How to Use WhatsApp Business API for FREE (or almost) with n8n & AI

If you run a business in 2026 and aren’t automating WhatsApp, you’re losing money. But if you’re doing it through intermediaries (BSPs) like WATI, ManyChat, or Twilio, you’re throwing money away.

Most agencies and companies pay a “revolutionary tax” to use WhatsApp:

1. They pay Meta per conversation.
2. They pay the BSP a monthly subscription (€50 - €200).
3. They pay the BSP a markup on every message sent.

In this guide, I’ll teach you how to eliminate points 2 and 3 by setting up your own WhatsApp Gateway with Evolution API v2 and n8n.

The Great BSP Lie

To understand how much you can save, first you need to know what Meta actually charges (Official 2026 pricing, typically for Europe):

Conversation Type	Meta Cost (Europe Avg)	Typical BSP Cost	Your Savings
Marketing	~0.05 €	~0.07 €	37%
Utility (Orders)	~0.02 €	~0.03 €	40%
Authentication (OTP)	~0.03 €	~0.05 €	40%
Service (User-initiated)	FREE	~0.01 €	100%

What is Evolution API v2?

Evolution API is an incredible Open Source project that acts as a WhatsApp “Gateway”. You install it on your own server (Docker), and it allows you to control WhatsApp via HTTP requests.

It has two operating modes:

Mode 1: Official API (Professional) 🛡️

You connect directly to Meta’s Cloud API.

• Cost: You pay only what’s in the table above. Zero markups.
• Advantage: Official, scalable, no ban risk.
• Ideal for: Massive marketing notifications, large enterprises.

Mode 2: Baileys (Unofficial) 🏴‍☠️

You scan a QR code just like WhatsApp Web.

• Cost: €0 per message. Doesn’t matter if it’s marketing or utility. You only pay your mobile bill.
• Advantage: Totally free. You can use groups, status updates, etc.
• Risk: If you do aggressive spam, Meta can ban your number.
• Ideal for: Internal chatbots, idea validation, personal CRMs, low-volume notifiers.

Technical Tutorial: Your Own WhatsApp Stack

To build this, you need a server (VPS) running Docker, Redis, and Postgres. (Note: At AIBuildr, our servers come with Evolution API v2 pre-installed and configured with Redis & Postgres, ready to scan the QR).

If you build it yourself, the docker-compose.yml looks like this (simplified):

services:
  evolution-api:
    image: attdevelopers/evolution-api:v2.1.0
    environment:
      - SERVER_URL=https://api.yourdomain.com
      - DATABASE_PROVIDER=postgresql
      - REDIS_ENABLED=true

Step 1: Connect n8n to WhatsApp

Once Evolution is running, go to n8n. You don’t need complex nodes, just the HTTP Request node or a Webhook.

Receive Messages (Webhook):

1. In Evolution, go to your instance and enable “Webhooks”.
2. Paste your n8n Production Webhook URL.
3. Enable MESSAGES_UPSERT events.

Now, every time someone writes to your number, n8n will receive a JSON like this:

{
  "data": {
    "key": {
      "remoteJid": "34666555444@s.whatsapp.net"
    },
    "message": {
      "conversation": "Hi, I'd like info on your pricing."
    }
  }
}

Step 2: The Brain (AI Agent)

Here’s where we disrupt the market. We’ll connect that message to an AI Agent to answer automatically, for free (because it’s a user-initiated service conversation).

Agent Configuration in n8n

1. Use the AI Agent node.
2. Connect it to a Vector Store (Qdrant) if you want it to know about your business (RAG).
3. In the System Prompt, give clear sales instructions and tone.

Step 3: Send the Response

To reply, use an HTTP Request node in n8n pointing to Evolution API:

• Method: POST
• URL: https://your-evolution-api.com/message/sendText/instance
• Body:

  {
    "number": "34666555444",
    "text": "Hi! Sure, our pricing starts at..."
  }

Conclusion: Massive Savings

If you run an agency or SaaS, WhatsApp costs can eat your margin. By switching from WATI/ManyChat to Evolution API + n8n:

1. You eliminate the monthly subscription (~100€/mo savings).
2. You eliminate the per-message markup (30-50% savings).
3. You gain full control of your data (it’s on your VPS, not third-party servers).

At AIBuildr, we hand you the infrastructure ready: n8n + Evolution API + DBs on a private server in Europe. You just scan the QR and start automating.

Deploy your WhatsApp Automation server today →