fix(think): telegramMessenger nativeStreaming option (#2397)

.changeset/think-telegram-native-streaming.md

@@ -0,0 +1,5 @@
+---
+"@cloudflare/think": patch
+---
+
+Add a `nativeStreaming` option to `telegramMessenger` and forward it to the adapter (#2397). `@chat-adapter/telegram` 4.38 made native draft streaming opt-in, so private-chat replies always posted and edited, with no way to turn drafts back on. `telegramMessenger` also passes `allowUnverifiedWebhooks` when there's no `secretToken`, so `verifyWebhook: false` or a custom `verifyWebhook` no longer throws "secretToken is required in webhook mode" on those adapter versions. Think still refuses a webhook with neither a secret token nor an explicit `verifyWebhook`.

docs/think/messengers.md

@@ -47,6 +47,11 @@ https://<your-worker>/messengers/telegram/webhook
 custom `verifyWebhook` function or explicitly opt out with
 `verifyWebhook: false`.
 
+To stream private-chat replies as native Telegram drafts instead of posting a
+message and editing it, pass `nativeStreaming: true`. With
+`@chat-adapter/telegram` 4.38 or later it defaults to `false`; earlier versions
+always use drafts in private chats. Group chats always post and edit.
+
 If one Think agent owns multiple Telegram bots, give each provider a distinct
 Chat SDK adapter name:
 

packages/think/src/messengers/telegram.ts

@@ -9,13 +9,29 @@ export const TELEGRAM_FOLLOWUP_CHUNK_LIMIT = 3_500;
 
 const TELEGRAM_DEDUPE_PREFIX = "dedupe:telegram:";
 
+/**
+ * `@chat-adapter/telegram` 4.38 added `nativeStreaming` and
+ * `allowUnverifiedWebhooks`. Older adapters in the supported range ignore them.
+ */
+type TelegramAdapterConfigCompat = TelegramAdapterConfig & {
+  allowUnverifiedWebhooks?: boolean;
+  nativeStreaming?: boolean;
+};
+
 export interface TelegramMessengerOptions extends Omit<
   ChatSdkMessengerOptions,
   "adapter" | "provider" | "userName" | "verifyWebhook"
 > {
   apiBaseUrl?: string;
   apiUrl?: string;
   mode?: TelegramAdapterConfig["mode"];
+  /**
+   * Stream private-chat replies as native Telegram drafts instead of posting
+   * a message and editing it. Requires `@chat-adapter/telegram` 4.38 or later,
+   * where it defaults to `false`; earlier versions always use drafts in
+   * private chats. Group chats always post and edit.
+   */
+  nativeStreaming?: boolean;
   secretToken?: string;
   token: string;
   userName: string;
@@ -42,14 +58,19 @@ export function telegramMessenger(
     );
   }
 
-  const adapter = createTelegramAdapter({
+  const adapterConfig: TelegramAdapterConfigCompat = {
+    // Without a secret token, Think verifies the webhook itself (or the caller
+    // opted out above), so the adapter must not reject the missing token.
+    allowUnverifiedWebhooks: !options.secretToken,
     apiBaseUrl: options.apiBaseUrl,
     apiUrl: options.apiUrl,
     botToken: options.token,
     mode: options.mode ?? "webhook",
+    nativeStreaming: options.nativeStreaming,
     secretToken: options.secretToken,
     userName: options.userName
-  });
+  };
+  const adapter = createTelegramAdapter(adapterConfig);
 
   return chatSdkMessenger({
     ...options,

packages/think/src/tests/telegram-messenger.test.ts

@@ -0,0 +1,59 @@
+import { createTelegramAdapter } from "@chat-adapter/telegram";
+import { describe, expect, it, vi } from "vitest";
+import { telegramMessenger } from "../messengers/telegram";
+
+vi.mock("@chat-adapter/telegram", async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import("@chat-adapter/telegram")>();
+  return {
+    ...actual,
+    createTelegramAdapter: vi.fn(actual.createTelegramAdapter)
+  };
+});
+
+function lastAdapterConfig(): Record<string, unknown> {
+  return vi.mocked(createTelegramAdapter).mock.lastCall?.[0] as Record<
+    string,
+    unknown
+  >;
+}
+
+describe("telegram messenger adapter config (#2397)", () => {
+  it("forwards nativeStreaming to the adapter", () => {
+    telegramMessenger({
+      nativeStreaming: true,
+      secretToken: "secret",
+      token: "token",
+      userName: "fake_bot"
+    });
+    expect(lastAdapterConfig()).toMatchObject({ nativeStreaming: true });
+
+    telegramMessenger({
+      secretToken: "secret",
+      token: "token",
+      userName: "fake_bot"
+    });
+    expect(lastAdapterConfig().nativeStreaming).toBeUndefined();
+  });
+
+  it("allows unverified adapter webhooks only when Think verifies them", () => {
+    telegramMessenger({
+      secretToken: "secret",
+      token: "token",
+      userName: "fake_bot"
+    });
+    expect(lastAdapterConfig()).toMatchObject({
+      allowUnverifiedWebhooks: false,
+      secretToken: "secret"
+    });
+
+    telegramMessenger({
+      token: "token",
+      userName: "fake_bot",
+      verifyWebhook: false
+    });
+    expect(lastAdapterConfig()).toMatchObject({
+      allowUnverifiedWebhooks: true
+    });
+  });
+});