/seo-drift

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-invokable: true
argument-hint: "baseline|compare|history <url>"
license: MIT
metadata:
  author: AgriciDaniel
  original_author: "Dan Colta (Pro Hub Challenge)"
  version: "1.9.6"
  category: seo

SEO Drift Monitor (April 2026)

Shared Data Cache

**Step 0 -- Check shared data cache:**

Before gathering, check `.seo-cache/` for reusable context from related SEO skills. Reference: `../seo/references/shared-data-cache.md` for schemas and dependency map.

Check these cache files when present:

• `.seo-cache/site-meta.json` for domain, business type, industry, and crawl context
• `.seo-cache/audit-scores.json` for prior full-audit priorities
• `.seo-cache/pages/{url-slug}/page-analysis.json` for page-level context when a URL is provided

• If found: parse and use clearly valid fields (note "Using cached [X] from [date]")
• If missing, corrupt, or irrelevant: continue with fresh evidence
• If the user says "refresh" or "re-run": ignore cache reads and overwrite on write

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/codex-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:**

python scripts/drift_baseline.py <url>
python 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:**

python scripts/drift_compare.py <url>
python scripts/drift_compare.py <url> --baseline-id 5
python 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:

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

---

Command: `history`

Shows all baselines and comparisons for a URL.

**Execution:**

python scripts/drift_history.py <url>
python 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 d