diff --git a/core/signals/server.py b/core/signals/server.py
index 1a745cb..0d822a9 100644
--- a/core/signals/server.py
+++ b/core/signals/server.py
@@ -1,24 +1,55 @@
+import logging
 import os
 from threading import Thread
-from flask import Flask, request, jsonify
+
+try:
+    from flask import Flask, jsonify, request
+except ImportError:  # pragma: no cover - optional dependency
+    Flask = None  # type: ignore[assignment]
+    jsonify = None  # type: ignore[assignment]
+    request = None  # type: ignore[assignment]
+
 from core.signals.adapter import ingest_signal
+
+
 def create_app():
-    app=Flask(__name__)
-    @app.get('/healthz')
-    def h(): return {'ok': True}
-    @app.post('/signal')
+    if Flask is None:
+        raise RuntimeError("Flask is not available; signals server cannot be started")
+
+    app = Flask(__name__)
+
+    @app.get("/healthz")
+    def h():
+        return {"ok": True}
+
+    @app.post("/signal")
     def s():
         try:
-            data=request.get_json(force=True, silent=True) or {}
-            out=ingest_signal(data)
-            return jsonify({'ok': bool(out), 'action': (out or {}).get('guard_action')})
-        except Exception as e:
-            return jsonify({'ok': False, 'error': str(e)}), 400
+            data = request.get_json(force=True, silent=True) or {}
+            out = ingest_signal(data)
+            return jsonify({"ok": bool(out), "action": (out or {}).get("guard_action")})
+        except Exception as e:  # pragma: no cover - defensive
+            return jsonify({"ok": False, "error": str(e)}), 400
+
     return app
+
+
 def start_signals_server_if_enabled():
-    enable = os.getenv('SIGNALS_HTTP','0').lower() in {'1','true','yes'}
-    if not enable: return None
-    bind=os.getenv('SIGNALS_BIND','0.0.0.0:8080'); host,port=(bind.split(':',1)+['8080'])[:2]
-    app=create_app()
-    def run(): app.run(host=host, port=int(port), debug=False, use_reloader=False)
-    th=Thread(target=run, daemon=True); th.start(); return th
+    enable = os.getenv("SIGNALS_HTTP", "0").lower() in {"1", "true", "yes"}
+    if not enable:
+        return None
+
+    if Flask is None:
+        logging.warning("Signals HTTP server requested but Flask is not installed")
+        return None
+
+    bind = os.getenv("SIGNALS_BIND", "0.0.0.0:8080")
+    host, port = (bind.split(":", 1) + ["8080"])[:2]
+    app = create_app()
+
+    def run():
+        app.run(host=host, port=int(port), debug=False, use_reloader=False)
+
+    th = Thread(target=run, daemon=True)
+    th.start()
+    return th
diff --git a/reports/aggregates.py b/reports/aggregates.py
index ec6d256..6e97400 100644
--- a/reports/aggregates.py
+++ b/reports/aggregates.py
@@ -1,23 +1,75 @@
 from decimal import Decimal
-def _D(x): return Decimal(str(x or 0))
+
+
+def _dec(value) -> Decimal:
+    return Decimal(str(value or 0))
+
+
 def aggregate_per_asset(entries, wallet=None):
-    acc={}
-    for e in entries:
-        if wallet and (e.get("wallet") or "").lower()!=wallet.lower(): continue
-        a=(e.get("asset") or "?").upper()
-        acc.setdefault(a, {"in_qty":_D(0),"out_qty":_D(0),"in_usd":_D(0),"out_usd":_D(0),"realized_usd":_D(0)})
-        side=(e.get("side") or "").upper(); qty=_D(e.get("qty")); usd=_D(e.get("usd"))
-        if side=="IN": acc[a]["in_qty"]+=qty; acc[a]["in_usd"]+=usd
-        elif side=="OUT": acc[a]["out_qty"]+=qty; acc[a]["out_usd"]+=usd
-        acc[a]["realized_usd"]+=_D(e.get("realized_usd"))
-    rows=[]
-    for a,v in acc.items():
-        netq=v["in_qty"]-v["out_qty"]; netu=v["in_usd"]-v["out_usd"]
-        rows.append({"asset":a, **{k:str(vv) for k,vv in v.items()}, "net_qty":str(netq), "net_usd":str(netu)})
+    acc = {}
+    for entry in entries:
+        if wallet and (entry.get("wallet") or "").lower() != wallet.lower():
+            continue
+        asset = (entry.get("asset") or "?").upper()
+        bucket = acc.setdefault(
+            asset,
+            {
+                "in_qty": Decimal("0"),
+                "out_qty": Decimal("0"),
+                "in_usd": Decimal("0"),
+                "out_usd": Decimal("0"),
+                "realized_usd": Decimal("0"),
+                "tx_count": 0,
+            },
+        )
+
+        side = (entry.get("side") or "").upper()
+        qty = _dec(entry.get("qty"))
+        usd = _dec(entry.get("usd"))
+        if side == "IN":
+            bucket["in_qty"] += qty
+            bucket["in_usd"] += usd
+        elif side == "OUT":
+            bucket["out_qty"] += qty
+            bucket["out_usd"] += usd
+
+        bucket["realized_usd"] += _dec(entry.get("realized_usd"))
+        bucket["tx_count"] += 1
+
+    rows = []
+    for asset, values in acc.items():
+        net_qty = values["in_qty"] - values["out_qty"]
+        net_usd = values["in_usd"] - values["out_usd"]
+        rows.append(
+            {
+                "asset": asset,
+                "in_qty": values["in_qty"],
+                "out_qty": values["out_qty"],
+                "in_usd": values["in_usd"],
+                "out_usd": values["out_usd"],
+                "realized_usd": values["realized_usd"],
+                "tx_count": values["tx_count"],
+                "net_qty": net_qty,
+                "net_usd": net_usd,
+            }
+        )
+
     return rows
+
+
 def totals(rows):
-    from decimal import Decimal
-    t={k:Decimal("0") for k in ["in_qty","out_qty","in_usd","out_usd","net_qty","net_usd","realized_usd"]}
-    for r in rows:
-        for k in t: t[k]+=Decimal(str(r.get(k) or 0))
-    return {k:str(v) for k,v in t.items()}
+    totals_map = {
+        "in_qty": Decimal("0"),
+        "out_qty": Decimal("0"),
+        "in_usd": Decimal("0"),
+        "out_usd": Decimal("0"),
+        "net_qty": Decimal("0"),
+        "net_usd": Decimal("0"),
+        "realized_usd": Decimal("0"),
+    }
+
+    for row in rows:
+        for key in totals_map:
+            totals_map[key] += _dec(row.get(key))
+
+    return totals_map