semgreplisted
Install: claude install-skill backspace-shmackspace/claude-devkit
# Semgrep Security Scan
Run a Semgrep scan with automatic language detection, parallel execution across language groups, and merged SARIF output.
## Essential Principles
1. **Always use `--metrics=off`** — Semgrep sends telemetry by default; `--config auto` also phones home. Every `semgrep` command must include `--metrics=off` to prevent data leakage during security audits.
2. **User must approve the scan plan (Step 3 is a hard gate)** — The original "scan this codebase" request is NOT approval. Present exact rulesets, target, engine, and mode; wait for explicit "yes"/"proceed" before running scanners.
3. **Third-party rulesets are required, not optional** — Trail of Bits, 0xdea, and Decurity rules catch vulnerabilities absent from the official registry. Include them whenever the detected language matches.
4. **Run all scan workers in parallel** — Parallel execution is the core performance advantage. Do not run language scans strictly one-after-another when independence allows overlap.
5. **Always check for Semgrep Pro before scanning** — Pro enables cross-file taint tracking and catches ~250% more true positives. Skipping the check means silently missing critical inter-file vulnerabilities.
## When to Use
- Security audit of a codebase
- Finding vulnerabilities before code review
- Scanning for known bug patterns
- First-pass static analysis
## When NOT to Use
- Binary analysis → Use binary analysis tools
- Already have Semgrep CI configured → Use existing pipeline
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