How Can I Make A Custom Annotation Plugin?

isamatlas · September 28, 2026, 3:18pm

Godot Version

Godot 4.7.2

Question

Hi okay, so I want to make a plugin that uses a custom annotation like the @abstract method type or the @rpc method type. More specifically like @rpc. With rpc functions, you can use a special function called (roughly) multiplayer.get_sender_id() where, outside of RPC functions, the value returned would be 0, but inside of them, it would get the multiplayer sender id.

The specific plugin I’m trying to make isn’t very relevant but I’ll include it in case. I need an annotation that’s something like @silent_reciever() that silently gives the following function the calling node as a hidden last parameter called something like sender_node. By default the type sender_node would take would be “Node” or “Object” but can be specified in the parenthesis. But it’s also different from the rpc example I mentioned earlier because it HAS to be a parameter as I want static functions to be able to silently recieve the sending node too.

(this is mostly to just deal with the laziness of inputing “self” everytime i want to use a relavent function)

mrcdk · September 28, 2026, 3:44pm

It’s not possible to add custom annotations. There’s an open proposal for it:

github.com/godotengine/godot-proposals

Allow custom GDScript annotations which can be read at runtime

opened 08:42PM - 05 Aug 20 UTC

Wavesonics

topic:gdscript

**Describe the project you are working on:** Multiplayer game **Describe the pr…oblem or limitation you are having in your project:** Automaticly serializing custom data classes **Describe the feature / enhancement and how it helps to overcome the problem or limitation:** In 4.0 GDScript now has annotations. What I propose is two fold: 1. User's can declare their own custom annotations much like how Java allows you to (override a built in Annotation class) 2. User's can query a classes properties and methods for their associated annotations at runtime **Describe how your proposal will work, with code, pseudocode, mockups, and/or diagrams:** ```gdscript extends Reference class_name MyDataClass @Serialize(name="json_foo") var foo: int @Serialize var bar: String var x: Boolean ``` Then I can wrote some code to introspect `MyDataClass` and find it's properties that it wants serialized, and produce something like: ```json { "json_foo": 0, "bar": "test" } ``` **If this enhancement will not be used often, can it be worked around with a few lines of script?:** It can be worked around, it will just be less flexible and elegant. **Is there a reason why this should be core and not an add-on in the asset library?:** At least this particular approach would not be possible without support from GDScript it's self. But other approaches are possible, such as just listing all of the properties using the current inspection methods, and serializing all of them.

The @rpc annotation is just a shorthand for Node.rpc_config() internally. multiplayter.get_sender_id() just returns the state at the point of calling the rpc method.

I don’t think what you want to do is possible.

isamatlas · September 28, 2026, 6:32pm

ahh I see, it was very weird to see there not being anything about it but I mean that makes sense, thank you for the response.