Models & Router

Models are the speech and language layer under every live turn: speech-to-text, the LLM, and text-to-speech. The router is what keeps a turn alive. On Agent Studio agents each of the three has a standby, and Unpod fails over to it automatically - before the greeting or mid-call - so a provider outage is not a dropped call. On SDK agents, STT and TTS fail over when the session starts. Model choice is yours. A voice profile fixes the speech pair for a language; the agent’s brain fixes the LLM. The router keeps that choice running. It does not swap in a cheaper model behind your back.

The primitives

Primitive	What it is	Where it lives today
Voice profiles	A benchmarked STT + TTS pairing for a language, with its measured cost and latency	`client.voice_profiles.list(language=...)` - production
LLM	The model behind the agent’s brain	Prompt or Playbook brain on the hosted runtime; an `Endpoint` brain to bring your own OpenAI-compatible model - production
Failover	A standby per modality, switched in automatically	STT, LLM and TTS, mid-call, on Agent Studio agents; STT and TTS at session start on SDK agents - production
Routing	How LLM traffic reaches the model: gateway, managed host, or direct	Decided per model, internally - production

step1_voices.py

import asyncio
from unpod import AsyncClient

async def main() -> None:
    async with AsyncClient() as client:
        profiles = await client.voice_profiles.list(language="hi")
        for p in profiles:
            print(p.name, p.profile_id)

asyncio.run(main())

Pass the profile name to client.agents.voice.create() - see the Quickstart. To bring your own LLM, use an Endpoint brain - see Which brain.

On the spine

Models sit in the Talk layer, under every interaction. They read the live audio and the agent’s reply text, and write nothing to the spine themselves - the interaction’s transcript and outcome are what persist.

What stays hidden

Which vendor served an utterance, the order of standbys, timeouts and health probes. You choose a profile and a brain; which provider carries a given turn is Unpod’s problem.

Status

Production: multi-vendor STT, TTS and LLM; voice profiles; automatic failover for all three, mid-call, on Agent Studio agents (STT and TTS at session start on SDK agents); LLM routing.
In build: Unpod-served speech and language models.
Not offered: picking a model per request by cost or latency. Choose the profile and model you want; the router keeps them running.

Go deeper

Quickstart

Pick a voice profile and place a call in six SDK calls.

Voice profiles

What a profile pins, and how to choose one.

Calling Engine

The voice runtime the models serve.

Agents

The brains that use the LLM.

Overview

Talk

Remember

Act

The primitives

On the spine

What stays hidden

Status

Go deeper

Quickstart

Voice profiles

Calling Engine

Agents

​The primitives

​On the spine

​What stays hidden

​Status

​Go deeper

Quickstart

Voice profiles

Calling Engine

Agents

The primitives

On the spine

What stays hidden

Status

Go deeper