Product Overview#
Supafone is an S2S routing hub with Supervisor. Choose the model that talks to callers, then use a separate reasoning model to observe the call and guide it. One API connects Ultravox, OpenAI, Gemini, Grok and Smallest AI Hydra.
Agent Factory saves your agent's instructions, tools and call stages. Switching the speaking model keeps that setup together. You choose the saved model; Supafone connects the call to it.
Choose how to connect#
| Option | What you supply |
|---|---|
| One Supafone API key | Your account key; Supafone supplies the configured speaking and Supervisor credentials |
| Bring your own keys | A speaking-provider key, a Supervisor reasoning key, or both |
Speaking and Supervisor choices are independent. For example, use your OpenAI key for speech and your Anthropic key for Supervisor, or use Supafone's managed Supervisor with your own speaking key.
Create a supervised agent · Connect your own keys
Shared S2S interface#
Use the same SupafoneS2S interface for Ultravox, OpenAI, Gemini, Grok, and Smallest AI Hydra. Provider subclasses supply the selection while Agent Factory keeps the agent and phone identity. Ultravox stays the default; the native catalog offers six model choices. See the common interface for the class contract and switching examples.
Ordinary model updates apply to new calls; native live handoff requires a separate opt-in runtime policy. Capabilities remain provider-specific: Hydra has no native transcripts and cannot change its persona or voice mid-session. Check credentials and test the selected provider before a customer call.
Two voice-output choices in one Agent Factory#
Ultravox + custom TTS keeps the existing managed phone agent and lets a compatible Cartesia, ElevenLabs, Inworld, or Ultravox catalog voice supply its speech. Native S2S selects OpenAI, Gemini, Grok, or Hydra and uses that model's own voice list. Both are available through SupafoneS2S; external TTS is not a universal voice override for native models.
Compare both paths and create an Ultravox agent with custom TTS.
Build once, choose the model#
Create an agent with a realtime: { provider, model, voice } selection. The native catalog includes OpenAI gpt-realtime-2.1, OpenAI gpt-live-1, Google gemini-3.1-flash-live-preview, xAI grok-voice-latest, and Smallest AI hydra-v1.0 and hydra-v1.1. Use the shared provider classes or the underlying realtime selection; UltravoxS2S keeps the existing managed default.
The same agent can use authenticated browser previews, Supafone-managed phone, BYO Twilio, BYO Telnyx, BYO Plivo, or BYO SIP. Update the selection before a new session to compare another model. Your agent identity, instructions, supported tools, custom stage plan, and carrier configuration stay together; choose a model-compatible voice with each switch.
Managed keys first#
Your Supafone key authenticates your application. Supafone then resolves the selected speaking model's credential on the server: an encrypted account BYOK key, if supplied, otherwise a configured platform key. A platform key means customers can use the model without creating their own provider account.
Read the selected provider's runtime status before launch. Missing credentials are reported as setup required. A catalog entry and a configured credential do not establish model entitlement or successful live calls. Carrier readiness is checked separately from model readiness.
Three product surfaces#
| Surface | Purpose | Runtime boundary |
|---|---|---|
| Native realtime Agent Factory | Build and switch S2S agents through the hosted API and dashboard | Six native catalog models, shared custom stages, supported server tools, browser and phone |
| Managed compatibility Agent Factory | Continue existing Ultravox-backed hosted workflows | Selected when realtime is omitted; shares the planner and workflow; retains compatible external TTS and live language/voice profiles |
| Supafone Supervisor | Observe the call and guide the speaking agent | Hosted agents use the supervisor setting; external stacks use a separate adapter |
Supafone Supervisor is an independent reasoning layer available on all five Agent Factory speaking families, as well as supported external stacks. Native models receive guidance through the check_guidance tool. Hydra provides model-reported context rather than transcripts. See the framework matrix for delivery differences.
API and SDK surfaces#
Use Python, TypeScript, REST, or the dashboard with the same hosted agent contract. Hosted agents and model readiness live at https://api.supafone.ai/api/v1/labs; Labs Cloud supervision, QA, TTS/STT, usage, and logs live at https://api.labs.supafone.ai. One sl_live_... key can authenticate both APIs with the linked account; scoped sf_live_... keys remain available for hosted-agent-only integrations.
Start the quickstart, read the native runtime limits, or see Agent Factory for a complete creation workflow.