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

# Silence-Based EOS

> Configure silence-based end-of-speech detection in assistant-api.

Silence-Based EOS triggers end-of-speech after a fixed duration of silence following the last speech activity or transcript. No ML model, no inference overhead.

**Provider identifier:** `silence_based_eos`

***

## Source Location

```
api/assistant-api/internal/end_of_speech/internal/silence_based/
└── silence_based_end_of_speech.go
```

***

## How It Works

1. A single worker goroutine manages a timer
2. When a final `SpeechToTextPacket` arrives, text is accumulated and the timer is set to `timeout`
3. When a `VadSpeechActivityPacket` or interim `SpeechToTextPacket` arrives, the timer resets
4. When the timer expires, `EndOfSpeechPacket` fires with the accumulated text
5. State resets for the next turn

```
STT final → accumulate text → start timer (1000ms)
VAD activity → reset timer
STT interim → reset timer
...silence...
Timer fires → EndOfSpeechPacket → LLM starts
```

***

## Parameters

| Option Key               | Default   | Range       | Description                                      |
| ------------------------ | --------- | ----------- | ------------------------------------------------ |
| `microphone.eos.timeout` | `1000 ms` | 500–4000 ms | Silence duration before triggering end-of-speech |

The UI sets a default of **700 ms** when switching to this provider. The backend default (when no value is configured) is **1000 ms**.

***

## Setup

No model files or downloads required. Works out of the box with both Docker and source builds.

To select this provider, set `microphone.eos.provider` to `silence_based_eos` in the assistant's audio options (or leave it unset — it is the default).