How to properly upload images with alt text using Payload CMS API

[lightlogic5]

I'm trying to create a media collection in Payload CMS that allows image uploads with required alt text. Here's my collection configuration:

import type { CollectionConfig } from 'payload'

export const Media: CollectionConfig = {
  slug: 'media',
  access: {
    read: () => true,
    create: () => true,
  },
  fields: [
    {
      name: 'alt',
      type: 'text',
      required: true,
    },
  ],
  upload: true,
}

When attempting to upload an image via cURL:

curl -X POST -H "Authorization: Bearer mytoken" -F "file=@aa.jpg" -F "alt=test222" http://localhost:3001/api/media

I receive this validation error:

{
  "errors": [
    {
      "name": "ValidationError",
      "data": {
        "collection": "media",
        "errors": [
          {
            "label": "Alt",
            "message": "This field is required.",
            "path": "alt"
          }
        ]
      },
      "message": "The following field is invalid: Alt"
    }
  ]
}

Questions:

1. What's the correct way to format the cURL request to include both the file and alt text?
2. Could you provide an example of a Next.js API route implementation that handles this upload properly?

Additional context:

• The alt field is marked as required in the collection config
• The error indicates the alt field isn't being properly submitted
• I've tried different variations of multipart/form-data formatting without success

Thank you for your help!

[andershermansen]

The additional fields needs to be set in a json object with name _payload. Not 100% of the syntax, I have not tested it, but something like this:

curl -X POST -H "Authorization: Bearer mytoken" \
  -F "file=@aa.jpg" \
  -F '_payload={"alt": "test222"};type=application/json' \
  http://localhost:3001/api/media

[lightlogic5]

Thank you so much for your help! The solution you provided works perfectly.