Create foundryWidgetTokenProvider helper (#2241) (#2269)

Author: tzyl

.changeset/wild-streets-sneeze.md

@@ -0,0 +1,5 @@
+---
+"@osdk/widget.client": patch
+---
+
+Create createFoundryWidgetTokenProvider helper

packages/widget.client/src/index.ts

@@ -38,3 +38,4 @@ export {
 export { createFoundryWidgetClient } from "./client.js";
 export type { FoundryWidgetClient } from "./client.js";
 export { FoundryHostEventTarget } from "./host.js";
+export { createFoundryWidgetTokenProvider } from "./tokenProvider.js";

packages/widget.client/src/tokenProvider.ts

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2025 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * A token provider for use in OSDK clients within the Foundry Custom Widgets
+ * runtime environment. It resolves to a placeholder value which is replaced
+ * on the actual request.
+ */
+export function createFoundryWidgetTokenProvider(): () => Promise<string> {
+  return () => Promise.resolve("widgets-auth");
+}