gdharness

An agent cannot see a running game. It reads your scripts and guesses at the rest: whether the button is on screen, whether the panel updated, whether that error mattered.

gdharness makes the engine answerable instead. What the screen says, where a control is, what a property reads right now, what the console printed, what broke and on which line.

Install

Hand this to your agent:

Install gdharness here by following https://aureliolo.github.io/gdharness/agent.md,
then tell me what it asked you to recommend back to me.

Or do it yourself, and pick your harness: aureliolo.github.io/gdharness.

The loop it exists for

editor_run      { "op": "start", "projectPath": "C:/games/hall" }
runtime_inspect { "op": "find", "says": "Buy" }              // the button, by the word on it
runtime_input   { "op": "click", "nodePath": "/root/Hall/Ledger/BuyButton" }
runtime_inspect { "op": "text", "nodePath": "/root/Hall/Ledger" }   // what the panel says now
editor_output   { "projectPath": "C:/games/hall" }           // errors and warnings, with backtraces

The open editor plays the game, so its debugger holds it, which is what lets you set a breakpoint and read the variables in scope when it stops.

Every answer is read back out of the engine after the fact, never echoed from the request. A tool that cannot answer says which state it is in and what would change it, rather than answering emptily, so a call that succeeded is a call that was understood.

At a glance

Older 4.x is likely to work and is not tested.

Documentation

aureliolo.github.io/gdharness: installing it, how the parts connect, and every tool, op and argument.

SECURITY.md is how to report something. CONTRIBUTING.md is what a change has to clear.

Project

Fork of GoPeak v2.3.9, September 2026, MIT: the original MCP server godot-mcp by Solomon Elias, GoPeak by HaD0Yun, and completely reworked since to be hardened, condensed and more streamlined.

Not affiliated with the Godot Foundation.