diff --git a/front/src/Api/iframe/IframeApiContribution.ts b/front/src/Api/iframe/IframeApiContribution.ts
index dc261762..77739f7e 100644
--- a/front/src/Api/iframe/IframeApiContribution.ts
+++ b/front/src/Api/iframe/IframeApiContribution.ts
@@ -9,21 +9,28 @@ export function sendToWorkadventure(content: IframeEvent<keyof IframeEventMap>)
 }
 type GuardedType<Guard extends tg.TypeGuard<unknown>> = Guard extends tg.TypeGuard<infer T> ? T : never
 
-export function apiCallback<T extends tg.TypeGuard<unknown>>(callbackData: IframeCallbackContribution<T>) {
-    registeredCallbacks[callbackData.type] = {
+export function apiCallback<T extends keyof IframeResponseEventMap>(callbackData: IframeCallbackContribution<T>): IframeCallbackContribution<keyof IframeResponseEventMap> {
+    const iframeCallback = {
         typeChecker: callbackData.typeChecker,
         callback: callbackData.callback
-    }
-    return callbackData
+    } as IframeCallback<T>;
+
+    const newCallback = { [callbackData.type]: iframeCallback };
+    Object.assign(registeredCallbacks, newCallback)
+    return callbackData as unknown as IframeCallbackContribution<keyof IframeResponseEventMap>;
 }
 
-export interface IframeCallbackContribution<Guard extends tg.TypeGuard<unknown>, T = GuardedType<Guard>> {
+export interface IframeCallback<Key extends keyof IframeResponseEventMap, T = IframeResponseEventMap[Key], Guard = tg.TypeGuard<T>> {
 
-    type: keyof IframeResponseEventMap,
     typeChecker: Guard,
     callback: (payloadData: T) => void
 }
 
+export interface IframeCallbackContribution<Key extends keyof IframeResponseEventMap> extends IframeCallback<Key> {
+
+    type: Key
+}
+
 export type PossibleSubobjects = "zone" | "chat" | "ui" | "nav" | "sound" | "cowebsite" | "player" | "bubble"
 /**
  * !! be aware that the implemented attributes (addMethodsAtRoot and subObjectIdentifier) must be readonly
@@ -32,9 +39,7 @@ export type PossibleSubobjects = "zone" | "chat" | "ui" | "nav" | "sound" | "cow
  */
 
 export abstract class IframeApiContribution<T extends {
-    // i think this is specific enough
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    callbacks: Array<IframeCallbackContribution<tg.TypeGuard<any>>>,
+    callbacks: Array<IframeCallbackContribution<keyof IframeResponseEventMap>>,
     readonly subObjectIdentifier: PossibleSubobjects,
     readonly addMethodsAtRoot: boolean | undefined
 }> {
diff --git a/front/src/iframe_api.ts b/front/src/iframe_api.ts
index 136edb8e..60080303 100644
--- a/front/src/iframe_api.ts
+++ b/front/src/iframe_api.ts
@@ -1,10 +1,9 @@
-import { IframeResponseEventMap, isIframeResponseEventWrapper } from "./Api/Events/IframeEvent";
+import { IframeResponseEvent, IframeResponseEventMap, isIframeResponseEventWrapper, TypedMessageEvent } from "./Api/Events/IframeEvent";
+import type { IframeCallback } from './Api/iframe/IframeApiContribution';
 import type { WorkAdventureApi } from './iframe_api.d';
 
-export const registeredCallbacks: { [K in keyof IframeResponseEventMap]?: {
-    typeChecker: Function
-    callback: Function
-} } = {}
+
+export const registeredCallbacks: { [K in keyof IframeResponseEventMap]?: IframeCallback<K> } = {}
 
 const importType = Promise.all([
     import("./Api/iframe/popup"),
@@ -52,7 +51,7 @@ async function populateWa(): Promise<void> {
 
 populateWa()
 
-window.addEventListener('message', message => {
+window.addEventListener('message', <T extends keyof IframeResponseEventMap>(message: TypedMessageEvent<IframeResponseEvent<T>>) => {
     if (message.source !== window.parent) {
         return; // Skip message in this event listener
     }
@@ -62,9 +61,9 @@ window.addEventListener('message', message => {
     if (isIframeResponseEventWrapper(payload)) {
         const payloadData = payload.data;
 
-        if (registeredCallbacks[payload.type] && registeredCallbacks[payload.type]?.typeChecker(payloadData)) {
-            registeredCallbacks[payload.type]?.callback(payloadData)
-            return
+        const callback = registeredCallbacks[payload.type] as IframeCallback<T> | undefined
+        if (callback?.typeChecker(payloadData)) {
+            callback?.callback(payloadData)
         }
     }