> ## Documentation Index > Fetch the complete documentation index at: https://docs.summerengine.com/llms.txt > Use this file to discover all available pages before exploring further. # Extending Summer > Summer is an extensible engine. Three ways to add capability: GDScript editor plugins, native GDExtension libraries, and engine modules — what each one can reach, and which to pick. Summer is a fork of Godot 4.6.1-stable with an unmodified `core/`. Everything Godot's extension system does, Summer does, and the extension points are the same ones you already know. There are three of them. They differ in what they can reach, what they cost to build, and whether you can use them at all. | You want to | Use | Language | Needs a compiler | Available to you | | ---------------------------------------------------------------------------------------------------------------- | ------------------------------------------ | ----------------- | ----------------------- | -------------------------------------------- | | Drive the editor: bakes, forced reimports, custom docks, registering autoloads, anything under `EditorInterface` | [Editor plugin](/extending/editor-plugins) | GDScript | No | **Yes, today** | | Add fast native types, wrap a C/C++/Rust library, or do heavy per-frame work | [GDExtension](/extending/gdextension) | C++, Rust, others | Yes | **Yes**, ABI-identical to stock Godot 4.6.1 | | Change the engine itself: new servers, new core types, editor internals | [Engine module](/extending/modules) | C++ | Yes, plus engine source | **No.** Summer's engine source is not public | If you are an agent, or you are automating Summer, the answer is almost always the first row. An editor plugin is a text file you write and a line you add to `project.godot`. It needs no build step, no signing, and no engine source, and it hands you the entire `EditorInterface` — which is the only way to reach a large set of engine capability that is simply not exposed to ordinary scripts. ## Editor plugins A `@tool` script extending `EditorPlugin`, declared by a `plugin.cfg` in `addons//`, enabled through `project.godot`. It runs inside the editor process with full editor context. This is the path that turns "the API is not exposed to scripting" into "the API is reachable". Occluder baking, forcing the import of a file an agent just wrote, saving a scene from code, registering an autoload — none of those are available to a plain script, and all of them are available from inside an editor plugin. It also works without a window. `Summer --headless --editor` boots the editor, loads enabled plugins, and gives you a live `EditorInterface` from a shell — with one sharp hazard around your running editor that the deep page documents in full. Templates, the three ways to enable a plugin and why they behave differently, what `EditorInterface` actually unlocks, the verification step you must not skip, and the headless-editor hazard ## GDExtension Native shared libraries loaded from a `.gdextension` file. No engine recompile, no custom binary — the same mechanism stock Godot uses. Summer branches from the 4.6.1-stable tag, so the GDExtension ABI is the stock 4.6.1 ABI. A library built against godot-cpp for 4.6 loads in Summer. Building, loading, and shipping native extensions in Summer ## Engine modules C++ compiled directly into the binary. This requires building the engine from source, and [Summer's engine source is not public](/knowledge-base/source-status), so modules are not an option for external developers today. The page exists because the distinction matters when you are reading Godot documentation and deciding which extension mechanism a tutorial is describing. What modules are, why they are internal-only in Summer, and what to use instead ## Using community Godot addons Most Godot 4 addons work in Summer unchanged. Judge one by these rules rather than by whether it names Summer anywhere: * **Godot 4.6 or 4.x, pure GDScript, `@tool` + `EditorPlugin`** — the safe case. No ABI, no compilation, no signing. Install into `addons/` and enable it like any plugin you wrote yourself. * **Godot 4.x with a GDExtension binary** — depends on the addon shipping a build for 4.6 and for your platform. The ABI is stock, so if it loads in Godot 4.6 it loads in Summer. Check [GDExtension](/extending/gdextension) before assuming. * **Godot 3.x** — dead. The 3.x plugin API does not exist in 4.x. This is not a Summer limitation; the same addon fails on stock Godot 4. * **Anything shipped as an engine module or a custom engine build** — cannot be used. There is no way to compile it into Summer. Enabling a plugin runs its code inside your editor process with full filesystem access. Read what you are enabling. This is true of stock Godot too, but it is worth saying once. ## Next steps The deep page: templates, enabling, `EditorInterface`, traps Run the engine from a shell with no window: baking, importing, exporting *** Need help or have questions? Reach out to our founders at [founders@summerengine.com](mailto:founders@summerengine.com) or join our community on [Discord](https://discord.gg/yUpgtxnZky) for fast responses.