> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flipt.io/llms.txt
> Use this file to discover all available pages before exploring further.

# validate

> Validate Flipt flag state (.yaml, .yml) files

```
flipt validate [flags]
```

### Options

```
  -e, --extra-schema string   path to extra schema constraints
  -F, --format string         output format: json, text (default "text")
  -h, --help                  help for validate
      --issue-exit-code int   exit code to use when issues are found (default 1)
  -d, --work-dir              set the working directory
```

### Behavior

This command validates Flipt's declarative feature configuration files.

It looks for feature flag definitions in the same way as Flipt's declarative backends. Checkout the documentation on [locating flag state](/v1/configuration/storage#locating-flag-state) to learn more about this process.

### Extra Schema

The flag `--extra-schema` (short form `-e`) can be used to pass additional constraints via a [CUE](https://cuelang.org/) schema file.
This file will be unified with the base schema used within `flipt validate` to ensure the format of Flipt files.
You can find the base schema [here](https://github.com/flipt-io/flipt/blob/main/internal/cue/flipt.cue).

As an example, take the following flipt `features.yaml` file:

```yaml theme={null}
flags:
  - key: someFeature
    name: Some Feature
```

Running validate will succeed when provided with a path to this file.

```console theme={null}
➜ flipt validate
➜ echo $?
0
```

By default, the flag `description` field is not required. However, imagine that you want to ensure this field is always provided with a non-empty string. You can do this via the `--extra-schema` flag and a CUE definition.
In this instance we're going to create a CUE file named `extended.cue`.
Within this file we will add a constraint to the `#Flag` CUE definition, which ensures our desired behavior.

```cue theme={null}
#Flag: {
  description: =~"^.+$"
}
```

This definition ensures that description is both supplied and that the value matches the regular expression.
The regular expression in this example ensures a string with a length of at least 1 character.

Now when invoking the validate sub-command, we pass the path to this extra CUE definition:

```console theme={null}
➜ flipt validate -e extended.cue
Validation failed!

- Message  : flags.0.description: incomplete value =~"^.+$"
  File     : features.yaml
  Line     : 2
```

Here we see that our additional constraint on description is being validated and described in the output.

### More Info

See the [flag state](/v1/configuration/storage#flag-state-configuration) section of the documentation for more information.