jgrusewski acdafe508e feat(rl): Phase 4.2 — DuelingQHead trainer integration (diagnostic mode)
Implements §6 of the Phase 4 spec — wires DuelingQHead into
IntegratedTrainer in DIAGNOSTIC-ONLY mode (V_dq trains via Bellman
loss every step, but does NOT yet feed PPO advantage — that's
Phase 4.3, a 10-LOC follow-up commit).

IntegratedTrainer additions:
  - dueling_q_head: DuelingQHead field
  - 4 AdamW states (w_v, b_v, w_a, b_a) — LR from RL_LR_Q_INDEX
  - 19 per-step buffer fields:
    Forward outputs:
      dueling_v_d [B], dueling_v_tp1_d [B], dueling_a_d [B×N],
      dueling_q_composed_d [B×N]
    Target net forward scratch:
      dueling_q_target_composed_d [B×N], dueling_v_target_tp1_d [B],
      dueling_a_target_tp1_d [B×N]
    Loss path scratch:
      dueling_v_loss_d [B], dueling_a_loss_d [B×N],
      dueling_target_value_d [B], dueling_loss_pb_d [B],
      dueling_grad_composed_d [B×N]
    Per-batch weight grads:
      dueling_grad_w_v_pb_d [B×HIDDEN_DIM], dueling_grad_b_v_pb_d [B],
      dueling_grad_w_a_pb_d [B×HIDDEN_DIM×N], dueling_grad_b_a_pb_d [B×N]
    Reduced weight grads:
      dueling_grad_w_v_d [HIDDEN_DIM], dueling_grad_b_v_d [1],
      dueling_grad_w_a_d [HIDDEN_DIM×N], dueling_grad_b_a_d [N]

10-step launch sequence in step_with_lobsim_gpu_body (after existing
IQN forward block):

  1. dueling_q_head.forward(h_t_borrow)            → V_dq, A, composed_Q
  2. dueling_q_head.forward(h_tp1_d)               → V_dq_tp1
  3. dueling_q_head.forward(sampled_h_t_d)         → online composed_Q for loss
  4. dueling_q_head.forward_target(sampled_h_tp1_d) → target composed_Q
  5. build_bellman_target(target_composed, r, dones, γ^n) → target_value
  6. compute_loss_and_grad(online, target, actions)    → loss + grad_composed
  7. decompose_and_backward_to_weights(sampled_h_t, grad, actions)
                                                       → per-batch w/b grads
  8. reduce_axis0_free × 4 → final weight grads
  9. LR ← ISV[RL_LR_Q_INDEX] (DuelingQHead is a Q learner)
 10. Adam step × 4 (w_v, b_v, w_a, b_a)

What's NOT yet done (Phase 4.3):
  - compute_advantage_return STILL uses v_pred_d / v_pred_tp1_d
    (Plan A v2 path UNTOUCHED — qpa should stay healthy in cluster smoke)
  - Soft-update of target net weights (recommend reusing
    dqn_target_soft_update_fn kernel in Phase 4.3)
  - Diag JSONL fields for dueling_v_at_taken_ema, dueling_loss

Validated:
  - cargo build --release clean
  - integrated_trainer_smoke (1 step end-to-end) passes
  - alpha_rl_train --steps 3 --n-backtests 128 under compute-sanitizer
    memcheck: 0 errors, l_q rising 0 → 0.024, l_v = 0.0001

CRITICAL: This commit should be cluster-validated BEFORE Phase 4.3.
At b=1024 5k steps, expected:
  - qpa stays healthy (composed_Q_dq doesn't feed ensemble)
  - pnl matches Plan A v2 trajectory exactly (V_dq doesn't drive PPO)
  - V_dq trains stably (visible in compute-sanitizer's grad flow)

If cluster shows any regression, the bug is in this commit's wiring,
NOT in Plan A v2 (which is structurally preserved).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-30 08:48:35 +02:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
No description provided
Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
PLpgSQL 0.8%
Other 0.8%