Architecture: hftbacktest replaces _fill_from_levels() + manual book updates Everything above transition() stays the same What changes: - HftBacktestCWM: new class implementing CodeWorldModel protocol - transition(): submit/cancel via hftbacktest, convert state back - fill model: ProbQueueModel (queue-position-aware) - latency: interpolated from historical data What does NOT change: - Planner (SM-MCTS, EXP3, Thompson, etc.) - Counterparty ecology (ToxicTaker, PassiveMaker, etc.) - Risk gate (all 6 checks) - CMA-ES trainer - PerformanceMatrix - Reward function (same PnL + adverse selection + risk) - Action menu, FulfilmentAction, ScenarioFactory - ALL existing tests Integration: 3 steps, zero core changes: 1. Create malkhut/cwm/hft_cwm.py 2. Swap cwm_factory in PolicyEvaluator 3. Done
360 lines
16 KiB
Markdown
360 lines
16 KiB
Markdown
# hftbacktest CWM Integration Design
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**Goal:** Use hftbacktest as the simulated exchange/OB engine underneath MALKHUT's
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CWM, while keeping the entire game-theoretic layer (planner, counterparty ecology,
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CMA-ES, risk gate, PerformanceMatrix) unchanged.
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**Principle:** hftbacktest replaces `_fill_from_levels()` + manual book updates.
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Everything above `transition()` stays the same.
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---
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## Architecture: What Changes, What Doesn't
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```
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MALKHUT (unchanged)
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┌──────────────────────────────────────────────────────────────┐
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│ Planner (DecoupledUCBPlanner / EXP3 / Thompson / ...) │
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│ CounterpartyEcology (ToxicTaker / PassiveMaker / ...) │
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│ RiskGate (kill_switch / self_trade / leverage / ...) │
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│ CMA-ES Trainer + PerformanceMatrix + StrategySelector │
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│ FulfilmentAction (order_type × time_in_force × post_only) │
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└──────────────┬───────────────────────────────────────────────┘
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│ calls transition(state, joint_action)
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▼
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┌──────────────────────────────────────────────────────────────┐
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│ CWM Protocol: transition() / reward() / terminal() │
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│ ┌────────────────────────────────────────────────────────┐ │
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│ │ HftBacktestCWM (NEW — replaces MinimalCryptoLOBCWM) │ │
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│ │ │ │
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│ │ transition() → hftbacktest submit/cancel + elapse │ │
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│ │ reward() → MALKHUT reward function (unchanged) │ │
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│ │ terminal() → unchanged │ │
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│ └────────────────────────────────────────────────────────┘ │
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└──────────────┬───────────────────────────────────────────────┘
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│ internally calls
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▼
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┌──────────────────────────────────────────────────────────────┐
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│ hftbacktest HashMapMarketDepthBacktest │
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│ (Rust-backed, event-driven LOB simulation) │
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│ │
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│ .submit_buy_order() ← our PLACE/CROSS_SPREAD │
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│ .submit_sell_order() ← our PLACE/CROSS_SPREAD │
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│ .cancel() ← our CANCEL │
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│ .elapse(nanoseconds) ← time progression │
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│ .depth() ← current book snapshot │
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│ .position() ← our current position │
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│ │
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│ Features: │
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│ - ProbQueueModel: probabilistic fill based on queue pos │
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│ - Interpolated latency: exchange + local event ordering │
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│ - Partial fills: order fills across multiple levels │
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│ - Fee models: flat_per_trade or trading_value │
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│ - Tick/lot: enforced by the engine │
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└──────────────────────────────────────────────────────────────┘
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```
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## The Bridge: HftBacktestCWM
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```python
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class HftBacktestCWM:
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"""CWM backed by hftbacktest's event-driven LOB engine.
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Implements the same CodeWorldModel protocol as MinimalCryptoLOBCWM.
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Drop-in replacement: same transition() / reward() / terminal() API.
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"""
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def __init__(
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self,
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symbol: str = "BTCUSDT",
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tick_size: float = 0.1,
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lot_size: float = 0.001,
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maker_fee_bps: float = 2.0,
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taker_fee_bps: float = 5.0,
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latency_ns: int = 100_000_000, # 100ms order latency
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data: Optional[np.ndarray] = None, # pre-loaded L2 event data
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):
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import hftbacktest as hbt
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asset = (hbt.BacktestAsset()
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.linear_asset(1.0) # linear (not inverse) perp
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.tick_size(tick_size)
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.lot_size(lot_size)
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.flat_per_trade_fee_model(maker_fee_bps / 10_000,
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taker_fee_bps / 10_000)
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.constant_order_latency(latency_ns, latency_ns)
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.power_prob_queue_model(3) # queue position model
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.partial_fill_exchange()
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)
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if data is not None:
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asset.add_data(data)
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self.hbt = hbt.build_hashmap_backtest([asset])
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self._symbol = symbol
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self._tick_size = tick_size
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self._lot_size = lot_size
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self._order_id_seq = 0
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self._pending_fills = [] # filled orders awaiting retrieval
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def transition(
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self,
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state: MarketWorldState,
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joint_action: JointAction,
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) -> MarketWorldState:
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our_action = joint_action[0]
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counterparty_actions = joint_action[1:]
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# 1. Process our action through hftbacktest
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if isinstance(our_action, FulfilmentAction):
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self._process_our_action(our_action, state)
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# 2. Process counterparty actions through hftbacktest
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for cp in counterparty_actions:
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if isinstance(cp, CounterpartyAction):
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self._process_counterparty(cp, state)
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# 3. Elapse time (advance the engine by one tick)
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self.hbt.elapse(1_000_000) # 1ms
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# 4. Wait for order responses
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self.hbt.wait_next_feed()
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self.hbt.wait_order_response()
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# 5. Convert hftbacktest state → MALKHUT MarketWorldState
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return self._build_next_state(state, our_action)
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def _process_our_action(self, action: FulfilmentAction, state: MarketWorldState):
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"""Convert MALKHUT FulfilmentAction → hftbacktest order submission."""
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import hftbacktest as hbt
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if action.kind.value in ("PLACE", "CANCEL_REPLACE"):
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price = materialize_price_from_action(state, action)
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if price is None:
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return
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qty = action.qty_fraction * state.account.available_balance / max(price, 1e-12)
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qty = _round_lot(qty, self._lot_size)
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if qty <= 0:
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return
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self._order_id_seq += 1
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if action.side == Side.BUY:
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self.hbt.submit_buy_order(
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self._order_id_seq, qty, price,
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hbt.Trigger.GTC,
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)
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else:
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self.hbt.submit_sell_order(
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self._order_id_seq, qty, price,
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hbt.Trigger.GTC,
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)
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elif action.kind.value == "CROSS_SPREAD":
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# Aggressive fill: submit at best available
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price = materialize_price_from_action(state, action)
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if price is None:
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return
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qty = action.qty_fraction * state.account.available_balance / max(price, 1e-12)
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qty = _round_lot(qty, self._lot_size)
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if qty <= 0:
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return
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self._order_id_seq += 1
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# Submit IOC-like (aggressive limit at market price)
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if action.side == Side.BUY:
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self.hbt.submit_buy_order(
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self._order_id_seq, qty, state.book.best_ask,
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hbt.Trigger.IOC,
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)
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else:
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self.hbt.submit_sell_order(
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self._order_id_seq, qty, state.book.best_bid,
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hbt.Trigger.IOC,
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)
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elif action.kind.value == "CANCEL":
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if action.cancel_order_id:
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oid = self._parse_order_id(action.cancel_order_id)
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self.hbt.cancel(oid)
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def _process_counterparty(self, cp: CounterpartyAction, state: MarketWorldState):
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"""Counterparty actions hit the hftbacktest book as external events."""
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if cp.kind.value == "CROSS_SPREAD" and cp.side:
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# Counterparty crosses spread → inject as external trade
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qty = cp.qty_fraction_of_top * state.account.available_balance / max(
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state.book.mid if state.book.bids and state.book.asks else 1.0, 1e-12)
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price = state.book.best_ask if cp.side == Side.BUY else state.book.best_bid
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# hftbacktest handles this via feed events (external trades)
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# For simplicity, we submit as IOC from "other" side
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self._order_id_seq += 1
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if cp.side == Side.BUY:
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self.hbt.submit_sell_order(
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self._order_id_seq, qty, price, hbt.Trigger.IOC,
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)
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else:
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self.hbt.submit_buy_order(
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self._order_id_seq, qty, price, hbt.Trigger.IOC,
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)
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def _build_next_state(
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self,
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prev_state: MarketWorldState,
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action: FulfilmentAction,
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) -> MarketWorldState:
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"""Convert hftbacktest engine state → MALKHUT MarketWorldState."""
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# Get current position from hftbacktest
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hbt_pos = self.hbt.position(0) # asset index 0
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# Get current book depth
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bid_depth = self.hbt.depth(0, is_ask=False) # bid levels
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ask_depth = self.hbt.depth(0, is_ask=True) # ask levels
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# Convert to MALKHUT OrderBookState
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bids = tuple(
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PriceLevel(float(level.px), float(level.qty))
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for level in bid_depth[:20] # top 20 levels
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if level.qty > 0
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)
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asks = tuple(
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PriceLevel(float(level.px), float(level.qty))
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for level in ask_depth[:20]
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if level.qty > 0
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)
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book = OrderBookState(
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ts_ns=prev_state.ts_ns + 1_000_000,
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symbol=self._symbol,
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bids=bids or (PriceLevel(0.0, 0.0),),
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asks=asks or (PriceLevel(0.0, 0.0),),
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)
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# Convert position
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pos_qty = float(hbt_pos.qty)
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pos_avg = float(hbt_pos.avg_entry_price) if pos_qty != 0 else 0.0
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# ... (equity, available_balance, path_state calculation same as current CWM)
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return MarketWorldState(
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ts_ns=prev_state.ts_ns + 1_000_000,
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mode=prev_state.mode,
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venue=prev_state.venue,
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book=book,
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account=new_account,
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open_orders=(), # hftbacktest tracks internally
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trade_path=new_trade_path,
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intent=prev_state.intent,
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)
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def reward(self, prev_state, action, next_state, params):
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"""Same reward function as current CWM — unchanged."""
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return compute_reward_vectorized(...)
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def terminal(self, state, depth):
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"""Same terminal check — unchanged."""
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return depth <= 0
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```
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## Data Flow: How Actions Become Fills
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```
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Step 1: Planner calls plan(state, params) → PlannedPolicy
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selected_action = FulfilmentAction(PLACE, BUY, LIMIT, offset=5, tif=IOC)
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Step 2: CMA-ES calls transition(state, (our_action, cp1, cp2, cp3))
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Step 3: HftBacktestCWM.transition():
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a. submit_buy_order(id=42, qty=0.01, price=63999.5, IOC)
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b. Counterparty ToxicTaker: submit_sell_order(id=43, qty=0.005, IOC)
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c. hbt.elapse(1ms) → engine processes events
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d. hbt.wait_order_response() → fills collected
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e. _build_next_state() → MarketWorldState with updated book/position
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Step 4: CMA-ES calls reward(prev, action, next, params)
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→ Same reward function (unchanged)
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Step 5: Repeat for next step
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```
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## What We Get vs Current CWM
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| Feature | Current CWM | hftbacktest CWM |
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|---------|-------------|-----------------|
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| **Fill model** | Deterministic level consumption | Probabilistic queue position (PowerProbQueue) |
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| **Queue position** | Estimated (qty * 0.5) | Modeled from order arrival/cancel dynamics |
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| **Latency** | Instant fill | Interpolated from historical (100ms exchange latency) |
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| **Partial fills** | Yes (level-by-level) | Yes (queue-aware) |
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| **Market impact** | Simple 0.5 * fraction | Implicit in book consumption + refill |
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| **Fee model** | Manual calculation | Built-in (flat_per_trade) |
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| **Counterparty fills** | External trade injection | Same (IOC orders from other side) |
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| **Reward function** | MALKHUT custom | **UNCHANGED** — same PnL + adverse selection + risk |
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| **Path state** | MALKHUT MAE/MFE | **UNCHANGED** |
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| **Risk gate** | MALKHUT RiskGate | **UNCHANGED** |
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| **Planner** | MALKHUT SM-MCTS | **UNCHANGED** |
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## Data Requirement
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hftbacktest needs L2 depth data in its event array format:
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```python
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# Event array dtype:
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# (ev, exch_ts, local_ts, px, qty, order_id, ival, fval)
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# ev: event type (1=depth, 2=trade, etc.)
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# exch_ts: exchange timestamp (nanoseconds)
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# local_ts: local receive timestamp (nanoseconds)
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# px: price (float64)
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# qty: quantity (float64)
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data = hbt.Recorder.data("BTCUSDT", "2026-07-01")
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```
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Sources:
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- **Tardis.dev** (tardis.dev) — historical L2 data for Binance, Bybit, etc.
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- **Binance data portal** — free daily L2 snapshots
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- **Live recording** — hftbacktest has `LiveInstrument` for real-time capture
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For our current use case (behavior-driven simulation), we can also SYNTHESIZE
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L2 data from our AssetBehavior profiles:
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```python
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def synthesize_l2_data(behavior: AssetBehavior, duration_ns: int) -> np.ndarray:
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"""Generate synthetic L2 events matching the asset's behavior profile."""
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events = []
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mid = behavior.reference_price
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for t in range(0, duration_ns, 1_000_000): # 1ms steps
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# Generate depth events from power-law profile
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for d_bps in range(1, 100):
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depth_usd = behavior.depth_at_bps(d_bps)
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price = mid * (1 + d_bps / 10_000)
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events.append(make_depth_event(t, price, depth_usd / mid))
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# Generate trade events from flow profile
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n_trades = int(behavior.flow.orders_per_sec_normal / 1000)
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for _ in range(n_trades):
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trade_price = mid * (1 + random.gauss(0, behavior.vol.annualized_normal / 100))
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events.append(make_trade_event(t, trade_price, behavior.flow.avg_trade_usd / trade_price))
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return np.array(events, dtype=EVENT_ARRAY)
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```
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## Integration Steps (no code changes to MALKHUT core)
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1. **Create `malkhut/cwm/hft_cwm.py`** — `HftBacktestCWM` class implementing
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`CodeWorldModel` protocol (transition/reward/terminal).
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2. **Wire `create_planner()` to accept CWM class** — already supports this:
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`create_planner("sm_mcts", cwm=HftBacktestCWM(...), ...)`
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3. **Update `PolicyEvaluator.cwm_factory`** — swap `MinimalCryptoLOBCWM()`
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with `HftBacktestCWM(symbol=..., data=...)`.
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4. **No changes to:** planner, counterparty ecology, CMA-ES, risk gate,
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PerformanceMatrix, ScenarioFactory, action menu, or any test.
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## Why This Is Safe
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The CWM is a **leaf dependency** — nothing depends ON it except the evaluator
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and the planner, both of which use it through the `CodeWorldModel` protocol.
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Swapping the implementation behind that protocol is a textbook Strategy pattern.
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The planner doesn't know or care whether the book is synthesized or hftbacktest.
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The reward function is pure math on (prev_state, action, next_state) — identical
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regardless of how next_state was computed.
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