Communication · Integration
Add WhatsApp to your product for your customers, and give your AI agents governed access to it.
A WhatsApp integration is governed by two rules that decide whether your feature is possible at all. First, you cannot message somebody freely. Outside a 24-hour window that opens when the user last wrote to you, only a template Meta has already reviewed and approved may be sent, and approval takes real time and can be refused. Second, everything is addressed by phone number id on a business account, rather than by anything resembling a channel or a thread. Inside the window you can reply with ordinary messages, and receipts tell you what was sent, delivered and read. fastn stores each business account's credentials and stays current with the platform's versioned API.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Have each customer connect their own business account and phone number id, so messages come from their brand.
Send an approved template for the notifications your product owes people, and get the template written before you need it.
Detect when a user's reply opens the 24-hour window, and allow free-form replies only while it is open.
Follow the sent, delivered and read receipts so your product knows a notification actually landed.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent drafts a reply while the service window is open, and falls back to a template once it closes.
An agent reports which approved templates exist before anyone promises a customer a new message type.
An agent reads the receipts for one number and says whether the last notification was read.
Example prompt
Is this customer's 24-hour window still open, and which approved template do we use if it is not?
Set up WhatsApp in 4 steps
- 01Enable the WhatsApp connector from your fastn dashboard.
- 02Have each customer authorise their own WhatsApp account, so calls run under their credentials rather than a shared key.
- 03Decide which message templates, phone number ids and delivery receipts your product needs, and get your templates approved first, since free-form replies are only allowed inside the 24-hour window.
- 04Call it from your product and expose it to your agents through the same governed connection.
Why teams use the WhatsApp integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a WhatsApp integration without building it. Your customers connect their own WhatsApp account inside your product and work their messages, conversations and participants there, with no per-customer code on your side.
- Handle the part that actually costs time: anything sent is user-visible, so duplicates and misfires are immediately embarrassing. fastn owns the auth, token refresh, rate limits, pagination and breaking-change fixes, so a WhatsApp update is not your on-call problem.
- One integration serves your product and your agents. The same governed WhatsApp connection powers in-product features and gives AI agents scoped, audited access, so you put the right message in front of the right team automatically without wiring it twice.
Used by these teams
Compare with
Twilio
Infobip
TelegramOften used alongside
Tools the same teams tend to run next to WhatsApp, across other categories.
Aircall
Calendly
Gong
Google CalendarWhatsApp integration FAQ
How do I add a WhatsApp integration to my product?
Enable the WhatsApp connector in your fastn dashboard, then let each customer authenticate their own WhatsApp account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no WhatsApp client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own WhatsApp account?
Yes. Every connection is scoped to the individual customer, so each authorises their own WhatsApp account and only ever sees their own messages, conversations and participants. That per-tenant isolation is the point of an embedded integration: you support the long tail of customer setups without maintaining an integration per customer.
Can AI agents use this WhatsApp integration?
Yes. The same connection is exposed to your agents through the fastn MCP gateway, with permissions scoped per tenant and every call audited. An agent drafts a reply while the service window is open, and falls back to a template once it closes.
Who maintains the WhatsApp integration?
fastn does. When WhatsApp changes an endpoint, deprecates a field or alters its auth, the fix lands in the connector rather than in your backlog, and your customers' connections keep working.
Does each customer connect their own WhatsApp account?
Yes. Every customer authorises their own WhatsApp account, so messages, meetings and notifications originate from their workspace under their permissions. You never proxy through a shared account, which also means a customer revoking access affects only their own connection.
How are duplicate notifications avoided?
Sends are deduplicated per event, so a retry after a network failure does not post the same message twice into a channel people are reading.
What can I build with the WhatsApp integration?
A common starting point: have each customer connect their own business account and phone number id, so messages come from their brand. Teams also use it for the other use cases listed above, and expose it to agents for governed reads and writes.
How much does the WhatsApp integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding WhatsApp does not change your per-connector cost. You can start free with 3 connected accounts.
Add WhatsApp to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.