Telnyx VoiceAI Assistants now support OpenAI’s GPT-5.2 model, giving developers access to the latest generation of frontier LLM capabilities for real-time telephony-centric voice applications.
This integration enhances intelligence and flexibility in multi-turn conversational workflows while addressing real-world performance needs.
What’s new
- GPT-5.2 model support: Select GPT-5.2 in the AI Assistant model picker or via API.
- Extended context: Bigger context handling for more complex dialogs and history.
- Fallback routing: Developers can configure automated model mode switches based on task complexity.
- Unified billing: Usage of GPT-5.2 through Telnyx bills at consistent pricing without separate API billing.
Why it matters
- Improves reasoning and long-context understanding for multi-turn conversations.
- Offers configurable performance profiles so teams can optimize for latency or depth.
- Reduces retries and custom prompt logic in pipeline workflows.
- Enables handling large task contexts (documents, histories) without fragmenting user state.
Example use cases
- Contact center assistants that require consistent handling of multi-step support flows.
- Enterprise knowledge bots that use extended context for policies, contracts, or manuals.
- Interactive IVRs that combine natural language with backend system lookups.
Getting started

- Open the Mission Control Portal and go to AI Assistants.
- Edit or create an Assistant and choose GPT-5.2 in the model configuration.
- Optionally choose Instant, Thinking, or Pro to tailor latency vs. reasoning effort.
- Test end-to-end dialogs in the Assistant Builder before deploying.
- Monitor interaction latency and intent accuracy via Conversation History.
Log in to the Mission Control Portal, navigate to AI Assistants, and set the maximum assistant duration as required.