# Managing group subscribers
If you want to automate certain actions, like opt in / opt out responses, you can easily do this with Flow Builder; you can learn how to set this specific flow [here](https://support.messagebird.com/hc/en-us/articles/360000358457-How-to-set-up-opt-in-opt-out-automatic-SMS-subscriptions).
**Opt out**
When sending out a campaign, make sure your contacts are in a group.
If you configure a rule like the one shown below, those users who reply ‘Stop’ will be automatically removed from the group specified:
\
This will remove the contacts from the group, but they will remain in your address book.
**Opt in**
You can also create multiple flows for one Number, allowing you to trigger different actions depending on pre-specified keywords within the response of the user.
A company could use this to keep track of customers who are interested in a certain offer. For example: if you send ‘Reply SPA to enter our prize draw’, and want to keep all the replies for this offer in one place, you can set up something like this:\
\
\
The relevant replies would be automatically forwarded to a phone, email or added to a group, or you could even configure an automatic response.
There is no limit to how many contacts can send you to opt in or opt out responses
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.bird.com/connectivity-platform/contacts/managing-group-subscribers.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.