fix: send DTMF to active session room

.changeset/send-dtmf-active-room.md

@@ -0,0 +1,5 @@
+---
+'@livekit/agents': minor
+---
+
+Add a beta DTMF sending tool that publishes to the active agent session room.

agents/src/beta/index.ts

@@ -33,6 +33,8 @@ export { Instructions } from '../llm/index.js';
 export {
   END_CALL_DESCRIPTION,
   createEndCallTool,
+  sendDtmfEvents,
+  type DtmfEvent,
   type EndCallToolCalledEvent,
   type EndCallToolCompletedEvent,
   type EndCallToolOptions,

agents/src/beta/tools/index.ts

@@ -8,3 +8,4 @@ export {
   type EndCallToolCompletedEvent,
   type EndCallToolOptions,
 } from './end_call.js';
+export { sendDtmfEvents, type DtmfEvent } from './send_dtmf.js';

agents/src/beta/tools/send_dtmf.ts

@@ -0,0 +1,77 @@
+// SPDX-FileCopyrightText: 2026 LiveKit, Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+import { setTimeout as waitFor } from 'node:timers/promises';
+import { z } from 'zod';
+import { getJobContext } from '../../job.js';
+import { tool } from '../../llm/index.js';
+
+const DEFAULT_DTMF_PUBLISH_DELAY = 300;
+
+const DTMF_EVENTS = [
+  '1',
+  '2',
+  '3',
+  '4',
+  '5',
+  '6',
+  '7',
+  '8',
+  '9',
+  '0',
+  '*',
+  '#',
+  'A',
+  'B',
+  'C',
+  'D',
+] as const;
+
+export type DtmfEvent = (typeof DTMF_EVENTS)[number];
+
+function dtmfEventToCode(event: DtmfEvent): number {
+  if (/^\d$/.test(event)) {
+    return Number(event);
+  }
+  if (event === '*') {
+    return 10;
+  }
+  if (event === '#') {
+    return 11;
+  }
+
+  return event.charCodeAt(0) - 'A'.charCodeAt(0) + 12;
+}
+
+export const sendDtmfEvents = tool({
+  name: 'send_dtmf_events',
+  description: `
+Send a list of DTMF events to the telephony provider.
+
+Call when:
+- User wants to send DTMF events
+`,
+  parameters: z.object({
+    events: z.array(z.enum(DTMF_EVENTS)).describe('The DTMF events to send.'),
+  }),
+  execute: async ({ events }, { ctx }) => {
+    const room = ctx.session._roomIO?.rtcRoom ?? getJobContext().room;
+
+    for (const event of events) {
+      try {
+        const code = dtmfEventToCode(event);
+        if (!room.localParticipant) {
+          throw new Error('room local participant is not available');
+        }
+
+        await room.localParticipant.publishDtmf(code, event);
+        await waitFor(DEFAULT_DTMF_PUBLISH_DELAY);
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        return `Failed to send DTMF event: ${event}. Error: ${message}`;
+      }
+    }
+
+    return `Successfully sent DTMF events: ${events.join(', ')}`;
+  },
+});