The WhatsApp API for outreach.
Link a WhatsApp number with one scan, then send WhatsApp steps in the same sequence as LinkedIn and email on the Smart API, or call one endpoint per action on the Raw API. Per-number caps and WhatsApp’s own limits are handled, and visible in the API.
1 scan
Links a number
A QR code or a pairing code, like WhatsApp Web. No Business account needed.
3 channels
In one sequence
WhatsApp steps sit next to LinkedIn and email steps in the same campaign.
40 / 500
New chats / messages a day
Hard caps per number on the Raw API, before anything reaches WhatsApp.
60 s
Between two new chats
Enforced per number, so a runaway loop cannot burst a fresh number.
WhatsApp numbers, on your senders
On the Smart API a sender is the person your campaigns speak as: one LinkedIn account, several mailboxes, and now several WhatsApp numbers. Link a number, attach it to the sender, and add WhatsApp message steps to the sequence. Leads need a phone number with its country code; the engine paces each number, applies its warm-up, and stops the follow-ups as soon as the lead replies.
Schemas and examples at developer.swarmhit.com.
The WhatsApp channel, in four calls
api/v1POST /whatsapp-accounts · start a link, get a QR
GET /whatsapp-accounts/{id}/link · until it reads active
POST /campaigns · whatsapp_message steps
POST /campaigns/{id}/leads · leads with a phone
Every WhatsApp action, one endpoint each
On the Raw API each action is its own call and your code decides when it runs. See the WhatsApp guide.
Link a number
QR code or pairing code, a linked device
Check a number
is it on WhatsApp? Kept for a week
Start a chat
the number is checked first
Messages and files
text, files, replies to a message
Groups
create one, add or remove people
React, edit, forward
edits within 15 minutes of sending
Delivered and read
every status change by webhook
Full history
chats, messages, older history on request
WhatsApp follow-ups in the same sequence as LinkedIn and email
A WhatsApp message step takes text, a file, or both, and sits in the sequence next to invitations, LinkedIn messages and emails. A reply stops the follow-ups for that lead. Replies land in the same inbox as the other channels and reach your webhooks, so your product reads one conversation per lead instead of three. See the LinkedIn channel and the cold email channel for the other two.
Limits you can read before WhatsApp enforces them
WhatsApp limits how many new chats a number may start. Swarmhit stops a runaway client first: on the Raw API each number is capped at 40 new chats, 500 messages and 300 “is this number on WhatsApp” checks a day, with at least 60 seconds between two new chats, and every refusal happens before anything reaches WhatsApp. When WhatsApp blocks new chats on a number, the API says so with the time the block ends; existing chats keep working. On the Smart API, each number lists today’s caps with its warm-up applied, its usage, and its health.
Sends that never go out twice
Give each send your own id and a retry within 24 hours returns the first answer instead of sending again. Add a “unless replied since” date to a follow-up and nothing is sent if the person wrote back in the meantime. A sandbox number simulates what a person does, so your webhooks see the same events as live.
Not the WhatsApp Business Platform, on purpose
The number is linked as a device of the phone, like WhatsApp Web, on an IP in the number’s own country. That means no Business account and no templates to get approved, and it also means the number behaves like a person’s phone: WhatsApp expects it to talk to people who know it. Swarmhit is not affiliated with or endorsed by Meta or WhatsApp.
One infrastructure. Every outreach channel.
FAQ
The WhatsApp API, answered.
- Smart API and Raw API
- Per-number caps built in
- REST API and webhooks
WhatsApp is in early access.
Add it to your sequences.
Book a call, we open WhatsApp on your workspace, and you link your first number with one scan.