| [Table of contents](../readme.md) / [Hyperion](./intro.md) | |
| # Hyperion development | |
| ### Normal development workflow | |
| When you develop Spectrum you're running two processes, `yarn run dev:web` for the frontend and `yarn run dev:api` for API, the GraphQL API. This means in your browser you access `localhost:3000`, which is a fully client-side React app, and that then fetches data from `localhost:3001/api`. | |
| In production, the client-side app is bundled and server-side rendered by Hyperion. | |
| This means we get the best development experience locally with hot module reloading etc, and in production we have single server responsible for serving files, rendering and the API. | |
| ### When developing SSR | |
| **DO NOT USE THIS UNLESS YOU'RE DEVELOPING SSR** | |
| To test server-side rendering locally run the client and the API locally, and then start Hyperion with `yarn run dev:hyperion`. Open Hyperion's URL, `http://localhost:3006` (instead of `:3000`), which will request the server-side rendered HTML from Hyperion rather than `webpack-dev-server`. | |
| The downside is that when you're testing SSR and changing the frontend those changes won't be reflected immediately. To get changes from the frontend when you're requesting `localhost:3001` you have to: | |
| 1. Stop the `yarn run dev:web` process | |
| 2. Run `yarn run dev:web` | |
| 3. Wait for the first compilation to complete | |
| 4. Restart the `yarn run dev:hyperion` process by stopping and then starting it again | |
| ## When doing all other client development | |
| Just stick to the normal workflow of `yarn run dev:web` and enjoy the hot reloading at `localhost:3000`! | |