What You Don't Need Plugins For

Most third-party functionality you want to add to your website will follow standard JavaScript and React.js patterns for importing packages and composing UIs. These do not require a Gatsby plugin!

Some examples:

• Importing JavaScript packages that provide general functionality, such as lodash or axios
• Integrating visualization libraries, such as Highcharts or d3.

As a general rule, any npm package you might use while working on another JavaScript or React application can also be used with a Gatsby application. What plugins offer is a prepackaged integration into the core Gatsby APIs to save you time and energy, with minimal configuration.

A good use case would be using Styled Components, you could manually render the Provider component near the root of your application, or you could use gatsby-plugin-styled-components which takes care of this step for you in addition to any other difficulties when configuring Styled Components to work with server-side rendering.