# Validate hook

The validate hook is the hook called to validate your input after it has been parsed. The default expected error for a validation error by the error hook is a `map[string]error` . By default the hook use [ozzo-validation](https://github.com/go-ozzo/ozzo-validation).

A validate hook must have this signature:

```go
type ValidateHook func(ctx context.Context, input interface{}) error
```

{% hint style="info" %}
Check out the default [validate hook implementation here](https://github.com/expectedsh/kcd/blob/master/pkg/hook/validate.go).

Check out the signature of the [validate hook](https://github.com/expectedsh/kcd/blob/master/pkg/hook/hooks.go#L27).
{% endhint %}


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