diff --git a/prepare_pages_and_registry.py b/prepare_pages_and_registry.py
new file mode 100644
index 0000000..4b0ac16
--- /dev/null
+++ b/prepare_pages_and_registry.py
@@ -0,0 +1,252 @@
+import os
+import re
+import json
+import shutil
+import html
+from pathlib import Path
+from collections import defaultdict
+
+SOURCE_DIR = Path("../original_index")
+OUTPUT_DIR = Path("../output")
+
+PAGES_DIR = Path(OUTPUT_DIR / "pages")
+REGISTRY_PATH = Path(OUTPUT_DIR / "equivalence_registry.json")
+REPORT_PATH = Path(OUTPUT_DIR / "migration_report.txt")
+
+OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
+PAGES_DIR.mkdir(parents=True, exist_ok=True)
+
+# --------------------------------------------------
+# Helpers
+# --------------------------------------------------
+
+INVALID_WIN_CHARS = r'[<>:"/\\|?*]'
+ARTICLE_ID_RE = re.compile(r'"wgArticleId":\s*(\d+)')
+IS_REDIRECT_RE = re.compile(r'"wgIsRedirect"\s*:\s*true')
+NAMESPACE_RE = re.compile(r'"wgCanonicalNamespace"\s*:\s*"([^"]*)"')
+
+def normalize_title(title: str) -> str:
+    title = title.strip()
+    title = title.replace("_", " ")
+    title = re.sub(r"\s+", " ", title)
+    return title.casefold()
+
+
+def sanitize_filename(name: str) -> str:
+    name = re.sub(INVALID_WIN_CHARS, "_", name)
+    return name[:180]
+
+
+def extract_wg_page_name(page_html: str) -> str | None:
+    m = re.search(r'"wgPageName"\s*:\s*"([^"]+)"', page_html)
+    if m:
+        return html.unescape(m.group(1)).replace("_", " ")
+    return None
+
+
+def extract_page_identity(html: str):
+    page = extract_wg_page_name(html)
+    if page:
+        return page
+
+    # fallback title tag
+    m = re.search(r"<title>(.*?) -", html, re.I)
+    if m:
+        return html.unescape(m.group(1))
+
+    return None
+
+
+def extract_article_id(html: str) -> int | None:
+    m = ARTICLE_ID_RE.search(html)
+    if m:
+        aid = int(m.group(1))
+        if aid > 0:
+            return aid
+    return None
+
+
+def extract_redirect(html: str) -> str | None:
+    m = re.search(r"#REDIRECT\s*\[\[(.*?)]]", html, re.I)
+    if m:
+        return m.group(1).strip()
+    return None
+
+
+def namespace_of(title: str):
+    if ":" in title:
+        return title.split(":", 1)[0]
+
+
+def extract_internal_redirect(page_html: str):
+    m = re.search(r'"wgRedirectedFrom"\s*:\s*"([^"]+)"', page_html)
+    if m:
+        return html.unescape(m.group(1)).replace("_", " ")
+    return None
+
+
+def extract_namespace(html: str) -> str:
+    m = NAMESPACE_RE.search(html)
+    if m:
+        return m.group(1)
+    return ""
+
+# --------------------------------------------------
+# Registry structures
+# --------------------------------------------------
+
+canonical_pages = {}
+equivalences = {}
+redirects = {}
+ignored_pages = []
+problems = []
+
+files = list(SOURCE_DIR.glob("*.html"))
+print(f"{len(files)} fichiers trouvés")
+
+
+# --------------------------------------------------
+# PASS 1 — analyse
+# --------------------------------------------------
+
+for i, path in enumerate(files, 1):
+
+    try:
+        page_html = path.read_text(encoding="utf-8", errors="ignore")
+
+        article_id = extract_article_id(page_html)
+        if not article_id:
+            ignored_pages.append(path.name)
+            continue
+
+        title = extract_page_identity(page_html)
+        if not title:
+            problems.append(f"No title: {path}")
+            continue
+
+        ns = extract_namespace(page_html)
+
+        # -------------------------
+        # Ignore namespaces
+        # -------------------------
+        if ns in ("File", "Template", "User", "Talk", "File talk", "Category talk", "User talk"):
+            ignored_pages.append(path.name)
+            continue
+
+        title = html.unescape(title)
+        norm = normalize_title(title)
+
+
+        # -------------------------
+        # Category pages
+        # -------------------------
+        # Category pages CAN be canonical content
+        if ns == "Category":
+            norm = normalize_title(title)
+            equivalences[norm] = norm
+
+        # -------------------------
+        # Redirect detection
+        # -------------------------
+        redir = extract_internal_redirect(page_html)
+        if redir:
+            redirects[normalize_title(redir)] = norm
+        # -------------------------
+        # Canonical article
+        # -------------------------
+
+        is_redirect = bool(IS_REDIRECT_RE.search(page_html))
+        if article_id not in canonical_pages:
+            canonical_pages[article_id] = {
+                "path": path,
+                "title": norm,
+                "redirect": is_redirect,
+            }
+        elif canonical_pages[article_id]["redirect"] and not is_redirect:
+            canonical_pages[article_id] = {
+                "path": path,
+                "title": norm,
+                "redirect": is_redirect,
+            }
+        # self equivalence
+        equivalences[norm] = norm
+
+    except Exception as e:
+        problems.append(f"{path}: {e}")
+
+    if i % 200 == 0:
+        print(f"{i}/{len(files)} analysés")
+
+
+# --------------------------------------------------
+# PASS 2 — resolve redirects
+# --------------------------------------------------
+
+def resolve_redirect(key):
+    seen = set()
+    while key in redirects and key not in seen:
+        seen.add(key)
+        key = redirects[key]
+    return key
+
+
+for k, v in list(redirects.items()):
+    equivalences[k] = resolve_redirect(v)
+
+
+# --------------------------------------------------
+# PASS 3 — copy canonical pages
+# --------------------------------------------------
+
+copied = 0
+
+# for key, src in canonical_pages.items():
+for key, data in canonical_pages.items():
+
+    src = data["path"]
+    dst_name = sanitize_filename(src.name)
+    dst = PAGES_DIR / dst_name
+
+    try:
+        shutil.copy2(src, dst)
+        canonical_pages[key] = dst_name
+        copied += 1
+    except Exception as e:
+        problems.append(f"Copy failed {src}: {e}")
+
+print(f"{copied} pages copiées")
+
+
+# --------------------------------------------------
+# SAVE REGISTRY
+# --------------------------------------------------
+
+registry = {
+    "canonical_pages": canonical_pages,
+    "equivalences": equivalences,
+    "redirects": redirects,
+    "ignored_pages": ignored_pages,
+}
+
+REGISTRY_PATH.parent.mkdir(exist_ok=True)
+
+with open(REGISTRY_PATH, "w", encoding="utf-8") as f:
+    json.dump(registry, f, indent=2, ensure_ascii=False)
+
+
+# --------------------------------------------------
+# REPORT
+# --------------------------------------------------
+
+with open(REPORT_PATH, "w", encoding="utf-8") as f:
+    f.write("=== MIGRATION REPORT ===\n")
+    f.write(f"Canonical pages: {len(canonical_pages)}\n")
+    f.write(f"Equivalences: {len(equivalences)}\n")
+    f.write(f"Redirects: {len(redirects)}\n")
+    f.write(f"Ignored: {len(ignored_pages)}\n")
+    f.write(f"Problems: {len(problems)}\n\n")
+
+    for p in problems[:200]:
+        f.write(p + "\n")
+
+print("\n✅ PREPARATION COMPLETE")
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