> For the complete documentation index, see [llms.txt](https://developers.felt.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.felt.com/felt-style-language/getting-started.md).

# Getting started

The Felt Style Language is a way for advanced users to style data quickly, through simple JSON code. This document is a guide to use as you test data files in Felt. For an exhaustive guide to all supported properties see the Reference Documentation.

## Style definition blocks

Learn how to define and configure the code blocks that compose the Felt Style Language

{% content-ref url="/pages/ia98n0VZ2bW0rDUZjF49" %}
[Style definition blocks](/felt-style-language/style-definition-blocks.md)
{% endcontent-ref %}

## Types of visualizations

Learn about visualization types, including simple, categorical, numeric (color by & size by), heatmaps, H3, and raster (imagery, numeric, categorical, and hillshade).

{% content-ref url="/pages/t1uG4exfWZRod1VeBRFi" %}
[Types of visualizations](/felt-style-language/types-of-visualizations.md)
{% endcontent-ref %}

## Colors, icons & classification

Shared building blocks referenced throughout the language: smart `"auto"` colors and named palettes, the icon catalog, and the classification methods used to turn numbers into classes.

{% content-ref url="/pages/T2CzLFRxCIMHaz4WjYm8" %}
[Colors & palettes](/felt-style-language/colors-and-palettes.md)
{% endcontent-ref %}

{% content-ref url="/pages/x4VFtWKNEKYOiqWp7dAQ" %}
[Icons](/felt-style-language/icons.md)
{% endcontent-ref %}

{% content-ref url="/pages/fdqlMScWxZO7qFHImPxT" %}
[Classification methods](/felt-style-language/classification-methods.md)
{% endcontent-ref %}

## Legends

Details on how to customize legends on a per-layer basis.

{% content-ref url="/pages/1fKJtssIMYNDGoHaGUKl" %}
[Legends](/felt-style-language/legends.md)
{% endcontent-ref %}

## Errors

Definitions for errors raised when validating the Felt Style Language.

{% content-ref url="/pages/X4xQjPoTGzipaOEgV5zN" %}
[Errors](/felt-style-language/errors.md)
{% endcontent-ref %}


---

# 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 dynamically by asking a question.

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

```
GET https://developers.felt.com/felt-style-language/getting-started.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.