We had WhatsApp API support in Zernio for a few months, but we weren't giving it the attention it deserved.
The demand made it impossible to ignore.
So instead of shipping quietly, we decided to make it a moment: five days, five releases, and by Friday, a complete WhatsApp conversational layer.
Here's how it went.
Day 1: WhatsApp Workflows
We opened with Workflows, since it's the most visual feature (and it ended up getting some unexpected traction on Reddit).
Workflows is a visual builder for WhatsApp automations. Drop nodes onto a canvas, wire them together, publish. Once it's live, it runs on your WhatsApp number and responds as soon as someone sends a message.
For anyone running a business on WhatsApp, or building it into a product, this is where it gets interesting. You can route leads based on their answers, handle support requests automatically, onboard new users, or confirm and reschedule appointments. The trigger is a message, while everything that happens after is up to you.
And if you don't want to build it yourself, just describe the workflow to Claude through MCP and the agent can create it for you.
Read the full release note: Introducing WhatsApp Workflows
Day 2: WhatsApp phone numbers in 53 countries
Every WhatsApp feature runs on a number. Without one, nothing else works.
Some users come to Zernio with a number already. Others are starting from scratch, and before this week, that meant leaving to sort it out somewhere else: a telecom provider, registration paperwork, WhatsApp setup, all in different places.
Day 2 fixed that. You can now buy a number in 53 countries directly inside Zernio. We handle the provisioning, verification, and WhatsApp connection for you. In most countries, the setup takes about 30 seconds. Others require you to submit identity documents and an address — a KYC (Know Your Customer) verification process, after which your number is usually live within 1–3 days.
Read the full release note: Buy a WhatsApp number inside Zernio
NEW: One more thing we shipped quietly alongside this: if you're in a regulated country and don't want to build the document collection form (KYC) yourself, you don't have to. One API call gives you a hosted, white-labeled KYC link. Your customer opens it, submits their ID and address, and the number provisions under your account. You can put your own name and logo on the page, so they never see Zernio.
Day 3: WhatsApp Calling
Messaging has been part of Zernio's WhatsApp integration for a while. Adding calling felt like the obvious next step.
Your WhatsApp number can now receive and make calls. In both cases, you decide where those calls go: a phone number, a SIP endpoint, or an AI voice agent such as Vapi, Retell, ElevenLabs, or LiveKit.
It also works directly with Workflows. For example, during a chat, you can detect when a conversation needs a voice call and ask the user to call, route them to a human, or hand them off to an AI voice agent automatically.
Read the full release note: WhatsApp Calling API
Stop building WhatsApp from scratch.
One API for numbers, messaging, calling, and automation on the official WhatsApp Business API.
Day 4: WhatsApp Flows
The thing about WhatsApp is that your users are already in the chat. Sending them to a form, booking page, or survey link creates unnecessary friction. Flows remove that by keeping the entire experience inside WhatsApp.
A Flow is an interactive form that opens directly in the chat. It can be a booking form, lead capture, onboarding flow, or customer survey. You build it once through the Zernio API, preview it, and send it to as many conversations as you need.
Responses come back as structured data, so there's no need to parse messages or chase users for missing details.
It sounds simple. The use cases it unlocks aren't.
Read the full release note: Build WhatsApp flows
Day 5: Product Hunt
We put the whole week on Product Hunt on Friday and let the community decide what they thought.
We debated the timing. Launching on a Friday goes against most of the 'conventional rules'. But the week had built its own momentum and it felt right to close it there rather than hold it for a better day.
The support was genuinely unexpected. More on that below.
By the numbers
We know this is just the start and we're improving the WhatsApp API daily and there's a lot more coming. But the first response from the community made the week feel real.
400+ new WhatsApp accounts connected during the week. Developers and builders who went from zero to a live WhatsApp integration while the week was still running.
#2 product of the day on Product Hunt. The comments section turned into a proper conversation: developers asking questions, sharing what they were building, swapping ideas. That doesn't happen without a community that actually cares, and we felt your support.
Support from our community on socials
This is the part where I get to show off something I genuinely enjoyed building. The report below was pulled by Claude using our own Analytics API over MCP: LinkedIn impressions, X views, Reddit upvotes, all in one place.
We used Zernio social media analytics API to report on Zernio's own WhatsApp launch week, which made perfect sense.
What's live now
All four pieces work together. Buy a number, build a workflow, add calling, and collect responses with Flows. The complete WhatsApp conversational layer through a single integration.
And we're far from done with WhatsApp. There's more coming these weeks. And if something that you're looking for is missing, let us know in the chat of your Zernio account or tag us on X or LinkedIn.