How to validate entire document without persisting data?

[nathanbowang]

How to validate entire document without persisting data?

I need to validate collection data using all custom validate functions without saving to database.

Current Setup

export const MyCollection: CollectionConfig = {
  slug: 'my-collection',
  fields: [
    {
      name: 'title',
      type: 'text',
      validate: (value) => value?.length >= 3 || 'Too short'
    },
    {
      name: 'email', 
      type: 'email',
      validate: async (value, { req }) => {
        // custom validation logic
        return true
      }
    },
    // many more fields with validate functions
  ],
}

What I Need

A built-in API to execute all field validations without persistence:

// Desired API
const result = await payload.validate({
  collection: 'my-collection', 
  data: myData
})

// Or
const errors = await payload.collections['my-collection'].validate(myData)

Use Cases

• Form validation before submission
• Data import validation
• API validation endpoints

Currently no clean way exists to do this in Payload 3. Is this feature planned or is there an undocumented way?

[tyteen4a03]

Can you maybe explain the use case of this functionality? What are you trying to build?

[nathanbowang]

I’m building a lightweight AI agent that auto-fills Payload documents. My goal is for Payload CMS to be the single source of truth for validation—without duplicating schemas in Zod or other tools. After the AI generates a partial or full document, I’d like to send it to Payload and get validation results based on the exact same rules (native + custom validate functions), without needing to attempt a real write.

Right now I see two imperfect options:

• Export all validators and re-compose them elsewhere (a lot of boilerplate).
• Trigger a 400 by sending an intentionally invalid field, which does return useful error info, but everything comes back as a failed write.

What would really help is a validate-only mode or endpoint, something like a dry-run that returns structured per-field results with 200 OK. That would let the agent iterate and fix issues before persisting anything.

If anyone has suggestions on the best way to approach this with the current API, I’d love to hear them. And if the team thinks a dry-run validation feature makes sense, I’d be happy to try contributing a PR.

[tyteen4a03]

Looking at

payload/packages/ui/src/forms/Form/index.tsx

Line 138 in 5e433aa

const validationPromises = Object.entries(contextRef.current.fields).map(

this looks like what you're looking for.

It would definitely be ideal to have this as a built-in API function.

[nathanbowang]

Thanks! I see that’s the Admin UI validation logic. But Payload also runs validation on the server/API side, right? For example, if I send data directly via REST or GraphQL, I still get validation errors.