analyzing-dependabot

name	analyzing-dependabot
description	Use when working with Dependabot — dependabot and Renovate dependency update management. Covers vulnerability alerts, dependency update PRs, auto-merge configuration, version pinning, update scheduling, and security advisory tracking. Use when managing dependency updates, reviewing vulnerability alerts, configuring auto-merge policies, or auditing dependency health.
connection_type	dependabot
preload	false

Dependabot/Renovate Dependency Analysis Skill

Manage and analyze dependency updates, vulnerability alerts, and auto-merge configurations.

MANDATORY: Discovery-First Pattern

Always check current configuration and alert status before modifying update policies.

Phase 1: Discovery

#!/bin/bash

echo "=== Dependabot Configuration ==="
cat .github/dependabot.yml 2>/dev/null || cat .github/dependabot.yaml 2>/dev/null || echo "No Dependabot config found"

echo ""
echo "=== Renovate Configuration ==="
cat renovate.json 2>/dev/null || cat .renovaterc 2>/dev/null || cat .renovaterc.json 2>/dev/null || echo "No Renovate config found"

echo ""
echo "=== Dependency Files Detected ==="
find . -maxdepth 3 \( \
    -name "package.json" -o -name "package-lock.json" -o \
    -name "requirements.txt" -o -name "Pipfile" -o \
    -name "go.mod" -o -name "Gemfile" -o \
    -name "pom.xml" -o -name "build.gradle" -o \
    -name "Cargo.toml" -o -name "composer.json" \
\) -not -path "*/node_modules/*" 2>/dev/null | head -15

echo ""
echo "=== Open Dependency PRs ==="
gh pr list --label dependencies 2>/dev/null | head -10 || \
gh pr list --search "author:dependabot" 2>/dev/null | head -10

Core Helper Functions

#!/bin/bash

# GitHub API for Dependabot
gh_dependabot() {
    local endpoint="$1"
    gh api "$endpoint" 2>/dev/null
}

# List vulnerability alerts
gh_alerts() {
    local repo="${1:?Repo required (owner/name)}"
    gh api "repos/${repo}/dependabot/alerts?state=open&sort=created&direction=desc" 2>/dev/null
}

# Renovate API (self-hosted)
renovate_api() {
    local endpoint="$1"
    curl -s -H "Authorization: Bearer $RENOVATE_TOKEN" \
        "${RENOVATE_URL}/api/${endpoint}" 2>/dev/null
}

Output Rules

• TOKEN EFFICIENCY: Target <=50 lines per output
• Use GitHub API with jq for structured alert data
• Group alerts by severity and ecosystem
• Never dump full advisory details -- extract key fields

Common Operations

Vulnerability Alerts

#!/bin/bash
REPO="${1:?Repository required (owner/name)}"

echo "=== Open Vulnerability Alerts ==="
gh api "repos/${REPO}/dependabot/alerts?state=open&sort=created&direction=desc&per_page=30" 2>/dev/null | jq '{
    total_open: length,
    by_severity: (group_by(.security_advisory.severity) | map({
        severity: .[0].security_advisory.severity,
        count: length
    })),
    by_ecosystem: (group_by(.dependency.package.ecosystem) | map({
        ecosystem: .[0].dependency.package.ecosystem,
        count: length
    })),
    top_alerts: [.[:10][] | {
        number: .number,
        severity: .security_advisory.severity,
        package: .dependency.package.name,
        ecosystem: .dependency.package.ecosystem,
        vulnerable_range: .security_vulnerability.vulnerable_version_range,
        fixed_version: .security_vulnerability.first_patched_version.identifier,
        summary: .security_advisory.summary
    }]
}'

Dependency Update PRs

#!/bin/bash
REPO="${1:?Repository required (owner/name)}"

echo "=== Open Dependency PRs ==="
gh pr list --repo "$REPO" --search "author:dependabot OR author:renovate" --json number,title,createdAt,labels --limit 20 2>/dev/null | jq '[.[] | {
    number: .number,
    title: .title,
    created: .createdAt,
    labels: [.labels[].name]
}]'

echo ""
echo "=== PR Age Distribution ==="
gh pr list --repo "$REPO" --search "author:dependabot OR author:renovate" --json number,title,createdAt --limit 50 2>/dev/null | jq '
    [.[] | {
        number: .number,
        title: .title[:50],
        age_days: ((now - (.createdAt | fromdateiso8601)) / 86400 | floor)
    }] | sort_by(-.age_days) | .[0:10]
'

Auto-Merge Configuration

#!/bin/bash
echo "=== Dependabot Auto-Merge Config ==="
cat .github/dependabot.yml 2>/dev/null | head -30

echo ""
echo "=== GitHub Actions Auto-Merge Workflow ==="
cat .github/workflows/dependabot-auto-merge.yml 2>/dev/null || \
cat .github/workflows/auto-merge.yml 2>/dev/null || \
echo "No auto-merge workflow found"

echo ""
echo "=== Renovate Auto-Merge Config ==="
cat renovate.json 2>/dev/null | jq '{
    automerge: .automerge,
    automergeType: .automergeType,
    packageRules: [.packageRules[]? | select(.automerge != null) | {
        matchPackagePatterns: .matchPackagePatterns,
        matchUpdateTypes: .matchUpdateTypes,
        automerge: .automerge
    }]
}' 2>/dev/null

Security Advisory Tracking

#!/bin/bash
REPO="${1:?Repository required (owner/name)}"

echo "=== Critical/High Alerts Requiring Action ==="
gh api "repos/${REPO}/dependabot/alerts?state=open&severity=critical,high&per_page=20" 2>/dev/null | jq '[.[] | {
    number: .number,
    package: .dependency.package.name,
    severity: .security_advisory.severity,
    cvss: .security_advisory.cvss.score,
    cve: .security_advisory.cve_id,
    fix_available: (.security_vulnerability.first_patched_version != null),
    fix_version: .security_vulnerability.first_patched_version.identifier,
    manifest: .dependency.manifest_path
}]'

echo ""
echo "=== Alert Dismissal History ==="
gh api "repos/${REPO}/dependabot/alerts?state=dismissed&per_page=10" 2>/dev/null | jq '[.[] | {
    package: .dependency.package.name,
    severity: .security_advisory.severity,
    dismissed_reason: .dismissed_reason,
    dismissed_by: .dismissed_by.login
}]'

Dependency Health Overview

#!/bin/bash
echo "=== Dependency File Analysis ==="
for dep_file in $(find . -maxdepth 3 \( -name "package.json" -o -name "requirements.txt" -o -name "go.mod" -o -name "Gemfile" \) -not -path "*/node_modules/*" 2>/dev/null | head -5); do
    echo "--- $dep_file ---"
    case "$dep_file" in
        */package.json) jq '.dependencies // {} | length' "$dep_file" 2>/dev/null | xargs -I{} echo "  Dependencies: {}" ;;
        */requirements.txt) wc -l < "$dep_file" 2>/dev/null | xargs -I{} echo "  Packages: {}" ;;
        */go.mod) grep -c 'require' "$dep_file" 2>/dev/null | xargs -I{} echo "  Modules: {}" ;;
        */Gemfile) grep -c 'gem ' "$dep_file" 2>/dev/null | xargs -I{} echo "  Gems: {}" ;;
    esac
done

echo ""
echo "=== Update Schedule ==="
cat .github/dependabot.yml 2>/dev/null | grep -A2 'schedule' | head -10

Safety Rules

• Review all dependency update PRs before merging -- even minor updates can introduce breaking changes
• Auto-merge only for patch versions with passing CI -- never auto-merge major version bumps
• Vulnerability alerts should be prioritized by severity and exploitability
• Dismissing alerts requires justification -- document why in the dismissal reason
• Lock file updates should be tested in CI before merging

Output Format

Present results as a structured report:

Analyzing Dependabot Report
═══════════════════════════
Resources discovered: [count]

Resource       Status    Key Metric    Issues
──────────────────────────────────────────────
[name]         [ok/warn] [value]       [findings]

Summary: [total] resources | [ok] healthy | [warn] warnings | [crit] critical
Action Items: [list of prioritized findings]

Target ≤50 lines of output. Use tables for multi-resource comparisons.

Anti-Hallucination Rules

1. NEVER assume resource names — always discover via CLI/API in Phase 1 before referencing in Phase 2.
2. NEVER fabricate metric names or dimensions — verify against the service documentation or --help output.
3. NEVER mix CLI commands between service versions — confirm which version/API you are targeting.
4. ALWAYS use the discovery → verify → analyze chain — every resource referenced must have been discovered first.
5. ALWAYS handle empty results gracefully — an empty response is valid data, not an error to retry.

Counter-Rationalizations

Shortcut	Counter	Why
"I'll skip discovery and check known resources"	Always run Phase 1 discovery first	Resource names change, new resources appear — assumed names cause errors
"The user only asked for a quick check"	Follow the full discovery → analysis flow	Quick checks miss critical issues; structured analysis catches silent failures
"Default configuration is probably fine"	Audit configuration explicitly	Defaults often leave logging, security, and optimization features disabled
"Metrics aren't needed for this"	Always check relevant metrics when available	API/CLI responses show current state; metrics reveal trends and intermittent issues
"I don't have access to that"	Try the command and report the actual error	Assumed permission failures prevent useful investigation; actual errors are informative

Common Pitfalls

• Transitive dependencies: Vulnerability may be in a transitive dependency -- updating direct dependency may not fix it
• Breaking changes in minor versions: Semver violations are common -- always run tests after updates
• Rate limiting: Too many open PRs can overwhelm CI systems -- configure PR limits
• Rebase conflicts: Dependency PRs frequently conflict with each other -- merge incrementally
• Private registries: Dependabot/Renovate need credentials for private registries -- configure secrets
• Monorepo handling: Multiple dependency files may need coordinated updates -- use groups
• Auto-merge security: Auto-merging without CI checks can introduce vulnerabilities or broken code
• Version constraints: Overly tight version constraints prevent security updates -- use ranges appropriately