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

# Pipelines Overview

> How voice and text interactions flow in Kupe AI.

## Overview

In Kupe AI, each agent interaction runs through a **pipeline** that handles both **voice** and **text** with low latency and clear turn-taking.

There are two main pipeline types:

* **Speech pipeline** – For real-time voice conversations (phone or web).
* **Text pipeline** – For chat or text-only interfaces.

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## Speech pipeline

The **speech pipeline** runs the full loop from user speech to agent speech.

### 1. User audio input

Audio can come from:

* **Twilio** (phone calls)
* **Web** (browser-based calls)

Audio is **resampled** to a standard format and **noise reduction** is applied before processing.

***

### 2. Voice activity detection (VAD)

**VAD** decides when the user is speaking and when they have finished. It uses:

* **Acoustic cues** (energy, silence)
* **Semantic cues** (end-of-utterance)

So the system knows **when to respond** and **when to keep listening**.

***

### 3. Transcription

Detected speech is sent to the **transcription model** in **streaming mode**:

* **Partial transcripts** are produced in near real time.
* Transcripts are updated as the user keeps talking.
* The agent can start reasoning before the user fully stops.

***

### 4. Agent processing

The transcript is sent to the **agent (LLM)**, which:

* Interprets intent.
* Produces a contextual reply.
* Can call **tools or integrations** (e.g. MCP, HTTP).

The system keeps listening for **interruptions**: if the user speaks again, the current response is **stopped and cleared**, and the new input is processed.

***

### 5. Text-to-speech (TTS)

The agent’s text is sent to **TTS**, which:

* Converts it to natural speech.
* Supports **streaming**, so playback can start with minimal delay.

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### 6. Audio output

The generated speech is **streamed** back to the user via:

* The browser, or
* The Twilio call.

That completes one **speech loop**: user voice → agent reasoning → agent voice.

***

## Text pipeline

The **text pipeline** is a shorter path for chat or text-only use:

1. **User text** – The user sends a message.
2. **Agent processing** – The same LLM and tool logic as in the speech pipeline.
3. **Integrations** – Tools and APIs run as needed.
4. **Text output** – The reply is returned as text (no TTS).

It reuses the same agent and integrations as the speech pipeline, without any voice stages (VAD, STT, TTS).

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## Summary

| Stage        | Speech pipeline                   | Text pipeline  |
| ------------ | --------------------------------- | -------------- |
| Input        | User voice (Twilio/Web)           | Text message   |
| Processing   | VAD + Transcription + Agent + TTS | Agent only     |
| Output       | Agent voice (streamed)            | Text reply     |
| Interruption | Handled in real time              | Not applicable |

***

### Takeaways

* Both pipelines share the **same agent and integration logic**.
* The speech pipeline adds **streaming**, **turn detection**, and **TTS**.
* Interruptions are handled so the conversation stays smooth.
* Use the speech pipeline for **voice-first** and the text pipeline for **text-first** experiences.