# Preflight Actions

{% hint style="info" %}
Preflight actions are an enterprise feature. Please [reach out to us](https://steadybit.com/contact) if you want to get access.
{% endhint %}

Preflight actions are triggered by Steadybit whenever an experiment is about to start and allow you to prevent an experiment from running. To decide whether that specific experiment run is allowed to start, you get a list of all expected affected targets in the extension action call. Please note that, due to concurrency, these affected targets may change in case one of the targets is gone when the actual step starts or new ones are discovered.

Preflight actions can additionally be used to perform checks during the experiment run, e.g., to check if a target is still healthy or if the environment is still in a state that allows the experiment to run. An interval can be configured as an additional trigger.

## Precondition

You need to write your own extension with [preflight kit](https://github.com/steadybit/preflight-kit) added to it. Implement the preflight action at your needs. See [docs](https://github.com/steadybit/preflight-kit/blob/main/docs/preflight-api.md).

## Configure

You can add preflight actions at `Settings` -> `Integrations` -> `Preflight Actions`.

![Add Preflight Action Integration](https://853194531-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZLJS2c8EXBcu8PiwteIJ%2Fuploads%2Fgit-blob-759ccc144853a3bb7d6b077c6084ae1a1a60cc5d%2FaddPreflightAction.png?alt=media)

A preflight action integration has the following parameters to be specified:

|                                      |                                                                                                                                                   |
| ------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Name**                             | The preflight action's name, it is shown in the experiment run.                                                                                   |
| **Team**                             | If no team is specified, preflight actions will be performed for all teams. If you specify a team, preflight actions are only made for this team. |
| **Preflight Action**                 | The Preflight Action to use from a registered extension                                                                                           |
| **Triggers**                         | When the Preflight Action should trigger                                                                                                          |
| - *Before the experiment is started* | default - can't be turned off                                                                                                                     |
| - *While the experiment is running*  | The interval specifies the time Steadybit will wait between the end and the next execution of a preflight action.                                 |

## Experiment Runs

During the experiment run, you can see the triggered preflight actions. If an preflight action fails, the experiment run fails, and no targets are attacked.

![Preflight Action Success](https://853194531-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZLJS2c8EXBcu8PiwteIJ%2Fuploads%2Fgit-blob-9b396c79f5c340cecc577dd31711d7e32cc62b03%2FprefligtRunStatusSuccess.png?alt=media\&token=ed0d73f2-f17c-4b3f-895e-55257a92e96d)

![Preflight Action Failure - Stopped Experiment Run](https://853194531-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZLJS2c8EXBcu8PiwteIJ%2Fuploads%2Fgit-blob-def4b8506190c8313469913b66492c9e18b4f127%2FprefligtRunStatusFail.png?alt=media)

## Developing actions

A preflight action uses [preflight kit](https://github.com/steadybit/preflight-kit). See our [docs](https://github.com/steadybit/preflight-kit/blob/main/README.md#getting-started) to get started.

### Lifecycle of Preflight actions

A preflight action can be in one of the following lifecycle statuses, indicated in the experiment run:

|                |                                                                                                                                                            |
| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **CREATED**    | The preflight action was created and has sent the request to the configured action in the extension. It is still waiting for the response.                 |
| **SUCCESSFUL** | The preflight action was resolved successfully. The experiment is allowed to continue (if all preflight actions are successful).                           |
| **FAILED**     | The preflight action resolved with a failure. The experiment will fail. Optionally, the response may contain a message as a reason for experiment failure. |
| **ERRORED**    | Technical error happened while requesting the preflight action, e.g., the extension URL couldn't be resolved, or the HTTP request timed out.               |

{% hint style="info" %}
A action will timeout after 55 seconds. In that case, the preflight action is marked as `ERRORED`, and the experiment will not start. If the action resolves later, the actual result will be submitted to the preflight action step in the experiment.
{% endhint %}