Extending interfaces with RPCTarget and issues with Promise<any>

[userNotFoundByDefault]

Hi,

i am a little bit confused about extending interfaces with "RPCTarget". In some of your examples, you extend interfaces with RPCTarget, in some you don't. I know that i have to extend classes, but i did not know, that you also have to extend interfaces (when not extending the interfaces the types of the return values of the interfaces's methods are lost somehow and i get a Promise <any>).
However when an interface method returns an Array of strings, i get a Promise<any>, so the type is lost again. I want to transmit the array of strings as a value, but without needing to cast the Promise<any> to a Promise<string[]>. I could not find any way of getting that to work, so if you guys could give me a hint or an idea of why this is happening, i would be very grateful.

Have a nice weekend and thank you for your support and this wonderful library
UserNotFoundByDefault

PS:
Here is the code, but its pretty much what i wrote above:
interfaces.ts:
export interface IPersonDirect extends RpcTarget { readonly directory: IPersonDirectory; }
export interface IPersonDirectory extends RpcTarget { list(): string[]; }
The classes on serverside implementing IPersonDirect and IPersonDirectory do extend RPCTarget aswell.
When calling the method 'list()' using IPersonDirect and IPersonDirectory inside a promise-chain i get:

[userNotFoundByDefault]

Okei, found the issue with Promise<any>: in tsconfig.json the target-compiler-option had to be "EsNext", which was "Es2022" before.
Still i am wondering if i have to extend the interfaces with "RPCTarget" or not.

[kentonv]

Concrete classes (declared with class) which implement RPC interface must be declared with extends RpcTarget.

However, interfaces (declared with interface) describing RPC interfaces do not need to extend RpcTarget (but can, if you want). The class that ultimately implements said interface must extend RpcTarget, but the interface itself doesn't have to.