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

# Make Agent Hold and Respond Nothing

> Keep your UponAI agent silent when a caller asks it to hold or wait.

Sometimes you want the agent to stay silent — for example, when the caller says "hold on" or "give me a minute".

## How It Works

UponAI has a hard-coded stop sequence in the LLM: `NO_RESPONSE_NEEDED`. When the LLM outputs this exact sequence, response generation stops immediately and the agent says nothing.

## Setup

Add a prompt instruction telling the agent to output the stop sequence on hold requests:

```
If user says "hold on", reply exactly the following: "NO_RESPONSE_NEEDED"
```

<Note>
  This feature does not apply to reasoning models (e.g., GPT-5, GPT-5.1), which do not support custom stop sequences. For those models, use prompt engineering instead: `When user says "hold on", simply do not respond.`
</Note>