# Intro

The Stencil File Editor offers you the option of direct browser access to the code that makes up your theme, without having to install [Stencil CLI](https://stencil.bigcommerce.com/docs/what-is-stencil) (command-line interface). This is ideal for making minor adjustments to your theme that cannot be done directly within Theme Editor, or for adding scripts to integrate apps.

These instructions cover the basic steps to access [Stencil-based themes](https://support.bigcommerce.com/articles/Public/The-Stencil-Theme-Platform?q=theme+edit\&l=en_US\&fs=Search\&pn=1) template files and edit their HTML/CSS using the in-browser editor. For information about customizing Blueprint themes, see [Accessing and Customizing Template Files (Blueprint)](https://support.bigcommerce.com/articles/Public/Accessing-and-Customizing-Template-Files?q=theme+edit\&l=en_US\&fs=Search\&pn=1).

This is an advanced feature, and requires knowledge of [HTML/CSS](http://www.w3schools.com/) and [Handlebars](http://handlebarsjs.com/). For major design adjustments, or new theme development, we recommend that you or your developer use Stencil CLI, which provides access to all theme files.

{% hint style="info" %}
Before making large changes we suggest downloading your current theme.
{% endhint %}


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# Agent Instructions: Querying This Documentation

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

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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.