/**
 * `assistant_text_delta` SSE event.
 *
 * Streaming text chunk emitted by the daemon as the model produces
 * assistant output. Multiple deltas accumulate into a single assistant
 * message; the matching `message_complete` event marks the turn done.
 *
 * `messageId` is the database row id of the assistant message this
 * delta belongs to — stamped from the pre-allocated turn anchor (see
 * `reserveMessage` / `AssistantTurnStartEvent`). Absent on streams
 * produced by older daemons that pre-date the anchor protocol, or on
 * synthetic deltas (canned greetings, slash-command echoes, live-voice
 * transcript injections) that don't bind to a row.
 *
 * Canonical wire-contract source. Daemon code imports the type directly
 * from this file; external consumers import via `@vellumai/assistant-api`.
 */

import { z } from "zod";

export const AssistantTextDeltaEventSchema = z.object({
  type: z.literal("assistant_text_delta"),
  text: z.string(),
  messageId: z.string().optional(),
  conversationId: z.string().optional(),
});

export type AssistantTextDeltaEvent = z.infer<
  typeof AssistantTextDeltaEventSchema
>;