Return Cloudflare AIChatAgent response from raw string (2 solutions)

chat-agent-msg-from-str.ts

export class Chat extends AIChatAgent<Env, CommonState> {
  async sendChatMessage(s: string, role: "user" | "assistant") {
    const msg = {
        sentFromServer: true,
        id: generateId(),
        role,
        parts: [
          {
            type: "text",
            text: s,
          }
        ],
        metadata: {
          createdAt: new Date()
        }
      };
    await this.saveMessages([...this.messages, msg as any]);
  }
  
  async onChatMessage() {
    // Ensure we do not reply to ourselves
    let lastMsg = this.messages[this.messages.length - 1];
    if ((lastMsg as any).sentFromServer) return;
  
    this.sendChatMessage("Hello !", "assistant");
  }
}

chat-agent-resp-from-str.ts

  
export class Chat extends AIChatAgent<Env, CommonState> {
  async responseFromString(s: string): Promise<Response> {
    let id = Math.random().toString(36).slice(2, 7);
    let TEXT = `\
data: {"type":"text-start","id":"${id}"}
data: {"type":"text-delta","id":"${id}","delta":" ${s}"}
data: {"type":"text-end","id":"${id}"}
data: [DONE]
`;
    const resp = new Response(TEXT, {
      headers: {
        "Content-Type": "text/event-stream",
      }
    });
    return resp;
  }
  
  async onChatMessage() {
    return this.responseFromString("Hello !");
  }
}