# Tokens

Tokens are a single source of truth to name and store Atlassian design decisions.

## Installation

```sh
yarn add @atlaskit/tokens
```

## Usage

[View documentation](https://atlassian.design/components/tokens).

# BabelPlugin

A babel plugin to optimise performance and support fallbacks for Design System tokens.

It replaces any calls to the `@atlaskit/tokens` token() function with the CSS value the function
would return (i.e. var(--token-name) or variations with fallbacks).

If there’s no fallback, the plugin (optionally) finds the token’s value from the default Atlassian
theme, and sets it as the fallback.

If there is a fallback defined in code, it’s inserted into the style (expressions are inserted using
template strings).

## Usage

Add the plugin to your babel configuration:

```
{
  "plugins": [
    ["@atlaskit/tokens/babel-plugin", { "shouldUseAutoFallback": true }]
  ]
}
```

### Options

Currently the plugin supports one option, `shouldUseAutoFallback`. When not disabled, the plugin
will fetch the token's value in the default Atlassian theme (currently `atlassian-light`) and use it
as the fallback value.

This is useful for cases where tokens are in use, but token definitions aren't guaranteed to be
present in the top-level page CSS.