You can integrate Call Loop messaging into virtually any app using our Triggers feature. This enables you to create a message and trigger it using a Webhook URL.
Step 1: Create a Trigger
Head over to Triggers to create your first Custom Trigger to create your SMS text.
Step 2: Copy Your Trigger URL
After you create your Custom Trigger, copy the Webhook URL.
Step 3: Trigger The Webhook
From your application, trigger the Call Loop Webhook and append the variables to deliver your message. Be sure to send over the variables in the proper format. The parameters must be as shown or else it will fail.
Call Loop Parameters |
phone |
first |
last |
How to Use Dynamic Audio in a Ringless Voicemail Webhook
You can now send a dynamic audio file when triggering a Custom Ringless Voicemail (RVM) via webhook.
This allows you to pass an audio file URL directly in the webhook request — making it easy to send personalized or externally generated audio without pre-configuring it inside the platform.
What’s New
A new parameter has been added to Custom RVM webhooks:
audio=
When included in your webhook URL, the system will fetch the provided MP3 file and use it as the voicemail audio.
How It Works
When using a Custom RVM Trigger, your webhook URL typically looks like this:
https://api.callloop.com/webhook/Custom/{uuid}?phone= You can now append the audio parameter:
&audio=PUBLIC_AUDIO_FILE_URL
Example
https://api.callloop.com/webhook/Custom/4d6333c3-777f-4808-b4dc-ee6afa4320e7?phone=+17755382277&audio=https://yourdomain.com/audio-file.mp3
When the webhook is triggered:
The system reads the phone number.
It retrieves the audio file from the provided URL.
The Ringless Voicemail is sent using that audio.
Successful Response
If the request is processed successfully, you’ll receive a JSON response confirming the message was queued.
Example response:
{ "message": "Message sent with ID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" } The Message ID confirms that the voicemail has been successfully submitted for delivery.
Requirements
To use dynamic audio:
The audio file must be publicly accessible (no login required).
The file must be in MP3 format.
The file must be reachable at the time the webhook is triggered.
If the file cannot be accessed, the voicemail will not be sent.
When to Use This Feature
Dynamic audio via webhook is ideal for:
AI-generated voice files
CRM-triggered voicemail automation
Personalized audio per contact
External system integrations
Real-time audio generation workflows
Need Help?
If you need assistance setting up your Custom RVM webhook or passing dynamic audio, contact support and we’ll be happy to help.