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- 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)
How to use seo-drift
- 1.Run `/seo drift baseline <url>` to capture the current SEO state as a known-good snapshot
- 2.Make changes to your site (deploy, update content, etc.)
- 3.Run `/seo drift compare <url>` to fetch the current state and diff it against the stored baseline
- 4.Review the JSON output showing triggered rules, severity levels, and old vs. new values
- 5.Optionally run `/seo drift history <url>` to see all past baselines and comparisons for the URL
- 6.Use cross-skill recommendations in the output (e.g., run `/seo schema` if schema changed, `/seo technical` if CWV regressed)
Use cases
- 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
- 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
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.
Yes, use the `--baseline-id` flag with the compare command to specify which baseline to compare against.
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.
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.
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
| Command | Purpose |
|---|---|
/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:
| Element | Field | Source |
|---|---|---|
| Title tag | title | parse_html.py |
| Meta description | meta_description | parse_html.py |
| Canonical URL | canonical | parse_html.py |
| Robots directives | meta_robots | parse_html.py |
| H1 headings | h1 (array) | parse_html.py |
| H2 headings | h2 (array) | parse_html.py |
| H3 headings | h3 (array) | parse_html.py |
| JSON-LD schema | schema (array) | parse_html.py |
| Open Graph tags | open_graph (dict) | parse_html.py |
| Core Web Vitals | cwv (dict) | pagespeed_check.py |
| HTTP status code | status_code | fetch_page.py |
| HTML content hash | html_hash (SHA-256) | Computed |
| Schema content hash | schema_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
| Level | Meaning | Response Time |
|---|---|---|
| CRITICAL | SEO-breaking change, likely traffic loss | Immediate |
| WARNING | Potential impact, needs investigation | Within 1 week |
| INFO | Awareness only, may be intentional | Review 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:
- Validate URL (SSRF protection via
google_auth.validate_url()) - Fetch page via
scripts/fetch_page.py - Parse HTML via
scripts/parse_html.py - Optionally fetch CWV via
scripts/pagespeed_check.py(use--skip-cwvto skip) - Hash HTML body and schema content (SHA-256)
- 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:
- Validate URL
- Load most recent baseline from SQLite (or specific
--baseline-id) - Fetch and parse current page state
- Run all 17 comparison rules
- Classify findings by severity
- Store comparison result
- 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:
| Finding | Recommendation |
|---|---|
| Schema removed or modified | Run /seo schema <url> for full validation |
| CWV regression | Run /seo technical <url> for performance audit |
| Title or meta description changed | Run /seo page <url> for content analysis |
| Canonical changed or removed | Run /seo technical <url> for indexability check |
| Noindex added | Run /seo technical <url> for crawlability audit |
| H1/heading structure changed | Run /seo content <url> for E-E-A-T review |
| OG tags removed | Run /seo page <url> for social sharing analysis |
| Status code changed to error | Run /seo technical <url> for full diagnostics |
Error Handling
| Scenario | Action |
|---|---|
| URL unreachable | Report error from fetch_page.py. Do not guess state. Suggest user verify URL. |
| No baseline exists for URL | Inform user and suggest running baseline first. |
| SSRF blocked (private IP) | Report validate_url() rejection. Never bypass. |
| SQLite database missing | Auto-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/5xx | Still capture as baseline (status code IS a tracked field). |
| Multiple baselines exist | Use most recent unless --baseline-id specified. |
Security
- All URL fetching goes through
scripts/fetch_page.pywhich 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=Falseanywhere 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?
Related skills
More from agricidaniel/claude-seo and the wider catalog.

seo-ecommerce
Analyze product pages, Google Shopping visibility, and marketplace SEO with schema validation and competitor pricing.

seo-flow
Evidence-led SEO using the FLOW framework — Find, Leverage, Optimize, Win with 41 structured AI prompts.

seo-geo
Optimize content for AI search engines (Google AI Overviews, ChatGPT, Perplexity) with citability scoring and platform-specific analysis.

seo-google
Access Google's real SEO data: Search Console, PageSpeed, CrUX field metrics, GA4 organic traffic, and Indexing API.

seo-hreflang
Audit, validate, and generate hreflang tags for multi-language and multi-region SEO.

seo-image-gen
Generate SEO-optimized images (OG, hero, product, infographics) powered by Gemini via banana MCP.