A Twilio WhatsApp alternative that links the number you already use

Twilio's WhatsApp API is one of the most common ways developers reach WhatsApp, because it sits next to Twilio's SMS and voice products and uses the same Messages endpoint. It runs on the official WhatsApp Cloud API: your number is registered as a business sender, messages outside a customer's 24 hour window need approved templates, and each message carries fees. wuapi is a different model, linking a number you already use as a device. This page covers when each one is right.

#How Twilio's WhatsApp API works

You register a WhatsApp sender in the Twilio console. Self sign-up connects a WhatsApp Business Account to your Twilio account, the display name has to meet WhatsApp's guidelines, and a new business portfolio has to complete business verification before production use. The number can be a Twilio number or one you own, as long as it is not already registered with WhatsApp. Twilio's docs say plainly that once it is registered you can no longer use the WhatsApp or WhatsApp Business app with that number.

Sending is a POST to https://api.twilio.com/2010-04-01/Accounts/{AccountSid}/Messages.json with From and To written as whatsapp:+15551234567, and either a Body or a ContentSid pointing at a template from the Content Template Builder. Delivery updates arrive at a StatusCallback URL, signed with X-Twilio-Signature, an HMAC-SHA1 keyed with your auth token.

For testing there is a sandbox: a shared number that people join by sending a code, with three preset templates and one message every three seconds.

#What it costs

From Twilio's WhatsApp pricing page, in US dollars:

• Twilio's fee is $0.005 per message, sent or received.
• WhatsApp's own fee per template message is passed through. Utility and authentication templates start at $0.0034 a message, and marketing templates cost more and vary by country.
• Failed messages cost $0.001 each.
• A US phone number, if you rent one from Twilio, is $1.15 a month.

Inside a customer service window, the official platform does not charge for free-form replies or utility templates today. That changes on October 1, 2026: the platform's pricing docs say service messages start to be charged from that date, at the same rate as utility and authentication templates in each market, and utility templates inside the window stop being free. Each business phone number keeps 1,000 free service messages a month, service messages get no volume tiers, and free entry point windows stay free. Twilio's pricing page did not mention it yet on the day we checked.

#One support line, priced both ways

Take a single support number that receives 2,500 messages a month and sends 2,500 replies, all inside each customer's window.

On Twilio, the platform fee alone is $0.005 on each of the 5,000 messages, which is $25 a month, plus $1.15 if you rent the number from Twilio. From October 2026, WhatsApp's own fee is added on top for the 1,500 replies past the free 1,000, at the utility rate for each customer's country. If the same line also sent reminders to customers whose window had closed, each one would be a template with its own fee.

On wuapi, that number costs $6 a month, and the price does not move with the count. The reminders are normal messages. What you watch instead is the pace: a number that suddenly writes first to hundreds of people looks different from one that answers, which is why pacing exists and why we recommend it for that kind of sending.

The official platform starts to make sense on price when the traffic is mostly outbound and high volume, which is also where it makes sense for every other reason.

#When Twilio is the right call

The official platform exists for good reasons, and for some teams it is the only sensible choice.

• You send notifications that start with you. Order updates, delivery windows, reminders and one-time codes to people who have not written to you recently are what approved templates are designed for.
• You are a regulated or large sender. Banks, airlines and healthcare providers usually need the paper trail, the verified business name and a contract with a provider.
• You want the verified business path. A verified sender and the official business badge live only on the official platform.
• You already run SMS and voice on Twilio. One vendor, one bill and one webhook format across channels is worth something.
• Your volume is high and outbound. The official platform scales a sender through messaging tiers, from 250 unique recipients a day for a new business up to no cap, instead of pacing a single phone.

If that is your case, stay. Linked device or Cloud API lays out the split in more detail.

#When a linked number fits better

wuapi links a number to our API the way WhatsApp Web links to a phone. Nothing is registered: the number keeps working in the WhatsApp app, and the API sends and receives alongside it.

• Your number stays on the phone. The owner keeps chatting from the app, and every message, from the app or the API, shows up in both.
• No templates and no window. A linked number sends normal messages at any time, to anyone who expects them, without an approval step.
• A flat price per number. $6 for the first, $4.50 each from the second to the fiftieth, $3.50 after, and no fee per message from anyone. The price is the same whether the number sends ten messages a month or ten thousand.
• Groups as a member. A linked number can create groups, add and remove people, and post in them.
• A Free plan. 1 number, 2,000 messages a month and 0.5 GB of proxy traffic, with no card. See pricing.

The trade is the one the platform sets: a linked number is a person's account used by software. It has no templates, no buttons or list messages, and no verified business badge. It sends at a person's pace, and WhatsApp can restrict it for what it sends, the same as any account. Turn on pacing for anything that starts with you, and read keep your number healthy first.

#What wuapi adds around the number

• A residential proxy per number. Each number connects through a sticky residential exit in the country and city you pick, and stays offline rather than falling back to a datacenter IP.
• Pacing per number, off by default. A per-minute cap, a lower cap for first contacts and a typing indicator, set with PATCH /v1/accounts/{accountId}. We recommend 12 a minute and 5 to new contacts for outbound sending.
• Webhooks. Wuapi-Signature carries an HMAC-SHA256 of the timestamp and the raw body, and a failed delivery is retried at 30s, 2m, 10m, 1h and 6h. Twilio's default is one retry, on a connection failure, which you can raise per URL.
• Idempotent sends. Idempotency-Key on any POST, kept 24 hours.
• A typed SDK and an MCP server. @wuapidev/sdk for TypeScript, and an MCP server whose tools send and read messages. Twilio's hosted MCP server, in public beta, searches its docs and API reference.

#Side by side

#Moving from Twilio

The code is the easy part.

// Twilio
await client.messages.create({
  from: "whatsapp:+15551234567",
  to: "whatsapp:+15557654321",
  body: "Your table for two is ready.",
})

// wuapi
await wuapi.messages.send({ accountId, to: "+15557654321", text: "Your table for two is ready." })

The part that takes planning is the number:

1. A number registered with the official platform cannot be linked as it is. It has to be released from the platform first and set up in the WhatsApp or WhatsApp Business app again. Ask Twilio how to deregister the sender. Many teams link a different number instead.
2. Keep templated traffic where it is. If some of what you send needs templates, keep that on Twilio and move the conversational traffic. Plenty of products run both.
3. Replace the signature check with the one in the docs.

#Questions people ask