feat(agents-core): add React Native support with platform-specific shims

Author: monadoid

packages/agents-core/package.json

@@ -69,6 +69,11 @@
         "types": "./dist/shims/shims-node.d.ts",
         "default": "./dist/shims/shims-node.mjs"
       },
+      "react-native": {
+        "require": "./dist/shims/shims-react-native.js",
+        "types": "./dist/shims/shims-react-native.d.ts",
+        "default": "./dist/shims/shims-react-native.mjs"
+      },
       "require": {
         "types": "./dist/shims/shims-node.d.ts",
         "default": "./dist/shims/shims-node.js"
@@ -89,8 +94,12 @@
   },
   "dependencies": {
     "@openai/zod": "npm:zod@^3.25.40",
+    "@ungap/structured-clone": "^1.3.0",
     "debug": "^4.4.0",
-    "openai": "^5.0.1"
+    "event-target-shim": "^6.0.2",
+    "events": "^3.3.0",
+    "openai": "^5.0.1",
+    "react-native-uuid": "^2.0.3"
   },
   "peerDependencies": {
     "zod": "^3.25.40"
@@ -121,6 +130,7 @@
   },
   "devDependencies": {
     "@types/debug": "^4.1.12",
+    "@types/ungap__structured-clone": "^1.2.0",
     "zod": "^3.25.40"
   },
   "files": [

packages/agents-core/src/shims/shims-react-native.ts

@@ -0,0 +1,105 @@
+/// <reference lib="dom" />
+export { EventEmitter, EventEmitterEvents } from './interface';
+import type { EventEmitterEvents, Timeout, Timer } from './interface';
+
+import { EventEmitter as NodeEventEmitter } from 'events';
+import 'event-target-shim';
+import structuredClone from '@ungap/structured-clone';
+import uuid from 'react-native-uuid';
+
+if (!('structuredClone' in globalThis)) {
+  // @ts-expect-error - This is the recommended approach from ungap/structured-clone
+  globalThis.structuredClone = structuredClone;
+}
+export const randomUUID = (): string => uuid.v4();
+
+export function loadEnv(): Record<string, string | undefined> {
+  return {};
+}
+
+export class ReactNativeEventEmitter<
+  Events extends EventEmitterEvents = Record<string, any[]>,
+> extends NodeEventEmitter {
+  override on<K extends keyof Events & (string | symbol)>(
+    type: K,
+    listener: (...args: Events[K]) => void,
+  ): this {
+    // Node's typings accept string | symbol; cast is safe.
+    return super.on(type as string | symbol, listener);
+  }
+
+  override off<K extends keyof Events & (string | symbol)>(
+    type: K,
+    listener: (...args: Events[K]) => void,
+  ): this {
+    return super.off(type as string | symbol, listener);
+  }
+
+  override emit<K extends keyof Events & (string | symbol)>(
+    type: K,
+    ...args: Events[K]
+  ): boolean {
+    return super.emit(type as string | symbol, ...args);
+  }
+
+  override once<K extends keyof Events & (string | symbol)>(
+    type: K,
+    listener: (...args: Events[K]) => void,
+  ): this {
+    return super.once(type as string | symbol, listener);
+  }
+}
+
+export { ReactNativeEventEmitter as RuntimeEventEmitter };
+
+// Streams – placeholders (unused by the SDK on RN)
+export const Readable = class {};
+export const ReadableStream = globalThis.ReadableStream;
+export const ReadableStreamController =
+  globalThis.ReadableStreamDefaultController;
+export const TransformStream = globalThis.TransformStream;
+
+export class AsyncLocalStorage {
+  #ctx: unknown = null;
+
+  run<T>(store: T, fn: () => unknown) {
+    this.#ctx = store;
+    return fn();
+  }
+  getStore<T>() {
+    return this.#ctx as T;
+  }
+  enterWith<T>(store: T) {
+    this.#ctx = store;
+  }
+}
+
+export function isBrowserEnvironment(): boolean {
+  return true;
+}
+
+export function isTracingLoopRunningByDefault(): boolean {
+  return false;
+}
+
+/* MCP not supported on mobile; export browser stubs */
+export { MCPServerStdio, MCPServerStreamableHttp } from './mcp-server/browser';
+
+class RNTimer implements Timer {
+  setTimeout(cb: () => void, ms: number): Timeout {
+    const id: any = setTimeout(cb, ms);
+    // RN timers don’t expose ref/unref; shim them
+    id.ref ??= () => id;
+    id.unref ??= () => id;
+    id.hasRef ??= () => true;
+    id.refresh ??= () => id;
+    return id;
+  }
+
+  clearTimeout(id: Timeout | string | number | undefined) {
+    clearTimeout(id as number);
+  }
+}
+
+const timer = new RNTimer();
+export { timer };