diff --git a/Script/SOCMINT-Twitter/Readme.md b/Script/SOCMINT-Twitter/Readme.md
index 4993407..79209c8 100644
--- a/Script/SOCMINT-Twitter/Readme.md
+++ b/Script/SOCMINT-Twitter/Readme.md
@@ -21,6 +21,10 @@
 15. Update view as graph in archive 
 16. Add date and timestamp pattern in sentiment analysis 
 17. Delete entry node in graph visualizer 
+18. Add new features save project (load case or load new case)
+19. Checkpoint or save data 
+20. Auto resume archive and dump data with state (state data to checkpoint)
+21. Add date or timestamp paramater for all search module 
 
 ## Features
 
@@ -289,6 +293,13 @@ Dasboard Home
 
 <img width="2423" height="1217" alt="Image" src="https://github.com/user-attachments/assets/6ba91a78-5845-4e17-87e2-8171da3cec19" />
 
+Load Case / Project 
+<img width="2532" height="1217" alt="image" src="https://github.com/user-attachments/assets/433d6f8a-a10f-4add-afeb-8935fc643e67" />
+
+Checkpoint or Save the Project
+
+<img width="2557" height="1218" alt="image" src="https://github.com/user-attachments/assets/d2ef01d6-108c-4ba7-ac90-52bb1fd881ce" />
+
 Archive 
 
 <img width="2511" height="1228" alt="Image" src="https://github.com/user-attachments/assets/9e4fab45-edda-45f5-a88c-963e6bfdaeaf" />
diff --git a/Script/SOCMINT-Twitter/app.py b/Script/SOCMINT-Twitter/app.py
index 422c166..07de6a4 100644
--- a/Script/SOCMINT-Twitter/app.py
+++ b/Script/SOCMINT-Twitter/app.py
@@ -7,6 +7,7 @@ import threading
 import time
 from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime
+from pathlib import Path
 import requests as _req
 from flask import Flask, g, jsonify, render_template, request, Response, stream_with_context, send_from_directory
 
@@ -416,12 +417,22 @@ def run_tool():
     source_errors = None   # multi_source_search only — {source: error} for lanes that failed this page
 
     try:
+        # Common date range — validated once; all tools except wayback (which uses its
+        # own waybackFrom/waybackTo keys) and article_extractor (single item, no date)
+        # can receive these to narrow results.
+        from_date = body.get("dateFrom", "").strip()
+        to_date   = body.get("dateTo",   "").strip()
+        for d_label, d_val in (("dateFrom", from_date), ("dateTo", to_date)):
+            if d_val and not _valid_date8(d_val):
+                return jsonify({"ok": False, "error": f"{d_label} must be YYYYMMDD"}), 400
+
         if tool_type == "tweet_search_extractor":
-            query = body.get("searchQuery", "")
+            query = _apply_date_operators(body.get("searchQuery", ""), from_date, to_date)
             if mode == "cookie":
                 data, next_cursor = cookie_tweet_search(query, count=count, config=config, cursor=cursor)
             else:
                 data = XquikClient(config).tweet_search(query)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "follower_explorer":
             username = body.get("targetUsername", "")
@@ -429,12 +440,14 @@ def run_tool():
                 data, next_cursor = cookie_follower_explorer(username, count=count, config=config, cursor=cursor)
             else:
                 data = XquikClient(config).follower_explorer(username)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "following_explorer":
             username = body.get("targetUsername", "")
             if mode != "cookie":
                 return jsonify({"ok": False, "error": "following_explorer requires cookie mode"}), 400
             data, next_cursor = cookie_following_explorer(username, count=count, config=config, cursor=cursor)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "article_extractor":
             tweet_id = body.get("targetTweetId", "")
@@ -449,6 +462,7 @@ def run_tool():
                 data, next_cursor = cookie_community_post_extractor(community_id, count=count, config=config, cursor=cursor)
             else:
                 data = XquikClient(config).community_post_extractor(community_id)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "post_extractor":
             username = body.get("targetUsername", "")
@@ -456,41 +470,40 @@ def run_tool():
                 data, next_cursor = cookie_post_extractor(username, count=count, config=config, cursor=cursor)
             else:
                 data = XquikClient(config).post_extractor(username)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "tweet_replies_extractor":
             tweet_id = body.get("targetTweetId", "")
             if mode != "cookie":
                 return jsonify({"ok": False, "error": "tweet_replies_extractor requires cookie mode"}), 400
             data, next_cursor = cookie_tweet_replies(tweet_id, count=count, config=config, cursor=cursor)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "tweet_retweeters_extractor":
             tweet_id = body.get("targetTweetId", "")
             if mode != "cookie":
                 return jsonify({"ok": False, "error": "tweet_retweeters_extractor requires cookie mode"}), 400
             data, next_cursor = cookie_tweet_retweeters(tweet_id, count=count, config=config, cursor=cursor)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "geo_post_extractor":
-            keyword = body.get("searchQuery", "")
+            keyword = _apply_date_operators(body.get("searchQuery", ""), from_date, to_date)
             if mode != "cookie":
                 return jsonify({"ok": False, "error": "geo_post_extractor requires cookie mode"}), 400
             data, next_cursor = cookie_geo_search(keyword, count=count, config=config, cursor=cursor)
+            data = _filter_by_date(data, from_date, to_date)
 
         elif tool_type == "wayback_archive_search":
-            target    = body.get("searchQuery", "")
-            from_date = body.get("waybackFrom", "")
-            to_date   = body.get("waybackTo", "")
-            for label, val in (("waybackFrom", from_date), ("waybackTo", to_date)):
-                if val and not _valid_date8(val):
-                    return jsonify({"ok": False, "error": f"{label} must be an 8-digit date (YYYYMMDD)"}), 400
-            data, next_cursor = wayback_search(target, count=count, from_date=from_date, to_date=to_date, cursor=cursor)
+            target  = body.get("searchQuery", "")
+            wb_from = body.get("waybackFrom", "")
+            wb_to   = body.get("waybackTo", "")
+            for d_label, d_val in (("waybackFrom", wb_from), ("waybackTo", wb_to)):
+                if d_val and not _valid_date8(d_val):
+                    return jsonify({"ok": False, "error": f"{d_label} must be an 8-digit date (YYYYMMDD)"}), 400
+            data, next_cursor = wayback_search(target, count=count, from_date=wb_from, to_date=wb_to, cursor=cursor)
 
         elif tool_type == "multi_source_search":
-            query     = body.get("searchQuery", "")
-            from_date = body.get("dateFrom", "")
-            to_date   = body.get("dateTo", "")
-            for label, val in (("dateFrom", from_date), ("dateTo", to_date)):
-                if val and not _valid_date8(val):
-                    return jsonify({"ok": False, "error": f"{label} must be an 8-digit date (YYYYMMDD)"}), 400
+            query = body.get("searchQuery", "")
             data, next_cursor, source_errors = _multi_source_search(query, count=count, from_date=from_date, to_date=to_date, cursor=cursor)
 
         else:
@@ -608,6 +621,151 @@ def archive_list():
     return jsonify({"ok": True, "archives": _archive.list_all()})
 
 
+# ── Cases (save / resume investigation sessions) ──────────────────────────────
+
+CASES_ROOT   = Path(__file__).parent / "cases"
+_CASE_ID_RE  = re.compile(r"^case_\d{8}_\d{6}_[0-9a-f]{6}$")
+
+
+def _valid_case_id(cid: str) -> bool:
+    return bool(_CASE_ID_RE.match(cid))
+
+
+@app.route("/api/cases")
+def cases_list():
+    CASES_ROOT.mkdir(exist_ok=True)
+    out = []
+    for d in CASES_ROOT.iterdir():
+        if not d.is_dir():
+            continue
+        mf = d / "meta.json"
+        if not mf.exists():
+            continue
+        try:
+            out.append(json.loads(mf.read_text()))
+        except Exception:
+            continue
+    out.sort(key=lambda c: c.get("updated_at", ""), reverse=True)
+    return jsonify({"ok": True, "cases": out})
+
+
+@app.route("/api/cases", methods=["POST"])
+def cases_create():
+    body  = request.get_json(silent=True) or {}
+    name  = str(body.get("name", "Unnamed Case")).strip()[:120]
+    page  = str(body.get("page", "index"))[:16]
+    state = body.get("state")
+    if state is None:
+        return jsonify({"ok": False, "error": "No state provided"}), 400
+
+    now      = datetime.now()
+    case_id  = f"case_{now.strftime('%Y%m%d_%H%M%S')}_{secrets.token_hex(3)}"
+    case_dir = CASES_ROOT / case_id
+    case_dir.mkdir(parents=True, exist_ok=True)
+
+    tool = str(body.get("tool", ""))[:80].strip()
+    ts   = now.strftime("%Y-%m-%d %H:%M:%S")
+    meta = {"id": case_id, "name": name, "page": page, "tool": tool, "created_at": ts, "updated_at": ts}
+    (case_dir / "meta.json").write_text(json.dumps(meta, indent=2))
+    (case_dir / "state.json").write_text(json.dumps(state))
+    return jsonify({"ok": True, "caseId": case_id, "meta": meta})
+
+
+@app.route("/api/cases/<case_id>")
+def cases_get(case_id):
+    if not _valid_case_id(case_id):
+        return jsonify({"ok": False, "error": "Invalid case ID"}), 400
+    mf = CASES_ROOT / case_id / "meta.json"
+    sf = CASES_ROOT / case_id / "state.json"
+    if not mf.exists():
+        return jsonify({"ok": False, "error": "Case not found"}), 404
+    try:
+        meta  = json.loads(mf.read_text())
+        state = json.loads(sf.read_text())
+    except Exception as e:
+        return jsonify({"ok": False, "error": str(e)}), 500
+    return jsonify({"ok": True, "meta": meta, "state": state})
+
+
+@app.route("/api/cases/<case_id>", methods=["PUT"])
+def cases_update(case_id):
+    if not _valid_case_id(case_id):
+        return jsonify({"ok": False, "error": "Invalid case ID"}), 400
+    mf = CASES_ROOT / case_id / "meta.json"
+    if not mf.exists():
+        return jsonify({"ok": False, "error": "Case not found"}), 404
+    body = request.get_json(silent=True) or {}
+    try:
+        meta = json.loads(mf.read_text())
+    except Exception as e:
+        return jsonify({"ok": False, "error": str(e)}), 500
+    if "name" in body:
+        meta["name"] = str(body["name"]).strip()[:120]
+    if "tool" in body:
+        meta["tool"] = str(body["tool"]).strip()[:80]
+    meta["updated_at"] = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+    if "state" in body:
+        (CASES_ROOT / case_id / "state.json").write_text(json.dumps(body["state"]))
+    mf.write_text(json.dumps(meta, indent=2))
+    return jsonify({"ok": True, "meta": meta})
+
+
+@app.route("/api/cases/<case_id>", methods=["DELETE"])
+def cases_delete(case_id):
+    if not _valid_case_id(case_id):
+        return jsonify({"ok": False, "error": "Invalid case ID"}), 400
+    case_dir = CASES_ROOT / case_id
+    if not case_dir.exists():
+        return jsonify({"ok": False, "error": "Case not found"}), 404
+    shutil.rmtree(case_dir)
+    return jsonify({"ok": True})
+
+
+@app.route("/api/cases/beacon", methods=["POST"])
+def cases_beacon():
+    """navigator.sendBeacon() target — called on beforeunload. Always 204; response is ignored."""
+    try:
+        body     = request.get_json(silent=True) or {}
+        state    = body.get("state")
+        if not state:
+            return "", 204
+        tool     = str(body.get("tool", ""))[:80].strip()
+        case_id  = str(body.get("caseId", "")).strip()
+        CASES_ROOT.mkdir(exist_ok=True)
+        if case_id and _valid_case_id(case_id):
+            mf = CASES_ROOT / case_id / "meta.json"
+            sf = CASES_ROOT / case_id / "state.json"
+            if mf.exists():
+                try:
+                    meta = json.loads(mf.read_text())
+                except Exception:
+                    meta = {}
+                if tool:
+                    meta["tool"] = tool
+                meta["updated_at"] = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+                mf.write_text(json.dumps(meta, indent=2))
+                sf.write_text(json.dumps(state))
+        else:
+            name    = str(body.get("name", ""))[:120].strip() or "Auto-save"
+            page    = str(body.get("page", "index"))[:16]
+            now     = datetime.now()
+            cid     = f"case_{now.strftime('%Y%m%d_%H%M%S')}_{secrets.token_hex(3)}"
+            cdir    = CASES_ROOT / cid
+            cdir.mkdir(parents=True, exist_ok=True)
+            ts   = now.strftime("%Y-%m-%d %H:%M:%S")
+            meta = {"id": cid, "name": name, "page": page, "tool": tool, "created_at": ts, "updated_at": ts}
+            (cdir / "meta.json").write_text(json.dumps(meta, indent=2))
+            (cdir / "state.json").write_text(json.dumps(state))
+    except Exception:
+        pass
+    return "", 204
+
+
+@app.route("/cases")
+def cases_page():
+    return render_template("cases.html")
+
+
 # ── Analytics (sentiment / clustering) ──────────────────────────────────────
 # Same background-thread + polling shape archive.py's downloads already use
 # (start() kicks off a thread and returns immediately, status() reports
diff --git a/Script/SOCMINT-Twitter/templates/analytics.html b/Script/SOCMINT-Twitter/templates/analytics.html
index 6db7803..27eea89 100644
--- a/Script/SOCMINT-Twitter/templates/analytics.html
+++ b/Script/SOCMINT-Twitter/templates/analytics.html
@@ -256,6 +256,15 @@
     background: var(--accent-bg); border: 1px solid var(--accent); border-radius: 20px;
     padding: 3px 10px; cursor: pointer; margin-left: 8px;
   }
+  .cal-date-stat {
+    margin-top: 8px;
+    padding: 7px 12px;
+    background: var(--bg);
+    border: 1px solid var(--border);
+    border-radius: 6px;
+    font-size: 12px;
+    color: var(--text);
+  }
 
   /* ── Sentiment badge (shared by tiles/list) ── */
   .sent-badge {
@@ -389,6 +398,7 @@
     <a href="/archives">Archives</a>
     <hr class="nav-divider">
     <a href="/analytics" class="current">Analytics</a>
+    <a href="/cases">Cases</a>
   </nav>
 </header>
 
@@ -725,7 +735,7 @@ function renderDashboard() {
     <div class="method-note">
       ${d.method === 'ml'
         ? 'Sentiment is scored by a multilingual model (XLM-RoBERTa, fine-tuned on tweets across 8 languages and reasonably capable well beyond those) — works on non-Indonesian text, not just the lexicon fallback below. Still a heuristic, not ground truth: short text, sarcasm and irony all still degrade accuracy. Click a tile below to see which items landed in it and the model\'s confidence per item.'
-        : 'Sentiment is scored against an Indonesian positive/negative word lexicon with negation handling (e.g. "tidak bagus" flips to con) — a transparent rule-based heuristic, Indonesian-only. Install torch+transformers (see requirements.txt) for multilingual ML-based scoring instead. Click a tile below to see exactly which items landed in it and which words drove each score.'}
+        : 'Sentiment is scored con an Indonesian positive/negative word lexicon with negation handling (e.g. "tidak bagus" flips to con) — a transparent rule-based heuristic, Indonesian-only. Install torch+transformers (see requirements.txt) for multilingual ML-based scoring instead. Click a tile below to see exactly which items landed in it and which words drove each score.'}
       ${d.total_items - d.total_scored > 0 ? `${d.total_items - d.total_scored} of ${d.total_items} record(s) had no text to score (bare follower/following/user entries) and are excluded below.` : ''}
     </div>
 
@@ -1135,6 +1145,18 @@ function calendarHtml(daily) {
     return `<div class="cal-week">${cells}</div>`;
   }).join('');
 
+  const selDay = activeDateFilter ? days.get(activeDateFilter) : null;
+  const selStat = selDay
+    ? (() => {
+        const d = selDay;
+        const parts = [];
+        if (d.pro     > 0) parts.push(`${d.pro} positive`);
+        if (d.neutral > 0) parts.push(`${d.neutral} neutral`);
+        if (d.con     > 0) parts.push(`${d.con} con`);
+        return `${d.total} item${d.total !== 1 ? 's' : ''} collected${parts.length ? ' — ' + parts.join(' / ') : ''}`;
+      })()
+    : null;
+
   return `
     <div class="cal-outer">
       <div class="cal-scroll">
@@ -1150,8 +1172,9 @@ function calendarHtml(daily) {
         <span class="cal-cell cal-has-data cal-level-4"></span>
         More
         ${undated ? `· ${undated} item(s) with no usable date not shown` : ''}
-        ${activeDateFilter ? `<span class="cal-filter-chip" id="calClearFilter">Filtered: ${esc(activeDateFilter)} ×</span>` : ''}
+        ${activeDateFilter ? `<span class="cal-filter-chip" id="calClearFilter">${esc(activeDateFilter)} &times;</span>` : ''}
       </div>
+      ${selStat ? `<div class="cal-date-stat">${esc(activeDateFilter)}: ${esc(selStat)}</div>` : ''}
     </div>`;
 }
 
diff --git a/Script/SOCMINT-Twitter/templates/archive.html b/Script/SOCMINT-Twitter/templates/archive.html
index 990f9e3..6ebb9b7 100644
--- a/Script/SOCMINT-Twitter/templates/archive.html
+++ b/Script/SOCMINT-Twitter/templates/archive.html
@@ -578,6 +578,8 @@
     <hr class="nav-divider">
     <a href="/archives" class="current">Archives</a>
     <a href="/analytics">Analytics</a>
+    <hr class="nav-divider">
+    <a href="/cases">Cases</a>
   </nav>
 </header>
 
diff --git a/Script/SOCMINT-Twitter/templates/cases.html b/Script/SOCMINT-Twitter/templates/cases.html
new file mode 100644
index 0000000..348e792
--- /dev/null
+++ b/Script/SOCMINT-Twitter/templates/cases.html
@@ -0,0 +1,260 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>Jieyab89 SOCMINT X — Cases</title>
+<style>
+  :root {
+    --bg: #0f1117;
+    --surface: #1a1d27;
+    --border: #2a2d3a;
+    --text: #e8eaf0;
+    --muted: #8890a4;
+    --accent: #5865f2;
+    --accent-bg: #1e2240;
+    --danger: #ef4444;
+    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
+  }
+  * { box-sizing: border-box; margin: 0; padding: 0; }
+  body { background: var(--bg); color: var(--text); font-family: var(--font); font-size: 14px; line-height: 1.6; min-height: 100vh; }
+
+  header {
+    padding: 14px 24px; border-bottom: 1px solid var(--border);
+    display: flex; align-items: center; gap: 10px;
+    background: var(--surface); position: sticky; top: 0; z-index: 100;
+  }
+  header h1 { font-size: 14px; font-weight: 600; letter-spacing: 0.02em; }
+  header .sep { color: var(--border); }
+  header .sub { color: var(--muted); font-size: 12px; }
+  .hamburger-btn {
+    margin-left: auto; background: none; border: 1px solid var(--border);
+    border-radius: 5px; color: var(--muted); cursor: pointer;
+    padding: 5px 9px; font-size: 16px; line-height: 1; transition: all 0.15s;
+  }
+  .hamburger-btn:hover { color: var(--text); border-color: var(--accent); }
+  .nav-menu {
+    position: absolute; top: 100%; right: 12px; margin-top: 6px;
+    background: var(--surface); border: 1px solid var(--border);
+    border-radius: 7px; padding: 5px; min-width: 175px;
+    box-shadow: 0 8px 28px rgba(0,0,0,0.5); z-index: 200;
+    display: flex; flex-direction: column; gap: 1px;
+  }
+  .nav-menu.hidden { display: none; }
+  .nav-menu a {
+    padding: 7px 12px; border-radius: 5px; color: var(--muted);
+    text-decoration: none; font-size: 13px; transition: all 0.12s; display: block;
+  }
+  .nav-menu a:hover { color: var(--text); background: var(--accent-bg); }
+  .nav-menu a.current { color: var(--accent); background: var(--accent-bg); }
+  .nav-divider { border: none; border-top: 1px solid var(--border); margin: 3px 0; }
+
+  .page { max-width: 900px; margin: 0 auto; padding: 28px 20px; }
+
+  .topbar { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; }
+  .topbar h2 { font-size: 15px; font-weight: 600; flex: 1; }
+  .search-wrap { position: relative; }
+  .search-input {
+    padding: 7px 12px; background: var(--surface); border: 1px solid var(--border);
+    border-radius: 6px; color: var(--text); font-family: var(--font);
+    font-size: 13px; width: 240px; transition: border-color 0.15s;
+  }
+  .search-input:focus { outline: none; border-color: var(--accent); }
+  .search-input::placeholder { color: var(--muted); }
+
+  .cases-table-wrap { overflow-x: auto; border-radius: 8px; border: 1px solid var(--border); }
+  table { width: 100%; border-collapse: collapse; }
+  thead th {
+    padding: 10px 14px; text-align: left; font-size: 11px; font-weight: 600;
+    text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted);
+    border-bottom: 1px solid var(--border); background: var(--surface); white-space: nowrap;
+  }
+  thead th.th-right { text-align: right; }
+  tbody tr { border-bottom: 1px solid var(--border); transition: background 0.1s; }
+  tbody tr:last-child { border-bottom: none; }
+  tbody tr:hover { background: rgba(88,101,242,0.04); }
+  tbody td { padding: 10px 14px; vertical-align: middle; font-size: 13px; }
+  .td-name { max-width: 280px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-weight: 500; }
+  .td-meta { color: var(--muted); font-size: 12px; font-variant-numeric: tabular-nums; white-space: nowrap; }
+  .td-actions { display: flex; gap: 6px; justify-content: flex-end; }
+
+  .page-badge {
+    display: inline-block; font-size: 10px; font-weight: 600;
+    text-transform: uppercase; letter-spacing: 0.04em;
+    padding: 2px 7px; border-radius: 3px; white-space: nowrap;
+  }
+  .pg-index { background: var(--accent-bg); color: #818cf8; border: 1px solid #34348a; }
+  .pg-graph { background: #1e1535; color: #a78bfa; border: 1px solid #4c3a8f; }
+
+  .btn-load {
+    padding: 4px 12px; font-size: 12px; border-radius: 5px;
+    background: transparent; border: 1px solid var(--accent); color: var(--accent);
+    font-family: var(--font); cursor: pointer; transition: all 0.12s; white-space: nowrap;
+  }
+  .btn-load:hover { background: var(--accent-bg); }
+  .btn-del {
+    padding: 4px 12px; font-size: 12px; border-radius: 5px;
+    background: transparent; border: 1px solid var(--border); color: var(--muted);
+    font-family: var(--font); cursor: pointer; transition: all 0.12s; white-space: nowrap;
+  }
+  .btn-del:hover { border-color: var(--danger); color: var(--danger); }
+
+  .empty-row td { padding: 48px 14px; text-align: center; color: var(--muted); font-size: 13px; }
+  .status-bar { font-size: 12px; color: var(--muted); margin-top: 10px; }
+</style>
+</head>
+<body>
+
+<header>
+  <h1>Jieyab89 SOCMINT X</h1>
+  <span class="sep">|</span>
+  <span class="sub">Cases</span>
+  <button id="navToggle" class="hamburger-btn" aria-label="Navigation menu">&#9776;</button>
+  <nav id="navMenu" class="nav-menu hidden">
+    <a href="/">Home</a>
+    <a href="/graph">Graph</a>
+    <hr class="nav-divider">
+    <a href="/archives">Archives</a>
+    <a href="/analytics">Analytics</a>
+    <hr class="nav-divider">
+    <a href="/cases" class="current">Cases</a>
+  </nav>
+</header>
+
+<div class="page">
+  <div class="topbar">
+    <h2>Saved Cases</h2>
+    <div class="search-wrap">
+      <input id="searchInput" class="search-input" type="text" placeholder="Search cases…" autocomplete="off" spellcheck="false">
+    </div>
+  </div>
+
+  <div class="cases-table-wrap">
+    <table>
+      <thead>
+        <tr>
+          <th>Name</th>
+          <th>Type</th>
+          <th>Last Saved</th>
+          <th class="th-right">Actions</th>
+        </tr>
+      </thead>
+      <tbody id="casesTbody">
+        <tr class="empty-row"><td colspan="4">Loading…</td></tr>
+      </tbody>
+    </table>
+  </div>
+  <div id="statusBar" class="status-bar"></div>
+</div>
+
+<script nonce="{{ g.csp_nonce }}">
+(function() {
+  var cases = [];
+
+  function esc(s) {
+    return String(s)
+      .replace(/&/g,'&amp;').replace(/</g,'&lt;')
+      .replace(/>/g,'&gt;').replace(/"/g,'&quot;');
+  }
+
+  function fmtDate(iso) {
+    if (!iso) return '—';
+    try {
+      var d = new Date(iso);
+      return d.toLocaleDateString() + ' ' + d.toLocaleTimeString([], {hour:'2-digit',minute:'2-digit'});
+    } catch(e) { return iso; }
+  }
+
+  function render(list) {
+    var tbody = document.getElementById('casesTbody');
+    if (!list.length) {
+      tbody.innerHTML = '<tr class="empty-row"><td colspan="4">No saved cases. Run a search on the Home or Graph page and click Checkpoint to save a case.</td></tr>';
+      return;
+    }
+    tbody.innerHTML = list.map(function(c) {
+      var typeLabel = c.tool || (c.page === 'graph' ? 'Graph' : 'Home');
+      var isGraph  = c.page === 'graph';
+      var badge    = '<span class="page-badge ' + (isGraph ? 'pg-graph' : 'pg-index') + '">' + esc(typeLabel) + '</span>';
+      var updated  = c.updated_at || c.created_at || '';
+      return '<tr data-id="' + esc(c.id) + '" data-page="' + esc(c.page || 'index') + '" data-name="' + esc(c.name) + '">' +
+        '<td class="td-name" title="' + esc(c.name) + '">' + esc(c.name) + '</td>' +
+        '<td>' + badge + '</td>' +
+        '<td class="td-meta">' + esc(fmtDate(updated)) + '</td>' +
+        '<td><div class="td-actions">' +
+          '<button class="btn-load" data-action="load">Load</button>' +
+          '<button class="btn-del"  data-action="del">Delete</button>' +
+        '</div></td>' +
+      '</tr>';
+    }).join('');
+  }
+
+  function applyFilter() {
+    var q = document.getElementById('searchInput').value.toLowerCase();
+    var filtered = q ? cases.filter(function(c) {
+      return c.name.toLowerCase().indexOf(q) !== -1 || (c.page || '').indexOf(q) !== -1;
+    }) : cases;
+    render(filtered);
+    document.getElementById('statusBar').textContent =
+      filtered.length + ' / ' + cases.length + ' case' + (cases.length !== 1 ? 's' : '');
+  }
+
+  async function loadCases() {
+    try {
+      var res  = await fetch('/api/cases');
+      var json = await res.json();
+      cases = (json.ok && Array.isArray(json.cases)) ? json.cases : [];
+      applyFilter();
+    } catch(e) {
+      document.getElementById('casesTbody').innerHTML =
+        '<tr class="empty-row"><td colspan="4">Failed to load cases: ' + esc(e.message) + '</td></tr>';
+    }
+  }
+
+  document.getElementById('searchInput').addEventListener('input', applyFilter);
+
+  document.getElementById('casesTbody').addEventListener('click', async function(e) {
+    var btn = e.target.closest('[data-action]');
+    if (!btn) return;
+    var row    = btn.closest('tr');
+    var caseId = row.dataset.id;
+    var page   = row.dataset.page;
+
+    if (btn.dataset.action === 'load') {
+      if (page === 'graph') {
+        window.location.href = '/graph?caseId=' + encodeURIComponent(caseId);
+      } else {
+        window.location.href = '/?caseId=' + encodeURIComponent(caseId);
+      }
+      return;
+    }
+
+    if (btn.dataset.action === 'del') {
+      var name = row.dataset.name;
+      if (!confirm('Delete case "' + name + '"?')) return;
+      btn.textContent = '…';
+      btn.disabled = true;
+      try {
+        var res  = await fetch('/api/cases/' + encodeURIComponent(caseId), { method: 'DELETE' });
+        var json = await res.json();
+        if (!json.ok) throw new Error(json.error || 'Delete failed');
+        cases = cases.filter(function(c) { return c.id !== caseId; });
+        applyFilter();
+      } catch(err) {
+        btn.textContent = 'Delete';
+        btn.disabled = false;
+        alert('Delete failed: ' + err.message);
+      }
+    }
+  });
+
+  var navToggle = document.getElementById('navToggle');
+  var navMenu   = document.getElementById('navMenu');
+  navToggle.addEventListener('click', function(e) { e.stopPropagation(); navMenu.classList.toggle('hidden'); });
+  document.addEventListener('click', function() { navMenu.classList.add('hidden'); });
+  navMenu.addEventListener('click', function(e) { e.stopPropagation(); });
+
+  loadCases();
+})();
+</script>
+</body>
+</html>
diff --git a/Script/SOCMINT-Twitter/templates/graph.html b/Script/SOCMINT-Twitter/templates/graph.html
index 036c7e3..2907a6e 100644
--- a/Script/SOCMINT-Twitter/templates/graph.html
+++ b/Script/SOCMINT-Twitter/templates/graph.html
@@ -89,7 +89,6 @@
   .nav-menu a:hover { color: var(--text); background: var(--accent-bg); }
   .nav-menu a.current { color: var(--accent); background: var(--accent-bg); }
   .nav-divider { border: none; border-top: 1px solid var(--border); margin: 3px 0; }
-
   /* ── Toolbar ── */
   #toolbar {
     display: flex;
@@ -559,6 +558,53 @@
     z-index: 5;
   }
   #emptyHint.hidden { display: none; }
+
+  /* Active case indicator in toolbar */
+  .case-indicator {
+    display: none; align-items: center; gap: 6px;
+    padding: 3px 8px; border-radius: 5px;
+    background: var(--accent-bg); border: 1px solid var(--accent); font-size: 11px;
+  }
+  .case-indicator.visible { display: flex; }
+  .case-indicator-name {
+    max-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
+    color: var(--accent); font-weight: 500; color: #fff;
+  }
+  .case-checkpoint-btn {
+    padding: 4px 10px; font-size: 12px; border-radius: 5px;
+    background: transparent; border: 1px solid var(--accent); color: var(--accent);
+    font-family: var(--font); cursor: pointer; transition: all 0.12s; flex-shrink: 0; color: #fff;
+  }
+  .case-checkpoint-btn:hover:not(:disabled) { background: var(--accent-bg); }
+  .case-checkpoint-btn:disabled { opacity: 0.5; cursor: wait; }
+  .case-save-bar {
+    background: var(--surface); border-bottom: 1px solid var(--border);
+    padding: 10px 16px; display: flex; flex-direction: column; gap: 8px;
+  }
+  .case-save-bar[hidden] { display: none; }
+  .case-save-label { font-size: 12px; color: var(--muted); font-weight: 500; }
+  .case-save-input {
+    width: 100%; padding: 7px 10px; box-sizing: border-box;
+    background: var(--bg); border: 1px solid var(--border); border-radius: 6px;
+    color: var(--text); font-family: var(--font); font-size: 13px;
+    transition: border-color 0.15s;
+  }
+  .case-save-input:focus { outline: none; border-color: var(--accent); }
+  .case-save-input::placeholder { color: var(--muted); }
+  .case-save-btns { display: flex; gap: 6px; }
+  .case-save-confirm {
+    padding: 6px 16px; font-size: 12px; border-radius: 5px; white-space: nowrap;
+    background: var(--accent); color: #fff; border: none;
+    font-family: var(--font); font-weight: 500; cursor: pointer; transition: opacity 0.15s;
+  }
+  .case-save-confirm:disabled { opacity: 0.45; cursor: wait; }
+  .case-save-confirm:not(:disabled):hover { opacity: 0.85; }
+  .case-save-cancel {
+    padding: 6px 10px; font-size: 12px; border-radius: 5px; white-space: nowrap;
+    background: transparent; color: var(--muted); border: 1px solid var(--border);
+    font-family: var(--font); cursor: pointer; transition: all 0.12s;
+  }
+  .case-save-cancel:hover { color: var(--text); border-color: var(--muted); }
 </style>
 </head>
 <body>
@@ -574,6 +620,8 @@
     <hr class="nav-divider">
     <a href="/archives">Archives</a>
     <a href="/analytics">Analytics</a>
+    <hr class="nav-divider">
+    <a href="/cases">Cases</a>
   </nav>
 </header>
 
@@ -602,6 +650,10 @@
   <input id="countInput" type="number" value="20" min="1" max="2000" title="Result count">
   <input id="graphFilterInput" type="text" placeholder="Filter graph…" spellcheck="false" autocomplete="off" style="display:none;width:160px" title="Show only nodes whose data matches this text">
   <span id="nodeCount">0 nodes</span>
+  <span id="caseIndicator" class="case-indicator">
+    <span class="case-indicator-name" id="caseIndicatorName"></span>
+  </span>
+  <button id="caseCheckpointBtn" class="case-checkpoint-btn">Save Case</button>
   <button id="btnSearch"     class="btn btn-primary">Search</button>
   <button id="btnArchiveAll" class="btn btn-ghost">Archive All</button>
   <button id="btnDump"       class="btn btn-ghost">Dump JSON</button>
@@ -609,6 +661,14 @@
 </div>
 
 <div id="archiveBar" class="archive-bar" style="display:none"></div>
+<div id="caseSaveForm" class="case-save-bar" hidden>
+  <span class="case-save-label">Case name</span>
+  <input id="caseSaveName" class="case-save-input" type="text" placeholder="Case name…" maxlength="120" autocomplete="off" spellcheck="false">
+  <div class="case-save-btns">
+    <button id="caseSaveConfirm" class="case-save-confirm">Save</button>
+    <button id="caseSaveCancel" class="case-save-cancel">Cancel</button>
+  </div>
+</div>
 
 <div id="main">
   <div id="cy"></div>
@@ -690,6 +750,7 @@
   {% include "_field_glossary.html" %}
 </div>
 
+
 <script src="https://unpkg.com/cytoscape@3.28.1/dist/cytoscape.min.js" crossorigin="anonymous"></script>
 <script nonce="{{ g.csp_nonce }}">
 (function () {
@@ -998,6 +1059,18 @@ function init() {
 
   var archiveIdParam = new URLSearchParams(location.search).get('archiveId');
   if (archiveIdParam) enterArchiveReadOnlyMode(archiveIdParam);
+
+  var caseIdParam = new URLSearchParams(location.search).get('caseId');
+  if (caseIdParam && !archiveIdParam) {
+    history.replaceState(null, '', location.pathname);
+    fetch('/api/cases/' + encodeURIComponent(caseIdParam))
+      .then(function(r) { return r.json(); })
+      .then(function(json) {
+        if (!json.ok) throw new Error(json.error || 'Case not found');
+        cmGRestoreState(json.state, json.meta);
+      })
+      .catch(function(e) { setStatus('Error loading case: ' + e.message, true); });
+  }
 }
 
 // ── Archive read-only bootstrap ─────────────────────────────────────────────
@@ -1142,10 +1215,11 @@ var NO_AUTH_TOOLS = ['wayback_archive_search', 'multi_source_search'];
 
 function updateModeVisibility() {
   var tool = document.getElementById('toolSelect').value;
-  var show = NO_AUTH_TOOLS.indexOf(tool) !== -1;
-  document.getElementById('modeSelect').style.display    = show ? 'none' : '';
-  document.getElementById('dateFromInput').style.display = show ? '' : 'none';
-  document.getElementById('dateToInput').style.display    = show ? '' : 'none';
+  var noAuth = NO_AUTH_TOOLS.indexOf(tool) !== -1;
+  var noDate = (tool === 'article_extractor');
+  document.getElementById('modeSelect').style.display    = noAuth ? 'none' : '';
+  document.getElementById('dateFromInput').style.display = noDate ? 'none' : '';
+  document.getElementById('dateToInput').style.display   = noDate ? 'none' : '';
 }
 
 // ── Status bar ────────────────────────────────────────────────────────────────
@@ -1235,7 +1309,7 @@ function buildBody(tool, query, count, mode) {
     body.targetCommunityId = query;
   }
 
-  if (tool === 'wayback_archive_search' || tool === 'multi_source_search') {
+  if (tool !== 'article_extractor') {
     var from = document.getElementById('dateFromInput').value.trim();
     var to   = document.getElementById('dateToInput').value.trim();
     if (tool === 'wayback_archive_search') {
@@ -2250,6 +2324,7 @@ async function archiveAll() {
     if (!json.ok) throw new Error(json.error);
     graphArchivedId = json.archiveId;
     document.getElementById('btnArchiveAll').textContent = 'Update Archive';
+    autoCheckpoint();   // persist graphArchivedId into the case so progress survives a page loss
     pollGraphArchive(json.archiveId);
   } catch (e) {
     archiveBar.innerHTML = '<span style="color:var(--danger)">Archive error: ' + esc(e.message) + '</span>';
@@ -2300,6 +2375,212 @@ function dumpJSON() {
   document.body.removeChild(a);
   URL.revokeObjectURL(url);
   setStatus('Exported ' + allItems.length + ' item(s)');
+  autoCheckpoint();   // checkpoint so archiveId is preserved if the page is lost after export
+}
+
+// ── Cases (save / resume investigation sessions) ─────────────────────────────
+
+var currentCaseId   = null;
+var currentCaseName = '';
+
+function updateCaseIndicator() {
+  var ind  = document.getElementById('caseIndicator');
+  var name = document.getElementById('caseIndicatorName');
+  var btn  = document.getElementById('caseCheckpointBtn');
+  if (currentCaseId) {
+    name.textContent = currentCaseName;
+    ind.classList.add('visible');
+    if (btn && btn.textContent !== 'Saving…' && btn.textContent !== 'Saved!' && btn.textContent !== 'Failed') btn.textContent = 'Checkpoint';
+  } else {
+    ind.classList.remove('visible');
+    if (btn && btn.textContent !== 'Saving…' && btn.textContent !== 'Saved!' && btn.textContent !== 'Failed') btn.textContent = 'Save Case';
+  }
+}
+
+function _graphToolName() {
+  var sel = document.getElementById('toolSelect');
+  return 'Graph · ' + sel.options[sel.selectedIndex].text;
+}
+
+document.getElementById('caseCheckpointBtn').addEventListener('click', async function() {
+  var toolName = _graphToolName();
+  if (currentCaseId) {
+    // update existing case directly
+    var state = cmGCaptureState();
+    if (!state) return;
+    this.disabled = true; this.textContent = 'Saving…';
+    try {
+      var res  = await fetch('/api/cases/' + currentCaseId, {
+        method: 'PUT', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ state: state, tool: toolName }),
+      });
+      var json = await res.json();
+      if (!json.ok) throw new Error(json.error);
+      this.textContent = 'Saved!';
+      setTimeout(function() { var b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Checkpoint'; }, 1800);
+    } catch (e) {
+      this.textContent = 'Failed';
+      setTimeout(function() { var b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Checkpoint'; }, 1800);
+    } finally {
+      this.disabled = false;
+    }
+    return;
+  }
+  // no active case → toggle save form
+  var state = cmGCaptureState();
+  var form  = document.getElementById('caseSaveForm');
+  if (!state) {
+    this.textContent = 'No data yet';
+    setTimeout(function() { var b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Save Case'; }, 1500);
+    return;
+  }
+  if (form.hidden) {
+    var dateStr = new Date().toLocaleDateString('en-CA');
+    document.getElementById('caseSaveName').value = toolName + ' · ' + dateStr;
+    form.hidden = false;
+    requestAnimationFrame(function() {
+      var inp = document.getElementById('caseSaveName');
+      inp.focus(); inp.select();
+    });
+  } else {
+    form.hidden = true;
+  }
+});
+
+document.getElementById('caseSaveName').addEventListener('keydown', function(e) {
+  if (e.key === 'Enter') { e.preventDefault(); document.getElementById('caseSaveConfirm').click(); }
+});
+
+document.getElementById('caseSaveCancel').addEventListener('click', function() {
+  document.getElementById('caseSaveForm').hidden = true;
+});
+
+document.getElementById('caseSaveConfirm').addEventListener('click', async function() {
+  var nameEl   = document.getElementById('caseSaveName');
+  var name     = nameEl.value.trim() || 'Unnamed Case';
+  var state    = cmGCaptureState();
+  if (!state) return;
+  var toolName = _graphToolName();
+  this.disabled = true; this.textContent = 'Saving…';
+  try {
+    var res  = await fetch('/api/cases', {
+      method: 'POST', headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ name: name, page: 'graph', tool: toolName, state: state }),
+    });
+    var json = await res.json();
+    if (!json.ok) throw new Error(json.error);
+    currentCaseId   = json.caseId;
+    currentCaseName = json.meta.name;
+    updateCaseIndicator();
+    document.getElementById('caseSaveForm').hidden = true;
+    nameEl.value = '';
+  } catch (e) {
+    // re-enable for retry
+  } finally {
+    this.disabled = false; this.textContent = 'Save';
+  }
+});
+
+// ── Auto-checkpoint (triggered by Archive All and Dump JSON) ─────────────────
+async function autoCheckpoint() {
+  var state    = cmGCaptureState();
+  if (!state) return;
+  var toolName = _graphToolName();
+  var dateStr  = new Date().toLocaleDateString('en-CA');
+  try {
+    if (currentCaseId) {
+      await fetch('/api/cases/' + currentCaseId, {
+        method: 'PUT', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ state: state, tool: toolName }),
+      });
+    } else {
+      var res  = await fetch('/api/cases', {
+        method: 'POST', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ name: 'Auto-save · ' + toolName + ' ' + dateStr, page: 'graph', tool: toolName, state: state }),
+      });
+      var json = await res.json();
+      if (json.ok) {
+        currentCaseId   = json.caseId;
+        currentCaseName = json.meta.name;
+        updateCaseIndicator();
+      }
+    }
+  } catch (e) { /* silent */ }
+}
+
+// ── Periodic auto-save (every 60 s) — guards against power loss / crash ───────
+setInterval(function() { autoCheckpoint(); }, 60000);
+
+// ── beforeunload beacon — fires on tab/browser close ─────────────────────────
+window.addEventListener('beforeunload', function() {
+  var state = cmGCaptureState();
+  if (!state) return;
+  var toolName = _graphToolName();
+  var dateStr  = new Date().toLocaleDateString('en-CA');
+  var payload  = currentCaseId
+    ? { caseId: currentCaseId, state: state, tool: toolName }
+    : { name: 'Auto-save · ' + toolName + ' ' + dateStr, page: 'graph', tool: toolName, state: state };
+  navigator.sendBeacon('/api/cases/beacon', new Blob([JSON.stringify(payload)], { type: 'application/json' }));
+});
+
+function cmGCaptureState() {
+  if (!cy || !cy.nodes().length) return null;
+  return {
+    elements: cy.elements().jsons(),
+    toolbar: {
+      tool:     document.getElementById('toolSelect').value,
+      mode:     document.getElementById('modeSelect').value,
+      query:    document.getElementById('queryInput').value.trim(),
+      count:    document.getElementById('countInput').value,
+      dateFrom: document.getElementById('dateFromInput').value.trim(),
+      dateTo:   document.getElementById('dateToInput').value.trim(),
+    },
+    graphArchivedId: graphArchivedId || null,
+  };
+}
+
+function cmGRestoreState(state, meta) {
+  if (!state || !meta) return;
+  clearGraph();
+
+  if (state.toolbar) {
+    var t = state.toolbar;
+    if (t.tool)     { document.getElementById('toolSelect').value = t.tool; updatePlaceholder(); updateModeVisibility(); }
+    if (t.mode)     document.getElementById('modeSelect').value   = t.mode;
+    if (t.query)    document.getElementById('queryInput').value   = t.query;
+    if (t.count)    document.getElementById('countInput').value   = t.count;
+    if (t.dateFrom) document.getElementById('dateFromInput').value = t.dateFrom;
+    if (t.dateTo)   document.getElementById('dateToInput').value   = t.dateTo;
+  }
+
+  if (Array.isArray(state.elements) && state.elements.length) {
+    try {
+      cy.add(state.elements);
+    } catch (e) {
+      setStatus('Error restoring graph: ' + e.message, true);
+      return;
+    }
+    // Rebuild allItems from node data (type + raw) without double-storing
+    cy.nodes().forEach(function(node) {
+      var raw  = node.data('raw');
+      var type = node.data('type');
+      if (raw && type) allItems.push({ type: type, item: raw });
+    });
+    cy.layout({ name: 'preset' }).run();
+    cy.fit(undefined, 60);
+    updateNodeCount();
+  }
+
+  currentCaseId   = meta.id;
+  currentCaseName = meta.name;
+  updateCaseIndicator();
+
+  if (state.graphArchivedId) {
+    graphArchivedId = state.graphArchivedId;
+    document.getElementById('btnArchiveAll').textContent = 'Update Archive';
+  }
+
+  setStatus('Case "' + esc(meta.name) + '" restored — ' + cy.nodes().length + ' node(s)');
 }
 
 // ── Clear ─────────────────────────────────────────────────────────────────────
diff --git a/Script/SOCMINT-Twitter/templates/index.html b/Script/SOCMINT-Twitter/templates/index.html
index 4ea4620..da2ed94 100644
--- a/Script/SOCMINT-Twitter/templates/index.html
+++ b/Script/SOCMINT-Twitter/templates/index.html
@@ -717,6 +717,53 @@
   }
   .leaflet-bar a:hover { background: var(--accent-bg) !important; color: #818cf8 !important; }
   .leaflet-control-attribution { background: rgba(26,29,39,0.8) !important; color: var(--muted) !important; font-size: 9px; }
+
+  /* Active-case indicator (sidebar) */
+  .case-indicator {
+    margin-top: 7px; padding: 6px 10px;
+    background: var(--accent-bg); border: 1px solid var(--accent); border-radius: 6px;
+    font-size: 11px; color: var(--text); gap: 8px; align-items: center; display: none;
+  }
+  .case-indicator.visible { display: flex; }
+  .case-indicator-name {
+    flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
+    color: var(--accent); font-weight: 500; color: #fff;
+  }
+  .case-checkpoint-btn {
+    width: 100%; padding: 8px; margin-top: 7px;
+    background: transparent; color: var(--accent);
+    border: 1px solid var(--accent); border-radius: 6px;
+    font-family: var(--font); font-size: 12px; font-weight: 500;
+    cursor: pointer; transition: all 0.15s; color: #fff;
+  }
+  .case-checkpoint-btn:hover:not(:disabled) { background: var(--accent-bg); }
+  .case-checkpoint-btn:disabled { opacity: 0.5; cursor: wait; }
+  .case-save-form {
+    margin-top: 7px; padding: 10px;
+    background: var(--accent-bg); border: 1px solid var(--accent); border-radius: 6px;
+  }
+  .case-save-form[hidden] { display: none; }
+  .case-save-input {
+    width: 100%; padding: 6px 9px; margin-bottom: 8px;
+    background: var(--bg); border: 1px solid var(--border); border-radius: 5px;
+    color: var(--text); font-family: var(--font); font-size: 12px;
+  }
+  .case-save-input:focus { outline: none; border-color: var(--accent); }
+  .case-save-input::placeholder { color: var(--muted); }
+  .case-save-btns { display: flex; gap: 6px; }
+  .case-save-confirm {
+    flex: 1; padding: 5px 0; font-size: 12px; border-radius: 5px;
+    background: var(--accent); color: #fff; border: none;
+    font-family: var(--font); font-weight: 500; cursor: pointer; transition: opacity 0.15s;
+  }
+  .case-save-confirm:disabled { opacity: 0.45; cursor: wait; }
+  .case-save-confirm:not(:disabled):hover { opacity: 0.85; }
+  .case-save-cancel {
+    padding: 5px 10px; font-size: 12px; border-radius: 5px;
+    background: transparent; color: var(--muted); border: 1px solid var(--border);
+    font-family: var(--font); cursor: pointer; transition: all 0.12s;
+  }
+  .case-save-cancel:hover { color: var(--text); border-color: var(--muted); }
 </style>
 <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js" crossorigin="anonymous"></script>
 <script src="{{ url_for('static', filename='js/card_constants.js') }}" nonce="{{ g.csp_nonce }}"></script>
@@ -734,6 +781,8 @@
     <hr class="nav-divider">
     <a href="/archives">Archives</a>
     <a href="/analytics">Analytics</a>
+    <hr class="nav-divider">
+    <a href="/cases">Cases</a>
   </nav>
 </header>
 
@@ -791,6 +840,17 @@
     <div id="dynamicFields"></div>
 
     <button class="btn-run" id="runBtn">Run</button>
+    <button id="caseCheckpointBtn" class="case-checkpoint-btn">Save Case</button>
+    <div id="caseSaveForm" class="case-save-form" hidden>
+      <input id="caseSaveName" class="case-save-input" type="text" placeholder="Case name…" maxlength="120" autocomplete="off" spellcheck="false">
+      <div class="case-save-btns">
+        <button id="caseSaveConfirm" class="case-save-confirm">Save</button>
+        <button id="caseSaveCancel" class="case-save-cancel">Cancel</button>
+      </div>
+    </div>
+    <div id="caseIndicator" class="case-indicator">
+      <span class="case-indicator-name" id="caseIndicatorName"></span>
+    </div>
 
     <div id="archiveBar" class="archive-bar" style="display:none"></div>
 
@@ -823,6 +883,7 @@
   </div>
 </div>
 
+
 <script nonce="{{ g.csp_nonce }}">
 // Hamburger nav
 (function() {
@@ -886,6 +947,29 @@ let currentPayload = null;   // last run payload (for archive queryInfo)
 // on every new Run, same as graph.html's clearGraph() resets its own.
 let archivedId = null;
 
+// ── Card render virtual scroll ───────────────────────────────────────────────
+const CARD_BATCH = 15;
+let _cardItems    = [];
+let _cardOffset   = 0;
+let _cardObserver = null;
+
+function _flushCardObserver() {
+  if (_cardObserver) { _cardObserver.disconnect(); _cardObserver = null; }
+}
+
+function _loadCardBatch() {
+  if (_cardOffset >= _cardItems.length) {
+    _flushCardObserver();
+    const s = resultBox.querySelector('#_crs');
+    if (s) s.remove();
+    return;
+  }
+  const batch = _cardItems.slice(_cardOffset, _cardOffset + CARD_BATCH);
+  _cardOffset += batch.length;
+  const grid = resultBox.querySelector('.cards-grid');
+  if (grid) grid.insertAdjacentHTML('beforeend', batch.map(buildCard).join(''));
+}
+
 // ── Scroll-triggered load-more ──────────────────────────────────────────────
 // Tools/modes the backend actually paginates — everything else (plain xquik/API
 // mode calls, article_extractor) just gets a single page.
@@ -988,28 +1072,35 @@ function renderFields() {
   }
 
   // Tool-specific input fields
+  const DATE_FIELDS = () => field('dateFrom', 'From date (YYYYMMDD, optional)', '20200101') +
+                            field('dateTo',   'To date (YYYYMMDD, optional)',   '20231231');
   if (t === 'tweet_search_extractor') {
     html += field('searchQuery', 'Search query', 'bitcoin');
+    html += DATE_FIELDS();
   } else if (t === 'follower_explorer' || t === 'following_explorer') {
     html += field('targetUsername', 'Username or User ID', 'elonmusk or 44196397');
+    html += DATE_FIELDS();
   } else if (t === 'article_extractor') {
     html += field('targetTweetId', 'Tweet ID', '1234567890');
   } else if (t === 'community_post_extractor') {
     html += field('targetCommunityId', 'Community ID', '1234567890');
+    html += DATE_FIELDS();
   } else if (t === 'post_extractor') {
     html += field('targetUsername', 'Username or User ID', 'elonmusk or 44196397');
+    html += DATE_FIELDS();
   } else if (t === 'tweet_replies_extractor' || t === 'tweet_retweeters_extractor') {
     html += field('targetTweetId', 'Tweet ID', '1234567890');
+    html += DATE_FIELDS();
   } else if (t === 'geo_post_extractor') {
     html += field('searchQuery', 'Search query', 'kopi jakarta');
+    html += DATE_FIELDS();
   } else if (t === 'wayback_archive_search') {
     html += field('searchQuery', 'Username or tweet URL', 'elonmusk or https://x.com/user/status/123');
     html += field('waybackFrom', 'From date (YYYYMMDD, optional)', '20200101');
     html += field('waybackTo',   'To date (YYYYMMDD, optional)', '20231231');
   } else if (t === 'multi_source_search') {
     html += field('searchQuery', 'Keyword, mention, username or URL', 'elonmusk');
-    html += field('dateFrom', 'From date (YYYYMMDD, optional)', '20200101');
-    html += field('dateTo',   'To date (YYYYMMDD, optional)', '20231231');
+    html += DATE_FIELDS();
   }
 
   // Count — for tools that support it, visible in cookie mode (or for no-auth tools)
@@ -1062,12 +1153,21 @@ document.getElementById('viewToggle').addEventListener('click', e => {
 
 // ── Search / filter results ───────────────────────────────────────────────────
 
-searchInput.addEventListener('input', () => renderCards(currentData, searchInput.value));
+let _searchDebounce = null;
+searchInput.addEventListener('input', () => {
+  clearTimeout(_searchDebounce);
+  _searchDebounce = setTimeout(() => renderCards(currentData, searchInput.value), 180);
+});
 
+const _ftCache = new WeakMap();
 function flatText(obj) {
   if (obj === null || obj === undefined) return '';
   if (typeof obj !== 'object') return String(obj);
-  return Object.values(obj).map(flatText).join(' ');
+  let c = _ftCache.get(obj);
+  if (c !== undefined) return c;
+  c = Object.values(obj).map(flatText).join(' ');
+  _ftCache.set(obj, c);
+  return c;
 }
 
 // PRIORITY / DRILLABLE / SOURCE_CLASS / AGE_LABELS come from
@@ -1126,21 +1226,33 @@ function renderMedia(mediaList) {
 }
 
 function renderCards(data, query = '') {
+  _flushCardObserver();
   if (!data) {
     resultBox.innerHTML = '<div class="empty-state">No results yet.</div>';
     return;
   }
-  const items    = Array.isArray(data) ? data : [data];
-  const q        = query.toLowerCase().trim();
-  const filtered = q ? items.filter(i => flatText(i).toLowerCase().includes(q)) : items;
+  const items = Array.isArray(data) ? data : [data];
+  const q     = query.toLowerCase().trim();
+  _cardItems  = q ? items.filter(i => flatText(i).toLowerCase().includes(q)) : items;
+  _cardOffset = 0;
 
-  resultCount.textContent = filtered.length + (q ? ' found' : ' results');
+  resultCount.textContent = _cardItems.length + (q ? ' found' : ' results');
 
-  if (!filtered.length) {
+  if (!_cardItems.length) {
     resultBox.innerHTML = '<div class="empty-state">No matching results.</div>';
     return;
   }
-  resultBox.innerHTML = '<div class="cards-grid">' + filtered.map(buildCard).join('') + '</div>';
+
+  resultBox.innerHTML = '<div class="cards-grid"></div><div id="_crs" style="height:4px"></div>';
+  _loadCardBatch();
+
+  const sentinel = resultBox.querySelector('#_crs');
+  if (sentinel) {
+    _cardObserver = new IntersectionObserver(entries => {
+      if (entries[0].isIntersecting) _loadCardBatch();
+    }, { rootMargin: '300px' });
+    _cardObserver.observe(sentinel);
+  }
 }
 
 // Tapping "Reply" on X auto-prefixes the compose box with every account the
@@ -1244,9 +1356,9 @@ function buildCard(item, nested = false) {
 }
 
 // ── Load more (scroll-triggered pagination) ─────────────────────────────────
-// The sentinel lives as a SIBLING of #resultBox, not inside it — renderCards()
-// replaces #resultBox.innerHTML wholesale on every run and every keystroke in
-// the search box, which would destroy an in-box sentinel and its observer tie.
+// loadMoreSentinel lives as a SIBLING of #resultBox (API-pagination sentinel).
+// The card-render sentinel #_crs lives inside #resultBox and is intentionally
+// recreated on each renderCards() call after disconnecting the old observer.
 
 function appendCards(newItems, query = '') {
   const q = query.toLowerCase().trim();
@@ -1595,8 +1707,12 @@ runBtn.addEventListener('click', async () => {
   }
   if (t === 'multi_source_search') {
     payload.searchQuery = val('searchQuery');
-    payload.dateFrom    = val('dateFrom');
-    payload.dateTo      = val('dateTo');
+  }
+  // Date range — sent for all tools that expose the date fields (not wayback which uses its own keys, not article_extractor)
+  if (t !== 'wayback_archive_search' && t !== 'article_extractor') {
+    const df = val('dateFrom'); const dt = val('dateTo');
+    if (df) payload.dateFrom = df;
+    if (dt) payload.dateTo   = dt;
   }
 
   currentPayload = payload;
@@ -1703,6 +1819,7 @@ async function archiveResults() {
 
     archivedId = json.archiveId;
     archiveBtn.textContent = 'Update Archive';
+    autoCheckpoint();   // persist archiveId into the case so the user can resume if the page is lost
     pollArchive(json.archiveId);
   } catch (e) {
     archiveBar.innerHTML = `<span style="color:var(--danger)">Archive failed: ${esc(e.message)}</span>`;
@@ -1761,6 +1878,7 @@ downloadBtn.addEventListener('click', () => {
   a.download      = filename;
   a.click();
   URL.revokeObjectURL(url);
+  autoCheckpoint();   // checkpoint so the archiveId is preserved if the page is lost after export
 });
 
 function val(id) { const el = document.getElementById(id); return el ? el.value.trim() : ''; }
@@ -1933,6 +2051,216 @@ async function updateMap() {
   else                       leafletMap.setView([20, 10], 2);
 }
 
+// ── Cases (save / resume investigation sessions) ─────────────────────────────
+
+var currentCaseId   = null;
+var currentCaseName = '';
+
+function updateCaseIndicator() {
+  const ind  = document.getElementById('caseIndicator');
+  const name = document.getElementById('caseIndicatorName');
+  const btn  = document.getElementById('caseCheckpointBtn');
+  if (currentCaseId) {
+    name.textContent = currentCaseName;
+    ind.classList.add('visible');
+    if (btn && btn.textContent !== 'Saving…' && btn.textContent !== 'Saved!' && btn.textContent !== 'Failed') btn.textContent = 'Checkpoint';
+  } else {
+    ind.classList.remove('visible');
+    if (btn && btn.textContent !== 'Saving…' && btn.textContent !== 'Saved!' && btn.textContent !== 'Failed') btn.textContent = 'Save Case';
+  }
+}
+
+document.getElementById('caseCheckpointBtn').addEventListener('click', async function() {
+  if (currentCaseId) {
+    // update existing case directly — no form needed
+    const state = cmCaptureState();
+    if (!state) return;
+    const tool = toolType.options[toolType.selectedIndex].text;
+    this.disabled = true; this.textContent = 'Saving…';
+    try {
+      const res  = await fetch('/api/cases/' + currentCaseId, {
+        method: 'PUT', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ state, tool }),
+      });
+      const json = await res.json();
+      if (!json.ok) throw new Error(json.error);
+      this.textContent = 'Saved!';
+      setTimeout(() => { const b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Checkpoint'; }, 1800);
+    } catch {
+      this.textContent = 'Failed';
+      setTimeout(() => { const b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Checkpoint'; }, 1800);
+    } finally {
+      this.disabled = false;
+    }
+    return;
+  }
+  // no active case → toggle save form
+  const state = cmCaptureState();
+  const form  = document.getElementById('caseSaveForm');
+  if (!state) {
+    // flash the button briefly if nothing to save
+    this.textContent = 'No data yet';
+    setTimeout(() => { const b = document.getElementById('caseCheckpointBtn'); if (b) b.textContent = 'Save Case'; }, 1500);
+    return;
+  }
+  if (form.hidden) {
+    const dateStr = new Date().toLocaleDateString('en-CA');
+    document.getElementById('caseSaveName').value = toolType.options[toolType.selectedIndex].text + ' · ' + dateStr;
+    form.hidden = false;
+    const inp = document.getElementById('caseSaveName');
+    inp.focus(); inp.select();
+  } else {
+    form.hidden = true;
+  }
+});
+
+document.getElementById('caseSaveCancel').addEventListener('click', function() {
+  document.getElementById('caseSaveForm').hidden = true;
+});
+
+document.getElementById('caseSaveConfirm').addEventListener('click', async function() {
+  const nameEl = document.getElementById('caseSaveName');
+  const name   = nameEl.value.trim() || 'Unnamed Case';
+  const state  = cmCaptureState();
+  if (!state) return;
+  const tool   = toolType.options[toolType.selectedIndex].text;
+  this.disabled = true; this.textContent = 'Saving…';
+  try {
+    const res  = await fetch('/api/cases', {
+      method: 'POST', headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ name, page: 'index', tool, state }),
+    });
+    const json = await res.json();
+    if (!json.ok) throw new Error(json.error);
+    currentCaseId   = json.caseId;
+    currentCaseName = json.meta.name;
+    updateCaseIndicator();
+    document.getElementById('caseSaveForm').hidden = true;
+    nameEl.value = '';
+  } catch {
+    // re-enable so user can retry
+  } finally {
+    this.disabled = false; this.textContent = 'Save';
+  }
+});
+
+function cmCaptureState() {
+  if (!currentData && !currentPayload) return null;
+  return {
+    payload:    currentPayload || null,
+    data:       Array.isArray(currentData) ? currentData : (currentData ? [currentData] : []),
+    nextCursor: nextCursor  || null,
+    archiveId:  archivedId  || null,
+  };
+}
+
+function cmRestoreState(state, meta) {
+  if (!state || !meta) return;
+  currentCaseId   = meta.id;
+  currentCaseName = meta.name;
+  updateCaseIndicator();
+  resetPagination();
+  currentData    = null;
+  currentPayload = null;
+
+  if (state.payload) {
+    const p = state.payload;
+    if (p.toolType) toolType.value = p.toolType;
+    if (p.mode)     currentMode    = p.mode;
+    renderFields();
+    const fieldMap = {
+      searchQuery: p.searchQuery, targetUsername: p.targetUsername,
+      targetTweetId: p.targetTweetId, targetCommunityId: p.targetCommunityId,
+      waybackFrom: p.waybackFrom, waybackTo: p.waybackTo,
+      dateFrom: p.dateFrom, dateTo: p.dateTo,
+    };
+    Object.entries(fieldMap).forEach(([id, v]) => {
+      const el = document.getElementById(id);
+      if (el && v) el.value = v;
+    });
+    const cnt = document.getElementById('countInput');
+    if (cnt && p.count) cnt.value = p.count;
+    currentPayload = p;
+  }
+
+  if (Array.isArray(state.data) && state.data.length) {
+    currentData               = state.data;
+    nextCursor                = state.nextCursor || null;
+    statusBadge.textContent   = 'restored';
+    statusBadge.className     = 'badge ok';
+    searchInput.style.display = state.data.length > 1 ? '' : 'none';
+    downloadBtn.style.display = '';
+    archiveBtn.style.display  = '';
+    renderCards(currentData);
+    resultCount.textContent   = state.data.length + ' results';
+  }
+  if (state.archiveId) {
+    archivedId             = state.archiveId;
+    archiveBtn.textContent = 'Update Archive';
+  }
+}
+
+// ── Auto-checkpoint (triggered by Archive and JSON dump) ─────────────────────
+// Silently saves to the active case if one is loaded, or creates a new
+// auto-save case if not. Never blocks the calling flow — errors are swallowed.
+async function autoCheckpoint() {
+  const state   = cmCaptureState();
+  if (!state) return;
+  const tool    = toolType.options[toolType.selectedIndex].text;
+  const dateStr = new Date().toLocaleDateString('en-CA');
+  try {
+    if (currentCaseId) {
+      await fetch('/api/cases/' + currentCaseId, {
+        method: 'PUT', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ state, tool }),
+      });
+    } else {
+      const res  = await fetch('/api/cases', {
+        method: 'POST', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ name: 'Auto-save · ' + tool + ' ' + dateStr, page: 'index', tool, state }),
+      });
+      const json = await res.json();
+      if (json.ok) {
+        currentCaseId   = json.caseId;
+        currentCaseName = json.meta.name;
+        updateCaseIndicator();
+      }
+    }
+  } catch { /* silent — autosave must never interrupt the user's flow */ }
+}
+
+// ── Periodic auto-save (every 60 s) — guards against power loss / crash ───────
+setInterval(function() { autoCheckpoint(); }, 60000);
+
+// ── beforeunload beacon — fires on tab/browser close ─────────────────────────
+window.addEventListener('beforeunload', function() {
+  const state = cmCaptureState();
+  if (!state) return;
+  const tool    = toolType.options[toolType.selectedIndex].text;
+  const dateStr = new Date().toLocaleDateString('en-CA');
+  const payload = currentCaseId
+    ? { caseId: currentCaseId, state, tool }
+    : { name: 'Auto-save · ' + tool + ' ' + dateStr, page: 'index', tool, state };
+  navigator.sendBeacon('/api/cases/beacon', new Blob([JSON.stringify(payload)], { type: 'application/json' }));
+});
+
+// Load case from URL param (e.g. when graph page redirects here with ?caseId=)
+(async function() {
+  const caseId = new URLSearchParams(location.search).get('caseId');
+  if (!caseId) return;
+  history.replaceState(null, '', location.pathname);
+  try {
+    const res  = await fetch('/api/cases/' + encodeURIComponent(caseId));
+    const json = await res.json();
+    if (!json.ok) throw new Error(json.error);
+    cmRestoreState(json.state, json.meta);
+  } catch (e) {
+    statusBadge.textContent = 'error';
+    statusBadge.className   = 'badge err';
+    resultBox.innerHTML     = `<div class="card"><div class="card-row"><div class="card-key">case load error</div><div class="card-val" style="color:#f87171">${esc(e.message)}</div></div></div>`;
+  }
+})();
+
 // ── Auto-run from URL params (drill-down new-tab entry point) ─────────────────
 
 (function () {