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<@1145576664366055464> whats the correct use of the - "NO_RESPONSE_NEEDED" function?

Thanks for tagging me <@822119446013149204>. I'll look through relevant sources and get back to you shortly.

### Answer
 `NO_RESPONSE_NEEDED` is a hard-coded stop sequence in the LLM that makes the agent hold and not respond to the user. [(1) ](<https://docs.retellai.com/build/no-response>)

**How to use it:**

Prompt the LLM to output this exact text when you want silence. For example: 
```
- if user says "hold on", reply exactly the following: "NO_RESPONSE_NEEDED".
```


**For reasoning models (gpt-5, gpt-5.1) :**

This feature is not supported. Instead, use a prompt like: `When user says hold on, simply do not respond`. [(2) ](<https://docs.retellai.com/build/prompt-situation-guide>)

**Important notes:**

- Be explicit in your prompt so the LLM outputs *only* `NO_RESPONSE_NEEDED` with nothing before or after it—otherwise it may say the phrase aloud. [(3) ](<https://discord.com/channels/1186424376300679209/1433483896179261480>)
- If the agent is still saying the words out loud, try switching to GPT-4o. [(4) ](<https://discord.com/channels/1186424376300679209/1376157747783143434>)
- `NO_RESPONSE_NEEDED` stops the agent entirely—it's a terminal command, so features like Reminder Message Frequency won't resume after it's used. [(8) ](<https://discord.com/channels/1186424376300679209/1407515064260624525>)

​
To learn more, see the sources I considered:

[[1] Make agent hold and respond nothing](https://docs.retellai.com/build/no-response)
[[2] Prompt guide & examples for specific situations](https://docs.retellai.com/build/prompt-situation-guide)
[[3] no_response_needed](https://discord.com/channels/1186424376300679209/1433483896179261480)
[[4] NO_RESPONSE_NEEDED ERRORS](https://discord.com/channels/1186424376300679209/1376157747783143434)
​

Feel free to tag <@1145576664366055464> with additional questions. I also appreciate feedback, it helps me improve.