Gitleaks

gitleaks Agent Skill

When to Use This Skill

Use this skill when:

• Auditing a git repository for leaked secrets, tokens, or credentials
• Setting up a pre-commit hook to prevent secrets from being committed
• Integrating secret scanning into GitHub Actions, GitLab CI, or other pipelines
• Writing custom detection rules for organization-specific secret formats
• The user asks about gitleaks, secret scanning, or credential leakage in git
• Reducing false positives via allowlists or baseline files
• Scanning a specific commit range, branch, or PR diff

What Gitleaks Does

Gitleaks scans git repository history (all commits, branches, tags) or staged/unstaged changes for patterns matching known secret formats — AWS keys, GitHub tokens, private keys, generic high-entropy strings, and hundreds of other types. It uses a TOML-based rule engine where each rule is a named regex with optional entropy, keyword, and allowlist conditions. Results are reported to stdout and optionally written to JSON, CSV, or SARIF files for integration with SIEM, DAST pipelines, or code-review tooling.

Installation

Homebrew (macOS/Linux)

brew install gitleaks

Go install

go install github.com/gitleaks/gitleaks/v8@latest

Binary release

VERSION=8.21.2
curl -sSL https://github.com/gitleaks/gitleaks/releases/download/v${VERSION}/gitleaks_${VERSION}_linux_x64.tar.gz \
  | tar -xz gitleaks && chmod +x gitleaks && sudo mv gitleaks /usr/local/bin/

Docker

docker pull zricethezav/gitleaks:latest
docker run --rm -v $(pwd):/repo zricethezav/gitleaks:latest detect --source /repo

Kali / Debian

# Not in default repos — use Go install or binary release above

Core Concepts

Two Primary Commands

• detect: scan a git repository (local or remote) for secrets in history and working tree
• protect: scan staged changes before commit (pre-commit hook mode)

Rule Engine

Each rule in .gitleaks.toml defines:

• id — unique rule identifier
• description — human-readable name
• regex — the detection pattern (applied to file content or git diff)
• entropy (optional) — minimum Shannon entropy threshold (0.0–8.0) to reduce false positives
• keywords — fast pre-filter strings (checked before regex for performance)
• allowlist — per-rule exceptions (regex on commit, path, or secret value)

Default Rules

Gitleaks ships with ~160 built-in rules covering: AWS access keys, secret keys, session tokens · GitHub/GitLab/Bitbucket tokens · Stripe, Twilio, SendGrid, Slack keys · JWT tokens · Private keys (RSA, EC, PGP) · Google API keys · Azure credentials · Generic high-entropy strings

CLI Reference

detect — scan a local repo

# Scan entire git history of current directory
gitleaks detect --source .

# Scan a specific directory
gitleaks detect --source /path/to/repo

# Scan only the last 30 commits
gitleaks detect --source . --log-opts="--since='30 days ago'"

# Scan a specific commit range
gitleaks detect --source . --log-opts="abc123..HEAD"

# Scan a specific branch
gitleaks detect --source . --log-opts="main..feature-branch"

# Include unstaged/untracked files (working tree scan)
gitleaks detect --source . --no-git

# Scan without git history (plain directory/file tree)
gitleaks detect --no-git --source /path/to/dir

# Verbose output
gitleaks detect --source . --verbose

# Exit code: 0 = no leaks, 1 = leaks found, 126 = error

detect — output formats

# JSON report
gitleaks detect --source . --report-format json --report-path leaks.json

# CSV report
gitleaks detect --source . --report-format csv --report-path leaks.csv

# SARIF (for GitHub Code Scanning / security dashboards)
gitleaks detect --source . --report-format sarif --report-path leaks.sarif

# Pretty print to stdout only (default)
gitleaks detect --source .

detect — remote repos

# Scan a GitHub repo directly (clones to temp dir)
gitleaks detect --source https://github.com/org/repo --verbose

# With GitHub token (avoids rate limits, access private repos)
GITHUB_TOKEN=ghp_xxx gitleaks detect --source https://github.com/org/repo

protect — pre-commit mode

# Scan staged changes (run before git commit)
gitleaks protect --staged

# Scan unstaged changes
gitleaks protect

# Verbose
gitleaks protect --staged --verbose

# Exit code: 0 = clean, 1 = secrets found (blocks commit when used as hook)

baseline — suppress known findings

# Generate a baseline from current findings (existing known secrets)
gitleaks detect --source . --report-format json --report-path baseline.json

# Future scans: only report NEW findings not in baseline
gitleaks detect --source . --baseline-path baseline.json

Config file selection

# Use a specific config file
gitleaks detect --source . --config /path/to/.gitleaks.toml

# Gitleaks searches for config in this order:
# 1. --config flag
# 2. GITLEAKS_CONFIG env var
# 3. .gitleaks.toml in repo root
# 4. ~/.config/gitleaks/config.toml
# 5. Built-in default rules

.gitleaks.toml Configuration

Full structure

title = "My Gitleaks Config"

[extend]
# Inherit built-in rules and add your own
useDefault = true

[allowlist]
description = "Global allowlist"
commits = ["abc123deadbeef"]   # Ignore specific commits
paths   = ['''(?i)test''']     # Ignore paths matching regex
regexes = ['''EXAMPLE_KEY''']  # Ignore secrets matching regex

[[rules]]
id          = "my-internal-api-key"
description = "Internal API Key"
regex       = '''MYCO-[A-Z0-9]{32}'''
entropy     = 3.5
keywords    = ["MYCO-"]

  [rules.allowlist]
  description = "Allow test fixtures"
  paths       = ['''(?i)(test|fixture|mock|fake)''']
  regexes     = ['''MYCO-TESTKEY00000000000000000000''']

[[rules]]
id          = "slack-webhook"
description = "Slack Incoming Webhook"
regex       = '''https://hooks\.slack\.com/services/T[A-Z0-9]+/B[A-Z0-9]+/[A-Za-z0-9]+'''
keywords    = ["hooks.slack.com"]

Extend-only (add rules without losing defaults)

title = "Org Config"

[extend]
useDefault = true

[[rules]]
id      = "internal-jwt-secret"
description = "Internal JWT signing key prefix"
regex   = '''jwt_secret\s*=\s*["']?[A-Za-z0-9+/]{40,}'''
entropy = 4.0
keywords = ["jwt_secret"]

Suppress a noisy built-in rule

[extend]
useDefault = true

# Override a specific rule by re-defining it with a no-match regex
# or add its ID to an allowlist at the rule level
[allowlist]
rules = ["generic-api-key"]   # Disable a built-in rule by ID

Custom Rules: Writing Patterns

High-entropy generic string

[[rules]]
id          = "high-entropy-env-var"
description = "High entropy value assigned in env"
regex       = '''(?i)(api_key|secret|token|password)\s*=\s*["']?([A-Za-z0-9+/=!@#$%^&*]{20,})'''
entropy     = 4.5
keywords    = ["api_key", "secret", "token", "password"]

Private key block

[[rules]]
id          = "pem-private-key"
description = "PEM Private Key"
regex       = '''-----BEGIN (RSA |EC |DSA |OPENSSH )?PRIVATE KEY-----'''
keywords    = ["BEGIN", "PRIVATE KEY"]

AWS-style pattern (already in defaults, shown for reference)

[[rules]]
id      = "aws-access-key"
description = "AWS Access Key"
regex   = '''(A3T[A-Z0-9]|AKIA|AGPA|AIDA|AROA|AIPA|ANPA|ANVA|ASIA)[A-Z0-9]{16}'''
keywords = ["AKIA", "ASIA"]

CI/CD Integration

GitHub Actions

name: Secret Scan
on: [push, pull_request]
jobs:
  gitleaks:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0          # Full history required

      - name: Run Gitleaks
        uses: gitleaks/gitleaks-action@v2
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          # GITLEAKS_LICENSE required for organizations (free for public repos)
          GITLEAKS_ENABLE_COMMENTS: true    # Post PR comments on findings

GitHub Actions (binary, more control)

      - name: Install Gitleaks
        run: |
          curl -sSL https://github.com/gitleaks/gitleaks/releases/download/v8.21.2/gitleaks_8.21.2_linux_x64.tar.gz \
            | tar -xz && chmod +x gitleaks && sudo mv gitleaks /usr/local/bin/

      - name: Scan
        run: gitleaks detect --source . --report-format sarif --report-path gitleaks.sarif || true

      - name: Upload SARIF
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: gitleaks.sarif

GitLab CI

gitleaks:
  image: zricethezav/gitleaks:latest
  stage: test
  script:
    - gitleaks detect --source . --report-format json --report-path gl-secret-detection-report.json
  artifacts:
    reports:
      secret_detection: gl-secret-detection-report.json
    when: always

Pre-commit Hook (local enforcement)

# Method 1: gitleaks protect as git hook
cat > .git/hooks/pre-commit /dev/null
  done

Merge all JSON reports

jq -s '[.[] | .[]]' reports/*.json > all-findings.json
jq 'group_by(.RuleID) | map({rule: .[0].RuleID, count: length})' all-findings.json

Find secrets in Docker image layers

# Save image layers as tar, mount and scan
docker save myimage:latest -o image.tar
mkdir image-fs && tar -xf image.tar -C image-fs
gitleaks detect --no-git --source image-fs/

Troubleshooting

| Problem | Cause | Fix | |---|---|---| | No config file found warning | No .gitleaks.toml in repo | Create one or pass --config | | Too many false positives | Overly broad rules | Add allowlist regexes or raise entropy threshold | | fatal: bad object log-opts error | Invalid commit ref | Verify the commit hash exists | | Slow scan on large repos | Massive history | Limit with --log-opts="-500" for initial run | | Docker permission denied | Volume mount | Use --user $(id -u):$(id -g) with Docker | | pre-commit hook not triggering | Hook not executable | chmod +x .git/hooks/pre-commit | | Baseline not suppressing findings | Baseline generated from different scan | Regenerate baseline with same config | ---

> Built by Red Hound InfoSec — On-demand offensive security expertise for SMBs. > 20+ years of Fortune 500 experience. Penetration testing, attack surface analysis, and security consulting. > > redhound.us | GitHub | Book a consultation

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: jph4cks
• Source: jph4cks/redhound-arsenal
• License: MIT
• Homepage: https://redhound.us

Install and usage instructions live in the source repository linked above.