Expanded LLM Support: GPT-5 and Groq gpt-oss-120b for Voice AI Agents
8, Aug 2025
Telnyx is excited to announce expanded LLM support for Voice AI Agents, adding OpenAI’s GPT-5 and Groq’s gpt-oss-120b to your agent’s toolkit. These models open up new possibilities for delivering lifelike, real-time conversations with more choice, flexibility, and cost efficiency.
What’s new
- Support for OpenAI GPT-5 with minimal reasoning effort enabled by default for real-time voice suitability.
- Support for Groq gpt-oss-120b for high-speed, open-source performance.
- Seamless integration with the AI Assistant Builder so you can test instantly.
Key benefits
- Lower latency and pricing for GPT-5: Response times stay under real-time thresholds, and aggressively low cached input costs make it ideal for voice agents where most tokens are cached.
- Open-source acceleration: Groq’s gpt-oss-120b delivers high-throughput inference with competitive performance.
- More choice: Select the LLM that fits your performance, cost, and capability needs.
Why it matters
Voice AI Agents succeed or fail on speed. By optimizing GPT-5 for minimal reasoning effort, we’ve made it viable for real-time interactions without sacrificing conversational quality. And because most voice agent tokens are cached input, GPT-5’s pricing structure offers significant cost advantages. Groq’s gpt-oss-120b brings another competitive option for developers seeking open-source speed and scalability.
Getting started
It only takes a few minutes to get started.