Add instruction parts support

.changeset/instructions-parts.md

@@ -0,0 +1,5 @@
+---
+'@livekit/agents': patch
+---
+
+Add beta workflow InstructionParts exports.

agents/src/beta/index.ts

@@ -6,4 +6,6 @@ export {
   type TaskCompletedEvent,
   type TaskGroupOptions,
   type TaskGroupResult,
+  type InstructionParts,
 } from './workflows/index.js';
+export { Instructions } from '../llm/index.js';

agents/src/beta/workflows/index.ts

@@ -7,3 +7,4 @@ export {
   type TaskGroupOptions,
   type TaskGroupResult,
 } from './task_group.js';
+export type { InstructionParts } from './utils.js';

agents/src/beta/workflows/utils.ts

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: 2026 LiveKit, Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+import type { Instructions } from '../../llm/index.js';
+
+/**
+ * Customizable instruction sections for built-in workflow tasks.
+ *
+ * Leave a field unset to preserve the workflow's built-in default. Set it to
+ * an empty string to remove that section entirely.
+ */
+export interface InstructionParts {
+  /** Agent persona/identity: who the agent is and how it behaves. */
+  persona?: Instructions | string;
+
+  /** Extra instructions appended to the prompt for domain-specific context. */
+  extra?: Instructions | string;
+}