> For the complete documentation index, see [llms.txt](https://help.brickspacelab.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.brickspacelab.com/keystone/guides/products/product-custom-field.md).
# Custom fields
The Custom field product block can be used to add additional fields to a product form. This can be used to collect more information. E.g. include a custom engraving field to let customers customize their purchase.
***
### Setup
1. Go to **Online Store** > **Themes** > **Customize**
2. From the dropdown in the top bar select **Product**
* You may want to create a new product template, if you want your custom field to show up on every product page then you can use the default product template. Otherwise you would want to create a new template.
3. On the lefthand side click **Add block** then select **Custom field**
4. Add a label and check Enable required field if you want to make this a mandatory field to use
5. Reposition the block - it's best to place this just above the Buy buttons block
6. Hit **Save**
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://help.brickspacelab.com/keystone/guides/products/product-custom-field.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
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.