Differential Review

What it does

When your agent uses it

• Tasks that involve Git workflow
• Tasks that involve Test coverage

Example prompts

• “Use the differential-review skill to perform security-focused differential review of code changes (PRs, commits, diffs)”
• “/differential-review”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

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

What it can do on your machine

Read from SKILL.md and the folder at commit 9dccb6d. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md.

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Differential Review loads about 1.6k tokens when it runs. Until then it costs about 81 tokens; SKILL.md has 518 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~81

When it runs · the whole SKILL.md, loaded when a task matches

~1.6k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from waybarrios/opencode-power-pack at commit 9dccb6d, republished under its MIT licence (© waybarrios). 518 words, ~1,620 tokens.

name

differential-review

description

Performs security-focused differential review of code changes (PRs, commits, diffs). Adapts analysis depth to codebase size, uses git history for context, calculates blast radius, checks test coverage, and generates comprehensive markdown reports. Automatically detects and prevents security regressions.

license

MIT (modified; see UPSTREAMS.json)

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

├─ 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

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

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

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

© waybarrios, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files in skills/differential-review of waybarrios/opencode-power-pack.

• SKILL.md
• adversarial.md
• methodology.md
• patterns.md
• reporting.md

Open the folder on GitHubat commit 9dccb6d

Used in 5 other repositories

We found 14 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 5 other GitHub owners. This page covers the copy in waybarrios/opencode-power-pack, which our catalogue first saw on October 7, 2026.

• vigolium/pioliumskills/differential-review
• CraftOS-dev/CraftBotskills/differential-review
• sickn33/agentic-awesome-skillsskills/differential-reviewplugins/agentic-awesome-skills/skills/differential-review+1 more
• lingxling/awesome-skills-cnantigravity-awesome-skills/skills/differential-reviewantigravity-awesome-skills/plugins/agentic-awesome-skills/skills/differential-review+1 more
• henryalouf/ruflow.agents/skills/differential-review.agents/skills/antigravity-awesome-skills/skills/differential-review+4 more