What is an App?

Forget servers. Think services instead. Learn the basic fortrabbit concepts.

Understanding the platform

We claim that the fortrabbit hosting platform is different to classical hosting. Our comparison pages give you a good picture what fortrabbit is about:

The App Concept

# simplified App topology
┃App                                                 ┃
┃  ┏━━━━━━━━━━━━━━━┓ ┏━━━━━━━━━━━━━┓ ┏━━━━━━━━━━━━━┓ ┃
┃  ┃               ┃ ┃Webserver    ┃ ┃Database     ┃ ┃
┃  ┃               ┣─┫& PHP        ┣─┫cluster      ┃ ┃
┃  ┃               ┃ ┃             ┃ ┃             ┃ ┃
┃  ┃Load Balancer  ┃ ┗━━━━━━┳━━━━━━┛ ┗━━━━━━┳━━━━━━┛ ┃
┃  ┃               ┃ ┏━━━━━━┻━━━━━━┓ ┏━━━━━━┻━━━━━━┓ ┃
┃  ┃               ┃ ┃Webserver    ┃ ┃Database     ┃ ┃
┃  ┃               ┣─┫& PHP        ┣─┫cluster      ┃ ┃
┃  ┃               ┃ ┃             ┃ ┃             ┃ ┃
┃  ┗━━━━━━━━━━━━━━━┛ ┗━━━━━━━━━━━━━┛ ┗━━━━━━━━━━━━━┛ ┃

An App is a virtual container for your web project, website, web application, staging branch, project or whatever you do.

Multiple Apps per Company

fortrabbit hosting has a multi-seat and multi-tenant model. Apps are owned by Companies (your business) and managed by Accounts (you). The App plans displayed on the pricing page are per App. You can create as many Apps as you want of course.

One website per App

With classical server hosting you rent out a machine to host multiple websites. While this seems to make economic sense — it's not smart. Just think about these scenarios:

  • "website A" needs runtime version y, while "website B" requires version x
  • "website C" has a nasty bug and crashes the whole server
  • "website D" has a security vulnerability, the whole server gets hacked
  • "website E" gets popular and receives lots of traffic, slowing other websites down
  • Your fellow web developer colleague "accidentally" removed all files on the server

Apps are better:

  • Apps start a fraction of a server but can be scaled across multiple servers
  • Each App has its own settings
  • Apps are isolated from each other

So, a fortrabbit App is designed to host one website:

  • There is only one MySQL database per App
  • Each App has only one Git repo
  • Each App has its own collaboration rules
  • Each App has its own performance metrics

Two App types

fortrabbit comes in two flavors (stacks): Universal & Professional. With each App you create, you can choose between either one. This can't be changed later on. The two Stacks are different from each other. The rule of thumb is: When unsure, choose Universal. Learn more here:

The following sections here are describing functionalities that are shared by the two different stacks.

Creating an App

When you sign up to fortrabbit, a new trial App will be created on the fly. Later on you can create any number Apps in the Dashboard — just find the accordingly named button. While creating an App, there are a few things to decide:

  1. App Name: see below
  2. Software Preset: see below
  3. Data center location: Where will your App be hosted?
  4. Stack & scaling: Uni or Pro, plan, or trial?

Software Preset

While creating an App you can choose from a variety of popular open source PHP software types. This will not install the software on your behalf, but prepare some settings, depending on the chosen software:

  • Set a matching PHP version — some legacy Apps need older versions
  • Enable/disable PHP extensions — for best performance
  • Set a root path — to serve the App from the right location
  • Populate ENV vars — to connect to the database automatically

So, the Software Preset saves you some work and helps to prevent errors. It does not install anything. It's non-destructive, you can change all settings later on as you wish. This is especially handy with modern software that supports ENV var configuration and environment detection — like Laravel or Craft CMS do. It makes the application really portable, you can deploy the same code base to any App and it will work out of the box.


Each App comes with a set of basic features and limits:

Most of it can be viewed and edited in the Dashboard. Here is what you'll need to know:


There are various settings to control the routing of domains. Please also see the domains help article.

App Name

The App name identifies your App. It is used in many instances — for example to login by SFTP or SSH. You will also find that App name on your invoices.

For quick boarding, your first trial App will have a generic App name, depending on the software you'll use, it will look something like this: wordpres-4wm7.

While creating your (second) fortrabbit App you will be asked for an App Name. Now, you can choose a name that is easier for you to identify your project like: bobs-cool-app. The App Name must be URL friendly (lowercase, no special chars, no spaces) as it will be your test domain as well. The App will be available under: bobs-cool-app.frb.io.

Changing the App Name

Please note, that it is not possible to change the App Name later on for technical reasons — cool URLs don't change, anyways.

This is not a bummer. Remember that the App Name is only an identifier to login and for development. The App URL is front-facing, but you'll only use it to develop, you will route your own domains later on anyways.

To identify the App within the Dashboard, you can also use App notes.

If you are really desperate for your own vanity App Name: delete your current App and start a new one, this time using the desired App name. Apps are disposable, so deploying everything again shouldn't take too long.

Re-using App names

Sometimes you can't get it to work and you want to start over again. So you can delete your App and create a new one from scratch. Please mind that you can not use the same App name immediately. It takes 7 days after you have deleted an App, before the same App Name will become available to use again.


The most prominent use of your App name is your default App URL which looks like this: https://your-app.frb.io/. This is where you can always reach your App thru the web browser. Use the App URL for development, testing and to connect to external services. Later on your App can also be reached through your own top-level-domain. The App URL can't be removed or renamed. Check out our htaccess article on forwarding and redirecting this URL.

Sending transactional mails from your App URL

Some clients asked how to setup TXT records for App URLs. They have the idea of sending mails over a transactional mail service from the App URL, for testing or even for production.

And it is probably not what you want. At the end of the day, you want your mails to be sent from own domain. Transactional mail providers need to take extra care that you are not a spammer, as they give very powerful tools. Our generic App URLs do NOT look good from their point of view. For the App URL there isn't an MX record. So that sub-domain looks suspicious to any mail-server.

We are using postmark app. It should work the same as mailgun or any other transactional mail provider. We have configured and verified our prime domain to be used with the service. Now, our dev and staging environments are also using the "real thing", but they are configured (in our code base) so that they are sending all mails to "info@fortrabbit.com" (instead of what is entered by the testers).

How other users are testing mails: some clients are using mailtrap to test mails. I have no experience, but as far as I know, it's easy to setup and use.

Set up a custom domain

You can register your App to accept requests from any external domain you route to fortrabbit — see also the domain article. To set up a domain routing, you add a new custom domain within your App's domain settings in the Dashboard.

Root path

Per default all the domains of the App will route to the same root path (sometimes this is also called: document root, docroot or root folder): htdocs. This path is where the first index.php will be called, when people are visiting your App on any domain. This path setting can vary, depending on what the framework or CMS you have selected in the software chooser when creating the App:

Framework/CMS Root path
Laravel, Phalcon, Craft 2, Symfony 5, Slim 3 htdocs/public
Symfony 2, Symfony 3, Craft 3, Craft 4 htdocs/web
Drupal 8, Drupal 9, WordPress, Grav htdocs

You can however set the root path afterwards at any given time by visiting the appropriate setting in the Dashboard under your App.

Individual root paths per domain

In some cases, you might want to route individual domains to different folders. Please mind that there are limited use cases for this and don't use one App to host multiple websites (see above as well).

When visiting the root path settings you will find a switch to change from a global root path for all domains to custom root paths for each domain. Bear in mind that you can also use .htaccess files with RewriteRule directives to handle different domains differently.


Most connections calls on most ports are forbidden for security reasons. You can request to white-list a port or port range. With the firewall setting of your App you can see custom white-listed ports and request a new firewall rule.


Each App comes with "Usage metrics": Those show you the current status of the Web storage, MySQL storage and Object Storage and context of your App.

Some Apps also come with "Performance metrics": Those show you how fast your App is and where you might need to improve. Performance metrics are: requests, PHP response time, traffic, errors and other useful stuff. You can set different time intervals to monitor performance over time.

  • https://dashboard.fortrabbit.com/apps/{{app-name}}/metrics

App team

The team settings of the App are showing you which other developers have access to the App. From here you can also invite new team members directly to the App.

See our collaboration article to learn more about joint development.

App Company

This setting links to the Company owning the App. From here you can also:

Changing App ownership

  1. Go to the App in the Dashboard
  2. Click the "Change ownership" button
  3. Choose a different Company (and Billing Contact)

The Change ownership button, linked from your App overview is a very powerful tool. You can move the App to a different Company or Billing Contact you have access to. That means, you can assign the App to a different team, and/or to be billed from a different Billing Contact.

This action can only be done by Accounts who have Owner or Admin privileges on at least two Companies or one Company with two Billing Contacts. In other words, you need to have something first, to change it to. Also the App must be paid, not in trial mode.

The App will be billed on the old Billing Contact until that day of change and from the next day on to the new Billing Contact. For example: If you move your App on the 15th of a month to the Billing Contact of another Company, it will be billed to the old Billing Contact until the 15th and to the new Billing Contact starting from the 16th.

Inviting a client to take over an App

Are you working on behalf of someone? You want your client or the boss of the agency to pay for hosting? Here you can start the invitation. See our client collaboration article for more details.

The App trial

You can test fortrabbit for free. Therefore each Account can have one trial App running. The purpose of the trial is to test-drive the platform. See if it works as advertised. See if fortrabbit is the right hosting solution for you.

Starting a new trial App

Find the "Create an App" button on the Dashboard home. When asked for the plan, you can choose the free trial option instead. Trial Apps are available for both stacks, Universal & Professional.

Trial limits

The trial App scaling specs are matching a small preset, always enough to get started. For the Pro Stack not all Components are enabled. The trial is NOT a forever-free tier. An important limitation is, that the trial has a limited lifetime.

Extending the trial

The default trial time is short. A timer in the Dashboard with your App will show you the time left. You can extend the evaluation period by completing some simple tasks like:

  • Confirming your Account's e-mail address
  • Setting your real name under your Account
  • Deploying some code to the trial App
  • Routing a domain to the trial App

A task that is completed has a check-mark . Tasks that are still todo will show how much time you will gain if you complete them.

Additionally, after some trial time has passed, we show a link to a contact form where you can ask us to extend the trial time. Here you'll write us something about your goals with the trial and we are happy to extend the trial for a much longer period. You can see those tasks in the Dashboard with the overview of your App.

Upgrading the trial

You can, of course, upgrade from your trial to a paid plan at any time. You can do so under your App's overview.

The end of a trial

When the trial is finally over, the trial App will be deleted. That might sound cruel, but please consider that we will not keep your data hostage until you pay us.

Good news is: We will inform you by e-mail before it happens and you can start a new trial right away, after your current trial ended. In many cases you can easily re-deploy your code base to the new App: When deploying with Git, you just change the remote and push again. When using our CMS/framework presets with predefined ENV vars database access will work without code modification.

Restarting an App

In some edge cases, like hanging PHP processes with 504 errors or 408 errors, restarting an App is an option. Here is how you can do this:

  1. visit the App in the Dashboard
  2. find and click the "Restart App" button
  3. wait a minute until changes are applied

This will restart the Apache service and the PHP-FPM processes. Nothing more, your data will stay safe. There will be a short downtime of the App. Use carefully, it should not be used on a regular basis. This button is not a silver bullet to fix all server issues. Please contact us, if you have ongoing trouble with your App.

Deleting an App

You can always delete Apps you own or administer. To delete an App, visit the App in the Dashboard, find and hit the "delete" button. You might need to enter your Account password and also confirm what you are about to do. The App will then get deleted within a couple of minutes. This includes all files and the database.

Recovering deleted Apps

Deleting Apps & Accounts is "mostly" (see below) FINAL here and can't be reversed. We delete as much as possible when a client requests so or when we have to because payments have bounced too often. We do so for privacy and security reasons. We believe that it should be your right to be forgotten. Imagine that we take your data as a hostage until you pay us. So in most cases that's actually good. Also read how we handle bounced payments.

Recovering Backups

While deleting an App is irrevocable, Backups might still be around. If your App plan included Backups and those have not yet faded out within their retention period, we might be able to restore the backups for you. We can then provide you a tar ball containing your data (web + MySQL). Please contact us for that via chat.


Here are some common gotchas that mostly happen with new Apps:

500 internal server error

Please see here.

Version mismatch without any changes made

Sometimes service reboots are issued to Apps. This usually doesn't happen often, but sometimes needs to be done in case of an incident, a scheduled maintenance or a re-distribution. Now, with these service restarts, the orchestration logic will look for an existing Git repo and re-deploy that.

Depending on your workflow, that might cause some strange results on Universal Apps.

As you hopefully know, we originally assume that you have a local development process, and that this is your "master" and all changes are done there first. Also, that the core code is always deployed with Git, and thus Git is up-to-date and that a re-deploy should therefore do no harm. So when you have been following our guides, everything should work for you.

The strangeness occurs when you are mixing workflows and are going offroad: For example, you have initially deployed by Git and then later updated your CMS directly on the App itself from the Control Panel in the browser. Using the overwrite but not delete strategy the old files from Git get re-deployed. This can get messy, when the files are outdated but the database is already migrated to the newer version. We also saw this overwriting session and cache files (which might be excluded from Git anyways).

The fix for that depends on your specific situation. In many cases we suggest to update your installation and bring that in order and then re-deploy the changes via Git one more time.

phpinfo to the rescue

Sometimes, you might be unsure on configuration settings, such as which extension in which version is exactly enabled or which ENV vars are actually available with your App. You can use phpinfo (see offcial doc) for that. Place a "info.php" file with the content <?php phpinfo(); ?> anywhere in your publicly accessible path and call that URL with the browser to see the config dump.

We are maintaining standard PHPinfo Apps as well here: fortrabbit.com/specs#php-extensions. Your CMS / framework might have its own dump of that. With Craft CMS for example you can visit a nicely formated phpinfo in the control panel.

A word of warning: Don't do that in production. Make sure to delete that file right away after you have finished your investigation. The output might contain sensitive information you don't want to share with the world. Keys and values of your ENV vars are visible, that can contain database access and API keys to external services.

Further reading

Now you know the basics about Apps on fortrabbit, keep going:

All articles

Craft CMS


Install guides

Code access














The Dashboard


Tips & tricks




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