How it works
WAGHL exposes a chatgpt-voice webhook that takes a text message and a voice selection, calls OpenAI's TTS API, and sends the resulting audio as a WhatsApp voice note — all from inside your GHL workflow.
Webhook URLs
The webhook URL differs by gateway. To find yours: Settings → Phone Numbers → Advanced Settings.
| Provider Name | Webhook URL |
|---|---|
| WhatsApp Gateway |
https://trigger.apimerger.com/chatgpt-voice
|
| WhatsApp Gateway 1 |
https://trigger1.apimerger.com/chatgpt-voice
|
| WA1 Connector |
https://wa1.apimerger.com/chatgpt-voice
|
| WA2 Connector |
https://wa2.apimerger.com/chatgpt-voice
|
Required custom data
Three keys go in your webhook action's Custom Data:
chat_gpt_api_key— your OpenAI API key (must have TTS access)voice— pick one of:alloy,echo,fable,onyx,nova,shimmermessage— the text you want converted to a voice note
alloy — neutral, balanced. echo — male, professional. fable — British, warm. onyx — male, deep authoritative. nova — female, energetic. shimmer — female, gentle.
Test all six with your typical message length to pick what sounds most on-brand.
Setup pattern
Build a GHL workflow
Create or open a workflow. Add a Webhook action. Method: POST. URL: from the table above. Add the three custom data keys with your values.
Save, publish, test
Save the workflow, publish it, then trigger it on a test contact. Within seconds the contact's WhatsApp should receive the voice note.
When to use this vs. ElevenLabs
ChatGPT TTS is fast, cheap, and reliable — perfect for most use cases. Choose ElevenLabs TTS if you need:
- Cloned voice (your own voice, or a custom branded voice)
- Higher emotional range or expressive narration
- Specific accent control beyond OpenAI's six voices
What's next?
- ElevenLabs TTS — for cloned-voice or branded voice notes
- Transcribe inbound voice notes — convert customer voice replies to text
- ChatGPT chat replies — full AI conversation, not just voice