git-patch-workflow

A Git workflow for creating, checking, and applying unified diff patches. A patch is a text file that records which lines should be removed and added in a source-code project.

In plain words
What is it for?
Use it to create patches from unstaged changes, staged changes, commits, or selected files; run a dry run; apply patches with different path settings; and understand patch contents.
Why use it?
It helps move code changes between branches, commits, or repositories in a reviewable form and lets you test whether a patch will apply before changing files.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/cxcscmu/skilllearnbench/git-patch-workflow
Any agent
npx skills add cxcscmu/SkillLearnBench --skill git-patch-workflow
Clone the repo
git clone --depth 1 https://github.com/cxcscmu/SkillLearnBench

Made for: Claude Code, Codex.

Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 625 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00022 $0.00625
Opus 5 $0.00011 $0.00313
Sonnet 5 $0.00004 $0.00125
Haiku 4.5 $0.00002 $0.00063

Measured 2d ago against content hash 0dcf37567830, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

git-patch-workflow 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 2d 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.

skills/b1-one-shot-claude-haiku-4-5/fix-security-bug/git-patch-workflow/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Git Patch Workflow

Creating Patch Files

Method 1: From Unstaged Changes

cd /path/to/repo
git diff path/to/file.java > /path/to/patch/fix.patch

Method 2: From Staged Changes

git diff --cached > /path/to/patch/fix.patch

Method 3: From Commits

# Create patch from last N commits
git format-patch -N HEAD

# Create patch from specific commit
git show COMMIT_HASH > /path/to/patch/fix.patch

Patch File Structure

A unified diff patch looks like:

--- a/original/path/file.java
+++ b/modified/path/file.java
@@ -10,5 +10,6 @@ class MyClass {
     // context line
-    old code here
+    new code here
     // context line

Key components:

  • --- prefix: original file
  • +++ prefix: modified file
  • @@ markers: line numbers and context
  • - prefix: removed lines
  • + prefix: added lines
  • No prefix: context lines

Applying Patches

Basic Application

cd /path/to/repo
patch -p1 < /path/to/patch/fix.patch

With Error Handling

# Dry-run to test application
patch -p1 --dry-run < /path/to/patch/fix.patch

# Apply with strict checking
patch -p1 < /path/to/patch/fix.patch

# Apply with less strict checking
patch -p0 < /path/to/patch/fix.patch

Best Practices

  1. Use Git Format: Create patches via git diff or git format-patch for consistency
  2. Include Context: Ensure adequate context lines (3+ lines around changes)
  3. Test Patches: Always dry-run before applying to ensure compatibility
  4. Modular Patches: Create separate patches for logically independent changes
  5. Clear Names: Name patches descriptively (e.g., fix-javascript-security-bypass.patch)
  6. Document Changes: Include explanation of what the patch fixes

Verifying Application

# Check if patch was applied
git status
git diff HEAD

# Verify specific file was patched
git show HEAD:path/to/file.java | grep "your fix"

Multiple Patches

For multiple related patches:

# Create patches in order
git diff HEAD~2 HEAD~1 > patch1.patch
git diff HEAD~1 HEAD > patch2.patch

# Apply in sequence
patch -p1 < patch1.patch
patch -p1 < patch2.patch

Read the full file on GitHub · 103 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. 2d ago First seen · 103 lines · 22 tokens per session scan A 0dcf37567830

Subscribe to this mod's changes

git-patch-workflow is a skill published in the GitHub repository cxcscmu/SkillLearnBench (80 stars, last pushed 1mo ago), licensed MIT. It adds 22 tokens to every session and 625 once invoked, about $0.0001 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.

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