feat: Only send custom notifications when ACP client specifies this capability in the initialization request (#9596)

ui/sdk/src/client-capabilities.ts

@@ -0,0 +1,8 @@
+import type { GooseMcpHostCapabilities } from "./mcp-apps.js";
+
+export interface GooseClientCapabilitiesMeta {
+  goose?: {
+    mcpHostCapabilities?: GooseMcpHostCapabilities;
+    customNotifications?: boolean;
+  };
+}

ui/sdk/src/generated/client.gen.ts

@@ -733,28 +733,37 @@ export interface GooseExtNotifications {
   ) => Promise<void>;
 }
 
-export type GooseClientCallbacks = Client & GooseExtNotifications;
+export type GooseClientCallbacks = Omit<Client, "extNotification"> &
+  Partial<Pick<Client, "extNotification">> &
+  GooseExtNotifications;
 
 export function installGooseExtNotificationDispatcher(
   callbacks: GooseClientCallbacks,
 ): Client {
-  const { unstable_sessionUpdate, ...rest } = callbacks;
-  const userExtNotification = rest.extNotification;
-  return {
-    ...rest,
+  const dispatcher: Pick<Client, "extNotification"> = {
     extNotification: async (method, params) => {
       switch (method) {
         case "_goose/unstable/session/update": {
           const parsed = zGooseSessionNotification_unstable.parse(
             params,
           ) as GooseSessionNotification_unstable;
-          await unstable_sessionUpdate?.(parsed);
+          await callbacks.unstable_sessionUpdate?.(parsed);
           return;
         }
         default:
-          await userExtNotification?.(method, params);
+          await callbacks.extNotification?.(method, params);
           return;
       }
     },
   };
+  return new Proxy(callbacks, {
+    get(target, property) {
+      if (property === "extNotification") {
+        return dispatcher.extNotification;
+      }
+
+      const value = Reflect.get(target, property, target);
+      return typeof value === "function" ? value.bind(target) : value;
+    },
+  }) as Client;
 }

ui/sdk/src/index.ts

@@ -6,6 +6,7 @@ export {
 } from "./generated/client.gen.js";
 export { GooseClient } from "./goose-client.js";
 export { createHttpStream } from "./http-stream.js";
+export * from "./client-capabilities.js";
 export * from "./mcp-apps.js";
 
 export {

ui/sdk/src/mcp-apps.ts

@@ -1,7 +1,3 @@
-import type {
-  Implementation,
-  InitializeRequest,
-} from "@agentclientprotocol/sdk";
 import { RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/app-bridge";
 import type {
   McpUiAppResourceConfig,
@@ -68,19 +64,6 @@ export interface GooseToolCallUpdateMeta {
   [key: string]: unknown;
 }
 
-export interface GooseClientMeta {
-  goose: {
-    mcpHostCapabilities: GooseMcpHostCapabilities;
-  };
-}
-
-export type GooseInitializeRequest = InitializeRequest & {
-  clientCapabilities: NonNullable<InitializeRequest["clientCapabilities"]> & {
-    _meta: GooseClientMeta;
-  };
-  clientInfo: Implementation;
-};
-
 export const DEFAULT_GOOSE_MCP_HOST_CAPABILITIES: GooseMcpHostCapabilities = {
   extensions: {
     [GOOSE_MCP_UI_EXTENSION_ID]: {