---
title: "Validate Slot values"
description: "Check Slot values with built-in and custom rules when your application needs them."
canonical_url: "https://tiptap.dev/docs/composable-docs/slots/guides/validate-submission"
---

# Validate Slot values

Check Slot values with built-in and custom rules when your application needs them.

Slots can include rules to describe what content is valid.

> **Interactive demo:** [SlotValidation](https://embed-pro.tiptap.dev/preview/Examples/SlotValidation)

Call `validateEditorSlots` when your application needs to check the content, for example before saving or submitting a form. Submission is an application action, not a built-in Slot event.

Validation reads a snapshot and returns findings; it does not resolve or rewrite Slot values. Built-in checks and registered async validators run only when you call the validation API. Editing invalidates previous results and cancels a pending editor validation run, but does not automatically start another run.

For validation while typing, register an editor `update` listener and debounce calls to `validateEditorSlots`. Handle cancelled runs, display only current results, and remove the listener and pending timer when your UI unmounts. Automatic scheduling belongs to the host; there is no built-in auto-validation option.

```ts
import { isSlotValidationCurrent, validateEditorSlots } from '@tiptap-pro/extension-slot'

try {
  const result = await validateEditorSlots({ editor })
  if (!isSlotValidationCurrent({ editor, result })) {
    showMessage('The document changed. Please submit again to validate the latest values.')
  } else if (result.valid) {
    save(editor.getJSON())
  } else {
    showIssues(result.issues)
  }
} catch (error) {
  if (error instanceof Error && error.name === 'AbortError') {
    showMessage('Validation was cancelled. Please submit again.')
  } else {
    throw error
  }
}
```

`isSlotValidationCurrent` checks that the result still matches the editor's current document and validation settings.

Define requiredness, length, content types and patterns in `attrs.config`:

```ts
const config = {
  required: true,
  constraints: {
    pattern: { source: '^ORD-\\d{4}$', message: 'Use ORD-0000' },
  },
}

editor.commands.insertSlot({ config })
```

For application-specific checks, persist a validator name and register its implementation:

```ts
Slot.configure({
  validators: {
    registeredPerson: async ({ slot, signal }) => {
      const found = await directory.find(slot.text, { signal })
      return found
        ? []
        : [
            {
              code: 'custom.person',
              message: 'Choose a registered person.',
            },
          ]
    },
  },
})

// When the slot is created, include the custom validator
editor.commands.insertSlot({
  config: {
    validators: [{ name: 'registeredPerson' }],
  },
})
```

Validation can be async, so an AbortSignal (the `signal` field) is passed to cancel the validation process if the document is edited during validation.

For checks that involve multiple fields, add a `crossFieldRules` entry to an owning Slot and register a `crossFieldValidators` function. [Learn more in the API Reference](https://tiptap.dev/docs/composable-docs/slots/api-reference/validation.md#crossfieldvalidator).

If some validators are missing or failed, `validateEditorSlots` returns `status: 'unavailable'`.

See [the API Reference](https://tiptap.dev/docs/composable-docs/slots/api-reference/validation.md#slotvalidator) for more info on validation.