SieFlow Phone is a phone and shared inbox for your team's WhatsApp Business number. They answer and make calls from the browser, reply to chats and share the conversations. You run it on your own server, in one container.
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SieFlow Phone · Inbox and phone
Screenshot from demo mode, with made-up data.
Your team's phone and chat, on one screen
Built for small support and sales teams: a few operators, one WhatsApp number and nothing to install on their computers.
Phone in the browser
Incoming calls ring for every operator who is signed in, and the first one to answer takes it. You can also call your customers, with mute, keypad and mic and speaker selection.
Shared inbox
Messages and calls from each customer in one thread: text, photos, voice notes, documents and locations. Mine, unassigned and all, with assignment and resolve.
Call permission from the chat
WhatsApp needs the customer to allow calls. You ask with an interactive message inside the 24-hour window, or with a template outside it, and the answer shows up in the thread.
Guided setup
A setup screen in the browser checks your Meta app and token live, finds your numbers, configures the webhook and tells you what is missing to turn calls on.
Floating phone
Pop the phone out into a window that stays on top, like a mini player, and keep talking while you work in another app (Chrome and Edge).
Your data on your server
Settings, operators, conversations and call logs are stored in your install. You decide how many days to keep them, and you can delete a contact with all their history.
Audio goes straight from the browser to WhatsApp
1
Meta tells your install
When a customer calls or writes, WhatsApp sends a signed webhook to your server, which passes it to the operators who are signed in.
2
You answer in the browser
The browser sets up the call with standard WebRTC and SieFlow Phone accepts it through the WhatsApp Cloud API. The server only carries the signaling.
3
Audio goes direct
The voice travels encrypted (DTLS-SRTP) between the browser and WhatsApp's media servers. No PBX, no SIP server and no media server.
Guided setup
From zero to your first call without editing files
A new install asks for everything in the browser. The first admin signs in with a one-time code printed in the server logs, so nobody else can claim the instance.
Checks your Meta App ID, App Secret and token live
Lists your WhatsApp accounts and numbers so you can pick one
Configures the app webhook and subscribes your account
Checks the calling requirements and turns calling on
Adds operators and admins
SieFlow Phone · Setup
Install it on your server
One container with zero npm dependencies. Caddy gets the HTTPS certificate and, if your operators sit behind strict firewalls, the coturn profile adds TURN.
Try it in one minute
Demo mode simulates WhatsApp, with made-up data and a customer simulator. When it starts, open localhost:8080.
docker run --rm -p 8080:8080 -e DEMO_MODE=true ghcr.io/integralaia/sieflow-phone
On your server
Docker with Compose, a domain pointing to the server and ports 80 and 443 free. Then follow the guided setup.
An open source web phone and shared inbox for WhatsApp Business. Your team answers and makes WhatsApp calls from the browser and handles the chats, in a container you run on your own server.
How much does it cost?
SieFlow Phone is free: it is open source under the MIT license. You pay for your server and whatever Meta charges for WhatsApp messages and calls, at their rates.
Do I need a PBX or a SIP server?
No. The WhatsApp Cloud API sets up calls with standard WebRTC, so the browser talks straight to WhatsApp's media servers. SieFlow Phone carries the signaling and keeps the inbox.
What do I need from Meta?
A Meta app with a system user token and a WhatsApp Business number on the Cloud API with calling turned on. The guided setup checks each requirement live. Meta doesn't offer calling on numbers shared with the WhatsApp Business app (coexistence).
Where does my customers' data live?
On your server: settings, operators, conversations and call logs live in a SQLite database inside the container's data volume. Call audio never goes through the server, and RETENTION_DAYS sets how many days messages are kept.
Will there be a cloud version?
Yes, we're working on it: SieFlow Phone Cloud, the same thing without running a server. We'll host it, keep it updated and back it up. Pricing is not set yet. If you're interested, join the waitlist and we'll email you when it opens.
Will the self-hosted version stay free?
Yes. It stays open source under the MIT license, with no features held back. The cloud version is for teams that would rather not run a server.
Open source, on your server
Use it, change it and deploy it wherever you want. If it helps you, a star on GitHub helps more teams find it.
