Gatsby-image for API-fetched images

[decimoseptimo]

I followed the tutorials:
https://www.gatsbyjs.org/blog/2018-1-18-strapi-and-gatsby/
https://medium.com/@kyle.robert.gill/ridiculously-easy-image-optimization-with-gatsby-js-59d48e15db6e

So for a site, I'm doing image optimization for local images, and fetching content from an API. While also converting mardown to html in blog posts. But how to gatsby-image for files fetched from an API like strapi?

I suppose that somehow the files have to be fetched from the API and then transformed to the local filesystem.

[KyleAMathews]

This should be built into gatsby-source-strapi — perhaps raise an issue there?