> For the complete documentation index, see [llms.txt](https://docs.fireapis.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fireapis.com/the-basics/logics/dynamic-data-source-selection.md).
# Dynamic Data Source Selection
The Dynamic Data Source Selection popup allows you to customize dynamic data usage wherever needed. Data can be selected from:
* Previous actions
* Input payload
* Environment Secrets Manager
* Decoded tokens (e.g., user tokens)
#### Examples with Screenshots
**Using Email from Input Payload**:
* Select the email from the input payload of the API request.
* Use it for querying the database to check if the user exists.
Data is taken from input payload
**API Key from Secrets Manager**:
* Retrieve the API key for the SendGrid email service from the Secrets Manager.
* Use it securely for sending emails.
Data is taken from secrets manager
**Custom User Detail Handling**:
* Take user details from previous actions to build custom text.
* Return a custom object with data derived from the results of previous actions.
Data is taken from previous action results
This popup provides a flexible and intuitive way to manage dynamic data across various actions .
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