Reference

Integrations

Three packages on the same API: a Chat SDK bot that answers on WhatsApp, Instagram, Messenger, SMS and Gmail with one adapter, n8n nodes, and a browser SDK so your customers connect their channels in a popup. They are MIT and live next to the API.

Vercel Chat SDK: @heysteff/chat-adapter#

One adapter for every channel. It receives signed webhooks, turns them into Chat SDK messages, and every thread.post() goes out on the conversation's channel, number and recipient through the same POST /v1/messages.

npm install chat @heysteff/chat-adapter @chat-adapter/state-memory

import { Chat } from 'chat';
import { createMemoryState } from '@chat-adapter/state-memory';
import { createHeysteffAdapter, threadChannel } from '@heysteff/chat-adapter';

export const bot = new Chat({
  userName: 'my-bot',
  adapters: { heysteff: createHeysteffAdapter() }, // HEYSTEFF_API_KEY and HEYSTEFF_WEBHOOK_SECRET
  state: createMemoryState(),
});

bot.onDirectMessage(async (thread, message) => {
  await thread.post(`Writing from ${threadChannel(thread)}: ${message.text}`);
});

// app/api/webhooks/heysteff/route.ts
import { after } from 'next/server';
import { bot } from '@/lib/bot';

export async function POST(request: Request) {
  return bot.webhooks.heysteff(request, { waitUntil: (task) => after(() => task) });
}

• Text, files and buttons: files are uploaded with POST /v1/media; a card with Button becomes reply buttons (up to 3) or a list (up to 10) with content_type: "interactive", and taps reach onAction.
• A person took the conversation: with bot_paused the bot does not receive messages and thread.post throws HeysteffBotPausedError without sending.
• Channel: thread.channelId is heysteff:<channel> and threadChannel(thread) returns whatsapp_cloud, instagram, facebook, sms or gmail.
• History and DMs: fetchMessages uses GET /v1/conversations/{id}/messages; adapter.openDM("whatsapp_cloud:+56912345678") opens a thread to write first.

n8n: @heysteff/n8n-nodes-heysteff#

Install it from Settings → Community Nodes as @heysteff/n8n-nodes-heysteff and create a heysteff API credential with your API key.

• heysteff Trigger: on activation it creates its webhook with POST /v1/webhooks and the events you pick (message:received, customer.channel_connected, payment.paid…), deletes it on deactivation and verifies every signature. It can skip conversations a person took over.
• heysteff: send text, templates, files or buttons on any channel; mark as read; create and search contacts; create customers and their connection links.

Connection links in a popup: @heysteff/connect#

For a SaaS whose customers connect their own channel (see Customers and setup links). connect() opens the link in a popup and resolves with { channel_id, customer_id, channel_type }; it rejects if your customer closes the window. Calling it twice still opens one popup.

npm install @heysteff/connect

import { connect } from '@heysteff/connect';

const { channel_id, customer_id, channel_type } = await connect({
  // Your server creates the link with customers.createSetupLink.
  url: () => fetch('/api/connect-link', { method: 'POST' }).then((r) => r.text()),
});

import { ConnectButton } from '@heysteff/connect/react';

<ConnectButton url={createLink} onSuccess={(r) => save(r.channel_id)}>
  Connect your WhatsApp
</ConnectButton>

The link page notifies via postMessage only the origin of the window that opened it, and the SDK accepts messages only from the link's origin. For your backend, the customer.channel_connected webhook is still the source of truth.

Packages and repositories#

Everything is MIT and uses the same API: the same code for WhatsApp, Instagram, Messenger, SMS and email. Every README includes a prompt ready to paste into Claude Code, Cursor, Codex or ChatGPT. The public repos live at github.com/heysteff-com.

In n8n you can also install it from Settings → Community Nodes. In Claude Code, after the marketplace run /plugin install heysteff@heysteff.