Auto-reply agent

npm install @loomal/sdk @anthropic-ai/sdk

import { Loomal } from "@loomal/sdk";
import Anthropic from "@anthropic-ai/sdk";

const loomal = new Loomal({ apiKey: process.env.LOOMAL_API_KEY! });
const anthropic = new Anthropic({ apiKey: process.env.ANTHROPIC_API_KEY! });

async function processInbox() {
  const { messages } = await loomal.mail.listMessages({
    limit: 20,
    labels: "unread",
  });
  if (messages.length === 0) return;

  for (const m of messages) {
    // Pull the full thread for context — replies should know what came before.
    const thread = await loomal.mail.getThread(m.threadId);
    const transcript = thread.messages
      .map((t) => {
        const who = t.labels.includes("sent") ? "Agent" : t.from[0];
        return `${who}: ${t.extractedText || t.text}`;
      })
      .join("\n\n");

    // Ask Claude to draft a reply to the latest message in the thread.
    const completion = await anthropic.messages.create({
      model: "claude-sonnet-4-6",
      max_tokens: 512,
      system:
        "You are a helpful assistant replying to email on the user's behalf. " +
        "Reply only with the body of the message — no subject, no greeting boilerplate.",
      messages: [
        {
          role: "user",
          content: `Reply to the latest message in this thread:\n\n${transcript}`,
        },
      ],
    });
    const reply = completion.content
      .filter((b): b is Anthropic.TextBlock => b.type === "text")
      .map((b) => b.text)
      .join("\n");

    // Send the reply on the same thread, then label the original processed.
    await loomal.mail.reply(m.messageId, { text: reply });
    await loomal.mail.updateLabels(m.messageId, {
      addLabels: ["read", "auto-replied"],
      removeLabels: ["unread"],
    });

    console.log(`replied to ${m.from[0]} re: ${m.subject}`);
  }
}

// Poll every 30s. In production, use a webhook or scheduled job instead.
while (true) {
  await processInbox().catch((err) => console.error("loop error:", err));
  await new Promise((r) => setTimeout(r, 30_000));
}