Hi there, Has anyone ever encountered an issue with a Retell agent reading JSON extracts to the caller? We started seeing this behavior a couple days ago with multiple agents. Randomly after the Retell agent calls the extract_user_info function, she starts reading the JSON extract data to the cal…

I would stay with GPT 4.1, it’s the most stable one currently.

Yes, this issue has been reported. From Thursday, December 18, 2025, there’s a documented case where an agent verbally outputs tool-related technical data during calls (1) . The issue you’re experiencing—where the agent reads JSON extracts aloud—appears related to how the LLM handles function callin…

Kindly tell me where the “Speak during execution” setting is. For the Extract Variable function it does not appear in my node: [image]

I apologize for the confusion. Looking at the documentation more carefully, the “Speak during execution” setting appears in different contexts depending on which builder you’re using: For Conversation Flow (Extract Dynamic Variable Node) The Extract Dynamic Variable Node documentation (1) mentions…

Hello Jeremy Indeed the issue is coming from GPT 5.1 , try GPT 4.1 and that will fix the issue.

Thanks, Omar! I will try that. I also noticed GPT 5.2 was just released. I wonder if that also fixes the issue.

GPT-5.2 is available on Retell AI (1) (2) (3) (4) (5) . The available GPT-5 family models include: gpt-5, gpt-5.1, gpt-5.2, gpt-5-mini, and gpt-5-nano (1) (2) (3) (4) (5) . However, I don’t have specific information about whether GPT-5.2 addresses the JSON verbalization issue you’re experiencing. There is a d…

So far I didn’t recieve any issue about GPT 5.2 but its still new, you can give it a try it.

Based on the available information, GPT-5.2 is listed as one of the supported models in Retell AI’s post chat analysis model options (1) . There was a reported issue with GPT-5 where the AI Voice Agent would get stuck repeating the same question in a loop during the question phase, even after the use…

Agent reading JSON extract to callers

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jeremy December 18, 2025, 5:10pm 10

My first attempt using GPT 5.2 resulted in the agent reading back XML data with chinese characters this time… so I would not recommend it at this time.

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Agent reading JSON extract to callers

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