The five parts
- A connection to WhatsApp: the official API (through a provider, with business verification and templates) or QR linking, like WhatsApp Web.
- An AI model: the part that writes the replies.
- Memory: each contact's history, so it doesn't reply blind.
- Rules: your tone, your prices, what it must never promise and when to hand over to a person.
- Supervision: an inbox where you see what it does, correct it and find out when something breaks.
Choosing the connection
The official API is approved by Meta and suits high volumes, but starting a conversation needs approved templates and Meta charges per message. QR linking keeps your existing number and phone, with no templates, but it isn't official and Meta can restrict a number that sends in bulk. We compare both in MultiChats vs the WhatsApp Business API.
The tools people use
No-code workflow tools such as n8n and Make are the quickest way to wire the parts together; Python or Node give you full control. We have step-by-step notes for both popular routes: n8n and WhatsApp and connecting ChatGPT to WhatsApp.
What nobody tells you
The first few days go well. Then come the messages split into five, the voice notes, the customer writing at three in the morning, the AI replying twice, the number that disconnects on a Saturday. Each one is an afternoon of work. We know because we fixed them one by one building MultiChats.
When to build it yourself, and when not to
Build it yourself if you enjoy programming, have time to maintain it and your case is unusual. If what you want is more sales this week, a ready-made agent like MultiChats is running the same day for €150 a month excl. VAT.
Frequently asked questions
Can I build one for free?
The tools can be free, but the AI model, the server and, on the official API, Meta's messages cost money. So does your time.
n8n or Python?
n8n is quicker to start without coding; Python gives more control. Both need the same five parts.
Which AI model should I use?
Any capable large language model works; what matters more is the rules, the memory and the limits you put around it. MultiChats uses Anthropic's Claude models.
Can I start with MultiChats and build my own later?
Of course. There's no contract.