> ## Documentation Index
> Fetch the complete documentation index at: https://docs.persistence.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Models and voice pipelines

> Choose the language, models, and processing pipeline for an agent.

An agent can use a cascaded voice pipeline or a realtime model, depending on the models available in your workspace.

## Cascaded pipeline

A cascaded pipeline uses separate components for speech-to-text, language generation, and text-to-speech. It gives you direct control over the transcription model, LLM, and voice.

## Realtime pipeline

A realtime pipeline uses a realtime model for the conversation. Some configurations use realtime audio directly, while others pair a realtime model with a selected text-to-speech voice.

## Choose a configuration

Select the conversation language first, then choose compatible models and a voice. Review the model's supported language, context window, and specialization in the builder.

Use a representative simulated call to compare:

* Transcription accuracy for names, numbers, and domain terms
* Voice quality and pronunciation
* Response latency
* Interruption and endpointing behavior
* Action execution and structured output

Change one model or speech setting at a time so you can attribute the result.