Claude Code diff review
Claude Code changed your codebase — did it touch something risky?
Claude Code is fast. It can edit dependencies, auth middleware, config files, and secrets in a single session. The diff looks correct — until production breaks. This page shows you exactly what to check before merging a Claude Code patch, and how to automate the review with a local risk audit.
Why Claude Code diffs need special review
Claude Code and similar AI coding agents are powerful, but they introduce specific risks that manual code review often misses:
- Dependency changes hide in large diffs. A single Claude Code session might update 3 packages in
package.jsonalongside a feature implementation. Reviewers focus on the feature and skip the dependency changes. - Auth and session edits look intentional. When Claude Code modifies an auth middleware file, it reads like a deliberate improvement — not like a potential regression. You need a signal that says "auth path changed, review this file carefully."
- Config drift compounds over sessions. Each Claude Code session might make a small
.envordocker-composechange. Over 10 sessions, you have config drift that no single reviewer catches. - Secrets leak through generated patches. Claude Code might insert real API keys or tokens as placeholders that look like configuration. Pattern-based detection catches these before they reach the remote.
- Missing tests are the norm, not the exception. AI agents are better at generating implementation code than test code. A source change with no corresponding test change is a strong review-priority signal.
Step-by-step: review a Claude Code diff before merge
- Save the diff.
git diff > change.patch— or usegit diff main > change.patchto compare against the base branch. - Run the local risk audit.
This produces a risk score and a list of flags — no cloud upload, no API key, runs in under 1 second.python agent_change_risk_auditor.py audit --diff change.patch - Read the flags. Each flag points to a specific risk category:
DEPENDENCY_CHANGE,AUTH_PATH_MODIFIED,CONFIG_MODIFIED,SOURCE_CHANGED_WITHOUT_TEST_CHANGE,POSSIBLE_SECRET_LITERAL_IN_DIFF, orLARGE_CHANGE. - Inspect flagged areas manually. The tool tells you where to look. You decide whether the change is safe.
- Block or merge. If the risk score is high or secret-like literals are present, block the merge and investigate. If the score is low with no critical flags, merge with confidence.
Example: Claude Code diff audit output
$ python agent_change_risk_auditor.py --diff claude-session.patch
AI Agent Change Risk Audit
Risk level: high
Risk score: 63/100
Files changed: 2
Lines: +3 / -1
Flags:
- DEPENDENCY_CHANGE:package.json
- SOURCE_CHANGED_WITHOUT_TEST_CHANGE
- POSSIBLE_SECRET_LITERAL_IN_DIFF
Recommendations:
- Add or update tests for changed source files before merge.
- Remove secret-like literals and rotate exposed credentials if real.
- Review dependency changes manually and run lockfile/security checks.
CI integration: block risky Claude Code diffs automatically
Add the audit as a CI gate so Claude Code diffs with high risk never reach production without manual review:
# .github/workflows/risk-gate.yml
name: AI Change Risk Gate
on: [pull_request]
jobs:
risk-audit:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- name: AI Change Risk Audit
run: |
git diff origin/main > diff.patch
python agent_change_risk_auditor.py audit --diff diff.patch
# Exit code 1 on high risk → blocks the PR
The CLI returns exit code 1 on high-risk diffs, so you can gate merges in any CI system: GitHub Actions, GitLab CI, Bitbucket Pipelines, or a local .git/hooks/pre-commit hook.
HTTP API mode: integrate with your team tools
# Start the local API server
$ python agent_change_risk_auditor.py serve --port 8080
AI Agent Change Risk Audit API v1.2.0 running on http://127.0.0.1:8080
# Audit a Claude Code diff via HTTP
$ curl -X POST http://127.0.0.1:8080/audit \
--data-binary @change.patch \
-H "Content-Type: text/plain"
Use --serve mode to integrate with Slack notifications, team dashboards, or automated review workflows — all running locally, no cloud deployment required.
How this compares to manual Claude Code review
| Aspect | Manual review only | Manual + Risk Audit Kit |
|---|---|---|
| Time to triage a diff | 5–15 min | <1 second + targeted manual review |
| Catches dependency changes | Only if you remember to look | ✅ Always flagged |
| Catches auth path edits | Only if you notice the file | ✅ Always flagged |
| Catches missing tests | Only if you compare files | ✅ Always flagged |
| Catches secret-like literals | Easily missed in large diffs | ✅ Pattern-detected |
| CI integration | Manual process | ✅ Exit code + API mode |
| Code leaves your machine | N/A | ✅ Never — 100% local |
Get the local risk audit kit
Basic Kit
- Python CLI (standard library only)
- Local HTTP API server
- JSON output mode
- CI exit code (high risk = 1)
- GitHub Actions workflow template
- Test suite (11 tests)
- Commercial license
Gumroad checkout includes hosted file delivery. PayPal fallback available.
Pro Pack
- Everything in Basic, plus:
- Multi-repo batch audit
- Agency client review checklist
- Pre-commit hook template
- Slack / Teams webhook integration
- Multi-repo GitHub Actions template
- Priority email support
Gumroad checkout includes hosted file delivery. PayPal fallback available.
Free resources
FAQ: Claude Code diff review
- Does this only work with Claude Code?
- No. It works with any unified diff format — Claude Code, Cursor, Codex, Copilot agents, or manual edits. Claude Code is one of the most popular AI coding agents, so this page focuses on it, but the tool is agent-agnostic.
- Does it send my code to Claude or any cloud service?
- No. The audit runs entirely on your machine with standard-library Python. No network calls, no API keys, no cloud upload. The
--servemode binds to localhost only. - How is this different from Claude Code's built-in security review?
- Claude Code's security review is a suggestion feature inside the Claude IDE. This is an independent, local CLI that gives you an explicit risk score, flags, and CI exit code — you don't need to trust any AI provider with your diff. It complements Claude's review rather than replacing it.
- What about false positives?
- The tool uses pattern matching, so test fixtures may trigger "secret" flags and generated filenames may trigger "generated" flags. Use it as a triage signal to prioritize human review, not as ground truth. The full FAQ & objection handler has more detail.
- Can I use it in CI?
- Yes. The CLI returns exit code 1 on high-risk diffs. Add it as a step in any CI pipeline — GitHub Actions, GitLab CI, Bitbucket, or a pre-commit hook. The Pro Pack includes multi-repo GitHub Actions templates.
Compliance note
This tool does not guarantee security, revenue, or bug-free software. It is a local review aid that helps prioritize human review of AI-agent diffs. False positives are possible. Always run your own tests and security scans.