterns?
│  └─ Read: patterns.md
│     (Regressions, reentrancy, access control, overflow, etc.)
│
└─ Quick triage only?
   └─ Use Quick Reference above, skip detailed docs

Quality Checklist

Before delivering:

  • All changed files analyzed
  • Git blame on removed security code
  • Blast radius calculated for HIGH risk
  • Attack scenarios are concrete (not generic)
  • Findings reference specific line numbers + commits
  • Report file generated
  • User notified with summary

Integration

audit-context-building skill:

  • Pre-Analysis: Build baseline context
  • Phase 4: Deep context on HIGH RISK changes

issue-writer skill:

  • Transform findings into formal audit reports
  • Command: issue-writer --input DIFFERENTIAL_REVIEW_REPORT.md --format audit-report

Example Usage

Quick Triage (Small PR)

Input: 5 file PR, 2 HIGH RISK files
Strategy: Use Quick Reference
1. Classify risk level per file (2 HIGH, 3 LOW)
2. Focus on 2 HIGH files only
3. Git blame removed code
4. Generate minimal report
Time: ~30 minutes

Standard Review (Medium Codebase)

Input: 80 files, 12 HIGH RISK changes
Strategy: FOCUSED (see methodology.md)
1. Full workflow on HIGH RISK files
2. Surface scan on MEDIUM
3. Skip LOW risk files
4. Complete report with all sections
Time: ~3-4 hours

Deep Audit (Large, Critical Change)

Input: 450 files, auth system rewrite
Strategy: SURGICAL + audit-context-building
1. Baseline context with audit-context-building
2. Deep analysis on auth changes only
3. Blast radius analysis
4. Adversarial modeling
5. Comprehensive report
Time: ~6-8 hours

When NOT to Use This Skill

  • Greenfield code (no baseline to compare)
  • Documentation-only changes (no security impact)
  • Formatting/linting (cosmetic changes)
  • User explicitly requests quick summary only (they accept risk)

For these cases, use standard code review instead.


Red Flags (Stop and Investigate)

Immediate escalation triggers:

  • Removed code from "security", "CVE", or "fix" commits
  • Access control modifiers removed (onlyOwner, internal → external)
  • Validation removed without replacement
  • External calls added without checks
  • High blast radius (50+ callers) + HIGH risk change

These patterns require adversarial analysis even in quick triage.


Tips for Best Results

Do:

  • Start with git blame for removed code
  • Calculate blast radius early to prioritize
  • Generate concrete attack scenarios
  • Reference specific line numbers and commits
  • Be honest about coverage limitations
  • Always generate the output file

Don't:

  • Skip git history analysis
  • Make generic findings without evidence
  • Claim full analysis when time-limited
  • Forget to check test coverage
  • Miss high blast radius changes
  • Output report only to chat (file required)

Supporting Documentation

  • methodology.md - Detailed phase-by-phase workflow (Phases 0-4)
  • adversarial.md - Attacker modeling and exploit scenarios (Phase 5)
  • reporting.md - Report structure and formatting (Phase 6)
  • patterns.md - Common vulnerability patterns reference

For first-time users: Start with methodology.md to understand the complete workflow.

For experienced users: Use this page's Quick Reference and Decision Tree to navigate directly to needed content.