A reinforcement learning agent for Hollow Knight: Silksong boss fights.

Currently specialized for the Lace boss fight.

1. Disable Steam Cloud synchronization
2. Install BepInEx in the Steam game installation folder
3. Create steam_appid.txt in the game folder and enter 1030300

Note: Multiple game instances are automatically created at runtime using junctions and hard links. No manual copying required.

Copy resources/user1.dat to:

%USERPROFILE%\AppData\LocalLow\Team Cherry\Hollow Knight Silksong\default

1. Copy plugin/Directory.Build.props.example → plugin/Directory.Build.props
2. Copy .env.example → .env
3. Set SILKSONG_PATH to the game executable path

SILKSONG_PATH=D:/Games/Silksong/Hollow Knight Silksong.exe

dotnet build plugin

The built plugin will be automatically copied to the game's BepInEx/plugins/ folder.

uv run train.py
uv run train.py --n_envs 4
uv run train.py --n_envs 4 --checkpoint ./models/rl_model_1000_steps.zip

Tip: Use -nofx mode (enabled by default in training) for faster step processing.

uv run train.py --eval --checkpoint ./models/rl_model_1000_steps.zip

uv run tune.py --n_trials 30 --n_envs 2

tensorboard --logdir ./logs

When running with --n_envs > 1, the system automatically creates instance folders:

Hollow Knight Silksong/
├── Hollow Knight Silksong.exe           # Original (not used)
├── Hollow Knight Silksong_Data/
├── BepInEx/
├── MonoBleedingEdge/
└── instances/
    ├── 1/
    │   ├── Hollow Knight Silksong.exe   # Copy
    │   ├── Hollow Knight Silksong_Data/ # Junction → Original
    │   ├── MonoBleedingEdge/            # Junction → Original
    │   ├── UnityPlayer.dll              # Hard link → Original
    │   └── BepInEx/
    │       ├── plugins/                 # Junction → Original
    │       └── config/                  # Copy (separate per instance)
    ├── 2/
    │   └── ...

• Junctions: Folders (no admin required)
• Hard links: Large files like UnityPlayer.dll (saves disk space)
• Copies: Config files (avoid sharing conflicts)

The -nofx flag significantly reduces CPU/GPU usage by disabling:

• Visual effects (particles, trails, blur, post-processing)
• Audio components
• Camera effects
• Vibration/haptics

Press F9 to toggle minimal rendering (16x16 resolution) during NoFx mode.

When the game runs with the plugin installed, keyboard input is blocked and the Lace boss fight starts automatically. Use the -manual argument when you need to modify equipment/items.

"D:/Games/Silksong/Hollow Knight Silksong.exe" -manual

┌─────────────────┐     Shared Memory      ┌─────────────────┐
│                 │ ◄──────────────────────│                 │
│  Python (RL)    │     GameState          │  Game (Plugin)  │
│                 │ ──────────────────────►│                 │
└─────────────────┘     Command            └─────────────────┘

To train on other bosses, modify the following files:

Tip: Analyze the boss's state through PlayMakerFSM.

This project was inspired by HKRL.

MIT License