Class Thread

packages/bot/src/thread.ts:69–480

/** A concrete conversation thread: posts UI, runs the agent loop, and resolves HITL waiters. */
export class Thread implements ThreadInterface {
  readonly platform: string;
  /** Stable key identifying this conversation (used by transcript bridging). */
  readonly conversationKey: string;
  private readonly store: StateStore;

  constructor(private deps: ThreadDeps) {
    this.platform = deps.adapter.platform;
    this.conversationKey = deps.conversationKey;
    this.store = deps.state;
  }

  private async bindForPost(ui: Renderable) {
    return this.deps.registry.bindRenderable(ui, this.deps.conversationKey);
  }

  /**
   * Wire a posted message's `onReaction` to its returned id: cache it for this
   * process and, when it came from a component, persist a durable snapshot so a
   * reaction after a restart re-derives it (parity with a component `onClick`).
   */
  private async bindReaction(
    messageId: string,
    bound: Awaited<ReturnType<Thread["bindForPost"]>>,
  ): Promise<void> {
    if (bound.onReaction) {
      this.deps.registry.registerMessageReaction(messageId, bound.onReaction);
    }
    if (bound.reactionComponent) {
      await this.deps.registry.persistMessageReaction(messageId, {
        ...bound.reactionComponent,
        conversationKey: this.deps.conversationKey,
      });
    }
  }

  async post(ui: Renderable): Promise<MessageRef> {
    const bound = await this.bindForPost(ui);
    const ref = await this.deps.adapter.post(this.deps.replyTarget, bound.root);
    await this.bindReaction(ref.id, bound);
    return ref;
  }

  async update(ref: MessageRef, ui: Renderable): Promise<MessageRef> {
    const bound = await this.bindForPost(ui);
    await this.deps.adapter.update(ref, bound.root);
    await this.bindReaction(ref.id, bound);
    return ref;
  }

  async delete(ref: MessageRef): Promise<void> {
    await this.deps.adapter.delete(ref);
  }

  async stream(src: string | AsyncIterable<string>): Promise<MessageRef> {
    const iter =
      typeof src === "string"
        ? (async function* () {