Tool Defense

Mods games

Install Command

npx claude-code-templates@latest --mod games/tool-defense

Content

Early access. A mod is a complete Claude Code plugin built on function hooks (Anthropic's mods/ layout); it loads in Claude Code 2.1.259+ with CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1 and the $ API may still change between releases. Hooks module: hooks/register.tsx. Run claude plugin validate on the installed folder to see every event it hooks and every $ call it makes.

tool-defense

A tower defense above the Claude Code prompt where every enemy is one of Claude's real tool calls: Bash sends runners, an Edit or Write a slow tank, a web or MCP call a flyer, an Agent a boss. Build and upgrade towers by clicking beside the road, hold the base through Claude's turn. Zero tokens: the mod answers every key and click itself and never asks the model anything.

Play

/defense opens the board above the prompt (/defense stop or the close button closes it).
Click the board to give it the mouse and keyboard; Esc gives them back to the prompt.
Click a free cell to build a tower (25 gold), click a tower to upgrade it (30, then 50): more range, more damage, faster fire. Space or p pauses, r restarts.
Enemies walk the road from the left to your base on the right; ten get through and the base falls. Each kill pays gold and points.

Every tool call Claude makes releases one enemy the moment the call starts, shaped by the tool:

tool	enemy
Bash, PowerShell	`▶▶` runner: fast, fragile
Edit, Write, NotebookEdit	`██` tank: slow, tough
WebFetch, WebSearch, any MCP tool	`◢◣` flyer: crosses the bottom row over the towers' heads
Agent, Workflow	`▓▓` boss
anything else (Read, Grep, Glob, ...)	`▪▪` scout

Between Claude's calls a quiet trickle of scouts keeps the game alive, so it is playable on its own too. A long turn with many tool calls is the real wave: build before you press Enter.

Your best score is kept in the plugin's store across sessions.

Install

npx claude-code-templates@latest --mod games/tool-defense
CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1 claude

It is written to .claude/skills/tool-defense/, which Claude Code auto-loads as tool-defense@skills-dir. For one session with hot reload: CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1 claude --plugin-dir .claude/skills/tool-defense. claude plugin validate .claude/skills/tool-defense prints every event it hooks and every $ call it makes.

How it is built

hooks/register.tsx is the hooks module: it registers /defense, mounts the board on the AbovePrompt band and keeps the score in $.store. hooks/games/*.ts is the game's logic, pure functions with no drawing, and hooks/boards/*.tsx is the surface module that draws it in two-character cells on the drawing thread and takes the keys and the mouse. Written for aitmpl.com against Anthropic's published function-hooks declarations.

Requirements

Claude Code 2.1.269 or later (the first build whose function hooks draw above the prompt) with CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1. The $ API is early access and may change between releases.
An interactive terminal that reports the mouse. Nothing draws in claude -p, the desktop app or mobile.
A terminal font with box-drawing and block characters.

A clone of the genre, not affiliated with or endorsed by the original publisher.