| name | seo-drift |
| description | Capture an SEO baseline snapshot for a domain or URL, then on later runs compare the current state and surface regressions. Tracks authority, traffic, keywords, backlinks, and on-page content. Three subcommands — `baseline`, `compare`, `history`. Use when the user asks for "SEO drift", "baseline this site", "did anything break", "SEO regression check", "compare before and after", "deployment check", or "monthly SEO snapshot". |
Example output: examples/seo-drift-wix-com-20260514/compare/DRIFT-REPORT.md
SEO Drift
Git for SEO. Capture a snapshot of a domain or URL's SEO state ("baseline"), then on later runs diff the current state against the baseline and surface regressions. Catches the things that get worse silently after a deploy, redesign, or content cull.
Acknowledgements: drift-as-an-SEO-skill framework originated in claude-seo by AgriciDaniel (with the original concept credited to Dan Colta, Pro Hub Challenge). MIT-licensed both directions; this implementation is independent but the framing is theirs.
Prerequisites
- SE Ranking MCP server connected.
- Claude's
WebFetch tool available (for URL-mode page fingerprinting).
- User provides: target domain or URL, plus a subcommand (
baseline, compare, history).
Optional flags
| Flag | Mode | Effect |
|---|
--no-firecrawl | baseline, compare | Skip Firecrawl-based <head> + JSON-LD capture even when Firecrawl is installed (saves credits at the cost of canonical / robots / og:* / JSON-LD diff coverage). |
--skip-cwv | baseline, compare | Skip the Google CrUX capture (step 4b) even when google-api.json is configured. Useful when you only care about content/structural drift, or when CrUX rate-limit concerns outweigh CWV coverage. Mirrors theirs at seo-drift/SKILL.md:107, 131. |
--baseline-id <n> | compare | Compare against a specific baseline by ID rather than the most recent. |
--limit <n> | history | Cap the number of historical entries shown. |
Subcommands
baseline <target>
Capture the current SEO state and write it to a snapshot file. No diff produced.
compare <target>
Load the most recent baseline for the target. Capture the current state. Diff. Produce DRIFT-REPORT.md.
history <target>
List all stored baselines for the target with their dates and key metrics (DA, traffic, keyword count). No diff produced.
Process
baseline mode
- Validate target. Determine if domain or URL. Domain =
example.com; URL = anything starting with http(s)://.
- SSRF protection (URL mode). If target is a URL, validate via
python3 -c "from scripts.google_auth import validate_url; import sys; sys.exit(0 if validate_url('{target}') else 1)" (or import validate_url directly in any helper script). Reject loopback (127.0.0.1, ::1, localhost), private IP ranges (10/8, 172.16/12, 192.168/16), link-local (169.254/16), and Google metadata endpoints. If validation fails, abort with a clear error and don't proceed to fetch — feeding an unvalidated URL into Firecrawl / WebFetch / Google APIs would risk SSRF against internal services. Mirrors theirs at seo-drift/SKILL.md:97.
- Preflight. See
skills/seo-firecrawl/references/preflight.md for the canonical 3-stage preflight (credit balance, Firecrawl availability, Google APIs). Skill-specific notes:
- Estimated SE Ranking cost for this skill: typical baseline costs ~10–20 SE Ranking credits depending on whether step 4 (URL-mode page snapshot) is included.
- Firecrawl: optional with WebFetch fallback, +1 Firecrawl credit per URL if available (URL mode). When available, the snapshot also captures
<head> + JSON-LD content so canonical / robots / og:* / JSON-LD changes are detectable on diff. Without it the snapshot is partial. Pass --no-firecrawl to skip Firecrawl even when available (saves credits at the cost of diff coverage).
- Google APIs: tier 0 unlocks CrUX p75 LCP/INP/CLS capture (origin in domain mode, URL in URL mode); tier 1 (URL mode only) additionally captures URL Inspection state (
indexStatusVerdict, googleCanonical, lastCrawlTime) so subsequent compares can flag field-data and indexation drift. See skills/seo-google/references/cross-skill-integration.md § "seo-drift" for the full recipe.
- Domain snapshot (always):
DATA_getDomainOverviewWorldwide — DA, traffic, organic + paid keyword counts.DATA_getDomainKeywords — top 100 organic keywords with positions.DATA_getBacklinksSummary — backlinks total, referring domains total.DATA_getBacklinksRefDomains — top 20 referring domains with authority.
- Page snapshot (if target is a URL):
WebFetch (always) + mcp__firecrawl-mcp__firecrawl_scrape (when available)
- WebFetch (free): extract
<title>, all <h1..h6>, lang, word count, internal-link count, image count, body markdown for prose-level diff.
- Firecrawl (1 Firecrawl credit per URL) — recovers
<head> and <script> content WebFetch strips:
- From
metadata: canonical URL, robots meta, og:title, og:description, og:image, twitter:card.
- From returned
html: every <script type="application/ld+json"> block. Capture both detected @types and a hash of the full block content (so any schema-content change is detected on diff, not just type-list changes).
- If Firecrawl unavailable (or
--no-firecrawl passed): only WebFetch fields enter the fingerprint. BASELINE.md notes: Snapshot fields recovered via WebFetch only — canonical, robots, og:*, twitter:*, and JSON-LD changes will not be detected on subsequent compares. Install Firecrawl for full coverage.
- Compute a fingerprint hash of the captured fields.
- Also capture page authority:
DATA_getPageAuthority.
4b. Google field-data snapshot (only if google-api.json is present AND --skip-cwv not set)
- Tier 0 (always when configured):
python3 scripts/pagespeed_check.py "{target}" --crux-only --json (URL mode) or python3 scripts/pagespeed_check.py "https://{domain}" --crux-only --json (domain mode, origin-level CrUX). Store the resulting p75 LCP / INP / CLS / FCP / TTFB and the source label ("URL" or "origin").
- Tier 0 (always when configured):
python3 scripts/crux_history.py "{target_or_origin}" --json for the 25-week trend window snapshot — store as crux_history_baseline. Subsequent compares can detect drift against the most recent week.
- Tier 1 (URL mode only):
python3 scripts/gsc_inspect.py "{target_url}" --site-url "{config.default_property}" --json. Store indexStatusVerdict, coverageState, googleCanonical, userCanonical, lastCrawlTime.
- If
--skip-cwv was passed, skip this step entirely and store null for cwv / crux_history fields. The compare-mode rules then surface "Field-data drift: skipped — --skip-cwv flag passed at baseline."
- If CrUX returns insufficient data, store
null for the affected metrics and continue.
- Write snapshot file
seo-drift-{target-slug}-{YYYYMMDD}/snapshot.json.
- Update index
seo-drift-{target-slug}/baselines.json — append {date, snapshot_path} entry.
compare mode
- Validate target + locate latest baseline in
seo-drift-{target-slug}/baselines.json.
- SSRF protection (URL mode). Same
validate_url() check as baseline mode. Refuses to fetch private/loopback/metadata addresses.
- If no baseline exists, fall through to baseline mode and tell the user to come back later.
- Capture current state (same data as baseline mode).
- Diff each metric using
references/drift-thresholds.md:
- Domain authority: ±5 = yellow, ±10 = red.
- Estimated organic traffic: ±20% = yellow, ±50% = red.
- Organic keyword count: ±10% = yellow, ±30% = red.
- Top-3 keyword count: ±15% = yellow, ±40% = red.
- Top-100 keyword churn: any high-volume drop = red.
- Net referring domains: -5 to -20 = yellow, <-20 = red.
- Page-level (URL mode): any change to canonical / robots / lang / H1 = red; title or meta description change = yellow; schema types added/removed = yellow; og:* / twitter:* changes = yellow.
- Firecrawl-dependent diff caveat: canonical / robots / og:* / twitter:* / JSON-LD diffs require both baseline and current snapshots to have been captured with Firecrawl. If either snapshot was WebFetch-only, those fields surface as
not comparable — Firecrawl-only fields missing from {baseline | current} snapshot rather than as a green pass.
- Google-data drift (only if both snapshots have Google fields):
- LCP p75 increased ≥20% → red.
- INP p75 increased ≥20% → red.
- CLS p75 increased ≥0.05 absolute → yellow.
- FCP / TTFB p75 increased ≥30% → yellow.
- Inspection status changed from
INDEXED to anything else → red.
googleCanonical changed → yellow.lastCrawlTime >60 days old → yellow.- Caveat: if either snapshot lacks Google fields (creds were missing at one capture), surface
Field-data / indexation drift: not comparable — Google fields missing from {baseline | current} snapshot.
- Synthesise
DRIFT-REPORT.md — red findings first, then yellow, then green/positive deltas. End with a "what to investigate first" recommendation.
history mode
- Load
baselines.json.
- For each entry, render a one-row summary: date, DA, traffic, keyword count, top-3 count.
- Write
HISTORY.md with the table.
Output format
baseline mode
seo-drift-{target-slug}-{YYYYMMDD}/:
seo-drift-{target-slug}-{YYYYMMDD}/
├── snapshot.json (the captured state)
└── BASELINE.md (one-page human summary of what was captured)
compare mode
seo-drift-{target-slug}-{YYYYMMDD}/:
seo-drift-{target-slug}-{YYYYMMDD}/
├── DRIFT-REPORT.md (synthesised: red/yellow/green changes — primary deliverable; inlines 01-domain-deltas, 02-keyword-churn, 03-backlink-deltas, 04-page-deltas as sections)
└── evidence/
├── baseline-snapshot.json (the prior reference — kept for replay)
├── current-snapshot.json (today's state — kept for replay)
├── 01-domain-deltas.md (DA, traffic, keyword count changes — raw step output)
├── 02-keyword-churn.md (top-100 entries/exits)
├── 03-backlink-deltas.md (new + lost backlinks/domains)
└── 04-page-deltas.md (URL mode only: HTML fingerprint diff)
Top-level: DRIFT-REPORT.md only. The four delta step files are inlined into named sections in DRIFT-REPORT.md; evidence/ keeps the raw delta dumps and both snapshot JSONs so a future re-diff or audit can replay against them.
DRIFT-REPORT.md shape:
# Drift Report: {target}
> Baseline: {baseline date} · Current: {today's date}
## RED — investigate today
- {finding} ({severity rationale})
- ...
## YELLOW — investigate this week
- {finding}
- ...
## GREEN — positive deltas
- {finding}
- ...
## Field-data drift (CrUX + URL Inspection)
- LCP p75: {baseline} → {current} ms ({Δ%}) {↑ red / ↑ yellow / stable / ↓ green}
- INP p75: {baseline} → {current} ms ({Δ%}) {…}
- CLS p75: {baseline} → {current} ({Δ absolute}) {…}
- Indexation status: {baseline INDEXED → current EXCLUDED} (URL mode)
- googleCanonical: {baseline → current} (if changed)
- (Or: `Field-data / indexation drift: not configured` / `not comparable — missing from {snapshot}`)
## What to investigate first
1. {prioritised action with reasoning}
2. ...
history mode
seo-drift-{target-slug}-{YYYYMMDD}/HISTORY.md:
# History: {target}
| Date | DA | Traffic | Keywords | Top-3 |
|---|---|---|---|---|
| 2026-04-27 | 42 | 18,500/mo | 1,247 | 89 |
| 2026-03-15 | 41 | 17,200/mo | 1,213 | 85 |
| ...
Tips
- Respect rate limit: 10 req/sec. Baseline runs 4–6 sequential calls; pace easily.
- Call
DATA_getCreditBalance before running. Domain baseline ~10–15 SE Ranking credits; URL baseline ~15–20 SE Ranking credits + 1 Firecrawl credit; compare ~20–30 SE Ranking credits + 1 Firecrawl credit (current-state capture).
- Snapshot storage is local-only in v0.4.0. If your team needs shared baselines, point everyone at the same
seo-drift-{target-slug}/ directory in a shared filesystem or commit it to a private repo. Baselines are JSON — git-friendly.
- Baseline cadence: monthly is the natural rhythm because SE Ranking's history endpoints have monthly granularity. Weekly is too noisy for backlink data. Document recommended cadence in handoff to your team.
- For deploy-time "did anything break in the last hour" use cases, the URL-mode page-fingerprint half is the workhorse — that doesn't depend on monthly data.
- Don't auto-disavow or auto-fix anything based on drift findings. The skill diagnoses; humans decide.
- Authority-history all-zeros caveat: if
DATA_getPageAuthorityHistory (URL mode) or DATA_getDomainAuthorityHistory returns flat-zero values across the window, treat as "insufficient history" — don't compute a delta or surface a regression based on missing data. Cross-check the current-value endpoint (DATA_getPageAuthority / DATA_getDomainOverviewWorldwide) — if the current value is meaningful but history is flat, surface that as a data-quality flag in DRIFT-REPORT.md rather than fabricating a trend.
- Cost of doing nothing: silent regressions. Cost of running monthly: ~15 credits. Run monthly.
