There are two ways a piece of software can put a team behind a WhatsApp number. It can go through the official WhatsApp Business API, which means an application, a business verification, usually a dedicated number, message templates that need approving, and a bill that moves with your volume. Or it can link to the number you already use, the way WhatsApp Web links a computer, and add the team layer on its own side.
Spun takes the second route. You scan a QR code once from the phone that owns the number, and the conversations start appearing in Spun. This page explains exactly what that means, including the parts that are worse than the API, so you can tell in a few minutes which route you actually want.
One QR code, the same mechanism as WhatsApp Web
WhatsApp has a built-in system for putting your account on another screen: linked devices. When you open WhatsApp Web, it shows a QR code, you scan it from your phone, and the browser becomes a companion of your account. Spun uses that same door. In Settings, WhatsApp, Health you press Connect WhatsApp, a WhatsApp QR code appears, and you scan it from the phone with WhatsApp, Linked Devices, Link a Device, exactly as you would for the web client.
Behind the QR, Spun does not talk to WhatsApp directly. It connects through a third-party WhatsApp Business gateway provider, which holds the session and relays messages to and from Spun. That is how nearly every multi-agent WhatsApp tool works, because direct WhatsApp Business API access is reserved for very large companies, and it has a real consequence you should know before you connect: the gateway necessarily sees your message contents in plain text as it relays them, and so does Spun, which is what makes the inbox, search and AI features possible at all.
If there is no computer nearby when you need to scan, the reconnect screen offers Share QR link: open the link on any phone or tablet, enter the 3-digit PIN, and scan the QR that appears there.
Related: WhatsApp QR codes and linked devices, explained · How WhatsApp data is handled in Spun
Do you need the WhatsApp Business API?
The WhatsApp Business API is the official route, and for some businesses it is the correct one. It is what you use if you need the green verified badge, if you send templated notifications at genuine scale, or if you work somewhere that mandates an official integration on paper. Getting there means going through a Business Solution Provider: an application, a business verification, usually a number that is dedicated to the API rather than the one your customers already message, and message templates that have to be approved by category before you can send them outside a live conversation.
It also means a meter. Meta charges per delivered template message, priced by category and country, and providers add their own platform fee, per-message markup or per-agent seat pricing on top. The cost of the channel grows with how well it works.
The linked-device route trades officialness for speed and predictability. There is nothing to apply for, no template queue between you and a reply, and no per-message line item. You keep the number your customers already have, along with its existing chat history. What you give up is the official badge, official templates, and the guarantee that comes with being inside Meta's own program.
Related: What the WhatsApp Business API actually costs · Comparing Business API providers
What changes on your number, and what does not
- Your number stays yours. Spun links to it as a companion; it does not take it over or migrate it anywhere.
- WhatsApp on your phone keeps working normally. You can still answer from the app while the team answers from Spun.
- Existing history comes along, the same way it appears when you link WhatsApp Web.
- Group chats, media, voice notes and status all keep behaving like WhatsApp, because they are still WhatsApp.
- Calls stay in WhatsApp. Spun cannot place or answer a WhatsApp voice or video call; it has its own separate calling layer.
Related: How video calls work in Spun
Staying connected, and what to do when it drops
A linked device is a live session, not a permanent registration, and WhatsApp has rules about it. An account supports up to four companion devices at once, and a companion unlinks itself after roughly fourteen days if the phone never comes online in that window. Logging out of WhatsApp on the phone unlinks every companion, Spun included. None of that is specific to Spun; it is how linked devices work for everyone.
In practice the thing that decides how stable your line feels is the network the session appears to come from. Settings, WhatsApp, Health shows the current status and gives you two tools when a line keeps dropping: Change Channel, which rebuilds the session, and Self Proxy, which runs a small background service on one of your own Windows computers so the session appears to come from the same connection your phone uses. Self Proxy is the strongest fix for a line that will not stay up, and it needs a Windows 10 or 11 machine that stays powered on.
If a scan is refused, meaning your phone links and WhatsApp drops it moments later, the QR screen says so and offers Self Proxy, because that is usually what fixes it.
More than one number, and no number at all
You can run more than one WhatsApp number from a single Spun account. Each extra number is a separate inbox with its own chats, contacts, settings and team access list, and you switch between them in a click. Extra lines are added from the web app as paid add-ons.
The other direction is worth stating plainly, because the card on the features page is easy to skim past: connecting WhatsApp is optional. Spun runs completely without it. Spun Chat, tasks, the calendar, the pipeline, calls and the team layer all work with no number connected. WhatsApp is one channel you can add, not the thing the product is built on.
The honest limits of this route
- It is not the official Business API. No green verified badge, and no official template messages.
- Messaging through Spun is not end to end encrypted between you and your customer in the WhatsApp sense. It is encrypted in transit at every hop, but the gateway and Spun can read the contents.
- WhatsApp can restrict a number that behaves like a spammer, whichever route it uses. Messaging people who never opted in is the fastest way to get limited.
- The link is a session that needs your phone to come online periodically. A phone that is off for weeks will unlink.
- Four companion devices is a WhatsApp limit, and Spun occupies one of them.