GPT-5.4-mini Now Available for Telnyx Voice AI Assistants

GPT-5.4-mini is now available as an LLM model option for Telnyx Voice AI Assistants. Select OpenAI's compact, high-efficiency model directly in your assistant configuration, with no external API setup required for Telnyx-hosted inference.

What's new

• GPT-5.4-mini model option: Select GPT-5.4-mini as the LLM for any Voice AI Assistant, alongside existing models including Kimi-K2.6, GLM-5.2, and MiniMax-M3.
• Compact model for high-volume call flows: GPT-5.4-mini is built for cost-efficient inference at scale, making it suited for high-volume voice agent workloads where token cost per minute of conversation matters.
• Available across assistant configurations: Use GPT-5.4-mini on any assistant, including multi-node conversation flows where different nodes can run different models.
• Mission Control configuration: Select the model directly in your assistant settings, with no API call required.

Why it matters

• Voice AI production workloads live or die on cost per call. A compact model like GPT-5.4-mini lowers the inference cost floor for high-volume agent flows like IVR routing, FAQ lines, and intake screening, where you need reliable reasoning but not maximum model capacity.
• Model choice inside Telnyx means teams compare model fit, latency, and cost across providers while keeping telephony, orchestration, and agent configuration in one system. No second vendor contract, no separate inference bill, no integration tax.
• For multi-node conversation flows, you can assign GPT-5.4-mini to high-volume nodes and reserve larger models for complex reasoning steps. Match model cost to node complexity.
• On-network processing keeps audio and inference on the same private backbone, so the path between the caller and the model never leaves Telnyx infrastructure.

Example use cases

• High-volume customer support lines where a compact model handles intake, FAQ, and routing at lower cost per call.
• IVR replacement flows where the assistant needs enough reasoning to route calls accurately without needing maximum model intelligence.
• Multi-node agent flows that use GPT-5.4-mini for simple nodes and a larger model for complex resolution nodes.
• Teams evaluating model cost versus quality across their voice agent traffic to find the right price-performance point.

Getting started

1. In Mission Control, navigate to AI, then Assistants, and select your assistant.
2. In the assistant configuration, set the model to GPT-5.4-mini.
3. Save the assistant and test with real caller audio before routing production traffic.

For API-based configuration, set the model field on your assistant:

{
  "model": "openai/gpt-5.4-mini"
}

Learn more in the Telnyx AI Assistants docs or the Available Models guide.