diff --git a/agents/geo-analyzer.md b/agents/geo-analyzer.md
index b9d870f..66f845c 100644
--- a/agents/geo-analyzer.md
+++ b/agents/geo-analyzer.md
@@ -515,6 +515,17 @@ PRIORITY ACTIONS  : <top 3-5>
 
 ## STEP 8 — CONTENT SHAPE FOR AI `[both]`
 
+**Rendering gate first (R2).** `bash ~/.claude/lib/seo-data/fetch.sh
+rendercheck --url "https://$DOMAIN/"`. Verdict `client-rendered` → Content
+Shape is `N/A — content not in served HTML`, excluded from the weighted
+global, never scored zero. And say the thing that actually matters here: AI
+crawlers are **worse** at JS than Googlebot is. GPTBot, PerplexityBot and
+ClaudeBot fetch HTML and largely do not execute it, so a client-rendered site
+is not just unauditable by us — it is close to invisible to the engines this
+whole audit targets. That is a §0 alert and the top user action (SSR/SSG),
+not a schema tweak.
+Site-wide axes (crawler policy, llms.txt) are unaffected: those are files.
+
 Load: `~/.claude/agents/resources/content-shape-for-ai.md`
 
 Sample 5-10 key pages (homepage + top service/blog pages). For each:
diff --git a/agents/seo-analyzer.md b/agents/seo-analyzer.md
index 7477f96..6f315ff 100644
--- a/agents/seo-analyzer.md
+++ b/agents/seo-analyzer.md
@@ -472,6 +472,48 @@ Fetch rendered HTML. Extract and analyze:
 
 ## STEP 5 — ON-PAGE AUDIT `[both]`
 
+### Rendering gate — run this BEFORE anything else in STEP 5 (R2)
+
+```bash
+bash ~/.claude/lib/seo-data/fetch.sh rendercheck --url "https://$DOMAIN/"
+```
+
+STEP 2 has always recorded `RENDERING: SSR/SSG/SPA/hybrid` and nothing ever
+acted on it. This is the rule that does. The verdict comes from what the
+server actually sent, not from reading package.json — a React SPA and a
+Next.js SSR app are indistinguishable there.
+
+**`verdict: client-rendered` → REFUSE to score the On-page axis.** Do not
+score it low. Do not score it at all:
+- On-page → `N/A — content not in served HTML (client-rendered)`. Redistribute
+  nothing; a missing axis is not a zero.
+- Every curl-based meta/H1/JSON-LD check would report "missing" against a site
+  that may be perfectly correct once hydrated. Those are FALSE findings, and
+  a bundle built on them would "fix" meta tags that already exist.
+- **No bundle item may come from a live on-page check on this site.** Source
+  greps still apply — the JSX carries the tags — but you cannot tell which
+  route renders what, so treat them as inventory, not as per-page findings.
+- `linkgraph` will refuse too (`no_links_in_html`) — the same blindness. Do
+  not work around either refusal.
+
+Still fully auditable, and worth saying so rather than returning an empty
+report: robots.txt, sitemap.xml, HTTP headers, redirects, `.htaccess` /
+framework config, CWV via CrUX (field data is real-user, hydration included),
+GSC queries + index coverage, legal pages, image weights.
+
+**`verdict: partial`** → shell plus an SSR'd head, or a genuinely thin page.
+Score what is present, name what is not, and say which of the two you think
+it is.
+
+**§0 line, mandatory when not server-rendered:**
+`Rendering: client-rendered — On-page NOT scored (content absent from served
+HTML). Global score excludes it. Fix: SSR/SSG (CLAUDE.md: public sites are
+never SPAs).`
+
+This is the honest half of the R1/R2 call: we do not render JS (no Playwright,
+no Chromium), so we do not pretend to see what JS paints. Refusing is the
+finding.
+
 **Record the denominator BEFORE sampling.** This step samples; the report
 says "audit". On a 500-page site a 12-page sample is 2.4% — the On-page score
 is an extrapolation from it, and the reader cannot know unless you print it.
@@ -885,6 +927,14 @@ owns them (0-100 + Observatory/SecurityHeaders/SSL Labs). Run /harden
 Name what you saw. An omission has to stay legible — the same reason
 COVERAGE is mandatory in STEP 9.
 
+**On-page axis note (R2).** `rendercheck` verdict `client-rendered` → this
+axis is `N/A — content not in served HTML`, excluded from the weighted global,
+NOT scored zero. A zero says "your on-page is bad"; N/A says "we could not
+see it", and only one of those is true. Renormalise the remaining weights over
+the axes actually scored and say so on the SEO GLOBAL line. The code ceiling
+must state that no code fix raises an axis we did not measure — the unlock is
+SSR/SSG, and that is a user action, not a bundle item.
+
 **Off-page axis note (I1).** Score ONLY the unlinked brand mentions
 gathered in STEP 6 (`web_search "<business-name>" -site:<domain>`).
 Backlink profile and domain authority have NO data source here — no index,
diff --git a/lib/seo-data/README.md b/lib/seo-data/README.md
index 276a154..dfbbbfa 100644
--- a/lib/seo-data/README.md
+++ b/lib/seo-data/README.md
@@ -146,6 +146,29 @@ fetch.sh sitemap --url https://ex.com/sitemap.xml
       internals AND keeps this stdlib-only; defusedxml would drag in a venv for
       a document type that has no legitimate DTD.
 
+fetch.sh rendercheck --url https://ex.com/
+  → {"status":"ok","verdict":"server-rendered"|"client-rendered"|"partial",
+     "body_text_chars":7650,"h1_in_html":1,"jsonld_in_html":9,
+     "meta_description_in_html":true,"html_bytes":132447,
+     "warning":"…"}                       # warning only when not server-rendered
+
+  R2, the honest half of the SPA call. seo-analyzer has always recorded
+  `RENDERING: SSR/SSG/SPA` and never acted on it; this is the signal it acts
+  on. Verdict comes from what the server SENT — package.json cannot tell a
+  React SPA from a Next.js SSR app.
+    • client-rendered → the agent REFUSES to score On-page (N/A, not zero: a
+      zero says "your on-page is bad", N/A says "we could not see it"). Every
+      curl-based meta/H1/JSON-LD check would report "missing" against a site
+      that is fine once hydrated — false findings, and a bundle that "fixes"
+      tags which already exist.
+    • Does NOT render JS. No Playwright, no Chromium, no venv. Refusing IS the
+      finding.
+    • Script/style text is not page text: measured 7 chars on a React shell
+      whose inline window.__INITIAL_STATE__ is large. Without that, a 200 KB
+      bundle reads as a rich page.
+    • Measured 2026-07-17: zenquality 7650 chars/1 h1/9 jsonld and
+      lavageangels356 13973/1/1 → server-rendered; a Vite shell → 7/0/0.
+
 fetch.sh linkgraph --url https://ex.com/sitemap.xml [--max 500]
   → {"status":"ok","source":"linkgraph","pages_crawled":86,"pages_failed":0,
      "total_internal_links":2015,"capped":false,"max_depth":2,
diff --git a/lib/seo-data/fetch.sh b/lib/seo-data/fetch.sh
index 3f29dfa..7ba61fc 100644
--- a/lib/seo-data/fetch.sh
+++ b/lib/seo-data/fetch.sh
@@ -32,6 +32,8 @@ case "$cmd" in
   # No auth, no Google: stdlib-only, runs even without the venv.
   sitemap)
     exec "$PY" "$HERE/sitemap.py" --store "$STORE" "$@" ;;
+  rendercheck)
+    exec "$PY" "$HERE/render_check.py" --store "$STORE" "$@" ;;
   linkgraph)
     exec "$PY" "$HERE/linkgraph.py" --store "$STORE" "$@" ;;
   forget)
@@ -46,6 +48,6 @@ case "$cmd" in
     fi
     echo '{"status":"error","reason":"usage: fetch.sh forget {--label <label>|--all} (label charset: A-Za-z0-9._-)"}'
     exit 2 ;;
-  *) echo '{"status":"error","reason":"usage: fetch.sh {accounts|crux|queries|inspect|cannibal|sitemap|linkgraph|forget} [flags]"}'
+  *) echo '{"status":"error","reason":"usage: fetch.sh {accounts|crux|queries|inspect|cannibal|sitemap|rendercheck|linkgraph|forget} [flags]"}'
      exit 2 ;;
 esac
diff --git a/lib/seo-data/fixtures-spa/page.html b/lib/seo-data/fixtures-spa/page.html
new file mode 100644
index 0000000..b6cc5bb
--- /dev/null
+++ b/lib/seo-data/fixtures-spa/page.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html><html lang="fr"><head>
+<title>Mon App</title>
+<script type="module" crossorigin src="/assets/index-a1b2c3.js"></script>
+<link rel="stylesheet" href="/assets/index-d4e5f6.css">
+</head><body>
+<div id="root"></div>
+<script>window.__INITIAL_STATE__={"user":null,"routes":["/","/about","/contact"],"config":{"apiUrl":"https://api.example.com","features":["a","b","c"]}};</script>
+</body></html>
diff --git a/lib/seo-data/fixtures-ssr/page.html b/lib/seo-data/fixtures-ssr/page.html
new file mode 100644
index 0000000..6f96916
--- /dev/null
+++ b/lib/seo-data/fixtures-ssr/page.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html><html lang="fr"><head>
+<title>Lavage auto</title>
+<meta name="description" content="Lavage auto à la main en Seine-et-Marne.">
+<script type="application/ld+json">{"@context":"https://schema.org","@type":"LocalBusiness","name":"X"}</script>
+</head><body>
+<h1>Lavage auto à la main</h1>
+<p>Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique. Lavage automobile à la main à Lagny-sur-Marne, detailing et protection céramique.</p>
+</body></html>
\ No newline at end of file
diff --git a/lib/seo-data/render_check.py b/lib/seo-data/render_check.py
new file mode 100644
index 0000000..c98bac3
--- /dev/null
+++ b/lib/seo-data/render_check.py
@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+"""Is the content in the served HTML, or painted by JS? Stdlib only.
+
+seo-analyzer records `RENDERING: SSR/SSG/SPA/hybrid` and then does nothing
+with it. That is the gap this closes. On a client-rendered site `curl` returns
+an empty shell, so every meta/H1/JSON-LD check reports "missing" and the audit
+emits a page of false findings against a site that may be perfectly fine.
+
+The verdict is taken from what the server actually sent — not from guessing at
+package.json, where a React SPA and a Next.js SSR app look identical.
+
+R2, not R1: this REPORTS blindness so the agent can refuse to score. It does
+not render JS. No Playwright, no Chromium, no venv.
+"""
+import argparse, json, re
+from html.parser import HTMLParser
+
+import sitemap as sm                       # sibling: _fetch / _mock
+
+# A shell can still carry a title + a couple of nav words. These thresholds
+# separate "shell" from "page" on the two real sites measured 2026-07-17
+# (server-rendered: 1 h1, thousands of body chars) and on a hydration stub.
+MIN_TEXT = 400
+MIN_H1 = 1
+
+class _Doc(HTMLParser):
+    """Collect body text and the tags an SEO audit reads. Script/style content
+    is NOT text: a 200 KB React bundle would otherwise look like a rich page."""
+    SKIP = ("script", "style", "noscript", "template", "svg")
+
+    def __init__(self):
+        super().__init__(convert_charrefs=True)
+        self.text, self.h1, self.jsonld, self.meta_desc = [], 0, 0, False
+        self._skip = 0
+        self._ld = False
+
+    def handle_starttag(self, tag, attrs):
+        a = dict(attrs)
+        if tag in self.SKIP:
+            self._skip += 1
+            self._ld = tag == "script" and a.get("type") == "application/ld+json"
+        elif tag == "h1":
+            self.h1 += 1
+        elif tag == "meta" and a.get("name", "").lower() == "description":
+            self.meta_desc = bool((a.get("content") or "").strip())
+
+    def handle_endtag(self, tag):
+        if tag in self.SKIP and self._skip:
+            self._skip -= 1
+            self._ld = False
+
+    def handle_data(self, data):
+        if self._ld:
+            self.jsonld += 1
+        elif not self._skip:
+            s = data.strip()
+            if s:
+                self.text.append(s)
+
+def _verdict(text_chars, h1, jsonld):
+    if text_chars >= MIN_TEXT and h1 >= MIN_H1:
+        return "server-rendered"
+    if text_chars < MIN_TEXT and h1 == 0 and jsonld == 0:
+        return "client-rendered"
+    return "partial"                       # shell + some SSR'd head, or thin page
+
+def render_check(url):
+    raw = sm._mock("page.html")
+    if raw is None:
+        try:
+            raw = sm._fetch(url)
+        except Exception:
+            return {"status": "degraded", "reason": "fetch_failed"}
+    html = raw.decode("utf-8", "replace")
+    d = _Doc()
+    try:
+        d.feed(html)
+    except Exception:
+        pass                               # tolerate malformed markup
+    text = re.sub(r"\s+", " ", " ".join(d.text)).strip()
+    verdict = _verdict(len(text), d.h1, d.jsonld)
+    out = {"status": "ok", "source": "render_check", "verdict": verdict,
+           "body_text_chars": len(text), "h1_in_html": d.h1,
+           "jsonld_in_html": d.jsonld, "meta_description_in_html": d.meta_desc,
+           "html_bytes": len(raw)}
+    if verdict != "server-rendered":
+        out["warning"] = ("content is not in the served HTML — curl-based "
+                          "on-page checks will report false 'missing' findings")
+    return out
+
+def _cli():
+    try:
+        p = argparse.ArgumentParser()
+        p.add_argument("--url", required=True)
+        p.add_argument("--store", default=None)   # accepted+ignored
+        args = p.parse_args()
+        print(json.dumps(render_check(args.url), indent=2))
+    except SystemExit as e:
+        if e.code not in (0, None):
+            print(json.dumps({"status": "error", "reason": "bad_usage"}))
+        raise
+    except Exception:
+        print(json.dumps({"status": "degraded", "reason": "unexpected_error"}))
+
+if __name__ == "__main__":
+    _cli()
diff --git a/lib/seo-data/seo-data.test.sh b/lib/seo-data/seo-data.test.sh
index 719e4c3..18df37f 100644
--- a/lib/seo-data/seo-data.test.sh
+++ b/lib/seo-data/seo-data.test.sh
@@ -135,6 +135,22 @@ has "billion-laughs refused"     "$DTD" '"status": "degraded"'
 has "dtd reason is distinct"     "$DTD" 'unsafe_xml_dtd'
 hasnt "dtd never parsed"         "$DTD" '"count"'
 
+echo "── render_check (R2) ──"
+SPA="$(SEO_DATA_MOCK_DIR="$SD/fixtures-spa" python3 "$SD/render_check.py" \
+  --url https://spa.example/)"
+has "spa → client-rendered"      "$SPA" '"verdict": "client-rendered"'
+has "spa has no h1 in html"      "$SPA" '"h1_in_html": 0'
+has "spa warns about false negs" "$SPA" 'false'
+# the shell carries a fat window.__INITIAL_STATE__ script: script text is NOT
+# page text, or a 200KB React bundle would read as a rich page
+has "script text is not content" "$SPA" '"body_text_chars": 7'
+SSR="$(SEO_DATA_MOCK_DIR="$SD/fixtures-ssr" python3 "$SD/render_check.py" \
+  --url https://ssr.example/)"
+has "ssr → server-rendered"      "$SSR" '"verdict": "server-rendered"'
+has "ssr counts jsonld"          "$SSR" '"jsonld_in_html": 1'
+has "ssr sees meta description"  "$SSR" '"meta_description_in_html": true'
+hasnt "ssr emits no warning"     "$SSR" 'warning'
+
 echo "── linkgraph ──"
 LG="$(SEO_DATA_MOCK_DIR="$SD/fixtures-linkgraph" python3 "$SD/linkgraph.py" \
   --url https://ex.com/sitemap.xml)"