A POST request will be sent to your server whenever you receive a message if you configure a webhook. If your endpoint does not return an OK status code (200 - 299) we will attempt to retry with the following exponential delays: First attempt -> 180m -> 6h -> 12h

In order to receive a message you must have sent a message to that phone number previously or have used our Register Number function to register the number. To be able to receive messages without this limitation contact us about getting a dedicated phone number.

Webhook Body

The body of the webhook we will send you will have the following info for each message you receive:


An ISO timestamp representing the time the message was sent. The timezone is UTC.


The content of the message that was sent


The phone number the message was sent from


An array of strings where each string is a CDN URL to the image (or other media/file) sent. Will be empty if no files are attached.

Unlike other SMS providers Byteflow supports receiving HEIC/HEIF images when sent from an iPhone
Any images received will be normalized into a PNG for your convenience