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seo-drift

agricidaniel/claude-seo

Capture SEO baselines, detect regressions, and track on-page changes over time.

What is seo-drift?

SEO Drift Monitor acts as version control for your SEO, letting you capture snapshots of critical on-page elements (titles, meta descriptions, headings, schema, Core Web Vitals) and compare them over time to detect regressions. Use it before and after deployments, during ongoing monitoring, or when investigating unexpected traffic changes.

  • Capture baseline snapshots of 13 SEO-critical elements including titles, meta descriptions, headings, schema, Open Graph tags, and Core Web Vitals
  • Compare current page state against stored baselines using 17 rules across 3 severity levels (CRITICAL, WARNING, INFO)
  • Track change history with timestamps and past comparison results for any URL
  • Generate HTML drift reports showing old vs. new values and recommended actions
  • Validate URLs with SSRF protection and store all data locally in SQLite

How to install seo-drift

npx skills add https://github.com/agricidaniel/claude-seo --skill seo-drift
Prerequisites
  • Python 3.7+
  • SQLite (auto-created on first use at ~/.cache/claude-seo/drift/baselines.db)
  • Internet access to fetch pages and optionally Google PageSpeed Insights API key for Core Web Vitals (optional; CWV skipped if unavailable)
Claude Code
Cursor
Windsurf
Cline

How to use seo-drift

  1. 1.Run `/seo drift baseline <url>` to capture the current SEO state as a known-good snapshot
  2. 2.Make changes to your site (deploy, update content, etc.)
  3. 3.Run `/seo drift compare <url>` to fetch the current state and diff it against the stored baseline
  4. 4.Review the JSON output showing triggered rules, severity levels, and old vs. new values
  5. 5.Optionally run `/seo drift history <url>` to see all past baselines and comparisons for the URL
  6. 6.Use cross-skill recommendations in the output (e.g., run `/seo schema` if schema changed, `/seo technical` if CWV regressed)

Use cases

Good for
  • Pre- and post-deployment SEO checks to catch breaking changes before they impact traffic
  • Ongoing monitoring to detect unintended SEO regressions weeks or months after changes
  • Investigating traffic drops by comparing current page state to historical baselines
  • Auditing schema, heading structure, or meta tag changes across site updates
  • Tracking Core Web Vitals regressions and their correlation with SEO element changes
Who it's for
  • SEO specialists and content managers monitoring site health
  • DevOps and deployment engineers verifying SEO integrity in CI/CD pipelines
  • Site owners investigating unexpected traffic or ranking changes
  • Technical SEO auditors tracking changes across multiple deployments

seo-drift FAQ

What happens if I don't have a baseline for a URL?

The compare command will inform you that no baseline exists and suggest running `baseline` first. You must capture a baseline before you can detect drift.

Can I compare against a specific older baseline instead of the most recent one?

Yes, use the `--baseline-id` flag with the compare command to specify which baseline to compare against.

What if Core Web Vitals data is unavailable?

If the Google PageSpeed Insights API key is missing or the fetch fails, CWV fields are stored as null and CWV-related comparison rules are skipped. Use `--skip-cwv` to skip the fetch entirely.

How does URL normalization work?

URLs are normalized by converting the scheme and host to lowercase, stripping default ports (80/443), sorting query parameters, removing UTM parameters, and removing trailing slashes to ensure consistent matching across baselines.

Is my data stored securely?

All data is stored locally in SQLite at ~/.cache/claude-seo/drift/baselines.db. All URL fetching uses SSRF-protected pipelines, SQLite queries use parameterized placeholders, and TLS is always verified.

Full instructions (SKILL.md)

Source of truth, from agricidaniel/claude-seo.


name: seo-drift description: > SEO drift monitoring: capture baselines of SEO-critical elements, detect changes, and track regressions over time. Git for SEO — baseline, diff, and track changes to your on-page SEO. Use when user says "SEO drift", "baseline", "track changes", "did anything break", "SEO regression", "compare SEO", "before and after", "monitor SEO changes", or "deployment check". user-invocable: true argument-hint: "baseline|compare|history <url>" license: MIT metadata: author: AgriciDaniel original_author: "Dan Colta (Pro Hub Challenge)" version: "2.2.0" category: seo

SEO Drift Monitor (April 2026)

Git for your SEO. Capture baselines, detect regressions, track changes over time.


Commands

CommandPurpose
/seo drift baseline <url>Capture current SEO state as a "known good" snapshot
/seo drift compare <url>Compare current page state to stored baseline
/seo drift history <url>Show change history and past comparisons

What It Captures

Every baseline records these SEO-critical elements:

ElementFieldSource
Title tagtitleparse_html.py
Meta descriptionmeta_descriptionparse_html.py
Canonical URLcanonicalparse_html.py
Robots directivesmeta_robotsparse_html.py
H1 headingsh1 (array)parse_html.py
H2 headingsh2 (array)parse_html.py
H3 headingsh3 (array)parse_html.py
JSON-LD schemaschema (array)parse_html.py
Open Graph tagsopen_graph (dict)parse_html.py
Core Web Vitalscwv (dict)pagespeed_check.py
HTTP status codestatus_codefetch_page.py
HTML content hashhtml_hash (SHA-256)Computed
Schema content hashschema_hash (SHA-256)Computed

How Comparison Works

The comparison engine applies 17 rules across 3 severity levels. Load references/comparison-rules.md for the full rule set with thresholds, recommended actions, and cross-skill references.

Severity Levels

LevelMeaningResponse Time
CRITICALSEO-breaking change, likely traffic lossImmediate
WARNINGPotential impact, needs investigationWithin 1 week
INFOAwareness only, may be intentionalReview at convenience

Storage

All data is stored locally in SQLite:

~/.cache/claude-seo/drift/baselines.db

Tables

  • baselines: Captured snapshots with all SEO elements
  • comparisons: Diff results with triggered rules and severities

URL normalization ensures consistent matching: lowercase scheme/host, strip default ports (80/443), sort query parameters, remove UTM parameters, strip trailing slashes.


Command: baseline

Captures the current state of a page and stores it.

Steps:

  1. Validate URL (SSRF protection via google_auth.validate_url())
  2. Fetch page via scripts/fetch_page.py
  3. Parse HTML via scripts/parse_html.py
  4. Optionally fetch CWV via scripts/pagespeed_check.py (use --skip-cwv to skip)
  5. Hash HTML body and schema content (SHA-256)
  6. Store snapshot in SQLite

Execution:

python3 scripts/drift_baseline.py <url>
python3 scripts/drift_baseline.py <url> --skip-cwv

Output: JSON with baseline ID, timestamp, URL, and summary of captured elements.


Command: compare

Fetches the current page state and diffs it against the most recent baseline.

Steps:

  1. Validate URL
  2. Load most recent baseline from SQLite (or specific --baseline-id)
  3. Fetch and parse current page state
  4. Run all 17 comparison rules
  5. Classify findings by severity
  6. Store comparison result
  7. Output JSON diff report

Execution:

python3 scripts/drift_compare.py <url>
python3 scripts/drift_compare.py <url> --baseline-id 5
python3 scripts/drift_compare.py <url> --skip-cwv

Output: JSON with all triggered rules, old/new values, severity, and actions.

After comparison, offer to generate an HTML report:

python3 scripts/drift_report.py <comparison_json_file> --output drift-report.html

Command: history

Shows all baselines and comparisons for a URL.

Execution:

python3 scripts/drift_history.py <url>
python3 scripts/drift_history.py <url> --limit 10

Output: JSON array of baselines (newest first) with timestamps and comparison summaries.


Cross-Skill Integration

When drift is detected, recommend the appropriate specialized skill:

FindingRecommendation
Schema removed or modifiedRun /seo schema <url> for full validation
CWV regressionRun /seo technical <url> for performance audit
Title or meta description changedRun /seo page <url> for content analysis
Canonical changed or removedRun /seo technical <url> for indexability check
Noindex addedRun /seo technical <url> for crawlability audit
H1/heading structure changedRun /seo content <url> for E-E-A-T review
OG tags removedRun /seo page <url> for social sharing analysis
Status code changed to errorRun /seo technical <url> for full diagnostics

Error Handling

ScenarioAction
URL unreachableReport error from fetch_page.py. Do not guess state. Suggest user verify URL.
No baseline exists for URLInform user and suggest running baseline first.
SSRF blocked (private IP)Report validate_url() rejection. Never bypass.
SQLite database missingAuto-create on first use. No error.
CWV fetch fails (no API key)Store null for CWV fields. Skip CWV rules during comparison.
Page returns 4xx/5xxStill capture as baseline (status code IS a tracked field).
Multiple baselines existUse most recent unless --baseline-id specified.

Security

  • All URL fetching goes through scripts/fetch_page.py which enforces SSRF protection (blocks private IPs, loopback, reserved ranges, GCP metadata endpoints)
  • No curl, no subprocess HTTP calls -- only the project's validated fetch pipeline
  • All SQLite queries use parameterized placeholders (?), never string interpolation
  • TLS always verified -- no verify=False anywhere in the pipeline

Typical Workflows

Pre/Post Deployment Check

/seo drift baseline https://example.com     # Before deploy
# ... deploy happens ...
/seo drift compare https://example.com      # After deploy

Ongoing Monitoring

/seo drift baseline https://example.com     # Initial capture
# ... weeks later ...
/seo drift compare https://example.com      # Check for drift
/seo drift history https://example.com      # Review all changes

Investigating a Traffic Drop

/seo drift compare https://example.com      # What changed?
/seo drift history https://example.com      # When did it change?