> ## Documentation Index
> Fetch the complete documentation index at: https://ravion-b90c0359-devin-1786379042-config-change-phases-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# What happens after a configuration change?

> Understand which Ravion actions a module configuration change requires.

When you change a module input, Ravion identifies the actions required for the
change to take effect. Saving the configuration does not necessarily run every
required action.

For background on managing a project configuration file, see [Project config
file](/config-as-code/project-config-file).

## The actions

| Action           | What it does                                                         |
| ---------------- | -------------------------------------------------------------------- |
| **Stack update** | Runs the module's stack pipeline to create or update infrastructure. |
| **Build**        | Creates a new application image or other build artifact.             |
| **Deploy**       | Releases the new configuration or artifact to the running module.    |

The actions are separate. A stack update changes infrastructure, but does not
release a new application artifact. A build creates an artifact, but does not
make it the active release until a deploy promotes it.

See [Build](/modules/build) and [Deploy](/modules/deploy) for more about those
pipeline steps.

## Examples

The required actions depend on the module definition and the input you change.
These examples use inputs from Ravion's standard module definitions:

| Module input                                           | Required actions        | Why                                                                                                                   |
| ------------------------------------------------------ | ----------------------- | --------------------------------------------------------------------------------------------------------------------- |
| `rvn-ecs-web` `desired_count`                          | Stack update            | The desired service capacity is infrastructure configuration.                                                         |
| `rvn-ec2-service` `environment_variables` or `secrets` | Stack update and deploy | The stack carries the runtime configuration, and the deploy renders it into the app environment on running instances. |
| `rvn-aws-static` `build_environment_variables`         | Build and deploy        | The build uploads a versioned static directory, and the deploy promotes that directory to production.                 |

The per-input `applied_by` field records this lifecycle metadata in a module
definition. Ravion's compiler derives it from how the module's stack, build, and
deploy configuration reference each input, so definition authors do not set it by
hand. See the [module definition schema reference](/module-definitions/definition-schema/inputs).

## Check what a change requires

### Dashboard

When you save a module configuration, the confirmation dialog shows which
actions the change requires and what the selected save option will do.

Saving the configuration records the new values. It does not automatically
build an artifact or deploy it unless you choose an option that performs those
operations. If another action is required, run it after the configuration save
completes.

### CLI

The `ravion project config apply` command shows the required actions in the
`REQUIRES` column. In an interactive terminal, it also displays the planned
changes and asks you to confirm them:

```bash theme={null}
ravion project config apply <project-id> --file ravion.yaml
```

Use a dry run to inspect the plan without applying it:

```bash theme={null}
ravion project config apply <project-id> \
  --file ravion.yaml \
  --dry-run
```

Use `--yes` to skip the confirmation prompt in scripts:

```bash theme={null}
ravion project config apply <project-id> \
  --file ravion.yaml \
  --yes
```

The `REQUIRES` column uses **stack update**, **build**, and **deploy** so you
can see which work remains after the configuration apply.

## Older module definitions

<Warning>
  Module definitions published before lifecycle metadata was introduced do not
  provide enough information to determine every required action.
</Warning>

If Ravion reports unknown action metadata, assume the change requires a stack
update and a deploy. Run the stack update, build if the module needs a new
artifact, and then deploy the resulting configuration or artifact.