The goal is to authenticate users with firebase and store their auth token in sessions. A logged in user will see their messages on page load and then be able to post new messages.
Execute [`create-next-app`](https://github.com/zeit/next.js/tree/canary/packages/create-next-app) with [npm](https://docs.npmjs.com/cli/init) or [Yarn](https://yarnpkg.com/lang/en/docs/cli/create/) to bootstrap the example:
- Get your account credentials from the Firebase console at _project settings>service accounts_, where you can click on _generate new private key_ and download the credentials as a json file. It will contain keys such as `project_id`, `client_email` and `client_id`. Now copy them into your project in the `credentials/server.js` file.
- Get your authentication credentials from the Firebase console under _project settings>general>your apps_ Add a new web app if you don't already have one. Under _Firebase SDK snippet_ choose _Config_ to get the configuration as JSON. It will include keys like `apiKey`, `authDomain` and `databaseUrl` and it goes into your project in `credentials/client.js`.
- Back at the Firebase web console, go to _Authentication>Sign-in method_ and enable _Google_.
- Create a database in the "Database" tab and select Firestore. Then go to "rules" and set up your write, read rules to this:
```
// Allow read/write access on all documents to any user signed in to the application
Deploy it to the cloud with [ZEIT Now](https://zeit.co/new?filter=next.js&utm_source=github&utm_medium=readme&utm_campaign=next-example) ([Documentation](https://nextjs.org/docs/deployment)).
After deploying, copy the deployment URL and navigate to your Firebase project's Authentication tab. Scroll down in the page to "Authorized domains" and add that URL to the list.