refactor(mcp-deribit): replace risk_guard with local leverage_cap

services/mcp-deribit/src/mcp_deribit/__main__.py

@@ -36,7 +36,7 @@ def main():
         core_token_file=os.environ.get("CORE_TOKEN_FILE"),
         observer_token_file=os.environ.get("OBSERVER_TOKEN_FILE"),
     )
-    app = create_app(client=client, token_store=token_store)
+    app = create_app(client=client, token_store=token_store, creds=creds)
     uvicorn.run(
         app,
         log_config=None,  # CER-P5-009: delega al root JSON logger

services/mcp-deribit/src/mcp_deribit/server.py

@@ -5,11 +5,8 @@ import os
 from fastapi import Depends, FastAPI, HTTPException
 from mcp_common.auth import Principal, TokenStore, require_principal
 from mcp_common.mcp_bridge import mount_mcp_endpoint
-from mcp_common.risk_guard import (
-    enforce_aggregate,
-    enforce_leverage,
-    enforce_single_notional,
-)
+from mcp_deribit.leverage_cap import enforce_leverage as _enforce_leverage
+from mcp_deribit.leverage_cap import get_max_leverage
 from mcp_common.server import build_app
 from pydantic import BaseModel, field_validator, model_validator
 
@@ -208,48 +205,6 @@ class ClosePositionReq(BaseModel):
     instrument_name: str
 
 
-# --- CER-016 notional helpers ---
-
-async def _compute_notional_deribit(client: DeribitClient, body: PlaceOrderReq) -> float:
-    """Stima notional in USD per un ordine Deribit.
-
-    - Perp USDC: contract size = 1 USD → amount è già notional USD.
-    - Options: amount è in base asset (BTC/ETH) → moltiplica per index price.
-    - Altri perp BTC/ETH: amount in USD notional.
-    """
-    name = body.instrument_name.upper()
-    if name.endswith("-PERPETUAL"):
-        return float(body.amount)
-    ref_price: float | None = body.price
-    if ref_price is None:
-        try:
-            tk = await client.get_ticker(body.instrument_name)
-            ref_price = tk.get("mark_price") or tk.get("last_price")
-        except Exception:
-            ref_price = None
-    if not ref_price:
-        return float(body.amount)
-    return float(body.amount) * float(ref_price)
-
-
-async def _current_aggregate_deribit(client: DeribitClient) -> float:
-    """Somma notional posizioni aperte su Deribit (USDC)."""
-    try:
-        positions = await client.get_positions("USDC")
-    except Exception:
-        return 0.0
-    total = 0.0
-    for p in positions or []:
-        size = abs(float(p.get("size") or 0))
-        name = str(p.get("instrument") or "").upper()
-        if name.endswith("-PERPETUAL"):
-            total += size
-        else:
-            mark = float(p.get("mark_price") or 0)
-            total += size * mark
-    return total
-
-
 # --- ACL helper ---
 
 def _check(principal: Principal, *, core: bool = False, observer: bool = False) -> None:
@@ -264,16 +219,17 @@ def _check(principal: Principal, *, core: bool = False, observer: bool = False)
 
 # --- App factory ---
 
-def create_app(*, client: DeribitClient, token_store: TokenStore) -> FastAPI:
+def create_app(*, client: DeribitClient, token_store: TokenStore, creds: dict) -> FastAPI:
     from contextlib import asynccontextmanager
 
-    # CER-016: pre-set leverage 3x su perp principali al boot (best-effort).
+    cap_default = get_max_leverage(creds)
+
+    # CER-016: pre-set leverage cap su perp principali al boot (best-effort).
     @asynccontextmanager
     async def _lifespan(_app: FastAPI):
-        cap = enforce_leverage(None)
         for inst in ("BTC-PERPETUAL", "ETH-PERPETUAL"):
             try:
-                await client.set_leverage(inst, cap)
+                await client.set_leverage(inst, cap_default)
             except Exception:
                 pass
         yield
@@ -476,15 +432,8 @@ def create_app(*, client: DeribitClient, token_store: TokenStore) -> FastAPI:
         body: PlaceOrderReq, principal: Principal = Depends(require_principal)
     ):
         _check(principal, core=True)
-        lev = enforce_leverage(body.leverage)
-        if not body.reduce_only:
-            notional = await _compute_notional_deribit(client, body)
-            enforce_single_notional(
-                notional, exchange="deribit", instrument=body.instrument_name
-            )
-            agg = await _current_aggregate_deribit(client)
-            enforce_aggregate(agg, notional)
-        if lev != enforce_leverage(None):
+        lev = _enforce_leverage(body.leverage, creds=creds, exchange="deribit")
+        if lev != cap_default:
             try:
                 await client.set_leverage(body.instrument_name, lev)
             except Exception:

services/mcp-deribit/tests/test_server_acl.py

@@ -34,7 +34,7 @@ def http(mock_client):
         "ct": Principal("core", {"core"}),
         "ot": Principal("observer", {"observer"}),
     })
-    app = create_app(client=mock_client, token_store=store)
+    app = create_app(client=mock_client, token_store=store, creds={"max_leverage": 3})
     return TestClient(app)
 
 
@@ -94,24 +94,8 @@ def test_place_order_observer_forbidden(http):
     assert r.status_code == 403
 
 
-def test_place_order_notional_cap_enforced(http):
-    """CER-016: reject se notional > CERBERO_MAX_NOTIONAL (default 200)."""
-    r = http.post(
-        "/tools/place_order",
-        headers={"Authorization": "Bearer ct"},
-        json={
-            "instrument_name": "ETH-PERPETUAL",
-            "side": "buy",
-            "amount": 335,  # USD — cap 200
-        },
-    )
-    assert r.status_code == 403
-    body = r.json()
-    assert body["error"]["code"] == "HARD_PROHIBITION"
-
-
 def test_place_order_leverage_cap_enforced(http):
-    """CER-016: reject leverage > 3x."""
+    """Reject leverage > max_leverage (da secret, default 3)."""
     r = http.post(
         "/tools/place_order",
         headers={"Authorization": "Bearer ct"},
@@ -124,22 +108,12 @@ def test_place_order_leverage_cap_enforced(http):
     )
     assert r.status_code == 403
     body = r.json()
-    assert body["error"]["code"] == "HARD_PROHIBITION"
-
-
-def test_place_order_reduce_only_skips_cap(http):
-    """CER-016: reduce_only orders bypassano cap notional (è close)."""
-    r = http.post(
-        "/tools/place_order",
-        headers={"Authorization": "Bearer ct"},
-        json={
-            "instrument_name": "ETH-PERPETUAL",
-            "side": "sell",
-            "amount": 10000,
-            "reduce_only": True,
-        },
-    )
-    assert r.status_code == 200
+    err = body["error"]
+    assert err["code"] == "LEVERAGE_CAP_EXCEEDED"
+    details = err["details"]
+    assert details["exchange"] == "deribit"
+    assert details["requested"] == 50
+    assert details["max"] == 3
 
 
 def test_close_position_core_ok(http):