Butterfly Knife on Shop

Version 0.1.10 for How to Fish 1.0.9.

This BepInEx mod adds one focused custom Butterfly Knife plus the game's original M9 Bayonet to the normal knife shop item. Both choices cost exactly $45.

Included knives

• M9 Bayonet (original game model)
• Butterfly Knife

Features

• A Blender-authored Butterfly V4 with continuous curved surfaces, bevels, recessed cyan inlays, liners, bores, pivot hardware, and a purple/cyan titanium finish.
• The M9 Bayonet is never replaced: it uses the original game's detailed mesh, materials, hands, and inspect animation.
• The game's native hand, finger, wrist, and knife-bone Inspect clip remains active. The Butterfly adds a real two-pin mechanical flourish: its bite handle is fixed in the palm while the safe handle fans around the actual blade pivot with out-of-plane hand clearance.
• A visual shop selector with shaded thumbnails, selection highlighting, and a separate purchase confirmation button.
• A pre-rendered high-detail Butterfly shop thumbnail so the selector stays responsive even with the production mesh.
• Uses the vanilla knife's damage, range, sharpness, inventory, save, and purchase behavior.
• Stores a purchased variant as a vanilla knife plus a reserved skin code, so normal saves continue to work.
• Multiplayer synchronization uses the existing FishNet knife object. For correct shops and visuals, the host and every player should install the same mod version.

Installation

1. Install BepInEx 5 (x64) into the game's folder if it is not already installed.
2. Copy the included BepInEx folder into: Steam\steamapps\common\How to Fish\How to Fish
3. Start the game through Steam.

Use

Visit any shop that sells the normal knife and press E on it. A cursor menu opens with the original M9 and Butterfly choices. Click a knife card, then click Buy for $45 to confirm. Press Esc or the menu's X button to close without buying. Use the game's Weapon Inspect input to play the custom flourish; the M9 uses the native game inspect.

Compatibility notes

• Tested with How to Fish 1.0.9, Unity 6000.4.4f1, and BepInEx 5.4.23.5.
• The selection menu uses the original knife interaction, so it does not depend on the shop layout used by a particular map.
• A future game update may change game methods and require a mod update.
• Joining an unmodded server will not support the reserved purchase IDs.

Asset and trademark note

This package contains no Valve or Counter-Strike model, texture, sound, or animation files. The Butterfly geometry is authored for this mod; no third-party meshes are redistributed. Product and knife names may be trademarks of their respective owners; this is an unofficial fan mod.

Development disclosure

This project was developed with substantial assistance from OpenAI Codex. The package was compiled and tested against the live game before release; its two menu entries, native M9 restoration, Butterfly production mesh, renderer replacement, and knife hierarchy integration passed the included runtime self-test.