gdextension

gdextension is a skill for Claude Code from jame581/GodotPrompter. It costs 38 tokens per session (2,785 once invoked), scanned A, original, MIT.

Guidance for adding native C++ or Rust code to Godot as a shared library without rebuilding the Godot engine. Native code is compiled code that runs outside the usual scripting languages.

In plain words
What is it for?
Use it for performance-critical code, C or C++ library wrappers, and language bindings when GDScript or C# is not sufficient.
Why use it?
It provides an option for code that needs more speed or must call an existing C or C++ library, while keeping the standard Godot engine.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the godot-prompter plugin — 61 skills, 9 agents, 2 hooks shipped together

Good fit Use it for performance-critical code, C or C++ library wrappers, and language bindings when GDScript or C# is not sufficient.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jame581/godotprompter/gdextension
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add jame581/GodotPrompter --skill gdextension
Clone the repo
git clone --depth 1 https://github.com/jame581/GodotPrompter

Made for: Claude Code.

Or install godot-prompter, the plugin that ships this one along with the rest of its 61 skills, 9 agents, 2 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for gdextension

README.md
[![agentmods](https://agentmods.dev/badge/skills/jame581/godotprompter/gdextension/github.svg)](https://agentmods.dev/skills/jame581/godotprompter/gdextension)
Your own site
<a href="https://agentmods.dev/skills/jame581/godotprompter/gdextension"><img src="https://agentmods.dev/badge/skills/jame581/godotprompter/gdextension/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for gdextension

Your own site · 80×15
<a href="https://agentmods.dev/skills/jame581/godotprompter/gdextension"><img src="https://agentmods.dev/badge/skills/jame581/godotprompter/gdextension.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,785 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00038 $0.02785
Opus 5.5 $0.00015 $0.01114
Sonnet 5.5 $0.00008 $0.00557
Haiku 4.5 $0.00004 $0.00279

Measured 2d ago against content hash 5920c4db5cbb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

gdextension scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/gdextension/SKILL.md · 232 lines

How it starts

The opening of the file, as written. The whole thing — 232 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GDExtension

Run native C++ (or Rust) in Godot as a shared library without recompiling the engine. Use it for performance-critical code, wrapping existing C/C++ libraries, or language bindings.

Related skills: csharp-godot for when C# is enough, gdscript-advanced for GDScript performance idioms first, godot-optimization for profiling before going native, addon-development for distributing the result, export-pipeline for shipping the binaries.


1. When to reach for GDExtension

Reach for GDScript or C# for almost all game logic. Choose GDExtension only when you genuinely need it:

  • Native speed in a hot loop that GDScript/C# can't keep up with (profile first — see godot-optimization).
  • Wrapping a C/C++ library you must call directly.
  • Building a language binding.

Contrast with C++ modules, which are compiled into the engine and therefore require shipping a custom engine binary. GDExtension's key advantage is that it runs against a stock Godot — you distribute just a shared library. It is "more complicated to use than GDScript and C#," so don't reach for it by default.

⚠️ Changed in Godot 4.7: The engine's built-in text servers (text_server_adv, text_server_fb) can no longer be built as GDExtensions — their gdextension_build/ scripts were removed. Writing your own text server as a GDExtension by subclassing TextServerExtension is unaffected. See GH-117056.


2. Project & build setup

mkdir gdextension_example && cd gdextension_example
git init
# IMPORTANT: use the godot-cpp branch matching your target engine version (e.g. 4.3),
# not the literal "4.x".
git submodule add -b 4.3 https://github.com/godotengine/godot-cpp
cd godot-cpp && git submodule update --init && cd ..

Directory layout:

gdextension_example/
├── project/                # demo project to test the extension
│   └── bin/example.gdextension
├── godot-cpp/              # C++ bindings (submodule)
└── src/
    ├── register_types.{h,cpp}
    └── gdexample.{h,cpp}

Read the full file on GitHub · 232 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago Changed · +1 lines 5920c4db5cbb
  2. 12d ago Changed 0e633145a9a8
  3. 1mo ago First seen · 231 lines · 38 tokens per session scan A f295de63452f

Subscribe to this mod's changes

gdextension is a skill published in the GitHub repository jame581/GodotPrompter (867 stars, last pushed yesterday), licensed MIT. It adds 38 tokens to every session and 2,785 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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