Pendulum

Client-side JavaScript executor for Minecraft. Automate player actions — movement, construction, combat, inventory, world queries, and Baritone supported. Designed for both human players and AI agents.

This mod is partly inspired by Playwright.js, which allows agents to control web browsers via JavaScript. Pendulum brings that same power to Minecraft, enabling complex automation and AI integration through a simple JS API.

Version Support

Minecraft Fabric Forge NeoForge Status 1.20.1 ✅ ✅ Fully Supported 1.21.1 ✅ ❌ ✅ Fully Supported 26.1.2 🔨 ❌ 🔨 In development

Features

For detailed documentation, see the Documentation

🧑 For Players

/pendulum execute — run JavaScript inline in chat
/pendulum file — run .js scripts from .minecraft/pendulum/
mc.* — 80+ API functions: mc.player.forward(), mc.world.findBlocks(), mc.inv.hasItem(), mc.gui.click(), and more. Log via pendulum.log(), pendulum.warn(), pendulum.error().
br.* — 45 Baritone functions: pathfinding, mining, farming, building schematics

🤖 For AI Agents

MCP JSON-RPC 2.0 over TCP — native AI agent integration
script/eval — execute arbitrary JS and return results
script/status / script/abort — manage script state
gui/enumerateWidgets — full recursive widget tree
gui/guiElements — read all visible GUI controls
gui/screenshot — capture the game view
simulate/click / gui/clickButton — click GUI elements
simulate/typeText / simulate/pressKey — keyboard input
Compatible with VS Code Copilot, Claude Desktop, and any MCP client

Quick Start

// Walk forward 1 second /pendulum execute mc.player.forward(20) // Mine all pumpkins nearby /pendulum execute for(let p of mc.world.findBlocks('minecraft:pumpkin',8)){ mc.player.breakBlockAt(p.x,p.y,p.z) } // Run a script file /pendulum file farm.js // AI Agent workflow: screenshot + click gui/screenshot → gui/clickButton("Done") → simulate/typeText("Hello", true)